Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include <linux/highmem.h> |
35 | #include <linux/smp_lock.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <linux/interrupt.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
1da177e4 LT |
39 | #include <linux/completion.h> |
40 | #include <linux/kernel_stat.h> | |
9a11b49a | 41 | #include <linux/debug_locks.h> |
cdd6c482 | 42 | #include <linux/perf_event.h> |
1da177e4 LT |
43 | #include <linux/security.h> |
44 | #include <linux/notifier.h> | |
45 | #include <linux/profile.h> | |
7dfb7103 | 46 | #include <linux/freezer.h> |
198e2f18 | 47 | #include <linux/vmalloc.h> |
1da177e4 LT |
48 | #include <linux/blkdev.h> |
49 | #include <linux/delay.h> | |
b488893a | 50 | #include <linux/pid_namespace.h> |
1da177e4 LT |
51 | #include <linux/smp.h> |
52 | #include <linux/threads.h> | |
53 | #include <linux/timer.h> | |
54 | #include <linux/rcupdate.h> | |
55 | #include <linux/cpu.h> | |
56 | #include <linux/cpuset.h> | |
57 | #include <linux/percpu.h> | |
58 | #include <linux/kthread.h> | |
b5aadf7f | 59 | #include <linux/proc_fs.h> |
1da177e4 | 60 | #include <linux/seq_file.h> |
e692ab53 | 61 | #include <linux/sysctl.h> |
1da177e4 LT |
62 | #include <linux/syscalls.h> |
63 | #include <linux/times.h> | |
8f0ab514 | 64 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 65 | #include <linux/kprobes.h> |
0ff92245 | 66 | #include <linux/delayacct.h> |
dff06c15 | 67 | #include <linux/unistd.h> |
f5ff8422 | 68 | #include <linux/pagemap.h> |
8f4d37ec | 69 | #include <linux/hrtimer.h> |
30914a58 | 70 | #include <linux/tick.h> |
f00b45c1 PZ |
71 | #include <linux/debugfs.h> |
72 | #include <linux/ctype.h> | |
6cd8a4bb | 73 | #include <linux/ftrace.h> |
1da177e4 | 74 | |
5517d86b | 75 | #include <asm/tlb.h> |
838225b4 | 76 | #include <asm/irq_regs.h> |
1da177e4 | 77 | |
6e0534f2 GH |
78 | #include "sched_cpupri.h" |
79 | ||
a8d154b0 | 80 | #define CREATE_TRACE_POINTS |
ad8d75ff | 81 | #include <trace/events/sched.h> |
a8d154b0 | 82 | |
1da177e4 LT |
83 | /* |
84 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
85 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
86 | * and back. | |
87 | */ | |
88 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
89 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
90 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
91 | ||
92 | /* | |
93 | * 'User priority' is the nice value converted to something we | |
94 | * can work with better when scaling various scheduler parameters, | |
95 | * it's a [ 0 ... 39 ] range. | |
96 | */ | |
97 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
98 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
99 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
100 | ||
101 | /* | |
d7876a08 | 102 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 103 | */ |
d6322faf | 104 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 105 | |
6aa645ea IM |
106 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
107 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
108 | ||
1da177e4 LT |
109 | /* |
110 | * These are the 'tuning knobs' of the scheduler: | |
111 | * | |
a4ec24b4 | 112 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
113 | * Timeslices get refilled after they expire. |
114 | */ | |
1da177e4 | 115 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 116 | |
d0b27fa7 PZ |
117 | /* |
118 | * single value that denotes runtime == period, ie unlimited time. | |
119 | */ | |
120 | #define RUNTIME_INF ((u64)~0ULL) | |
121 | ||
e05606d3 IM |
122 | static inline int rt_policy(int policy) |
123 | { | |
3f33a7ce | 124 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
125 | return 1; |
126 | return 0; | |
127 | } | |
128 | ||
129 | static inline int task_has_rt_policy(struct task_struct *p) | |
130 | { | |
131 | return rt_policy(p->policy); | |
132 | } | |
133 | ||
1da177e4 | 134 | /* |
6aa645ea | 135 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 136 | */ |
6aa645ea IM |
137 | struct rt_prio_array { |
138 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
139 | struct list_head queue[MAX_RT_PRIO]; | |
140 | }; | |
141 | ||
d0b27fa7 | 142 | struct rt_bandwidth { |
ea736ed5 | 143 | /* nests inside the rq lock: */ |
0986b11b | 144 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
145 | ktime_t rt_period; |
146 | u64 rt_runtime; | |
147 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
148 | }; |
149 | ||
150 | static struct rt_bandwidth def_rt_bandwidth; | |
151 | ||
152 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
153 | ||
154 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
155 | { | |
156 | struct rt_bandwidth *rt_b = | |
157 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
158 | ktime_t now; | |
159 | int overrun; | |
160 | int idle = 0; | |
161 | ||
162 | for (;;) { | |
163 | now = hrtimer_cb_get_time(timer); | |
164 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
165 | ||
166 | if (!overrun) | |
167 | break; | |
168 | ||
169 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
170 | } | |
171 | ||
172 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
173 | } | |
174 | ||
175 | static | |
176 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
177 | { | |
178 | rt_b->rt_period = ns_to_ktime(period); | |
179 | rt_b->rt_runtime = runtime; | |
180 | ||
0986b11b | 181 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 182 | |
d0b27fa7 PZ |
183 | hrtimer_init(&rt_b->rt_period_timer, |
184 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
185 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
186 | } |
187 | ||
c8bfff6d KH |
188 | static inline int rt_bandwidth_enabled(void) |
189 | { | |
190 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
191 | } |
192 | ||
193 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
194 | { | |
195 | ktime_t now; | |
196 | ||
cac64d00 | 197 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
198 | return; |
199 | ||
200 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
201 | return; | |
202 | ||
0986b11b | 203 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 204 | for (;;) { |
7f1e2ca9 PZ |
205 | unsigned long delta; |
206 | ktime_t soft, hard; | |
207 | ||
d0b27fa7 PZ |
208 | if (hrtimer_active(&rt_b->rt_period_timer)) |
209 | break; | |
210 | ||
211 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
212 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
213 | |
214 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
215 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
216 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
217 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 218 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 219 | } |
0986b11b | 220 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
221 | } |
222 | ||
223 | #ifdef CONFIG_RT_GROUP_SCHED | |
224 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
225 | { | |
226 | hrtimer_cancel(&rt_b->rt_period_timer); | |
227 | } | |
228 | #endif | |
229 | ||
712555ee HC |
230 | /* |
231 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
232 | * detach_destroy_domains and partition_sched_domains. | |
233 | */ | |
234 | static DEFINE_MUTEX(sched_domains_mutex); | |
235 | ||
052f1dc7 | 236 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 237 | |
68318b8e SV |
238 | #include <linux/cgroup.h> |
239 | ||
29f59db3 SV |
240 | struct cfs_rq; |
241 | ||
6f505b16 PZ |
242 | static LIST_HEAD(task_groups); |
243 | ||
29f59db3 | 244 | /* task group related information */ |
4cf86d77 | 245 | struct task_group { |
052f1dc7 | 246 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
247 | struct cgroup_subsys_state css; |
248 | #endif | |
052f1dc7 | 249 | |
6c415b92 AB |
250 | #ifdef CONFIG_USER_SCHED |
251 | uid_t uid; | |
252 | #endif | |
253 | ||
052f1dc7 | 254 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
255 | /* schedulable entities of this group on each cpu */ |
256 | struct sched_entity **se; | |
257 | /* runqueue "owned" by this group on each cpu */ | |
258 | struct cfs_rq **cfs_rq; | |
259 | unsigned long shares; | |
052f1dc7 PZ |
260 | #endif |
261 | ||
262 | #ifdef CONFIG_RT_GROUP_SCHED | |
263 | struct sched_rt_entity **rt_se; | |
264 | struct rt_rq **rt_rq; | |
265 | ||
d0b27fa7 | 266 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 267 | #endif |
6b2d7700 | 268 | |
ae8393e5 | 269 | struct rcu_head rcu; |
6f505b16 | 270 | struct list_head list; |
f473aa5e PZ |
271 | |
272 | struct task_group *parent; | |
273 | struct list_head siblings; | |
274 | struct list_head children; | |
29f59db3 SV |
275 | }; |
276 | ||
354d60c2 | 277 | #ifdef CONFIG_USER_SCHED |
eff766a6 | 278 | |
6c415b92 AB |
279 | /* Helper function to pass uid information to create_sched_user() */ |
280 | void set_tg_uid(struct user_struct *user) | |
281 | { | |
282 | user->tg->uid = user->uid; | |
283 | } | |
284 | ||
eff766a6 PZ |
285 | /* |
286 | * Root task group. | |
84e9dabf AS |
287 | * Every UID task group (including init_task_group aka UID-0) will |
288 | * be a child to this group. | |
eff766a6 PZ |
289 | */ |
290 | struct task_group root_task_group; | |
291 | ||
052f1dc7 | 292 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
293 | /* Default task group's sched entity on each cpu */ |
294 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
295 | /* Default task group's cfs_rq on each cpu */ | |
ada3fa15 | 296 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct cfs_rq, init_tg_cfs_rq); |
6d6bc0ad | 297 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
298 | |
299 | #ifdef CONFIG_RT_GROUP_SCHED | |
300 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
1871e52c | 301 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq_var); |
6d6bc0ad | 302 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 303 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 304 | #define root_task_group init_task_group |
9a7e0b18 | 305 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 306 | |
8ed36996 | 307 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
308 | * a task group's cpu shares. |
309 | */ | |
8ed36996 | 310 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 311 | |
e9036b36 CG |
312 | #ifdef CONFIG_FAIR_GROUP_SCHED |
313 | ||
57310a98 PZ |
314 | #ifdef CONFIG_SMP |
315 | static int root_task_group_empty(void) | |
316 | { | |
317 | return list_empty(&root_task_group.children); | |
318 | } | |
319 | #endif | |
320 | ||
052f1dc7 PZ |
321 | #ifdef CONFIG_USER_SCHED |
322 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 323 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 324 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 325 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 326 | |
cb4ad1ff | 327 | /* |
2e084786 LJ |
328 | * A weight of 0 or 1 can cause arithmetics problems. |
329 | * A weight of a cfs_rq is the sum of weights of which entities | |
330 | * are queued on this cfs_rq, so a weight of a entity should not be | |
331 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
332 | * (The default weight is 1024 - so there's no practical |
333 | * limitation from this.) | |
334 | */ | |
18d95a28 | 335 | #define MIN_SHARES 2 |
2e084786 | 336 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 337 | |
052f1dc7 PZ |
338 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
339 | #endif | |
340 | ||
29f59db3 | 341 | /* Default task group. |
3a252015 | 342 | * Every task in system belong to this group at bootup. |
29f59db3 | 343 | */ |
434d53b0 | 344 | struct task_group init_task_group; |
29f59db3 SV |
345 | |
346 | /* return group to which a task belongs */ | |
4cf86d77 | 347 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 348 | { |
4cf86d77 | 349 | struct task_group *tg; |
9b5b7751 | 350 | |
052f1dc7 | 351 | #ifdef CONFIG_USER_SCHED |
c69e8d9c DH |
352 | rcu_read_lock(); |
353 | tg = __task_cred(p)->user->tg; | |
354 | rcu_read_unlock(); | |
052f1dc7 | 355 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
356 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
357 | struct task_group, css); | |
24e377a8 | 358 | #else |
41a2d6cf | 359 | tg = &init_task_group; |
24e377a8 | 360 | #endif |
9b5b7751 | 361 | return tg; |
29f59db3 SV |
362 | } |
363 | ||
364 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 365 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 366 | { |
052f1dc7 | 367 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
368 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
369 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 370 | #endif |
6f505b16 | 371 | |
052f1dc7 | 372 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
373 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
374 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 375 | #endif |
29f59db3 SV |
376 | } |
377 | ||
378 | #else | |
379 | ||
6f505b16 | 380 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
381 | static inline struct task_group *task_group(struct task_struct *p) |
382 | { | |
383 | return NULL; | |
384 | } | |
29f59db3 | 385 | |
052f1dc7 | 386 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 387 | |
6aa645ea IM |
388 | /* CFS-related fields in a runqueue */ |
389 | struct cfs_rq { | |
390 | struct load_weight load; | |
391 | unsigned long nr_running; | |
392 | ||
6aa645ea | 393 | u64 exec_clock; |
e9acbff6 | 394 | u64 min_vruntime; |
6aa645ea IM |
395 | |
396 | struct rb_root tasks_timeline; | |
397 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
398 | |
399 | struct list_head tasks; | |
400 | struct list_head *balance_iterator; | |
401 | ||
402 | /* | |
403 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
404 | * It is set to NULL otherwise (i.e when none are currently running). |
405 | */ | |
4793241b | 406 | struct sched_entity *curr, *next, *last; |
ddc97297 | 407 | |
5ac5c4d6 | 408 | unsigned int nr_spread_over; |
ddc97297 | 409 | |
62160e3f | 410 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
411 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
412 | ||
41a2d6cf IM |
413 | /* |
414 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
415 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
416 | * (like users, containers etc.) | |
417 | * | |
418 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
419 | * list is used during load balance. | |
420 | */ | |
41a2d6cf IM |
421 | struct list_head leaf_cfs_rq_list; |
422 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
423 | |
424 | #ifdef CONFIG_SMP | |
c09595f6 | 425 | /* |
c8cba857 | 426 | * the part of load.weight contributed by tasks |
c09595f6 | 427 | */ |
c8cba857 | 428 | unsigned long task_weight; |
c09595f6 | 429 | |
c8cba857 PZ |
430 | /* |
431 | * h_load = weight * f(tg) | |
432 | * | |
433 | * Where f(tg) is the recursive weight fraction assigned to | |
434 | * this group. | |
435 | */ | |
436 | unsigned long h_load; | |
c09595f6 | 437 | |
c8cba857 PZ |
438 | /* |
439 | * this cpu's part of tg->shares | |
440 | */ | |
441 | unsigned long shares; | |
f1d239f7 PZ |
442 | |
443 | /* | |
444 | * load.weight at the time we set shares | |
445 | */ | |
446 | unsigned long rq_weight; | |
c09595f6 | 447 | #endif |
6aa645ea IM |
448 | #endif |
449 | }; | |
1da177e4 | 450 | |
6aa645ea IM |
451 | /* Real-Time classes' related field in a runqueue: */ |
452 | struct rt_rq { | |
453 | struct rt_prio_array active; | |
63489e45 | 454 | unsigned long rt_nr_running; |
052f1dc7 | 455 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
456 | struct { |
457 | int curr; /* highest queued rt task prio */ | |
398a153b | 458 | #ifdef CONFIG_SMP |
e864c499 | 459 | int next; /* next highest */ |
398a153b | 460 | #endif |
e864c499 | 461 | } highest_prio; |
6f505b16 | 462 | #endif |
fa85ae24 | 463 | #ifdef CONFIG_SMP |
73fe6aae | 464 | unsigned long rt_nr_migratory; |
a1ba4d8b | 465 | unsigned long rt_nr_total; |
a22d7fc1 | 466 | int overloaded; |
917b627d | 467 | struct plist_head pushable_tasks; |
fa85ae24 | 468 | #endif |
6f505b16 | 469 | int rt_throttled; |
fa85ae24 | 470 | u64 rt_time; |
ac086bc2 | 471 | u64 rt_runtime; |
ea736ed5 | 472 | /* Nests inside the rq lock: */ |
0986b11b | 473 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 474 | |
052f1dc7 | 475 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
476 | unsigned long rt_nr_boosted; |
477 | ||
6f505b16 PZ |
478 | struct rq *rq; |
479 | struct list_head leaf_rt_rq_list; | |
480 | struct task_group *tg; | |
481 | struct sched_rt_entity *rt_se; | |
482 | #endif | |
6aa645ea IM |
483 | }; |
484 | ||
57d885fe GH |
485 | #ifdef CONFIG_SMP |
486 | ||
487 | /* | |
488 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
489 | * variables. Each exclusive cpuset essentially defines an island domain by |
490 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
491 | * exclusive cpuset is created, we also create and attach a new root-domain |
492 | * object. | |
493 | * | |
57d885fe GH |
494 | */ |
495 | struct root_domain { | |
496 | atomic_t refcount; | |
c6c4927b RR |
497 | cpumask_var_t span; |
498 | cpumask_var_t online; | |
637f5085 | 499 | |
0eab9146 | 500 | /* |
637f5085 GH |
501 | * The "RT overload" flag: it gets set if a CPU has more than |
502 | * one runnable RT task. | |
503 | */ | |
c6c4927b | 504 | cpumask_var_t rto_mask; |
0eab9146 | 505 | atomic_t rto_count; |
6e0534f2 GH |
506 | #ifdef CONFIG_SMP |
507 | struct cpupri cpupri; | |
508 | #endif | |
57d885fe GH |
509 | }; |
510 | ||
dc938520 GH |
511 | /* |
512 | * By default the system creates a single root-domain with all cpus as | |
513 | * members (mimicking the global state we have today). | |
514 | */ | |
57d885fe GH |
515 | static struct root_domain def_root_domain; |
516 | ||
517 | #endif | |
518 | ||
1da177e4 LT |
519 | /* |
520 | * This is the main, per-CPU runqueue data structure. | |
521 | * | |
522 | * Locking rule: those places that want to lock multiple runqueues | |
523 | * (such as the load balancing or the thread migration code), lock | |
524 | * acquire operations must be ordered by ascending &runqueue. | |
525 | */ | |
70b97a7f | 526 | struct rq { |
d8016491 | 527 | /* runqueue lock: */ |
05fa785c | 528 | raw_spinlock_t lock; |
1da177e4 LT |
529 | |
530 | /* | |
531 | * nr_running and cpu_load should be in the same cacheline because | |
532 | * remote CPUs use both these fields when doing load calculation. | |
533 | */ | |
534 | unsigned long nr_running; | |
6aa645ea IM |
535 | #define CPU_LOAD_IDX_MAX 5 |
536 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c SS |
537 | #ifdef CONFIG_NO_HZ |
538 | unsigned char in_nohz_recently; | |
539 | #endif | |
d8016491 IM |
540 | /* capture load from *all* tasks on this cpu: */ |
541 | struct load_weight load; | |
6aa645ea IM |
542 | unsigned long nr_load_updates; |
543 | u64 nr_switches; | |
544 | ||
545 | struct cfs_rq cfs; | |
6f505b16 | 546 | struct rt_rq rt; |
6f505b16 | 547 | |
6aa645ea | 548 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
549 | /* list of leaf cfs_rq on this cpu: */ |
550 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
551 | #endif |
552 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 553 | struct list_head leaf_rt_rq_list; |
1da177e4 | 554 | #endif |
1da177e4 LT |
555 | |
556 | /* | |
557 | * This is part of a global counter where only the total sum | |
558 | * over all CPUs matters. A task can increase this counter on | |
559 | * one CPU and if it got migrated afterwards it may decrease | |
560 | * it on another CPU. Always updated under the runqueue lock: | |
561 | */ | |
562 | unsigned long nr_uninterruptible; | |
563 | ||
36c8b586 | 564 | struct task_struct *curr, *idle; |
c9819f45 | 565 | unsigned long next_balance; |
1da177e4 | 566 | struct mm_struct *prev_mm; |
6aa645ea | 567 | |
3e51f33f | 568 | u64 clock; |
6aa645ea | 569 | |
1da177e4 LT |
570 | atomic_t nr_iowait; |
571 | ||
572 | #ifdef CONFIG_SMP | |
0eab9146 | 573 | struct root_domain *rd; |
1da177e4 LT |
574 | struct sched_domain *sd; |
575 | ||
a0a522ce | 576 | unsigned char idle_at_tick; |
1da177e4 | 577 | /* For active balancing */ |
3f029d3c | 578 | int post_schedule; |
1da177e4 LT |
579 | int active_balance; |
580 | int push_cpu; | |
d8016491 IM |
581 | /* cpu of this runqueue: */ |
582 | int cpu; | |
1f11eb6a | 583 | int online; |
1da177e4 | 584 | |
a8a51d5e | 585 | unsigned long avg_load_per_task; |
1da177e4 | 586 | |
36c8b586 | 587 | struct task_struct *migration_thread; |
1da177e4 | 588 | struct list_head migration_queue; |
e9e9250b PZ |
589 | |
590 | u64 rt_avg; | |
591 | u64 age_stamp; | |
1b9508f6 MG |
592 | u64 idle_stamp; |
593 | u64 avg_idle; | |
1da177e4 LT |
594 | #endif |
595 | ||
dce48a84 TG |
596 | /* calc_load related fields */ |
597 | unsigned long calc_load_update; | |
598 | long calc_load_active; | |
599 | ||
8f4d37ec | 600 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
601 | #ifdef CONFIG_SMP |
602 | int hrtick_csd_pending; | |
603 | struct call_single_data hrtick_csd; | |
604 | #endif | |
8f4d37ec PZ |
605 | struct hrtimer hrtick_timer; |
606 | #endif | |
607 | ||
1da177e4 LT |
608 | #ifdef CONFIG_SCHEDSTATS |
609 | /* latency stats */ | |
610 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
611 | unsigned long long rq_cpu_time; |
612 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
613 | |
614 | /* sys_sched_yield() stats */ | |
480b9434 | 615 | unsigned int yld_count; |
1da177e4 LT |
616 | |
617 | /* schedule() stats */ | |
480b9434 KC |
618 | unsigned int sched_switch; |
619 | unsigned int sched_count; | |
620 | unsigned int sched_goidle; | |
1da177e4 LT |
621 | |
622 | /* try_to_wake_up() stats */ | |
480b9434 KC |
623 | unsigned int ttwu_count; |
624 | unsigned int ttwu_local; | |
b8efb561 IM |
625 | |
626 | /* BKL stats */ | |
480b9434 | 627 | unsigned int bkl_count; |
1da177e4 LT |
628 | #endif |
629 | }; | |
630 | ||
f34e3b61 | 631 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 632 | |
7d478721 PZ |
633 | static inline |
634 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 635 | { |
7d478721 | 636 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
dd41f596 IM |
637 | } |
638 | ||
0a2966b4 CL |
639 | static inline int cpu_of(struct rq *rq) |
640 | { | |
641 | #ifdef CONFIG_SMP | |
642 | return rq->cpu; | |
643 | #else | |
644 | return 0; | |
645 | #endif | |
646 | } | |
647 | ||
674311d5 NP |
648 | /* |
649 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 650 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
651 | * |
652 | * The domain tree of any CPU may only be accessed from within | |
653 | * preempt-disabled sections. | |
654 | */ | |
48f24c4d IM |
655 | #define for_each_domain(cpu, __sd) \ |
656 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
657 | |
658 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
659 | #define this_rq() (&__get_cpu_var(runqueues)) | |
660 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
661 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 662 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 663 | |
aa9c4c0f | 664 | inline void update_rq_clock(struct rq *rq) |
3e51f33f PZ |
665 | { |
666 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
667 | } | |
668 | ||
bf5c91ba IM |
669 | /* |
670 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
671 | */ | |
672 | #ifdef CONFIG_SCHED_DEBUG | |
673 | # define const_debug __read_mostly | |
674 | #else | |
675 | # define const_debug static const | |
676 | #endif | |
677 | ||
017730c1 IM |
678 | /** |
679 | * runqueue_is_locked | |
e17b38bf | 680 | * @cpu: the processor in question. |
017730c1 IM |
681 | * |
682 | * Returns true if the current cpu runqueue is locked. | |
683 | * This interface allows printk to be called with the runqueue lock | |
684 | * held and know whether or not it is OK to wake up the klogd. | |
685 | */ | |
89f19f04 | 686 | int runqueue_is_locked(int cpu) |
017730c1 | 687 | { |
05fa785c | 688 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
689 | } |
690 | ||
bf5c91ba IM |
691 | /* |
692 | * Debugging: various feature bits | |
693 | */ | |
f00b45c1 PZ |
694 | |
695 | #define SCHED_FEAT(name, enabled) \ | |
696 | __SCHED_FEAT_##name , | |
697 | ||
bf5c91ba | 698 | enum { |
f00b45c1 | 699 | #include "sched_features.h" |
bf5c91ba IM |
700 | }; |
701 | ||
f00b45c1 PZ |
702 | #undef SCHED_FEAT |
703 | ||
704 | #define SCHED_FEAT(name, enabled) \ | |
705 | (1UL << __SCHED_FEAT_##name) * enabled | | |
706 | ||
bf5c91ba | 707 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
708 | #include "sched_features.h" |
709 | 0; | |
710 | ||
711 | #undef SCHED_FEAT | |
712 | ||
713 | #ifdef CONFIG_SCHED_DEBUG | |
714 | #define SCHED_FEAT(name, enabled) \ | |
715 | #name , | |
716 | ||
983ed7a6 | 717 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
718 | #include "sched_features.h" |
719 | NULL | |
720 | }; | |
721 | ||
722 | #undef SCHED_FEAT | |
723 | ||
34f3a814 | 724 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 725 | { |
f00b45c1 PZ |
726 | int i; |
727 | ||
728 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
729 | if (!(sysctl_sched_features & (1UL << i))) |
730 | seq_puts(m, "NO_"); | |
731 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 732 | } |
34f3a814 | 733 | seq_puts(m, "\n"); |
f00b45c1 | 734 | |
34f3a814 | 735 | return 0; |
f00b45c1 PZ |
736 | } |
737 | ||
738 | static ssize_t | |
739 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
740 | size_t cnt, loff_t *ppos) | |
741 | { | |
742 | char buf[64]; | |
743 | char *cmp = buf; | |
744 | int neg = 0; | |
745 | int i; | |
746 | ||
747 | if (cnt > 63) | |
748 | cnt = 63; | |
749 | ||
750 | if (copy_from_user(&buf, ubuf, cnt)) | |
751 | return -EFAULT; | |
752 | ||
753 | buf[cnt] = 0; | |
754 | ||
c24b7c52 | 755 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
756 | neg = 1; |
757 | cmp += 3; | |
758 | } | |
759 | ||
760 | for (i = 0; sched_feat_names[i]; i++) { | |
761 | int len = strlen(sched_feat_names[i]); | |
762 | ||
763 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
764 | if (neg) | |
765 | sysctl_sched_features &= ~(1UL << i); | |
766 | else | |
767 | sysctl_sched_features |= (1UL << i); | |
768 | break; | |
769 | } | |
770 | } | |
771 | ||
772 | if (!sched_feat_names[i]) | |
773 | return -EINVAL; | |
774 | ||
42994724 | 775 | *ppos += cnt; |
f00b45c1 PZ |
776 | |
777 | return cnt; | |
778 | } | |
779 | ||
34f3a814 LZ |
780 | static int sched_feat_open(struct inode *inode, struct file *filp) |
781 | { | |
782 | return single_open(filp, sched_feat_show, NULL); | |
783 | } | |
784 | ||
828c0950 | 785 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
786 | .open = sched_feat_open, |
787 | .write = sched_feat_write, | |
788 | .read = seq_read, | |
789 | .llseek = seq_lseek, | |
790 | .release = single_release, | |
f00b45c1 PZ |
791 | }; |
792 | ||
793 | static __init int sched_init_debug(void) | |
794 | { | |
f00b45c1 PZ |
795 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
796 | &sched_feat_fops); | |
797 | ||
798 | return 0; | |
799 | } | |
800 | late_initcall(sched_init_debug); | |
801 | ||
802 | #endif | |
803 | ||
804 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 805 | |
b82d9fdd PZ |
806 | /* |
807 | * Number of tasks to iterate in a single balance run. | |
808 | * Limited because this is done with IRQs disabled. | |
809 | */ | |
810 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
811 | ||
2398f2c6 PZ |
812 | /* |
813 | * ratelimit for updating the group shares. | |
55cd5340 | 814 | * default: 0.25ms |
2398f2c6 | 815 | */ |
55cd5340 | 816 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 817 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 818 | |
ffda12a1 PZ |
819 | /* |
820 | * Inject some fuzzyness into changing the per-cpu group shares | |
821 | * this avoids remote rq-locks at the expense of fairness. | |
822 | * default: 4 | |
823 | */ | |
824 | unsigned int sysctl_sched_shares_thresh = 4; | |
825 | ||
e9e9250b PZ |
826 | /* |
827 | * period over which we average the RT time consumption, measured | |
828 | * in ms. | |
829 | * | |
830 | * default: 1s | |
831 | */ | |
832 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
833 | ||
fa85ae24 | 834 | /* |
9f0c1e56 | 835 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
836 | * default: 1s |
837 | */ | |
9f0c1e56 | 838 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 839 | |
6892b75e IM |
840 | static __read_mostly int scheduler_running; |
841 | ||
9f0c1e56 PZ |
842 | /* |
843 | * part of the period that we allow rt tasks to run in us. | |
844 | * default: 0.95s | |
845 | */ | |
846 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 847 | |
d0b27fa7 PZ |
848 | static inline u64 global_rt_period(void) |
849 | { | |
850 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
851 | } | |
852 | ||
853 | static inline u64 global_rt_runtime(void) | |
854 | { | |
e26873bb | 855 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
856 | return RUNTIME_INF; |
857 | ||
858 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
859 | } | |
fa85ae24 | 860 | |
1da177e4 | 861 | #ifndef prepare_arch_switch |
4866cde0 NP |
862 | # define prepare_arch_switch(next) do { } while (0) |
863 | #endif | |
864 | #ifndef finish_arch_switch | |
865 | # define finish_arch_switch(prev) do { } while (0) | |
866 | #endif | |
867 | ||
051a1d1a DA |
868 | static inline int task_current(struct rq *rq, struct task_struct *p) |
869 | { | |
870 | return rq->curr == p; | |
871 | } | |
872 | ||
4866cde0 | 873 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 874 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 875 | { |
051a1d1a | 876 | return task_current(rq, p); |
4866cde0 NP |
877 | } |
878 | ||
70b97a7f | 879 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
880 | { |
881 | } | |
882 | ||
70b97a7f | 883 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 884 | { |
da04c035 IM |
885 | #ifdef CONFIG_DEBUG_SPINLOCK |
886 | /* this is a valid case when another task releases the spinlock */ | |
887 | rq->lock.owner = current; | |
888 | #endif | |
8a25d5de IM |
889 | /* |
890 | * If we are tracking spinlock dependencies then we have to | |
891 | * fix up the runqueue lock - which gets 'carried over' from | |
892 | * prev into current: | |
893 | */ | |
894 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
895 | ||
05fa785c | 896 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
897 | } |
898 | ||
899 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 900 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
901 | { |
902 | #ifdef CONFIG_SMP | |
903 | return p->oncpu; | |
904 | #else | |
051a1d1a | 905 | return task_current(rq, p); |
4866cde0 NP |
906 | #endif |
907 | } | |
908 | ||
70b97a7f | 909 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
910 | { |
911 | #ifdef CONFIG_SMP | |
912 | /* | |
913 | * We can optimise this out completely for !SMP, because the | |
914 | * SMP rebalancing from interrupt is the only thing that cares | |
915 | * here. | |
916 | */ | |
917 | next->oncpu = 1; | |
918 | #endif | |
919 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 920 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 921 | #else |
05fa785c | 922 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
923 | #endif |
924 | } | |
925 | ||
70b97a7f | 926 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
927 | { |
928 | #ifdef CONFIG_SMP | |
929 | /* | |
930 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
931 | * We must ensure this doesn't happen until the switch is completely | |
932 | * finished. | |
933 | */ | |
934 | smp_wmb(); | |
935 | prev->oncpu = 0; | |
936 | #endif | |
937 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
938 | local_irq_enable(); | |
1da177e4 | 939 | #endif |
4866cde0 NP |
940 | } |
941 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 942 | |
b29739f9 IM |
943 | /* |
944 | * __task_rq_lock - lock the runqueue a given task resides on. | |
945 | * Must be called interrupts disabled. | |
946 | */ | |
70b97a7f | 947 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
948 | __acquires(rq->lock) |
949 | { | |
3a5c359a AK |
950 | for (;;) { |
951 | struct rq *rq = task_rq(p); | |
05fa785c | 952 | raw_spin_lock(&rq->lock); |
3a5c359a AK |
953 | if (likely(rq == task_rq(p))) |
954 | return rq; | |
05fa785c | 955 | raw_spin_unlock(&rq->lock); |
b29739f9 | 956 | } |
b29739f9 IM |
957 | } |
958 | ||
1da177e4 LT |
959 | /* |
960 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 961 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
962 | * explicitly disabling preemption. |
963 | */ | |
70b97a7f | 964 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
965 | __acquires(rq->lock) |
966 | { | |
70b97a7f | 967 | struct rq *rq; |
1da177e4 | 968 | |
3a5c359a AK |
969 | for (;;) { |
970 | local_irq_save(*flags); | |
971 | rq = task_rq(p); | |
05fa785c | 972 | raw_spin_lock(&rq->lock); |
3a5c359a AK |
973 | if (likely(rq == task_rq(p))) |
974 | return rq; | |
05fa785c | 975 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 976 | } |
1da177e4 LT |
977 | } |
978 | ||
ad474cac ON |
979 | void task_rq_unlock_wait(struct task_struct *p) |
980 | { | |
981 | struct rq *rq = task_rq(p); | |
982 | ||
983 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
05fa785c | 984 | raw_spin_unlock_wait(&rq->lock); |
ad474cac ON |
985 | } |
986 | ||
a9957449 | 987 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
988 | __releases(rq->lock) |
989 | { | |
05fa785c | 990 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
991 | } |
992 | ||
70b97a7f | 993 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
994 | __releases(rq->lock) |
995 | { | |
05fa785c | 996 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
997 | } |
998 | ||
1da177e4 | 999 | /* |
cc2a73b5 | 1000 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1001 | */ |
a9957449 | 1002 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1003 | __acquires(rq->lock) |
1004 | { | |
70b97a7f | 1005 | struct rq *rq; |
1da177e4 LT |
1006 | |
1007 | local_irq_disable(); | |
1008 | rq = this_rq(); | |
05fa785c | 1009 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
1010 | |
1011 | return rq; | |
1012 | } | |
1013 | ||
8f4d37ec PZ |
1014 | #ifdef CONFIG_SCHED_HRTICK |
1015 | /* | |
1016 | * Use HR-timers to deliver accurate preemption points. | |
1017 | * | |
1018 | * Its all a bit involved since we cannot program an hrt while holding the | |
1019 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1020 | * reschedule event. | |
1021 | * | |
1022 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1023 | * rq->lock. | |
1024 | */ | |
8f4d37ec PZ |
1025 | |
1026 | /* | |
1027 | * Use hrtick when: | |
1028 | * - enabled by features | |
1029 | * - hrtimer is actually high res | |
1030 | */ | |
1031 | static inline int hrtick_enabled(struct rq *rq) | |
1032 | { | |
1033 | if (!sched_feat(HRTICK)) | |
1034 | return 0; | |
ba42059f | 1035 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1036 | return 0; |
8f4d37ec PZ |
1037 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1038 | } | |
1039 | ||
8f4d37ec PZ |
1040 | static void hrtick_clear(struct rq *rq) |
1041 | { | |
1042 | if (hrtimer_active(&rq->hrtick_timer)) | |
1043 | hrtimer_cancel(&rq->hrtick_timer); | |
1044 | } | |
1045 | ||
8f4d37ec PZ |
1046 | /* |
1047 | * High-resolution timer tick. | |
1048 | * Runs from hardirq context with interrupts disabled. | |
1049 | */ | |
1050 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1051 | { | |
1052 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1053 | ||
1054 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1055 | ||
05fa785c | 1056 | raw_spin_lock(&rq->lock); |
3e51f33f | 1057 | update_rq_clock(rq); |
8f4d37ec | 1058 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1059 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1060 | |
1061 | return HRTIMER_NORESTART; | |
1062 | } | |
1063 | ||
95e904c7 | 1064 | #ifdef CONFIG_SMP |
31656519 PZ |
1065 | /* |
1066 | * called from hardirq (IPI) context | |
1067 | */ | |
1068 | static void __hrtick_start(void *arg) | |
b328ca18 | 1069 | { |
31656519 | 1070 | struct rq *rq = arg; |
b328ca18 | 1071 | |
05fa785c | 1072 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1073 | hrtimer_restart(&rq->hrtick_timer); |
1074 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1075 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1076 | } |
1077 | ||
31656519 PZ |
1078 | /* |
1079 | * Called to set the hrtick timer state. | |
1080 | * | |
1081 | * called with rq->lock held and irqs disabled | |
1082 | */ | |
1083 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1084 | { |
31656519 PZ |
1085 | struct hrtimer *timer = &rq->hrtick_timer; |
1086 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1087 | |
cc584b21 | 1088 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1089 | |
1090 | if (rq == this_rq()) { | |
1091 | hrtimer_restart(timer); | |
1092 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1093 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1094 | rq->hrtick_csd_pending = 1; |
1095 | } | |
b328ca18 PZ |
1096 | } |
1097 | ||
1098 | static int | |
1099 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1100 | { | |
1101 | int cpu = (int)(long)hcpu; | |
1102 | ||
1103 | switch (action) { | |
1104 | case CPU_UP_CANCELED: | |
1105 | case CPU_UP_CANCELED_FROZEN: | |
1106 | case CPU_DOWN_PREPARE: | |
1107 | case CPU_DOWN_PREPARE_FROZEN: | |
1108 | case CPU_DEAD: | |
1109 | case CPU_DEAD_FROZEN: | |
31656519 | 1110 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1111 | return NOTIFY_OK; |
1112 | } | |
1113 | ||
1114 | return NOTIFY_DONE; | |
1115 | } | |
1116 | ||
fa748203 | 1117 | static __init void init_hrtick(void) |
b328ca18 PZ |
1118 | { |
1119 | hotcpu_notifier(hotplug_hrtick, 0); | |
1120 | } | |
31656519 PZ |
1121 | #else |
1122 | /* | |
1123 | * Called to set the hrtick timer state. | |
1124 | * | |
1125 | * called with rq->lock held and irqs disabled | |
1126 | */ | |
1127 | static void hrtick_start(struct rq *rq, u64 delay) | |
1128 | { | |
7f1e2ca9 | 1129 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1130 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1131 | } |
b328ca18 | 1132 | |
006c75f1 | 1133 | static inline void init_hrtick(void) |
8f4d37ec | 1134 | { |
8f4d37ec | 1135 | } |
31656519 | 1136 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1137 | |
31656519 | 1138 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1139 | { |
31656519 PZ |
1140 | #ifdef CONFIG_SMP |
1141 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1142 | |
31656519 PZ |
1143 | rq->hrtick_csd.flags = 0; |
1144 | rq->hrtick_csd.func = __hrtick_start; | |
1145 | rq->hrtick_csd.info = rq; | |
1146 | #endif | |
8f4d37ec | 1147 | |
31656519 PZ |
1148 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1149 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1150 | } |
006c75f1 | 1151 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1152 | static inline void hrtick_clear(struct rq *rq) |
1153 | { | |
1154 | } | |
1155 | ||
8f4d37ec PZ |
1156 | static inline void init_rq_hrtick(struct rq *rq) |
1157 | { | |
1158 | } | |
1159 | ||
b328ca18 PZ |
1160 | static inline void init_hrtick(void) |
1161 | { | |
1162 | } | |
006c75f1 | 1163 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1164 | |
c24d20db IM |
1165 | /* |
1166 | * resched_task - mark a task 'to be rescheduled now'. | |
1167 | * | |
1168 | * On UP this means the setting of the need_resched flag, on SMP it | |
1169 | * might also involve a cross-CPU call to trigger the scheduler on | |
1170 | * the target CPU. | |
1171 | */ | |
1172 | #ifdef CONFIG_SMP | |
1173 | ||
1174 | #ifndef tsk_is_polling | |
1175 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1176 | #endif | |
1177 | ||
31656519 | 1178 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1179 | { |
1180 | int cpu; | |
1181 | ||
05fa785c | 1182 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1183 | |
5ed0cec0 | 1184 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1185 | return; |
1186 | ||
5ed0cec0 | 1187 | set_tsk_need_resched(p); |
c24d20db IM |
1188 | |
1189 | cpu = task_cpu(p); | |
1190 | if (cpu == smp_processor_id()) | |
1191 | return; | |
1192 | ||
1193 | /* NEED_RESCHED must be visible before we test polling */ | |
1194 | smp_mb(); | |
1195 | if (!tsk_is_polling(p)) | |
1196 | smp_send_reschedule(cpu); | |
1197 | } | |
1198 | ||
1199 | static void resched_cpu(int cpu) | |
1200 | { | |
1201 | struct rq *rq = cpu_rq(cpu); | |
1202 | unsigned long flags; | |
1203 | ||
05fa785c | 1204 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1205 | return; |
1206 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1207 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1208 | } |
06d8308c TG |
1209 | |
1210 | #ifdef CONFIG_NO_HZ | |
1211 | /* | |
1212 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1213 | * idle CPU then this timer might expire before the next timer event | |
1214 | * which is scheduled to wake up that CPU. In case of a completely | |
1215 | * idle system the next event might even be infinite time into the | |
1216 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1217 | * leaves the inner idle loop so the newly added timer is taken into | |
1218 | * account when the CPU goes back to idle and evaluates the timer | |
1219 | * wheel for the next timer event. | |
1220 | */ | |
1221 | void wake_up_idle_cpu(int cpu) | |
1222 | { | |
1223 | struct rq *rq = cpu_rq(cpu); | |
1224 | ||
1225 | if (cpu == smp_processor_id()) | |
1226 | return; | |
1227 | ||
1228 | /* | |
1229 | * This is safe, as this function is called with the timer | |
1230 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1231 | * to idle and has not yet set rq->curr to idle then it will | |
1232 | * be serialized on the timer wheel base lock and take the new | |
1233 | * timer into account automatically. | |
1234 | */ | |
1235 | if (rq->curr != rq->idle) | |
1236 | return; | |
1237 | ||
1238 | /* | |
1239 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1240 | * lockless. The worst case is that the other CPU runs the | |
1241 | * idle task through an additional NOOP schedule() | |
1242 | */ | |
5ed0cec0 | 1243 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1244 | |
1245 | /* NEED_RESCHED must be visible before we test polling */ | |
1246 | smp_mb(); | |
1247 | if (!tsk_is_polling(rq->idle)) | |
1248 | smp_send_reschedule(cpu); | |
1249 | } | |
6d6bc0ad | 1250 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1251 | |
e9e9250b PZ |
1252 | static u64 sched_avg_period(void) |
1253 | { | |
1254 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1255 | } | |
1256 | ||
1257 | static void sched_avg_update(struct rq *rq) | |
1258 | { | |
1259 | s64 period = sched_avg_period(); | |
1260 | ||
1261 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1262 | rq->age_stamp += period; | |
1263 | rq->rt_avg /= 2; | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1268 | { | |
1269 | rq->rt_avg += rt_delta; | |
1270 | sched_avg_update(rq); | |
1271 | } | |
1272 | ||
6d6bc0ad | 1273 | #else /* !CONFIG_SMP */ |
31656519 | 1274 | static void resched_task(struct task_struct *p) |
c24d20db | 1275 | { |
05fa785c | 1276 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1277 | set_tsk_need_resched(p); |
c24d20db | 1278 | } |
e9e9250b PZ |
1279 | |
1280 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1281 | { | |
1282 | } | |
6d6bc0ad | 1283 | #endif /* CONFIG_SMP */ |
c24d20db | 1284 | |
45bf76df IM |
1285 | #if BITS_PER_LONG == 32 |
1286 | # define WMULT_CONST (~0UL) | |
1287 | #else | |
1288 | # define WMULT_CONST (1UL << 32) | |
1289 | #endif | |
1290 | ||
1291 | #define WMULT_SHIFT 32 | |
1292 | ||
194081eb IM |
1293 | /* |
1294 | * Shift right and round: | |
1295 | */ | |
cf2ab469 | 1296 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1297 | |
a7be37ac PZ |
1298 | /* |
1299 | * delta *= weight / lw | |
1300 | */ | |
cb1c4fc9 | 1301 | static unsigned long |
45bf76df IM |
1302 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1303 | struct load_weight *lw) | |
1304 | { | |
1305 | u64 tmp; | |
1306 | ||
7a232e03 LJ |
1307 | if (!lw->inv_weight) { |
1308 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1309 | lw->inv_weight = 1; | |
1310 | else | |
1311 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1312 | / (lw->weight+1); | |
1313 | } | |
45bf76df IM |
1314 | |
1315 | tmp = (u64)delta_exec * weight; | |
1316 | /* | |
1317 | * Check whether we'd overflow the 64-bit multiplication: | |
1318 | */ | |
194081eb | 1319 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1320 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1321 | WMULT_SHIFT/2); |
1322 | else | |
cf2ab469 | 1323 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1324 | |
ecf691da | 1325 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1326 | } |
1327 | ||
1091985b | 1328 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1329 | { |
1330 | lw->weight += inc; | |
e89996ae | 1331 | lw->inv_weight = 0; |
45bf76df IM |
1332 | } |
1333 | ||
1091985b | 1334 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1335 | { |
1336 | lw->weight -= dec; | |
e89996ae | 1337 | lw->inv_weight = 0; |
45bf76df IM |
1338 | } |
1339 | ||
2dd73a4f PW |
1340 | /* |
1341 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1342 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1343 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1344 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1345 | * scaled version of the new time slice allocation that they receive on time |
1346 | * slice expiry etc. | |
1347 | */ | |
1348 | ||
cce7ade8 PZ |
1349 | #define WEIGHT_IDLEPRIO 3 |
1350 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1351 | |
1352 | /* | |
1353 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1354 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1355 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1356 | * that remained on nice 0. | |
1357 | * | |
1358 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1359 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1360 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1361 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1362 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1363 | */ |
1364 | static const int prio_to_weight[40] = { | |
254753dc IM |
1365 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1366 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1367 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1368 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1369 | /* 0 */ 1024, 820, 655, 526, 423, | |
1370 | /* 5 */ 335, 272, 215, 172, 137, | |
1371 | /* 10 */ 110, 87, 70, 56, 45, | |
1372 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1373 | }; |
1374 | ||
5714d2de IM |
1375 | /* |
1376 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1377 | * | |
1378 | * In cases where the weight does not change often, we can use the | |
1379 | * precalculated inverse to speed up arithmetics by turning divisions | |
1380 | * into multiplications: | |
1381 | */ | |
dd41f596 | 1382 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1383 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1384 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1385 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1386 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1387 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1388 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1389 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1390 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1391 | }; |
2dd73a4f | 1392 | |
dd41f596 IM |
1393 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1394 | ||
1395 | /* | |
1396 | * runqueue iterator, to support SMP load-balancing between different | |
1397 | * scheduling classes, without having to expose their internal data | |
1398 | * structures to the load-balancing proper: | |
1399 | */ | |
1400 | struct rq_iterator { | |
1401 | void *arg; | |
1402 | struct task_struct *(*start)(void *); | |
1403 | struct task_struct *(*next)(void *); | |
1404 | }; | |
1405 | ||
e1d1484f PW |
1406 | #ifdef CONFIG_SMP |
1407 | static unsigned long | |
1408 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1409 | unsigned long max_load_move, struct sched_domain *sd, | |
1410 | enum cpu_idle_type idle, int *all_pinned, | |
1411 | int *this_best_prio, struct rq_iterator *iterator); | |
1412 | ||
1413 | static int | |
1414 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1415 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1416 | struct rq_iterator *iterator); | |
e1d1484f | 1417 | #endif |
dd41f596 | 1418 | |
ef12fefa BR |
1419 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1420 | enum cpuacct_stat_index { | |
1421 | CPUACCT_STAT_USER, /* ... user mode */ | |
1422 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1423 | ||
1424 | CPUACCT_STAT_NSTATS, | |
1425 | }; | |
1426 | ||
d842de87 SV |
1427 | #ifdef CONFIG_CGROUP_CPUACCT |
1428 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1429 | static void cpuacct_update_stats(struct task_struct *tsk, |
1430 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1431 | #else |
1432 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1433 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1434 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1435 | #endif |
1436 | ||
18d95a28 PZ |
1437 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1438 | { | |
1439 | update_load_add(&rq->load, load); | |
1440 | } | |
1441 | ||
1442 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1443 | { | |
1444 | update_load_sub(&rq->load, load); | |
1445 | } | |
1446 | ||
7940ca36 | 1447 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1448 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1449 | |
1450 | /* | |
1451 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1452 | * leaving it for the final time. | |
1453 | */ | |
eb755805 | 1454 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1455 | { |
1456 | struct task_group *parent, *child; | |
eb755805 | 1457 | int ret; |
c09595f6 PZ |
1458 | |
1459 | rcu_read_lock(); | |
1460 | parent = &root_task_group; | |
1461 | down: | |
eb755805 PZ |
1462 | ret = (*down)(parent, data); |
1463 | if (ret) | |
1464 | goto out_unlock; | |
c09595f6 PZ |
1465 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1466 | parent = child; | |
1467 | goto down; | |
1468 | ||
1469 | up: | |
1470 | continue; | |
1471 | } | |
eb755805 PZ |
1472 | ret = (*up)(parent, data); |
1473 | if (ret) | |
1474 | goto out_unlock; | |
c09595f6 PZ |
1475 | |
1476 | child = parent; | |
1477 | parent = parent->parent; | |
1478 | if (parent) | |
1479 | goto up; | |
eb755805 | 1480 | out_unlock: |
c09595f6 | 1481 | rcu_read_unlock(); |
eb755805 PZ |
1482 | |
1483 | return ret; | |
c09595f6 PZ |
1484 | } |
1485 | ||
eb755805 PZ |
1486 | static int tg_nop(struct task_group *tg, void *data) |
1487 | { | |
1488 | return 0; | |
c09595f6 | 1489 | } |
eb755805 PZ |
1490 | #endif |
1491 | ||
1492 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1493 | /* Used instead of source_load when we know the type == 0 */ |
1494 | static unsigned long weighted_cpuload(const int cpu) | |
1495 | { | |
1496 | return cpu_rq(cpu)->load.weight; | |
1497 | } | |
1498 | ||
1499 | /* | |
1500 | * Return a low guess at the load of a migration-source cpu weighted | |
1501 | * according to the scheduling class and "nice" value. | |
1502 | * | |
1503 | * We want to under-estimate the load of migration sources, to | |
1504 | * balance conservatively. | |
1505 | */ | |
1506 | static unsigned long source_load(int cpu, int type) | |
1507 | { | |
1508 | struct rq *rq = cpu_rq(cpu); | |
1509 | unsigned long total = weighted_cpuload(cpu); | |
1510 | ||
1511 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1512 | return total; | |
1513 | ||
1514 | return min(rq->cpu_load[type-1], total); | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Return a high guess at the load of a migration-target cpu weighted | |
1519 | * according to the scheduling class and "nice" value. | |
1520 | */ | |
1521 | static unsigned long target_load(int cpu, int type) | |
1522 | { | |
1523 | struct rq *rq = cpu_rq(cpu); | |
1524 | unsigned long total = weighted_cpuload(cpu); | |
1525 | ||
1526 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1527 | return total; | |
1528 | ||
1529 | return max(rq->cpu_load[type-1], total); | |
1530 | } | |
1531 | ||
ae154be1 PZ |
1532 | static struct sched_group *group_of(int cpu) |
1533 | { | |
1534 | struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); | |
1535 | ||
1536 | if (!sd) | |
1537 | return NULL; | |
1538 | ||
1539 | return sd->groups; | |
1540 | } | |
1541 | ||
1542 | static unsigned long power_of(int cpu) | |
1543 | { | |
1544 | struct sched_group *group = group_of(cpu); | |
1545 | ||
1546 | if (!group) | |
1547 | return SCHED_LOAD_SCALE; | |
1548 | ||
1549 | return group->cpu_power; | |
1550 | } | |
1551 | ||
eb755805 PZ |
1552 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1553 | ||
1554 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1555 | { | |
1556 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1557 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1558 | |
4cd42620 SR |
1559 | if (nr_running) |
1560 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1561 | else |
1562 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1563 | |
1564 | return rq->avg_load_per_task; | |
1565 | } | |
1566 | ||
1567 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1568 | |
4a6cc4bd | 1569 | static __read_mostly unsigned long *update_shares_data; |
34d76c41 | 1570 | |
c09595f6 PZ |
1571 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1572 | ||
1573 | /* | |
1574 | * Calculate and set the cpu's group shares. | |
1575 | */ | |
34d76c41 PZ |
1576 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1577 | unsigned long sd_shares, | |
1578 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1579 | unsigned long *usd_rq_weight) |
18d95a28 | 1580 | { |
34d76c41 | 1581 | unsigned long shares, rq_weight; |
a5004278 | 1582 | int boost = 0; |
c09595f6 | 1583 | |
4a6cc4bd | 1584 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1585 | if (!rq_weight) { |
1586 | boost = 1; | |
1587 | rq_weight = NICE_0_LOAD; | |
1588 | } | |
c8cba857 | 1589 | |
c09595f6 | 1590 | /* |
a8af7246 PZ |
1591 | * \Sum_j shares_j * rq_weight_i |
1592 | * shares_i = ----------------------------- | |
1593 | * \Sum_j rq_weight_j | |
c09595f6 | 1594 | */ |
ec4e0e2f | 1595 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1596 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1597 | |
ffda12a1 PZ |
1598 | if (abs(shares - tg->se[cpu]->load.weight) > |
1599 | sysctl_sched_shares_thresh) { | |
1600 | struct rq *rq = cpu_rq(cpu); | |
1601 | unsigned long flags; | |
c09595f6 | 1602 | |
05fa785c | 1603 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1604 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1605 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1606 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1607 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1608 | } |
18d95a28 | 1609 | } |
c09595f6 PZ |
1610 | |
1611 | /* | |
c8cba857 PZ |
1612 | * Re-compute the task group their per cpu shares over the given domain. |
1613 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1614 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1615 | */ |
eb755805 | 1616 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1617 | { |
cd8ad40d | 1618 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1619 | unsigned long *usd_rq_weight; |
eb755805 | 1620 | struct sched_domain *sd = data; |
34d76c41 | 1621 | unsigned long flags; |
c8cba857 | 1622 | int i; |
c09595f6 | 1623 | |
34d76c41 PZ |
1624 | if (!tg->se[0]) |
1625 | return 0; | |
1626 | ||
1627 | local_irq_save(flags); | |
4a6cc4bd | 1628 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1629 | |
758b2cdc | 1630 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1631 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1632 | usd_rq_weight[i] = weight; |
34d76c41 | 1633 | |
cd8ad40d | 1634 | rq_weight += weight; |
ec4e0e2f KC |
1635 | /* |
1636 | * If there are currently no tasks on the cpu pretend there | |
1637 | * is one of average load so that when a new task gets to | |
1638 | * run here it will not get delayed by group starvation. | |
1639 | */ | |
ec4e0e2f KC |
1640 | if (!weight) |
1641 | weight = NICE_0_LOAD; | |
1642 | ||
cd8ad40d | 1643 | sum_weight += weight; |
c8cba857 | 1644 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1645 | } |
c09595f6 | 1646 | |
cd8ad40d PZ |
1647 | if (!rq_weight) |
1648 | rq_weight = sum_weight; | |
1649 | ||
c8cba857 PZ |
1650 | if ((!shares && rq_weight) || shares > tg->shares) |
1651 | shares = tg->shares; | |
1652 | ||
1653 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1654 | shares = tg->shares; | |
c09595f6 | 1655 | |
758b2cdc | 1656 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1657 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1658 | |
1659 | local_irq_restore(flags); | |
eb755805 PZ |
1660 | |
1661 | return 0; | |
c09595f6 PZ |
1662 | } |
1663 | ||
1664 | /* | |
c8cba857 PZ |
1665 | * Compute the cpu's hierarchical load factor for each task group. |
1666 | * This needs to be done in a top-down fashion because the load of a child | |
1667 | * group is a fraction of its parents load. | |
c09595f6 | 1668 | */ |
eb755805 | 1669 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1670 | { |
c8cba857 | 1671 | unsigned long load; |
eb755805 | 1672 | long cpu = (long)data; |
c09595f6 | 1673 | |
c8cba857 PZ |
1674 | if (!tg->parent) { |
1675 | load = cpu_rq(cpu)->load.weight; | |
1676 | } else { | |
1677 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1678 | load *= tg->cfs_rq[cpu]->shares; | |
1679 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1680 | } | |
c09595f6 | 1681 | |
c8cba857 | 1682 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1683 | |
eb755805 | 1684 | return 0; |
c09595f6 PZ |
1685 | } |
1686 | ||
c8cba857 | 1687 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1688 | { |
e7097159 PZ |
1689 | s64 elapsed; |
1690 | u64 now; | |
1691 | ||
1692 | if (root_task_group_empty()) | |
1693 | return; | |
1694 | ||
1695 | now = cpu_clock(raw_smp_processor_id()); | |
1696 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1697 | |
1698 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1699 | sd->last_update = now; | |
eb755805 | 1700 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1701 | } |
4d8d595d PZ |
1702 | } |
1703 | ||
3e5459b4 PZ |
1704 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1705 | { | |
e7097159 PZ |
1706 | if (root_task_group_empty()) |
1707 | return; | |
1708 | ||
05fa785c | 1709 | raw_spin_unlock(&rq->lock); |
3e5459b4 | 1710 | update_shares(sd); |
05fa785c | 1711 | raw_spin_lock(&rq->lock); |
3e5459b4 PZ |
1712 | } |
1713 | ||
eb755805 | 1714 | static void update_h_load(long cpu) |
c09595f6 | 1715 | { |
e7097159 PZ |
1716 | if (root_task_group_empty()) |
1717 | return; | |
1718 | ||
eb755805 | 1719 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1720 | } |
1721 | ||
c09595f6 PZ |
1722 | #else |
1723 | ||
c8cba857 | 1724 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1725 | { |
1726 | } | |
1727 | ||
3e5459b4 PZ |
1728 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1729 | { | |
1730 | } | |
1731 | ||
18d95a28 PZ |
1732 | #endif |
1733 | ||
8f45e2b5 GH |
1734 | #ifdef CONFIG_PREEMPT |
1735 | ||
b78bb868 PZ |
1736 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1737 | ||
70574a99 | 1738 | /* |
8f45e2b5 GH |
1739 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1740 | * way at the expense of forcing extra atomic operations in all | |
1741 | * invocations. This assures that the double_lock is acquired using the | |
1742 | * same underlying policy as the spinlock_t on this architecture, which | |
1743 | * reduces latency compared to the unfair variant below. However, it | |
1744 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1745 | */ |
8f45e2b5 GH |
1746 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1747 | __releases(this_rq->lock) | |
1748 | __acquires(busiest->lock) | |
1749 | __acquires(this_rq->lock) | |
1750 | { | |
05fa785c | 1751 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1752 | double_rq_lock(this_rq, busiest); |
1753 | ||
1754 | return 1; | |
1755 | } | |
1756 | ||
1757 | #else | |
1758 | /* | |
1759 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1760 | * latency by eliminating extra atomic operations when the locks are | |
1761 | * already in proper order on entry. This favors lower cpu-ids and will | |
1762 | * grant the double lock to lower cpus over higher ids under contention, | |
1763 | * regardless of entry order into the function. | |
1764 | */ | |
1765 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1766 | __releases(this_rq->lock) |
1767 | __acquires(busiest->lock) | |
1768 | __acquires(this_rq->lock) | |
1769 | { | |
1770 | int ret = 0; | |
1771 | ||
05fa785c | 1772 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1773 | if (busiest < this_rq) { |
05fa785c TG |
1774 | raw_spin_unlock(&this_rq->lock); |
1775 | raw_spin_lock(&busiest->lock); | |
1776 | raw_spin_lock_nested(&this_rq->lock, | |
1777 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1778 | ret = 1; |
1779 | } else | |
05fa785c TG |
1780 | raw_spin_lock_nested(&busiest->lock, |
1781 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1782 | } |
1783 | return ret; | |
1784 | } | |
1785 | ||
8f45e2b5 GH |
1786 | #endif /* CONFIG_PREEMPT */ |
1787 | ||
1788 | /* | |
1789 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1790 | */ | |
1791 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1792 | { | |
1793 | if (unlikely(!irqs_disabled())) { | |
1794 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1795 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1796 | BUG_ON(1); |
1797 | } | |
1798 | ||
1799 | return _double_lock_balance(this_rq, busiest); | |
1800 | } | |
1801 | ||
70574a99 AD |
1802 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1803 | __releases(busiest->lock) | |
1804 | { | |
05fa785c | 1805 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1806 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1807 | } | |
18d95a28 PZ |
1808 | #endif |
1809 | ||
30432094 | 1810 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1811 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1812 | { | |
30432094 | 1813 | #ifdef CONFIG_SMP |
34e83e85 IM |
1814 | cfs_rq->shares = shares; |
1815 | #endif | |
1816 | } | |
30432094 | 1817 | #endif |
e7693a36 | 1818 | |
dce48a84 | 1819 | static void calc_load_account_active(struct rq *this_rq); |
0bcdcf28 | 1820 | static void update_sysctl(void); |
acb4a848 | 1821 | static int get_update_sysctl_factor(void); |
dce48a84 | 1822 | |
cd29fe6f PZ |
1823 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1824 | { | |
1825 | set_task_rq(p, cpu); | |
1826 | #ifdef CONFIG_SMP | |
1827 | /* | |
1828 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1829 | * successfuly executed on another CPU. We must ensure that updates of | |
1830 | * per-task data have been completed by this moment. | |
1831 | */ | |
1832 | smp_wmb(); | |
1833 | task_thread_info(p)->cpu = cpu; | |
1834 | #endif | |
1835 | } | |
dce48a84 | 1836 | |
dd41f596 | 1837 | #include "sched_stats.h" |
dd41f596 | 1838 | #include "sched_idletask.c" |
5522d5d5 IM |
1839 | #include "sched_fair.c" |
1840 | #include "sched_rt.c" | |
dd41f596 IM |
1841 | #ifdef CONFIG_SCHED_DEBUG |
1842 | # include "sched_debug.c" | |
1843 | #endif | |
1844 | ||
1845 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1846 | #define for_each_class(class) \ |
1847 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1848 | |
c09595f6 | 1849 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1850 | { |
1851 | rq->nr_running++; | |
9c217245 IM |
1852 | } |
1853 | ||
c09595f6 | 1854 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1855 | { |
1856 | rq->nr_running--; | |
9c217245 IM |
1857 | } |
1858 | ||
45bf76df IM |
1859 | static void set_load_weight(struct task_struct *p) |
1860 | { | |
1861 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1862 | p->se.load.weight = prio_to_weight[0] * 2; |
1863 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1864 | return; | |
1865 | } | |
45bf76df | 1866 | |
dd41f596 IM |
1867 | /* |
1868 | * SCHED_IDLE tasks get minimal weight: | |
1869 | */ | |
1870 | if (p->policy == SCHED_IDLE) { | |
1871 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1872 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1873 | return; | |
1874 | } | |
71f8bd46 | 1875 | |
dd41f596 IM |
1876 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1877 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1878 | } |
1879 | ||
2087a1ad GH |
1880 | static void update_avg(u64 *avg, u64 sample) |
1881 | { | |
1882 | s64 diff = sample - *avg; | |
1883 | *avg += diff >> 3; | |
1884 | } | |
1885 | ||
8159f87e | 1886 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1887 | { |
831451ac PZ |
1888 | if (wakeup) |
1889 | p->se.start_runtime = p->se.sum_exec_runtime; | |
1890 | ||
dd41f596 | 1891 | sched_info_queued(p); |
fd390f6a | 1892 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1893 | p->se.on_rq = 1; |
71f8bd46 IM |
1894 | } |
1895 | ||
69be72c1 | 1896 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1897 | { |
831451ac PZ |
1898 | if (sleep) { |
1899 | if (p->se.last_wakeup) { | |
1900 | update_avg(&p->se.avg_overlap, | |
1901 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1902 | p->se.last_wakeup = 0; | |
1903 | } else { | |
1904 | update_avg(&p->se.avg_wakeup, | |
1905 | sysctl_sched_wakeup_granularity); | |
1906 | } | |
2087a1ad GH |
1907 | } |
1908 | ||
46ac22ba | 1909 | sched_info_dequeued(p); |
f02231e5 | 1910 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1911 | p->se.on_rq = 0; |
71f8bd46 IM |
1912 | } |
1913 | ||
14531189 | 1914 | /* |
dd41f596 | 1915 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1916 | */ |
14531189 IM |
1917 | static inline int __normal_prio(struct task_struct *p) |
1918 | { | |
dd41f596 | 1919 | return p->static_prio; |
14531189 IM |
1920 | } |
1921 | ||
b29739f9 IM |
1922 | /* |
1923 | * Calculate the expected normal priority: i.e. priority | |
1924 | * without taking RT-inheritance into account. Might be | |
1925 | * boosted by interactivity modifiers. Changes upon fork, | |
1926 | * setprio syscalls, and whenever the interactivity | |
1927 | * estimator recalculates. | |
1928 | */ | |
36c8b586 | 1929 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1930 | { |
1931 | int prio; | |
1932 | ||
e05606d3 | 1933 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1934 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1935 | else | |
1936 | prio = __normal_prio(p); | |
1937 | return prio; | |
1938 | } | |
1939 | ||
1940 | /* | |
1941 | * Calculate the current priority, i.e. the priority | |
1942 | * taken into account by the scheduler. This value might | |
1943 | * be boosted by RT tasks, or might be boosted by | |
1944 | * interactivity modifiers. Will be RT if the task got | |
1945 | * RT-boosted. If not then it returns p->normal_prio. | |
1946 | */ | |
36c8b586 | 1947 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1948 | { |
1949 | p->normal_prio = normal_prio(p); | |
1950 | /* | |
1951 | * If we are RT tasks or we were boosted to RT priority, | |
1952 | * keep the priority unchanged. Otherwise, update priority | |
1953 | * to the normal priority: | |
1954 | */ | |
1955 | if (!rt_prio(p->prio)) | |
1956 | return p->normal_prio; | |
1957 | return p->prio; | |
1958 | } | |
1959 | ||
1da177e4 | 1960 | /* |
dd41f596 | 1961 | * activate_task - move a task to the runqueue. |
1da177e4 | 1962 | */ |
dd41f596 | 1963 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1964 | { |
d9514f6c | 1965 | if (task_contributes_to_load(p)) |
dd41f596 | 1966 | rq->nr_uninterruptible--; |
1da177e4 | 1967 | |
8159f87e | 1968 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1969 | inc_nr_running(rq); |
1da177e4 LT |
1970 | } |
1971 | ||
1da177e4 LT |
1972 | /* |
1973 | * deactivate_task - remove a task from the runqueue. | |
1974 | */ | |
2e1cb74a | 1975 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1976 | { |
d9514f6c | 1977 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1978 | rq->nr_uninterruptible++; |
1979 | ||
69be72c1 | 1980 | dequeue_task(rq, p, sleep); |
c09595f6 | 1981 | dec_nr_running(rq); |
1da177e4 LT |
1982 | } |
1983 | ||
1da177e4 LT |
1984 | /** |
1985 | * task_curr - is this task currently executing on a CPU? | |
1986 | * @p: the task in question. | |
1987 | */ | |
36c8b586 | 1988 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1989 | { |
1990 | return cpu_curr(task_cpu(p)) == p; | |
1991 | } | |
1992 | ||
cb469845 SR |
1993 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1994 | const struct sched_class *prev_class, | |
1995 | int oldprio, int running) | |
1996 | { | |
1997 | if (prev_class != p->sched_class) { | |
1998 | if (prev_class->switched_from) | |
1999 | prev_class->switched_from(rq, p, running); | |
2000 | p->sched_class->switched_to(rq, p, running); | |
2001 | } else | |
2002 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
2003 | } | |
2004 | ||
1da177e4 | 2005 | #ifdef CONFIG_SMP |
cc367732 IM |
2006 | /* |
2007 | * Is this task likely cache-hot: | |
2008 | */ | |
e7693a36 | 2009 | static int |
cc367732 IM |
2010 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2011 | { | |
2012 | s64 delta; | |
2013 | ||
e6c8fba7 PZ |
2014 | if (p->sched_class != &fair_sched_class) |
2015 | return 0; | |
2016 | ||
f540a608 IM |
2017 | /* |
2018 | * Buddy candidates are cache hot: | |
2019 | */ | |
f685ceac | 2020 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2021 | (&p->se == cfs_rq_of(&p->se)->next || |
2022 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2023 | return 1; |
2024 | ||
6bc1665b IM |
2025 | if (sysctl_sched_migration_cost == -1) |
2026 | return 1; | |
2027 | if (sysctl_sched_migration_cost == 0) | |
2028 | return 0; | |
2029 | ||
cc367732 IM |
2030 | delta = now - p->se.exec_start; |
2031 | ||
2032 | return delta < (s64)sysctl_sched_migration_cost; | |
2033 | } | |
2034 | ||
dd41f596 | 2035 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2036 | { |
e2912009 PZ |
2037 | #ifdef CONFIG_SCHED_DEBUG |
2038 | /* | |
2039 | * We should never call set_task_cpu() on a blocked task, | |
2040 | * ttwu() will sort out the placement. | |
2041 | */ | |
077614ee PZ |
2042 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2043 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2044 | #endif |
2045 | ||
de1d7286 | 2046 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2047 | |
0c69774e PZ |
2048 | if (task_cpu(p) != new_cpu) { |
2049 | p->se.nr_migrations++; | |
2050 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2051 | } | |
dd41f596 IM |
2052 | |
2053 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2054 | } |
2055 | ||
70b97a7f | 2056 | struct migration_req { |
1da177e4 | 2057 | struct list_head list; |
1da177e4 | 2058 | |
36c8b586 | 2059 | struct task_struct *task; |
1da177e4 LT |
2060 | int dest_cpu; |
2061 | ||
1da177e4 | 2062 | struct completion done; |
70b97a7f | 2063 | }; |
1da177e4 LT |
2064 | |
2065 | /* | |
2066 | * The task's runqueue lock must be held. | |
2067 | * Returns true if you have to wait for migration thread. | |
2068 | */ | |
36c8b586 | 2069 | static int |
70b97a7f | 2070 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 2071 | { |
70b97a7f | 2072 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2073 | |
2074 | /* | |
2075 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2076 | * the next wake-up will properly place the task. |
1da177e4 | 2077 | */ |
e2912009 | 2078 | if (!p->se.on_rq && !task_running(rq, p)) |
1da177e4 | 2079 | return 0; |
1da177e4 LT |
2080 | |
2081 | init_completion(&req->done); | |
1da177e4 LT |
2082 | req->task = p; |
2083 | req->dest_cpu = dest_cpu; | |
2084 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 2085 | |
1da177e4 LT |
2086 | return 1; |
2087 | } | |
2088 | ||
a26b89f0 MM |
2089 | /* |
2090 | * wait_task_context_switch - wait for a thread to complete at least one | |
2091 | * context switch. | |
2092 | * | |
2093 | * @p must not be current. | |
2094 | */ | |
2095 | void wait_task_context_switch(struct task_struct *p) | |
2096 | { | |
2097 | unsigned long nvcsw, nivcsw, flags; | |
2098 | int running; | |
2099 | struct rq *rq; | |
2100 | ||
2101 | nvcsw = p->nvcsw; | |
2102 | nivcsw = p->nivcsw; | |
2103 | for (;;) { | |
2104 | /* | |
2105 | * The runqueue is assigned before the actual context | |
2106 | * switch. We need to take the runqueue lock. | |
2107 | * | |
2108 | * We could check initially without the lock but it is | |
2109 | * very likely that we need to take the lock in every | |
2110 | * iteration. | |
2111 | */ | |
2112 | rq = task_rq_lock(p, &flags); | |
2113 | running = task_running(rq, p); | |
2114 | task_rq_unlock(rq, &flags); | |
2115 | ||
2116 | if (likely(!running)) | |
2117 | break; | |
2118 | /* | |
2119 | * The switch count is incremented before the actual | |
2120 | * context switch. We thus wait for two switches to be | |
2121 | * sure at least one completed. | |
2122 | */ | |
2123 | if ((p->nvcsw - nvcsw) > 1) | |
2124 | break; | |
2125 | if ((p->nivcsw - nivcsw) > 1) | |
2126 | break; | |
2127 | ||
2128 | cpu_relax(); | |
2129 | } | |
2130 | } | |
2131 | ||
1da177e4 LT |
2132 | /* |
2133 | * wait_task_inactive - wait for a thread to unschedule. | |
2134 | * | |
85ba2d86 RM |
2135 | * If @match_state is nonzero, it's the @p->state value just checked and |
2136 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2137 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2138 | * we return a positive number (its total switch count). If a second call | |
2139 | * a short while later returns the same number, the caller can be sure that | |
2140 | * @p has remained unscheduled the whole time. | |
2141 | * | |
1da177e4 LT |
2142 | * The caller must ensure that the task *will* unschedule sometime soon, |
2143 | * else this function might spin for a *long* time. This function can't | |
2144 | * be called with interrupts off, or it may introduce deadlock with | |
2145 | * smp_call_function() if an IPI is sent by the same process we are | |
2146 | * waiting to become inactive. | |
2147 | */ | |
85ba2d86 | 2148 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2149 | { |
2150 | unsigned long flags; | |
dd41f596 | 2151 | int running, on_rq; |
85ba2d86 | 2152 | unsigned long ncsw; |
70b97a7f | 2153 | struct rq *rq; |
1da177e4 | 2154 | |
3a5c359a AK |
2155 | for (;;) { |
2156 | /* | |
2157 | * We do the initial early heuristics without holding | |
2158 | * any task-queue locks at all. We'll only try to get | |
2159 | * the runqueue lock when things look like they will | |
2160 | * work out! | |
2161 | */ | |
2162 | rq = task_rq(p); | |
fa490cfd | 2163 | |
3a5c359a AK |
2164 | /* |
2165 | * If the task is actively running on another CPU | |
2166 | * still, just relax and busy-wait without holding | |
2167 | * any locks. | |
2168 | * | |
2169 | * NOTE! Since we don't hold any locks, it's not | |
2170 | * even sure that "rq" stays as the right runqueue! | |
2171 | * But we don't care, since "task_running()" will | |
2172 | * return false if the runqueue has changed and p | |
2173 | * is actually now running somewhere else! | |
2174 | */ | |
85ba2d86 RM |
2175 | while (task_running(rq, p)) { |
2176 | if (match_state && unlikely(p->state != match_state)) | |
2177 | return 0; | |
3a5c359a | 2178 | cpu_relax(); |
85ba2d86 | 2179 | } |
fa490cfd | 2180 | |
3a5c359a AK |
2181 | /* |
2182 | * Ok, time to look more closely! We need the rq | |
2183 | * lock now, to be *sure*. If we're wrong, we'll | |
2184 | * just go back and repeat. | |
2185 | */ | |
2186 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2187 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2188 | running = task_running(rq, p); |
2189 | on_rq = p->se.on_rq; | |
85ba2d86 | 2190 | ncsw = 0; |
f31e11d8 | 2191 | if (!match_state || p->state == match_state) |
93dcf55f | 2192 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2193 | task_rq_unlock(rq, &flags); |
fa490cfd | 2194 | |
85ba2d86 RM |
2195 | /* |
2196 | * If it changed from the expected state, bail out now. | |
2197 | */ | |
2198 | if (unlikely(!ncsw)) | |
2199 | break; | |
2200 | ||
3a5c359a AK |
2201 | /* |
2202 | * Was it really running after all now that we | |
2203 | * checked with the proper locks actually held? | |
2204 | * | |
2205 | * Oops. Go back and try again.. | |
2206 | */ | |
2207 | if (unlikely(running)) { | |
2208 | cpu_relax(); | |
2209 | continue; | |
2210 | } | |
fa490cfd | 2211 | |
3a5c359a AK |
2212 | /* |
2213 | * It's not enough that it's not actively running, | |
2214 | * it must be off the runqueue _entirely_, and not | |
2215 | * preempted! | |
2216 | * | |
80dd99b3 | 2217 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2218 | * running right now), it's preempted, and we should |
2219 | * yield - it could be a while. | |
2220 | */ | |
2221 | if (unlikely(on_rq)) { | |
2222 | schedule_timeout_uninterruptible(1); | |
2223 | continue; | |
2224 | } | |
fa490cfd | 2225 | |
3a5c359a AK |
2226 | /* |
2227 | * Ahh, all good. It wasn't running, and it wasn't | |
2228 | * runnable, which means that it will never become | |
2229 | * running in the future either. We're all done! | |
2230 | */ | |
2231 | break; | |
2232 | } | |
85ba2d86 RM |
2233 | |
2234 | return ncsw; | |
1da177e4 LT |
2235 | } |
2236 | ||
2237 | /*** | |
2238 | * kick_process - kick a running thread to enter/exit the kernel | |
2239 | * @p: the to-be-kicked thread | |
2240 | * | |
2241 | * Cause a process which is running on another CPU to enter | |
2242 | * kernel-mode, without any delay. (to get signals handled.) | |
2243 | * | |
2244 | * NOTE: this function doesnt have to take the runqueue lock, | |
2245 | * because all it wants to ensure is that the remote task enters | |
2246 | * the kernel. If the IPI races and the task has been migrated | |
2247 | * to another CPU then no harm is done and the purpose has been | |
2248 | * achieved as well. | |
2249 | */ | |
36c8b586 | 2250 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2251 | { |
2252 | int cpu; | |
2253 | ||
2254 | preempt_disable(); | |
2255 | cpu = task_cpu(p); | |
2256 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2257 | smp_send_reschedule(cpu); | |
2258 | preempt_enable(); | |
2259 | } | |
b43e3521 | 2260 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2261 | #endif /* CONFIG_SMP */ |
1da177e4 | 2262 | |
0793a61d TG |
2263 | /** |
2264 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2265 | * @p: the task to evaluate | |
2266 | * @func: the function to be called | |
2267 | * @info: the function call argument | |
2268 | * | |
2269 | * Calls the function @func when the task is currently running. This might | |
2270 | * be on the current CPU, which just calls the function directly | |
2271 | */ | |
2272 | void task_oncpu_function_call(struct task_struct *p, | |
2273 | void (*func) (void *info), void *info) | |
2274 | { | |
2275 | int cpu; | |
2276 | ||
2277 | preempt_disable(); | |
2278 | cpu = task_cpu(p); | |
2279 | if (task_curr(p)) | |
2280 | smp_call_function_single(cpu, func, info, 1); | |
2281 | preempt_enable(); | |
2282 | } | |
2283 | ||
970b13ba | 2284 | #ifdef CONFIG_SMP |
5da9a0fb PZ |
2285 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2286 | { | |
2287 | int dest_cpu; | |
2288 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2289 | ||
2290 | /* Look for allowed, online CPU in same node. */ | |
2291 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2292 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2293 | return dest_cpu; | |
2294 | ||
2295 | /* Any allowed, online CPU? */ | |
2296 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2297 | if (dest_cpu < nr_cpu_ids) | |
2298 | return dest_cpu; | |
2299 | ||
2300 | /* No more Mr. Nice Guy. */ | |
2301 | if (dest_cpu >= nr_cpu_ids) { | |
2302 | rcu_read_lock(); | |
2303 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); | |
2304 | rcu_read_unlock(); | |
2305 | dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed); | |
2306 | ||
2307 | /* | |
2308 | * Don't tell them about moving exiting tasks or | |
2309 | * kernel threads (both mm NULL), since they never | |
2310 | * leave kernel. | |
2311 | */ | |
2312 | if (p->mm && printk_ratelimit()) { | |
2313 | printk(KERN_INFO "process %d (%s) no " | |
2314 | "longer affine to cpu%d\n", | |
2315 | task_pid_nr(p), p->comm, cpu); | |
2316 | } | |
2317 | } | |
2318 | ||
2319 | return dest_cpu; | |
2320 | } | |
2321 | ||
e2912009 PZ |
2322 | /* |
2323 | * Called from: | |
2324 | * | |
2325 | * - fork, @p is stable because it isn't on the tasklist yet | |
2326 | * | |
38022906 | 2327 | * - exec, @p is unstable, retry loop |
e2912009 PZ |
2328 | * |
2329 | * - wake-up, we serialize ->cpus_allowed against TASK_WAKING so | |
2330 | * we should be good. | |
2331 | */ | |
970b13ba PZ |
2332 | static inline |
2333 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) | |
2334 | { | |
e2912009 PZ |
2335 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
2336 | ||
2337 | /* | |
2338 | * In order not to call set_task_cpu() on a blocking task we need | |
2339 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2340 | * cpu. | |
2341 | * | |
2342 | * Since this is common to all placement strategies, this lives here. | |
2343 | * | |
2344 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2345 | * not worry about this generic constraint ] | |
2346 | */ | |
2347 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2348 | !cpu_online(cpu))) |
5da9a0fb | 2349 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2350 | |
2351 | return cpu; | |
970b13ba PZ |
2352 | } |
2353 | #endif | |
2354 | ||
1da177e4 LT |
2355 | /*** |
2356 | * try_to_wake_up - wake up a thread | |
2357 | * @p: the to-be-woken-up thread | |
2358 | * @state: the mask of task states that can be woken | |
2359 | * @sync: do a synchronous wakeup? | |
2360 | * | |
2361 | * Put it on the run-queue if it's not already there. The "current" | |
2362 | * thread is always on the run-queue (except when the actual | |
2363 | * re-schedule is in progress), and as such you're allowed to do | |
2364 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2365 | * runnable without the overhead of this. | |
2366 | * | |
2367 | * returns failure only if the task is already active. | |
2368 | */ | |
7d478721 PZ |
2369 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2370 | int wake_flags) | |
1da177e4 | 2371 | { |
cc367732 | 2372 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2373 | unsigned long flags; |
f5dc3753 | 2374 | struct rq *rq, *orig_rq; |
1da177e4 | 2375 | |
b85d0667 | 2376 | if (!sched_feat(SYNC_WAKEUPS)) |
7d478721 | 2377 | wake_flags &= ~WF_SYNC; |
2398f2c6 | 2378 | |
e9c84311 | 2379 | this_cpu = get_cpu(); |
2398f2c6 | 2380 | |
04e2f174 | 2381 | smp_wmb(); |
f5dc3753 | 2382 | rq = orig_rq = task_rq_lock(p, &flags); |
03e89e45 | 2383 | update_rq_clock(rq); |
e9c84311 | 2384 | if (!(p->state & state)) |
1da177e4 LT |
2385 | goto out; |
2386 | ||
dd41f596 | 2387 | if (p->se.on_rq) |
1da177e4 LT |
2388 | goto out_running; |
2389 | ||
2390 | cpu = task_cpu(p); | |
cc367732 | 2391 | orig_cpu = cpu; |
1da177e4 LT |
2392 | |
2393 | #ifdef CONFIG_SMP | |
2394 | if (unlikely(task_running(rq, p))) | |
2395 | goto out_activate; | |
2396 | ||
e9c84311 PZ |
2397 | /* |
2398 | * In order to handle concurrent wakeups and release the rq->lock | |
2399 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2400 | * |
2401 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2402 | */ |
eb24073b IM |
2403 | if (task_contributes_to_load(p)) |
2404 | rq->nr_uninterruptible--; | |
e9c84311 | 2405 | p->state = TASK_WAKING; |
efbbd05a PZ |
2406 | |
2407 | if (p->sched_class->task_waking) | |
2408 | p->sched_class->task_waking(rq, p); | |
2409 | ||
ab19cb23 | 2410 | __task_rq_unlock(rq); |
e9c84311 | 2411 | |
970b13ba | 2412 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
ab19cb23 | 2413 | if (cpu != orig_cpu) |
5d2f5a61 | 2414 | set_task_cpu(p, cpu); |
ab19cb23 PZ |
2415 | |
2416 | rq = __task_rq_lock(p); | |
2417 | update_rq_clock(rq); | |
f5dc3753 | 2418 | |
e9c84311 PZ |
2419 | WARN_ON(p->state != TASK_WAKING); |
2420 | cpu = task_cpu(p); | |
1da177e4 | 2421 | |
e7693a36 GH |
2422 | #ifdef CONFIG_SCHEDSTATS |
2423 | schedstat_inc(rq, ttwu_count); | |
2424 | if (cpu == this_cpu) | |
2425 | schedstat_inc(rq, ttwu_local); | |
2426 | else { | |
2427 | struct sched_domain *sd; | |
2428 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2429 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2430 | schedstat_inc(sd, ttwu_wake_remote); |
2431 | break; | |
2432 | } | |
2433 | } | |
2434 | } | |
6d6bc0ad | 2435 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2436 | |
1da177e4 LT |
2437 | out_activate: |
2438 | #endif /* CONFIG_SMP */ | |
cc367732 | 2439 | schedstat_inc(p, se.nr_wakeups); |
7d478721 | 2440 | if (wake_flags & WF_SYNC) |
cc367732 IM |
2441 | schedstat_inc(p, se.nr_wakeups_sync); |
2442 | if (orig_cpu != cpu) | |
2443 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2444 | if (cpu == this_cpu) | |
2445 | schedstat_inc(p, se.nr_wakeups_local); | |
2446 | else | |
2447 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2448 | activate_task(rq, p, 1); |
1da177e4 LT |
2449 | success = 1; |
2450 | ||
831451ac PZ |
2451 | /* |
2452 | * Only attribute actual wakeups done by this task. | |
2453 | */ | |
2454 | if (!in_interrupt()) { | |
2455 | struct sched_entity *se = ¤t->se; | |
2456 | u64 sample = se->sum_exec_runtime; | |
2457 | ||
2458 | if (se->last_wakeup) | |
2459 | sample -= se->last_wakeup; | |
2460 | else | |
2461 | sample -= se->start_runtime; | |
2462 | update_avg(&se->avg_wakeup, sample); | |
2463 | ||
2464 | se->last_wakeup = se->sum_exec_runtime; | |
2465 | } | |
2466 | ||
1da177e4 | 2467 | out_running: |
468a15bb | 2468 | trace_sched_wakeup(rq, p, success); |
7d478721 | 2469 | check_preempt_curr(rq, p, wake_flags); |
4ae7d5ce | 2470 | |
1da177e4 | 2471 | p->state = TASK_RUNNING; |
9a897c5a | 2472 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2473 | if (p->sched_class->task_woken) |
2474 | p->sched_class->task_woken(rq, p); | |
eae0c9df MG |
2475 | |
2476 | if (unlikely(rq->idle_stamp)) { | |
2477 | u64 delta = rq->clock - rq->idle_stamp; | |
2478 | u64 max = 2*sysctl_sched_migration_cost; | |
2479 | ||
2480 | if (delta > max) | |
2481 | rq->avg_idle = max; | |
2482 | else | |
2483 | update_avg(&rq->avg_idle, delta); | |
2484 | rq->idle_stamp = 0; | |
2485 | } | |
9a897c5a | 2486 | #endif |
1da177e4 LT |
2487 | out: |
2488 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2489 | put_cpu(); |
1da177e4 LT |
2490 | |
2491 | return success; | |
2492 | } | |
2493 | ||
50fa610a DH |
2494 | /** |
2495 | * wake_up_process - Wake up a specific process | |
2496 | * @p: The process to be woken up. | |
2497 | * | |
2498 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2499 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2500 | * running. | |
2501 | * | |
2502 | * It may be assumed that this function implies a write memory barrier before | |
2503 | * changing the task state if and only if any tasks are woken up. | |
2504 | */ | |
7ad5b3a5 | 2505 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2506 | { |
d9514f6c | 2507 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2508 | } |
1da177e4 LT |
2509 | EXPORT_SYMBOL(wake_up_process); |
2510 | ||
7ad5b3a5 | 2511 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2512 | { |
2513 | return try_to_wake_up(p, state, 0); | |
2514 | } | |
2515 | ||
1da177e4 LT |
2516 | /* |
2517 | * Perform scheduler related setup for a newly forked process p. | |
2518 | * p is forked by current. | |
dd41f596 IM |
2519 | * |
2520 | * __sched_fork() is basic setup used by init_idle() too: | |
2521 | */ | |
2522 | static void __sched_fork(struct task_struct *p) | |
2523 | { | |
dd41f596 IM |
2524 | p->se.exec_start = 0; |
2525 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2526 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2527 | p->se.nr_migrations = 0; |
4ae7d5ce IM |
2528 | p->se.last_wakeup = 0; |
2529 | p->se.avg_overlap = 0; | |
831451ac PZ |
2530 | p->se.start_runtime = 0; |
2531 | p->se.avg_wakeup = sysctl_sched_wakeup_granularity; | |
6cfb0d5d IM |
2532 | |
2533 | #ifdef CONFIG_SCHEDSTATS | |
7793527b LDM |
2534 | p->se.wait_start = 0; |
2535 | p->se.wait_max = 0; | |
2536 | p->se.wait_count = 0; | |
2537 | p->se.wait_sum = 0; | |
2538 | ||
2539 | p->se.sleep_start = 0; | |
2540 | p->se.sleep_max = 0; | |
2541 | p->se.sum_sleep_runtime = 0; | |
2542 | ||
2543 | p->se.block_start = 0; | |
2544 | p->se.block_max = 0; | |
2545 | p->se.exec_max = 0; | |
2546 | p->se.slice_max = 0; | |
2547 | ||
2548 | p->se.nr_migrations_cold = 0; | |
2549 | p->se.nr_failed_migrations_affine = 0; | |
2550 | p->se.nr_failed_migrations_running = 0; | |
2551 | p->se.nr_failed_migrations_hot = 0; | |
2552 | p->se.nr_forced_migrations = 0; | |
7793527b LDM |
2553 | |
2554 | p->se.nr_wakeups = 0; | |
2555 | p->se.nr_wakeups_sync = 0; | |
2556 | p->se.nr_wakeups_migrate = 0; | |
2557 | p->se.nr_wakeups_local = 0; | |
2558 | p->se.nr_wakeups_remote = 0; | |
2559 | p->se.nr_wakeups_affine = 0; | |
2560 | p->se.nr_wakeups_affine_attempts = 0; | |
2561 | p->se.nr_wakeups_passive = 0; | |
2562 | p->se.nr_wakeups_idle = 0; | |
2563 | ||
6cfb0d5d | 2564 | #endif |
476d139c | 2565 | |
fa717060 | 2566 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2567 | p->se.on_rq = 0; |
4a55bd5e | 2568 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2569 | |
e107be36 AK |
2570 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2571 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2572 | #endif | |
dd41f596 IM |
2573 | } |
2574 | ||
2575 | /* | |
2576 | * fork()/clone()-time setup: | |
2577 | */ | |
2578 | void sched_fork(struct task_struct *p, int clone_flags) | |
2579 | { | |
2580 | int cpu = get_cpu(); | |
2581 | ||
2582 | __sched_fork(p); | |
06b83b5f PZ |
2583 | /* |
2584 | * We mark the process as waking here. This guarantees that | |
2585 | * nobody will actually run it, and a signal or other external | |
2586 | * event cannot wake it up and insert it on the runqueue either. | |
2587 | */ | |
2588 | p->state = TASK_WAKING; | |
dd41f596 | 2589 | |
b9dc29e7 MG |
2590 | /* |
2591 | * Revert to default priority/policy on fork if requested. | |
2592 | */ | |
2593 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2594 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2595 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2596 | p->normal_prio = p->static_prio; |
2597 | } | |
b9dc29e7 | 2598 | |
6c697bdf MG |
2599 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2600 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2601 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2602 | set_load_weight(p); |
2603 | } | |
2604 | ||
b9dc29e7 MG |
2605 | /* |
2606 | * We don't need the reset flag anymore after the fork. It has | |
2607 | * fulfilled its duty: | |
2608 | */ | |
2609 | p->sched_reset_on_fork = 0; | |
2610 | } | |
ca94c442 | 2611 | |
f83f9ac2 PW |
2612 | /* |
2613 | * Make sure we do not leak PI boosting priority to the child. | |
2614 | */ | |
2615 | p->prio = current->normal_prio; | |
2616 | ||
2ddbf952 HS |
2617 | if (!rt_prio(p->prio)) |
2618 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2619 | |
cd29fe6f PZ |
2620 | if (p->sched_class->task_fork) |
2621 | p->sched_class->task_fork(p); | |
2622 | ||
5f3edc1b | 2623 | #ifdef CONFIG_SMP |
970b13ba | 2624 | cpu = select_task_rq(p, SD_BALANCE_FORK, 0); |
5f3edc1b PZ |
2625 | #endif |
2626 | set_task_cpu(p, cpu); | |
2627 | ||
52f17b6c | 2628 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2629 | if (likely(sched_info_on())) |
52f17b6c | 2630 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2631 | #endif |
d6077cb8 | 2632 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2633 | p->oncpu = 0; |
2634 | #endif | |
1da177e4 | 2635 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2636 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2637 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2638 | #endif |
917b627d GH |
2639 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2640 | ||
476d139c | 2641 | put_cpu(); |
1da177e4 LT |
2642 | } |
2643 | ||
2644 | /* | |
2645 | * wake_up_new_task - wake up a newly created task for the first time. | |
2646 | * | |
2647 | * This function will do some initial scheduler statistics housekeeping | |
2648 | * that must be done for every newly created context, then puts the task | |
2649 | * on the runqueue and wakes it. | |
2650 | */ | |
7ad5b3a5 | 2651 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2652 | { |
2653 | unsigned long flags; | |
dd41f596 | 2654 | struct rq *rq; |
1da177e4 LT |
2655 | |
2656 | rq = task_rq_lock(p, &flags); | |
06b83b5f PZ |
2657 | BUG_ON(p->state != TASK_WAKING); |
2658 | p->state = TASK_RUNNING; | |
a8e504d2 | 2659 | update_rq_clock(rq); |
cd29fe6f | 2660 | activate_task(rq, p, 0); |
c71dd42d | 2661 | trace_sched_wakeup_new(rq, p, 1); |
a7558e01 | 2662 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2663 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2664 | if (p->sched_class->task_woken) |
2665 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2666 | #endif |
dd41f596 | 2667 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
2668 | } |
2669 | ||
e107be36 AK |
2670 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2671 | ||
2672 | /** | |
80dd99b3 | 2673 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2674 | * @notifier: notifier struct to register |
e107be36 AK |
2675 | */ |
2676 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2677 | { | |
2678 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2679 | } | |
2680 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2681 | ||
2682 | /** | |
2683 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2684 | * @notifier: notifier struct to unregister |
e107be36 AK |
2685 | * |
2686 | * This is safe to call from within a preemption notifier. | |
2687 | */ | |
2688 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2689 | { | |
2690 | hlist_del(¬ifier->link); | |
2691 | } | |
2692 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2693 | ||
2694 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2695 | { | |
2696 | struct preempt_notifier *notifier; | |
2697 | struct hlist_node *node; | |
2698 | ||
2699 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2700 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2701 | } | |
2702 | ||
2703 | static void | |
2704 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2705 | struct task_struct *next) | |
2706 | { | |
2707 | struct preempt_notifier *notifier; | |
2708 | struct hlist_node *node; | |
2709 | ||
2710 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2711 | notifier->ops->sched_out(notifier, next); | |
2712 | } | |
2713 | ||
6d6bc0ad | 2714 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2715 | |
2716 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2717 | { | |
2718 | } | |
2719 | ||
2720 | static void | |
2721 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2722 | struct task_struct *next) | |
2723 | { | |
2724 | } | |
2725 | ||
6d6bc0ad | 2726 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2727 | |
4866cde0 NP |
2728 | /** |
2729 | * prepare_task_switch - prepare to switch tasks | |
2730 | * @rq: the runqueue preparing to switch | |
421cee29 | 2731 | * @prev: the current task that is being switched out |
4866cde0 NP |
2732 | * @next: the task we are going to switch to. |
2733 | * | |
2734 | * This is called with the rq lock held and interrupts off. It must | |
2735 | * be paired with a subsequent finish_task_switch after the context | |
2736 | * switch. | |
2737 | * | |
2738 | * prepare_task_switch sets up locking and calls architecture specific | |
2739 | * hooks. | |
2740 | */ | |
e107be36 AK |
2741 | static inline void |
2742 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2743 | struct task_struct *next) | |
4866cde0 | 2744 | { |
e107be36 | 2745 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2746 | prepare_lock_switch(rq, next); |
2747 | prepare_arch_switch(next); | |
2748 | } | |
2749 | ||
1da177e4 LT |
2750 | /** |
2751 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2752 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2753 | * @prev: the thread we just switched away from. |
2754 | * | |
4866cde0 NP |
2755 | * finish_task_switch must be called after the context switch, paired |
2756 | * with a prepare_task_switch call before the context switch. | |
2757 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2758 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2759 | * |
2760 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2761 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2762 | * with the lock held can cause deadlocks; see schedule() for |
2763 | * details.) | |
2764 | */ | |
a9957449 | 2765 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2766 | __releases(rq->lock) |
2767 | { | |
1da177e4 | 2768 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2769 | long prev_state; |
1da177e4 LT |
2770 | |
2771 | rq->prev_mm = NULL; | |
2772 | ||
2773 | /* | |
2774 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2775 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2776 | * schedule one last time. The schedule call will never return, and |
2777 | * the scheduled task must drop that reference. | |
c394cc9f | 2778 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2779 | * still held, otherwise prev could be scheduled on another cpu, die |
2780 | * there before we look at prev->state, and then the reference would | |
2781 | * be dropped twice. | |
2782 | * Manfred Spraul <manfred@colorfullife.com> | |
2783 | */ | |
55a101f8 | 2784 | prev_state = prev->state; |
4866cde0 | 2785 | finish_arch_switch(prev); |
cdd6c482 | 2786 | perf_event_task_sched_in(current, cpu_of(rq)); |
4866cde0 | 2787 | finish_lock_switch(rq, prev); |
e8fa1362 | 2788 | |
e107be36 | 2789 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2790 | if (mm) |
2791 | mmdrop(mm); | |
c394cc9f | 2792 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2793 | /* |
2794 | * Remove function-return probe instances associated with this | |
2795 | * task and put them back on the free list. | |
9761eea8 | 2796 | */ |
c6fd91f0 | 2797 | kprobe_flush_task(prev); |
1da177e4 | 2798 | put_task_struct(prev); |
c6fd91f0 | 2799 | } |
1da177e4 LT |
2800 | } |
2801 | ||
3f029d3c GH |
2802 | #ifdef CONFIG_SMP |
2803 | ||
2804 | /* assumes rq->lock is held */ | |
2805 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2806 | { | |
2807 | if (prev->sched_class->pre_schedule) | |
2808 | prev->sched_class->pre_schedule(rq, prev); | |
2809 | } | |
2810 | ||
2811 | /* rq->lock is NOT held, but preemption is disabled */ | |
2812 | static inline void post_schedule(struct rq *rq) | |
2813 | { | |
2814 | if (rq->post_schedule) { | |
2815 | unsigned long flags; | |
2816 | ||
05fa785c | 2817 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2818 | if (rq->curr->sched_class->post_schedule) |
2819 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2820 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2821 | |
2822 | rq->post_schedule = 0; | |
2823 | } | |
2824 | } | |
2825 | ||
2826 | #else | |
da19ab51 | 2827 | |
3f029d3c GH |
2828 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2829 | { | |
2830 | } | |
2831 | ||
2832 | static inline void post_schedule(struct rq *rq) | |
2833 | { | |
1da177e4 LT |
2834 | } |
2835 | ||
3f029d3c GH |
2836 | #endif |
2837 | ||
1da177e4 LT |
2838 | /** |
2839 | * schedule_tail - first thing a freshly forked thread must call. | |
2840 | * @prev: the thread we just switched away from. | |
2841 | */ | |
36c8b586 | 2842 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2843 | __releases(rq->lock) |
2844 | { | |
70b97a7f IM |
2845 | struct rq *rq = this_rq(); |
2846 | ||
4866cde0 | 2847 | finish_task_switch(rq, prev); |
da19ab51 | 2848 | |
3f029d3c GH |
2849 | /* |
2850 | * FIXME: do we need to worry about rq being invalidated by the | |
2851 | * task_switch? | |
2852 | */ | |
2853 | post_schedule(rq); | |
70b97a7f | 2854 | |
4866cde0 NP |
2855 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2856 | /* In this case, finish_task_switch does not reenable preemption */ | |
2857 | preempt_enable(); | |
2858 | #endif | |
1da177e4 | 2859 | if (current->set_child_tid) |
b488893a | 2860 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2861 | } |
2862 | ||
2863 | /* | |
2864 | * context_switch - switch to the new MM and the new | |
2865 | * thread's register state. | |
2866 | */ | |
dd41f596 | 2867 | static inline void |
70b97a7f | 2868 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2869 | struct task_struct *next) |
1da177e4 | 2870 | { |
dd41f596 | 2871 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2872 | |
e107be36 | 2873 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2874 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2875 | mm = next->mm; |
2876 | oldmm = prev->active_mm; | |
9226d125 ZA |
2877 | /* |
2878 | * For paravirt, this is coupled with an exit in switch_to to | |
2879 | * combine the page table reload and the switch backend into | |
2880 | * one hypercall. | |
2881 | */ | |
224101ed | 2882 | arch_start_context_switch(prev); |
9226d125 | 2883 | |
710390d9 | 2884 | if (likely(!mm)) { |
1da177e4 LT |
2885 | next->active_mm = oldmm; |
2886 | atomic_inc(&oldmm->mm_count); | |
2887 | enter_lazy_tlb(oldmm, next); | |
2888 | } else | |
2889 | switch_mm(oldmm, mm, next); | |
2890 | ||
710390d9 | 2891 | if (likely(!prev->mm)) { |
1da177e4 | 2892 | prev->active_mm = NULL; |
1da177e4 LT |
2893 | rq->prev_mm = oldmm; |
2894 | } | |
3a5f5e48 IM |
2895 | /* |
2896 | * Since the runqueue lock will be released by the next | |
2897 | * task (which is an invalid locking op but in the case | |
2898 | * of the scheduler it's an obvious special-case), so we | |
2899 | * do an early lockdep release here: | |
2900 | */ | |
2901 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2902 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2903 | #endif |
1da177e4 LT |
2904 | |
2905 | /* Here we just switch the register state and the stack. */ | |
2906 | switch_to(prev, next, prev); | |
2907 | ||
dd41f596 IM |
2908 | barrier(); |
2909 | /* | |
2910 | * this_rq must be evaluated again because prev may have moved | |
2911 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2912 | * frame will be invalid. | |
2913 | */ | |
2914 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2915 | } |
2916 | ||
2917 | /* | |
2918 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2919 | * | |
2920 | * externally visible scheduler statistics: current number of runnable | |
2921 | * threads, current number of uninterruptible-sleeping threads, total | |
2922 | * number of context switches performed since bootup. | |
2923 | */ | |
2924 | unsigned long nr_running(void) | |
2925 | { | |
2926 | unsigned long i, sum = 0; | |
2927 | ||
2928 | for_each_online_cpu(i) | |
2929 | sum += cpu_rq(i)->nr_running; | |
2930 | ||
2931 | return sum; | |
2932 | } | |
2933 | ||
2934 | unsigned long nr_uninterruptible(void) | |
2935 | { | |
2936 | unsigned long i, sum = 0; | |
2937 | ||
0a945022 | 2938 | for_each_possible_cpu(i) |
1da177e4 LT |
2939 | sum += cpu_rq(i)->nr_uninterruptible; |
2940 | ||
2941 | /* | |
2942 | * Since we read the counters lockless, it might be slightly | |
2943 | * inaccurate. Do not allow it to go below zero though: | |
2944 | */ | |
2945 | if (unlikely((long)sum < 0)) | |
2946 | sum = 0; | |
2947 | ||
2948 | return sum; | |
2949 | } | |
2950 | ||
2951 | unsigned long long nr_context_switches(void) | |
2952 | { | |
cc94abfc SR |
2953 | int i; |
2954 | unsigned long long sum = 0; | |
1da177e4 | 2955 | |
0a945022 | 2956 | for_each_possible_cpu(i) |
1da177e4 LT |
2957 | sum += cpu_rq(i)->nr_switches; |
2958 | ||
2959 | return sum; | |
2960 | } | |
2961 | ||
2962 | unsigned long nr_iowait(void) | |
2963 | { | |
2964 | unsigned long i, sum = 0; | |
2965 | ||
0a945022 | 2966 | for_each_possible_cpu(i) |
1da177e4 LT |
2967 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2968 | ||
2969 | return sum; | |
2970 | } | |
2971 | ||
69d25870 AV |
2972 | unsigned long nr_iowait_cpu(void) |
2973 | { | |
2974 | struct rq *this = this_rq(); | |
2975 | return atomic_read(&this->nr_iowait); | |
2976 | } | |
2977 | ||
2978 | unsigned long this_cpu_load(void) | |
2979 | { | |
2980 | struct rq *this = this_rq(); | |
2981 | return this->cpu_load[0]; | |
2982 | } | |
2983 | ||
2984 | ||
dce48a84 TG |
2985 | /* Variables and functions for calc_load */ |
2986 | static atomic_long_t calc_load_tasks; | |
2987 | static unsigned long calc_load_update; | |
2988 | unsigned long avenrun[3]; | |
2989 | EXPORT_SYMBOL(avenrun); | |
2990 | ||
2d02494f TG |
2991 | /** |
2992 | * get_avenrun - get the load average array | |
2993 | * @loads: pointer to dest load array | |
2994 | * @offset: offset to add | |
2995 | * @shift: shift count to shift the result left | |
2996 | * | |
2997 | * These values are estimates at best, so no need for locking. | |
2998 | */ | |
2999 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3000 | { | |
3001 | loads[0] = (avenrun[0] + offset) << shift; | |
3002 | loads[1] = (avenrun[1] + offset) << shift; | |
3003 | loads[2] = (avenrun[2] + offset) << shift; | |
3004 | } | |
3005 | ||
dce48a84 TG |
3006 | static unsigned long |
3007 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 3008 | { |
dce48a84 TG |
3009 | load *= exp; |
3010 | load += active * (FIXED_1 - exp); | |
3011 | return load >> FSHIFT; | |
3012 | } | |
db1b1fef | 3013 | |
dce48a84 TG |
3014 | /* |
3015 | * calc_load - update the avenrun load estimates 10 ticks after the | |
3016 | * CPUs have updated calc_load_tasks. | |
3017 | */ | |
3018 | void calc_global_load(void) | |
3019 | { | |
3020 | unsigned long upd = calc_load_update + 10; | |
3021 | long active; | |
3022 | ||
3023 | if (time_before(jiffies, upd)) | |
3024 | return; | |
db1b1fef | 3025 | |
dce48a84 TG |
3026 | active = atomic_long_read(&calc_load_tasks); |
3027 | active = active > 0 ? active * FIXED_1 : 0; | |
db1b1fef | 3028 | |
dce48a84 TG |
3029 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3030 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3031 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
3032 | ||
3033 | calc_load_update += LOAD_FREQ; | |
3034 | } | |
3035 | ||
3036 | /* | |
3037 | * Either called from update_cpu_load() or from a cpu going idle | |
3038 | */ | |
3039 | static void calc_load_account_active(struct rq *this_rq) | |
3040 | { | |
3041 | long nr_active, delta; | |
3042 | ||
3043 | nr_active = this_rq->nr_running; | |
3044 | nr_active += (long) this_rq->nr_uninterruptible; | |
3045 | ||
3046 | if (nr_active != this_rq->calc_load_active) { | |
3047 | delta = nr_active - this_rq->calc_load_active; | |
3048 | this_rq->calc_load_active = nr_active; | |
3049 | atomic_long_add(delta, &calc_load_tasks); | |
3050 | } | |
db1b1fef JS |
3051 | } |
3052 | ||
48f24c4d | 3053 | /* |
dd41f596 IM |
3054 | * Update rq->cpu_load[] statistics. This function is usually called every |
3055 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 3056 | */ |
dd41f596 | 3057 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 3058 | { |
495eca49 | 3059 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
3060 | int i, scale; |
3061 | ||
3062 | this_rq->nr_load_updates++; | |
dd41f596 IM |
3063 | |
3064 | /* Update our load: */ | |
3065 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3066 | unsigned long old_load, new_load; | |
3067 | ||
3068 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
3069 | ||
3070 | old_load = this_rq->cpu_load[i]; | |
3071 | new_load = this_load; | |
a25707f3 IM |
3072 | /* |
3073 | * Round up the averaging division if load is increasing. This | |
3074 | * prevents us from getting stuck on 9 if the load is 10, for | |
3075 | * example. | |
3076 | */ | |
3077 | if (new_load > old_load) | |
3078 | new_load += scale-1; | |
dd41f596 IM |
3079 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3080 | } | |
dce48a84 TG |
3081 | |
3082 | if (time_after_eq(jiffies, this_rq->calc_load_update)) { | |
3083 | this_rq->calc_load_update += LOAD_FREQ; | |
3084 | calc_load_account_active(this_rq); | |
3085 | } | |
48f24c4d IM |
3086 | } |
3087 | ||
dd41f596 IM |
3088 | #ifdef CONFIG_SMP |
3089 | ||
1da177e4 LT |
3090 | /* |
3091 | * double_rq_lock - safely lock two runqueues | |
3092 | * | |
3093 | * Note this does not disable interrupts like task_rq_lock, | |
3094 | * you need to do so manually before calling. | |
3095 | */ | |
70b97a7f | 3096 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3097 | __acquires(rq1->lock) |
3098 | __acquires(rq2->lock) | |
3099 | { | |
054b9108 | 3100 | BUG_ON(!irqs_disabled()); |
1da177e4 | 3101 | if (rq1 == rq2) { |
05fa785c | 3102 | raw_spin_lock(&rq1->lock); |
1da177e4 LT |
3103 | __acquire(rq2->lock); /* Fake it out ;) */ |
3104 | } else { | |
c96d145e | 3105 | if (rq1 < rq2) { |
05fa785c TG |
3106 | raw_spin_lock(&rq1->lock); |
3107 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1da177e4 | 3108 | } else { |
05fa785c TG |
3109 | raw_spin_lock(&rq2->lock); |
3110 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1da177e4 LT |
3111 | } |
3112 | } | |
6e82a3be IM |
3113 | update_rq_clock(rq1); |
3114 | update_rq_clock(rq2); | |
1da177e4 LT |
3115 | } |
3116 | ||
3117 | /* | |
3118 | * double_rq_unlock - safely unlock two runqueues | |
3119 | * | |
3120 | * Note this does not restore interrupts like task_rq_unlock, | |
3121 | * you need to do so manually after calling. | |
3122 | */ | |
70b97a7f | 3123 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3124 | __releases(rq1->lock) |
3125 | __releases(rq2->lock) | |
3126 | { | |
05fa785c | 3127 | raw_spin_unlock(&rq1->lock); |
1da177e4 | 3128 | if (rq1 != rq2) |
05fa785c | 3129 | raw_spin_unlock(&rq2->lock); |
1da177e4 LT |
3130 | else |
3131 | __release(rq2->lock); | |
3132 | } | |
3133 | ||
1da177e4 | 3134 | /* |
38022906 PZ |
3135 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3136 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 | 3137 | */ |
38022906 | 3138 | void sched_exec(void) |
1da177e4 | 3139 | { |
38022906 | 3140 | struct task_struct *p = current; |
70b97a7f | 3141 | struct migration_req req; |
38022906 | 3142 | int dest_cpu, this_cpu; |
1da177e4 | 3143 | unsigned long flags; |
70b97a7f | 3144 | struct rq *rq; |
1da177e4 | 3145 | |
38022906 PZ |
3146 | again: |
3147 | this_cpu = get_cpu(); | |
3148 | dest_cpu = select_task_rq(p, SD_BALANCE_EXEC, 0); | |
3149 | if (dest_cpu == this_cpu) { | |
3150 | put_cpu(); | |
3151 | return; | |
3152 | } | |
3153 | ||
1da177e4 | 3154 | rq = task_rq_lock(p, &flags); |
38022906 PZ |
3155 | put_cpu(); |
3156 | ||
3157 | /* | |
3158 | * select_task_rq() can race against ->cpus_allowed | |
3159 | */ | |
96f874e2 | 3160 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
38022906 PZ |
3161 | || unlikely(!cpu_active(dest_cpu))) { |
3162 | task_rq_unlock(rq, &flags); | |
3163 | goto again; | |
3164 | } | |
1da177e4 LT |
3165 | |
3166 | /* force the process onto the specified CPU */ | |
3167 | if (migrate_task(p, dest_cpu, &req)) { | |
3168 | /* Need to wait for migration thread (might exit: take ref). */ | |
3169 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 3170 | |
1da177e4 LT |
3171 | get_task_struct(mt); |
3172 | task_rq_unlock(rq, &flags); | |
3173 | wake_up_process(mt); | |
3174 | put_task_struct(mt); | |
3175 | wait_for_completion(&req.done); | |
36c8b586 | 3176 | |
1da177e4 LT |
3177 | return; |
3178 | } | |
1da177e4 LT |
3179 | task_rq_unlock(rq, &flags); |
3180 | } | |
3181 | ||
1da177e4 LT |
3182 | /* |
3183 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
3184 | * Both runqueues must be locked. | |
3185 | */ | |
dd41f596 IM |
3186 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
3187 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 3188 | { |
2e1cb74a | 3189 | deactivate_task(src_rq, p, 0); |
1da177e4 | 3190 | set_task_cpu(p, this_cpu); |
dd41f596 | 3191 | activate_task(this_rq, p, 0); |
15afe09b | 3192 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
3193 | } |
3194 | ||
3195 | /* | |
3196 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
3197 | */ | |
858119e1 | 3198 | static |
70b97a7f | 3199 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 3200 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 3201 | int *all_pinned) |
1da177e4 | 3202 | { |
708dc512 | 3203 | int tsk_cache_hot = 0; |
1da177e4 LT |
3204 | /* |
3205 | * We do not migrate tasks that are: | |
3206 | * 1) running (obviously), or | |
3207 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
3208 | * 3) are cache-hot on their current CPU. | |
3209 | */ | |
96f874e2 | 3210 | if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { |
cc367732 | 3211 | schedstat_inc(p, se.nr_failed_migrations_affine); |
1da177e4 | 3212 | return 0; |
cc367732 | 3213 | } |
81026794 NP |
3214 | *all_pinned = 0; |
3215 | ||
cc367732 IM |
3216 | if (task_running(rq, p)) { |
3217 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 3218 | return 0; |
cc367732 | 3219 | } |
1da177e4 | 3220 | |
da84d961 IM |
3221 | /* |
3222 | * Aggressive migration if: | |
3223 | * 1) task is cache cold, or | |
3224 | * 2) too many balance attempts have failed. | |
3225 | */ | |
3226 | ||
708dc512 LH |
3227 | tsk_cache_hot = task_hot(p, rq->clock, sd); |
3228 | if (!tsk_cache_hot || | |
3229 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 3230 | #ifdef CONFIG_SCHEDSTATS |
708dc512 | 3231 | if (tsk_cache_hot) { |
da84d961 | 3232 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
3233 | schedstat_inc(p, se.nr_forced_migrations); |
3234 | } | |
da84d961 IM |
3235 | #endif |
3236 | return 1; | |
3237 | } | |
3238 | ||
708dc512 | 3239 | if (tsk_cache_hot) { |
cc367732 | 3240 | schedstat_inc(p, se.nr_failed_migrations_hot); |
da84d961 | 3241 | return 0; |
cc367732 | 3242 | } |
1da177e4 LT |
3243 | return 1; |
3244 | } | |
3245 | ||
e1d1484f PW |
3246 | static unsigned long |
3247 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3248 | unsigned long max_load_move, struct sched_domain *sd, | |
3249 | enum cpu_idle_type idle, int *all_pinned, | |
3250 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 3251 | { |
051c6764 | 3252 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
3253 | struct task_struct *p; |
3254 | long rem_load_move = max_load_move; | |
1da177e4 | 3255 | |
e1d1484f | 3256 | if (max_load_move == 0) |
1da177e4 LT |
3257 | goto out; |
3258 | ||
81026794 NP |
3259 | pinned = 1; |
3260 | ||
1da177e4 | 3261 | /* |
dd41f596 | 3262 | * Start the load-balancing iterator: |
1da177e4 | 3263 | */ |
dd41f596 IM |
3264 | p = iterator->start(iterator->arg); |
3265 | next: | |
b82d9fdd | 3266 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 3267 | goto out; |
051c6764 PZ |
3268 | |
3269 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 3270 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
3271 | p = iterator->next(iterator->arg); |
3272 | goto next; | |
1da177e4 LT |
3273 | } |
3274 | ||
dd41f596 | 3275 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 3276 | pulled++; |
dd41f596 | 3277 | rem_load_move -= p->se.load.weight; |
1da177e4 | 3278 | |
7e96fa58 GH |
3279 | #ifdef CONFIG_PREEMPT |
3280 | /* | |
3281 | * NEWIDLE balancing is a source of latency, so preemptible kernels | |
3282 | * will stop after the first task is pulled to minimize the critical | |
3283 | * section. | |
3284 | */ | |
3285 | if (idle == CPU_NEWLY_IDLE) | |
3286 | goto out; | |
3287 | #endif | |
3288 | ||
2dd73a4f | 3289 | /* |
b82d9fdd | 3290 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 3291 | */ |
e1d1484f | 3292 | if (rem_load_move > 0) { |
a4ac01c3 PW |
3293 | if (p->prio < *this_best_prio) |
3294 | *this_best_prio = p->prio; | |
dd41f596 IM |
3295 | p = iterator->next(iterator->arg); |
3296 | goto next; | |
1da177e4 LT |
3297 | } |
3298 | out: | |
3299 | /* | |
e1d1484f | 3300 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
3301 | * so we can safely collect pull_task() stats here rather than |
3302 | * inside pull_task(). | |
3303 | */ | |
3304 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
3305 | |
3306 | if (all_pinned) | |
3307 | *all_pinned = pinned; | |
e1d1484f PW |
3308 | |
3309 | return max_load_move - rem_load_move; | |
1da177e4 LT |
3310 | } |
3311 | ||
dd41f596 | 3312 | /* |
43010659 PW |
3313 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
3314 | * this_rq, as part of a balancing operation within domain "sd". | |
3315 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
3316 | * |
3317 | * Called with both runqueues locked. | |
3318 | */ | |
3319 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3320 | unsigned long max_load_move, |
dd41f596 IM |
3321 | struct sched_domain *sd, enum cpu_idle_type idle, |
3322 | int *all_pinned) | |
3323 | { | |
5522d5d5 | 3324 | const struct sched_class *class = sched_class_highest; |
43010659 | 3325 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3326 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3327 | |
3328 | do { | |
43010659 PW |
3329 | total_load_moved += |
3330 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3331 | max_load_move - total_load_moved, |
a4ac01c3 | 3332 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3333 | class = class->next; |
c4acb2c0 | 3334 | |
7e96fa58 GH |
3335 | #ifdef CONFIG_PREEMPT |
3336 | /* | |
3337 | * NEWIDLE balancing is a source of latency, so preemptible | |
3338 | * kernels will stop after the first task is pulled to minimize | |
3339 | * the critical section. | |
3340 | */ | |
c4acb2c0 GH |
3341 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) |
3342 | break; | |
7e96fa58 | 3343 | #endif |
43010659 | 3344 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3345 | |
43010659 PW |
3346 | return total_load_moved > 0; |
3347 | } | |
3348 | ||
e1d1484f PW |
3349 | static int |
3350 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3351 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3352 | struct rq_iterator *iterator) | |
3353 | { | |
3354 | struct task_struct *p = iterator->start(iterator->arg); | |
3355 | int pinned = 0; | |
3356 | ||
3357 | while (p) { | |
3358 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3359 | pull_task(busiest, p, this_rq, this_cpu); | |
3360 | /* | |
3361 | * Right now, this is only the second place pull_task() | |
3362 | * is called, so we can safely collect pull_task() | |
3363 | * stats here rather than inside pull_task(). | |
3364 | */ | |
3365 | schedstat_inc(sd, lb_gained[idle]); | |
3366 | ||
3367 | return 1; | |
3368 | } | |
3369 | p = iterator->next(iterator->arg); | |
3370 | } | |
3371 | ||
3372 | return 0; | |
3373 | } | |
3374 | ||
43010659 PW |
3375 | /* |
3376 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3377 | * part of active balancing operations within "domain". | |
3378 | * Returns 1 if successful and 0 otherwise. | |
3379 | * | |
3380 | * Called with both runqueues locked. | |
3381 | */ | |
3382 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3383 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3384 | { | |
5522d5d5 | 3385 | const struct sched_class *class; |
43010659 | 3386 | |
cde7e5ca | 3387 | for_each_class(class) { |
e1d1484f | 3388 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 | 3389 | return 1; |
cde7e5ca | 3390 | } |
43010659 PW |
3391 | |
3392 | return 0; | |
dd41f596 | 3393 | } |
67bb6c03 | 3394 | /********** Helpers for find_busiest_group ************************/ |
1da177e4 | 3395 | /* |
222d656d GS |
3396 | * sd_lb_stats - Structure to store the statistics of a sched_domain |
3397 | * during load balancing. | |
1da177e4 | 3398 | */ |
222d656d GS |
3399 | struct sd_lb_stats { |
3400 | struct sched_group *busiest; /* Busiest group in this sd */ | |
3401 | struct sched_group *this; /* Local group in this sd */ | |
3402 | unsigned long total_load; /* Total load of all groups in sd */ | |
3403 | unsigned long total_pwr; /* Total power of all groups in sd */ | |
3404 | unsigned long avg_load; /* Average load across all groups in sd */ | |
3405 | ||
3406 | /** Statistics of this group */ | |
3407 | unsigned long this_load; | |
3408 | unsigned long this_load_per_task; | |
3409 | unsigned long this_nr_running; | |
3410 | ||
3411 | /* Statistics of the busiest group */ | |
3412 | unsigned long max_load; | |
3413 | unsigned long busiest_load_per_task; | |
3414 | unsigned long busiest_nr_running; | |
3415 | ||
3416 | int group_imb; /* Is there imbalance in this sd */ | |
5c45bf27 | 3417 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
222d656d GS |
3418 | int power_savings_balance; /* Is powersave balance needed for this sd */ |
3419 | struct sched_group *group_min; /* Least loaded group in sd */ | |
3420 | struct sched_group *group_leader; /* Group which relieves group_min */ | |
3421 | unsigned long min_load_per_task; /* load_per_task in group_min */ | |
3422 | unsigned long leader_nr_running; /* Nr running of group_leader */ | |
3423 | unsigned long min_nr_running; /* Nr running of group_min */ | |
5c45bf27 | 3424 | #endif |
222d656d | 3425 | }; |
1da177e4 | 3426 | |
d5ac537e | 3427 | /* |
381be78f GS |
3428 | * sg_lb_stats - stats of a sched_group required for load_balancing |
3429 | */ | |
3430 | struct sg_lb_stats { | |
3431 | unsigned long avg_load; /*Avg load across the CPUs of the group */ | |
3432 | unsigned long group_load; /* Total load over the CPUs of the group */ | |
3433 | unsigned long sum_nr_running; /* Nr tasks running in the group */ | |
3434 | unsigned long sum_weighted_load; /* Weighted load of group's tasks */ | |
3435 | unsigned long group_capacity; | |
3436 | int group_imb; /* Is there an imbalance in the group ? */ | |
3437 | }; | |
408ed066 | 3438 | |
67bb6c03 GS |
3439 | /** |
3440 | * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. | |
3441 | * @group: The group whose first cpu is to be returned. | |
3442 | */ | |
3443 | static inline unsigned int group_first_cpu(struct sched_group *group) | |
3444 | { | |
3445 | return cpumask_first(sched_group_cpus(group)); | |
3446 | } | |
3447 | ||
3448 | /** | |
3449 | * get_sd_load_idx - Obtain the load index for a given sched domain. | |
3450 | * @sd: The sched_domain whose load_idx is to be obtained. | |
3451 | * @idle: The Idle status of the CPU for whose sd load_icx is obtained. | |
3452 | */ | |
3453 | static inline int get_sd_load_idx(struct sched_domain *sd, | |
3454 | enum cpu_idle_type idle) | |
3455 | { | |
3456 | int load_idx; | |
3457 | ||
3458 | switch (idle) { | |
3459 | case CPU_NOT_IDLE: | |
7897986b | 3460 | load_idx = sd->busy_idx; |
67bb6c03 GS |
3461 | break; |
3462 | ||
3463 | case CPU_NEWLY_IDLE: | |
7897986b | 3464 | load_idx = sd->newidle_idx; |
67bb6c03 GS |
3465 | break; |
3466 | default: | |
7897986b | 3467 | load_idx = sd->idle_idx; |
67bb6c03 GS |
3468 | break; |
3469 | } | |
1da177e4 | 3470 | |
67bb6c03 GS |
3471 | return load_idx; |
3472 | } | |
1da177e4 | 3473 | |
1da177e4 | 3474 | |
c071df18 GS |
3475 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3476 | /** | |
3477 | * init_sd_power_savings_stats - Initialize power savings statistics for | |
3478 | * the given sched_domain, during load balancing. | |
3479 | * | |
3480 | * @sd: Sched domain whose power-savings statistics are to be initialized. | |
3481 | * @sds: Variable containing the statistics for sd. | |
3482 | * @idle: Idle status of the CPU at which we're performing load-balancing. | |
3483 | */ | |
3484 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3485 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3486 | { | |
3487 | /* | |
3488 | * Busy processors will not participate in power savings | |
3489 | * balance. | |
3490 | */ | |
3491 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3492 | sds->power_savings_balance = 0; | |
3493 | else { | |
3494 | sds->power_savings_balance = 1; | |
3495 | sds->min_nr_running = ULONG_MAX; | |
3496 | sds->leader_nr_running = 0; | |
3497 | } | |
3498 | } | |
783609c6 | 3499 | |
c071df18 GS |
3500 | /** |
3501 | * update_sd_power_savings_stats - Update the power saving stats for a | |
3502 | * sched_domain while performing load balancing. | |
3503 | * | |
3504 | * @group: sched_group belonging to the sched_domain under consideration. | |
3505 | * @sds: Variable containing the statistics of the sched_domain | |
3506 | * @local_group: Does group contain the CPU for which we're performing | |
3507 | * load balancing ? | |
3508 | * @sgs: Variable containing the statistics of the group. | |
3509 | */ | |
3510 | static inline void update_sd_power_savings_stats(struct sched_group *group, | |
3511 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3512 | { | |
408ed066 | 3513 | |
c071df18 GS |
3514 | if (!sds->power_savings_balance) |
3515 | return; | |
1da177e4 | 3516 | |
c071df18 GS |
3517 | /* |
3518 | * If the local group is idle or completely loaded | |
3519 | * no need to do power savings balance at this domain | |
3520 | */ | |
3521 | if (local_group && (sds->this_nr_running >= sgs->group_capacity || | |
3522 | !sds->this_nr_running)) | |
3523 | sds->power_savings_balance = 0; | |
2dd73a4f | 3524 | |
c071df18 GS |
3525 | /* |
3526 | * If a group is already running at full capacity or idle, | |
3527 | * don't include that group in power savings calculations | |
3528 | */ | |
3529 | if (!sds->power_savings_balance || | |
3530 | sgs->sum_nr_running >= sgs->group_capacity || | |
3531 | !sgs->sum_nr_running) | |
3532 | return; | |
5969fe06 | 3533 | |
c071df18 GS |
3534 | /* |
3535 | * Calculate the group which has the least non-idle load. | |
3536 | * This is the group from where we need to pick up the load | |
3537 | * for saving power | |
3538 | */ | |
3539 | if ((sgs->sum_nr_running < sds->min_nr_running) || | |
3540 | (sgs->sum_nr_running == sds->min_nr_running && | |
3541 | group_first_cpu(group) > group_first_cpu(sds->group_min))) { | |
3542 | sds->group_min = group; | |
3543 | sds->min_nr_running = sgs->sum_nr_running; | |
3544 | sds->min_load_per_task = sgs->sum_weighted_load / | |
3545 | sgs->sum_nr_running; | |
3546 | } | |
783609c6 | 3547 | |
c071df18 GS |
3548 | /* |
3549 | * Calculate the group which is almost near its | |
3550 | * capacity but still has some space to pick up some load | |
3551 | * from other group and save more power | |
3552 | */ | |
d899a789 | 3553 | if (sgs->sum_nr_running + 1 > sgs->group_capacity) |
c071df18 | 3554 | return; |
1da177e4 | 3555 | |
c071df18 GS |
3556 | if (sgs->sum_nr_running > sds->leader_nr_running || |
3557 | (sgs->sum_nr_running == sds->leader_nr_running && | |
3558 | group_first_cpu(group) < group_first_cpu(sds->group_leader))) { | |
3559 | sds->group_leader = group; | |
3560 | sds->leader_nr_running = sgs->sum_nr_running; | |
3561 | } | |
3562 | } | |
408ed066 | 3563 | |
c071df18 | 3564 | /** |
d5ac537e | 3565 | * check_power_save_busiest_group - see if there is potential for some power-savings balance |
c071df18 GS |
3566 | * @sds: Variable containing the statistics of the sched_domain |
3567 | * under consideration. | |
3568 | * @this_cpu: Cpu at which we're currently performing load-balancing. | |
3569 | * @imbalance: Variable to store the imbalance. | |
3570 | * | |
d5ac537e RD |
3571 | * Description: |
3572 | * Check if we have potential to perform some power-savings balance. | |
3573 | * If yes, set the busiest group to be the least loaded group in the | |
3574 | * sched_domain, so that it's CPUs can be put to idle. | |
3575 | * | |
c071df18 GS |
3576 | * Returns 1 if there is potential to perform power-savings balance. |
3577 | * Else returns 0. | |
3578 | */ | |
3579 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3580 | int this_cpu, unsigned long *imbalance) | |
3581 | { | |
3582 | if (!sds->power_savings_balance) | |
3583 | return 0; | |
1da177e4 | 3584 | |
c071df18 GS |
3585 | if (sds->this != sds->group_leader || |
3586 | sds->group_leader == sds->group_min) | |
3587 | return 0; | |
783609c6 | 3588 | |
c071df18 GS |
3589 | *imbalance = sds->min_load_per_task; |
3590 | sds->busiest = sds->group_min; | |
1da177e4 | 3591 | |
c071df18 | 3592 | return 1; |
1da177e4 | 3593 | |
c071df18 GS |
3594 | } |
3595 | #else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3596 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3597 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3598 | { | |
3599 | return; | |
3600 | } | |
408ed066 | 3601 | |
c071df18 GS |
3602 | static inline void update_sd_power_savings_stats(struct sched_group *group, |
3603 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3604 | { | |
3605 | return; | |
3606 | } | |
3607 | ||
3608 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3609 | int this_cpu, unsigned long *imbalance) | |
3610 | { | |
3611 | return 0; | |
3612 | } | |
3613 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3614 | ||
d6a59aa3 PZ |
3615 | |
3616 | unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) | |
3617 | { | |
3618 | return SCHED_LOAD_SCALE; | |
3619 | } | |
3620 | ||
3621 | unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) | |
3622 | { | |
3623 | return default_scale_freq_power(sd, cpu); | |
3624 | } | |
3625 | ||
3626 | unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) | |
ab29230e PZ |
3627 | { |
3628 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3629 | unsigned long smt_gain = sd->smt_gain; | |
3630 | ||
3631 | smt_gain /= weight; | |
3632 | ||
3633 | return smt_gain; | |
3634 | } | |
3635 | ||
d6a59aa3 PZ |
3636 | unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) |
3637 | { | |
3638 | return default_scale_smt_power(sd, cpu); | |
3639 | } | |
3640 | ||
e9e9250b PZ |
3641 | unsigned long scale_rt_power(int cpu) |
3642 | { | |
3643 | struct rq *rq = cpu_rq(cpu); | |
3644 | u64 total, available; | |
3645 | ||
3646 | sched_avg_update(rq); | |
3647 | ||
3648 | total = sched_avg_period() + (rq->clock - rq->age_stamp); | |
3649 | available = total - rq->rt_avg; | |
3650 | ||
3651 | if (unlikely((s64)total < SCHED_LOAD_SCALE)) | |
3652 | total = SCHED_LOAD_SCALE; | |
3653 | ||
3654 | total >>= SCHED_LOAD_SHIFT; | |
3655 | ||
3656 | return div_u64(available, total); | |
3657 | } | |
3658 | ||
ab29230e PZ |
3659 | static void update_cpu_power(struct sched_domain *sd, int cpu) |
3660 | { | |
3661 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3662 | unsigned long power = SCHED_LOAD_SCALE; | |
3663 | struct sched_group *sdg = sd->groups; | |
ab29230e | 3664 | |
8e6598af PZ |
3665 | if (sched_feat(ARCH_POWER)) |
3666 | power *= arch_scale_freq_power(sd, cpu); | |
3667 | else | |
3668 | power *= default_scale_freq_power(sd, cpu); | |
3669 | ||
d6a59aa3 | 3670 | power >>= SCHED_LOAD_SHIFT; |
ab29230e PZ |
3671 | |
3672 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { | |
8e6598af PZ |
3673 | if (sched_feat(ARCH_POWER)) |
3674 | power *= arch_scale_smt_power(sd, cpu); | |
3675 | else | |
3676 | power *= default_scale_smt_power(sd, cpu); | |
3677 | ||
ab29230e PZ |
3678 | power >>= SCHED_LOAD_SHIFT; |
3679 | } | |
3680 | ||
e9e9250b PZ |
3681 | power *= scale_rt_power(cpu); |
3682 | power >>= SCHED_LOAD_SHIFT; | |
3683 | ||
3684 | if (!power) | |
3685 | power = 1; | |
ab29230e | 3686 | |
18a3885f | 3687 | sdg->cpu_power = power; |
ab29230e PZ |
3688 | } |
3689 | ||
3690 | static void update_group_power(struct sched_domain *sd, int cpu) | |
cc9fba7d PZ |
3691 | { |
3692 | struct sched_domain *child = sd->child; | |
3693 | struct sched_group *group, *sdg = sd->groups; | |
d7ea17a7 | 3694 | unsigned long power; |
cc9fba7d PZ |
3695 | |
3696 | if (!child) { | |
ab29230e | 3697 | update_cpu_power(sd, cpu); |
cc9fba7d PZ |
3698 | return; |
3699 | } | |
3700 | ||
d7ea17a7 | 3701 | power = 0; |
cc9fba7d PZ |
3702 | |
3703 | group = child->groups; | |
3704 | do { | |
d7ea17a7 | 3705 | power += group->cpu_power; |
cc9fba7d PZ |
3706 | group = group->next; |
3707 | } while (group != child->groups); | |
d7ea17a7 IM |
3708 | |
3709 | sdg->cpu_power = power; | |
cc9fba7d | 3710 | } |
c071df18 | 3711 | |
1f8c553d GS |
3712 | /** |
3713 | * update_sg_lb_stats - Update sched_group's statistics for load balancing. | |
e17b38bf | 3714 | * @sd: The sched_domain whose statistics are to be updated. |
1f8c553d GS |
3715 | * @group: sched_group whose statistics are to be updated. |
3716 | * @this_cpu: Cpu for which load balance is currently performed. | |
3717 | * @idle: Idle status of this_cpu | |
3718 | * @load_idx: Load index of sched_domain of this_cpu for load calc. | |
3719 | * @sd_idle: Idle status of the sched_domain containing group. | |
3720 | * @local_group: Does group contain this_cpu. | |
3721 | * @cpus: Set of cpus considered for load balancing. | |
3722 | * @balance: Should we balance. | |
3723 | * @sgs: variable to hold the statistics for this group. | |
3724 | */ | |
cc9fba7d PZ |
3725 | static inline void update_sg_lb_stats(struct sched_domain *sd, |
3726 | struct sched_group *group, int this_cpu, | |
1f8c553d GS |
3727 | enum cpu_idle_type idle, int load_idx, int *sd_idle, |
3728 | int local_group, const struct cpumask *cpus, | |
3729 | int *balance, struct sg_lb_stats *sgs) | |
3730 | { | |
3731 | unsigned long load, max_cpu_load, min_cpu_load; | |
3732 | int i; | |
3733 | unsigned int balance_cpu = -1, first_idle_cpu = 0; | |
3734 | unsigned long sum_avg_load_per_task; | |
3735 | unsigned long avg_load_per_task; | |
3736 | ||
cc9fba7d | 3737 | if (local_group) { |
1f8c553d | 3738 | balance_cpu = group_first_cpu(group); |
cc9fba7d | 3739 | if (balance_cpu == this_cpu) |
ab29230e | 3740 | update_group_power(sd, this_cpu); |
cc9fba7d | 3741 | } |
1f8c553d GS |
3742 | |
3743 | /* Tally up the load of all CPUs in the group */ | |
3744 | sum_avg_load_per_task = avg_load_per_task = 0; | |
3745 | max_cpu_load = 0; | |
3746 | min_cpu_load = ~0UL; | |
408ed066 | 3747 | |
1f8c553d GS |
3748 | for_each_cpu_and(i, sched_group_cpus(group), cpus) { |
3749 | struct rq *rq = cpu_rq(i); | |
908a7c1b | 3750 | |
1f8c553d GS |
3751 | if (*sd_idle && rq->nr_running) |
3752 | *sd_idle = 0; | |
5c45bf27 | 3753 | |
1f8c553d | 3754 | /* Bias balancing toward cpus of our domain */ |
1da177e4 | 3755 | if (local_group) { |
1f8c553d GS |
3756 | if (idle_cpu(i) && !first_idle_cpu) { |
3757 | first_idle_cpu = 1; | |
3758 | balance_cpu = i; | |
3759 | } | |
3760 | ||
3761 | load = target_load(i, load_idx); | |
3762 | } else { | |
3763 | load = source_load(i, load_idx); | |
3764 | if (load > max_cpu_load) | |
3765 | max_cpu_load = load; | |
3766 | if (min_cpu_load > load) | |
3767 | min_cpu_load = load; | |
1da177e4 | 3768 | } |
5c45bf27 | 3769 | |
1f8c553d GS |
3770 | sgs->group_load += load; |
3771 | sgs->sum_nr_running += rq->nr_running; | |
3772 | sgs->sum_weighted_load += weighted_cpuload(i); | |
5c45bf27 | 3773 | |
1f8c553d GS |
3774 | sum_avg_load_per_task += cpu_avg_load_per_task(i); |
3775 | } | |
5c45bf27 | 3776 | |
1f8c553d GS |
3777 | /* |
3778 | * First idle cpu or the first cpu(busiest) in this sched group | |
3779 | * is eligible for doing load balancing at this and above | |
3780 | * domains. In the newly idle case, we will allow all the cpu's | |
3781 | * to do the newly idle load balance. | |
3782 | */ | |
3783 | if (idle != CPU_NEWLY_IDLE && local_group && | |
3784 | balance_cpu != this_cpu && balance) { | |
3785 | *balance = 0; | |
3786 | return; | |
3787 | } | |
5c45bf27 | 3788 | |
1f8c553d | 3789 | /* Adjust by relative CPU power of the group */ |
18a3885f | 3790 | sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power; |
5c45bf27 | 3791 | |
1f8c553d GS |
3792 | |
3793 | /* | |
3794 | * Consider the group unbalanced when the imbalance is larger | |
3795 | * than the average weight of two tasks. | |
3796 | * | |
3797 | * APZ: with cgroup the avg task weight can vary wildly and | |
3798 | * might not be a suitable number - should we keep a | |
3799 | * normalized nr_running number somewhere that negates | |
3800 | * the hierarchy? | |
3801 | */ | |
18a3885f PZ |
3802 | avg_load_per_task = (sum_avg_load_per_task * SCHED_LOAD_SCALE) / |
3803 | group->cpu_power; | |
1f8c553d GS |
3804 | |
3805 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
3806 | sgs->group_imb = 1; | |
3807 | ||
bdb94aa5 | 3808 | sgs->group_capacity = |
18a3885f | 3809 | DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE); |
1f8c553d | 3810 | } |
dd41f596 | 3811 | |
37abe198 GS |
3812 | /** |
3813 | * update_sd_lb_stats - Update sched_group's statistics for load balancing. | |
3814 | * @sd: sched_domain whose statistics are to be updated. | |
3815 | * @this_cpu: Cpu for which load balance is currently performed. | |
3816 | * @idle: Idle status of this_cpu | |
3817 | * @sd_idle: Idle status of the sched_domain containing group. | |
3818 | * @cpus: Set of cpus considered for load balancing. | |
3819 | * @balance: Should we balance. | |
3820 | * @sds: variable to hold the statistics for this sched_domain. | |
1da177e4 | 3821 | */ |
37abe198 GS |
3822 | static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, |
3823 | enum cpu_idle_type idle, int *sd_idle, | |
3824 | const struct cpumask *cpus, int *balance, | |
3825 | struct sd_lb_stats *sds) | |
1da177e4 | 3826 | { |
b5d978e0 | 3827 | struct sched_domain *child = sd->child; |
222d656d | 3828 | struct sched_group *group = sd->groups; |
37abe198 | 3829 | struct sg_lb_stats sgs; |
b5d978e0 PZ |
3830 | int load_idx, prefer_sibling = 0; |
3831 | ||
3832 | if (child && child->flags & SD_PREFER_SIBLING) | |
3833 | prefer_sibling = 1; | |
222d656d | 3834 | |
c071df18 | 3835 | init_sd_power_savings_stats(sd, sds, idle); |
67bb6c03 | 3836 | load_idx = get_sd_load_idx(sd, idle); |
1da177e4 LT |
3837 | |
3838 | do { | |
1da177e4 | 3839 | int local_group; |
1da177e4 | 3840 | |
758b2cdc RR |
3841 | local_group = cpumask_test_cpu(this_cpu, |
3842 | sched_group_cpus(group)); | |
381be78f | 3843 | memset(&sgs, 0, sizeof(sgs)); |
cc9fba7d | 3844 | update_sg_lb_stats(sd, group, this_cpu, idle, load_idx, sd_idle, |
1f8c553d | 3845 | local_group, cpus, balance, &sgs); |
1da177e4 | 3846 | |
37abe198 GS |
3847 | if (local_group && balance && !(*balance)) |
3848 | return; | |
783609c6 | 3849 | |
37abe198 | 3850 | sds->total_load += sgs.group_load; |
18a3885f | 3851 | sds->total_pwr += group->cpu_power; |
1da177e4 | 3852 | |
b5d978e0 PZ |
3853 | /* |
3854 | * In case the child domain prefers tasks go to siblings | |
3855 | * first, lower the group capacity to one so that we'll try | |
3856 | * and move all the excess tasks away. | |
3857 | */ | |
3858 | if (prefer_sibling) | |
bdb94aa5 | 3859 | sgs.group_capacity = min(sgs.group_capacity, 1UL); |
1da177e4 | 3860 | |
1da177e4 | 3861 | if (local_group) { |
37abe198 GS |
3862 | sds->this_load = sgs.avg_load; |
3863 | sds->this = group; | |
3864 | sds->this_nr_running = sgs.sum_nr_running; | |
3865 | sds->this_load_per_task = sgs.sum_weighted_load; | |
3866 | } else if (sgs.avg_load > sds->max_load && | |
381be78f GS |
3867 | (sgs.sum_nr_running > sgs.group_capacity || |
3868 | sgs.group_imb)) { | |
37abe198 GS |
3869 | sds->max_load = sgs.avg_load; |
3870 | sds->busiest = group; | |
3871 | sds->busiest_nr_running = sgs.sum_nr_running; | |
3872 | sds->busiest_load_per_task = sgs.sum_weighted_load; | |
3873 | sds->group_imb = sgs.group_imb; | |
48f24c4d | 3874 | } |
5c45bf27 | 3875 | |
c071df18 | 3876 | update_sd_power_savings_stats(group, sds, local_group, &sgs); |
1da177e4 LT |
3877 | group = group->next; |
3878 | } while (group != sd->groups); | |
37abe198 | 3879 | } |
1da177e4 | 3880 | |
2e6f44ae GS |
3881 | /** |
3882 | * fix_small_imbalance - Calculate the minor imbalance that exists | |
dbc523a3 GS |
3883 | * amongst the groups of a sched_domain, during |
3884 | * load balancing. | |
2e6f44ae GS |
3885 | * @sds: Statistics of the sched_domain whose imbalance is to be calculated. |
3886 | * @this_cpu: The cpu at whose sched_domain we're performing load-balance. | |
3887 | * @imbalance: Variable to store the imbalance. | |
3888 | */ | |
3889 | static inline void fix_small_imbalance(struct sd_lb_stats *sds, | |
3890 | int this_cpu, unsigned long *imbalance) | |
3891 | { | |
3892 | unsigned long tmp, pwr_now = 0, pwr_move = 0; | |
3893 | unsigned int imbn = 2; | |
3894 | ||
3895 | if (sds->this_nr_running) { | |
3896 | sds->this_load_per_task /= sds->this_nr_running; | |
3897 | if (sds->busiest_load_per_task > | |
3898 | sds->this_load_per_task) | |
3899 | imbn = 1; | |
3900 | } else | |
3901 | sds->this_load_per_task = | |
3902 | cpu_avg_load_per_task(this_cpu); | |
1da177e4 | 3903 | |
2e6f44ae GS |
3904 | if (sds->max_load - sds->this_load + sds->busiest_load_per_task >= |
3905 | sds->busiest_load_per_task * imbn) { | |
3906 | *imbalance = sds->busiest_load_per_task; | |
3907 | return; | |
3908 | } | |
908a7c1b | 3909 | |
1da177e4 | 3910 | /* |
2e6f44ae GS |
3911 | * OK, we don't have enough imbalance to justify moving tasks, |
3912 | * however we may be able to increase total CPU power used by | |
3913 | * moving them. | |
1da177e4 | 3914 | */ |
2dd73a4f | 3915 | |
18a3885f | 3916 | pwr_now += sds->busiest->cpu_power * |
2e6f44ae | 3917 | min(sds->busiest_load_per_task, sds->max_load); |
18a3885f | 3918 | pwr_now += sds->this->cpu_power * |
2e6f44ae GS |
3919 | min(sds->this_load_per_task, sds->this_load); |
3920 | pwr_now /= SCHED_LOAD_SCALE; | |
3921 | ||
3922 | /* Amount of load we'd subtract */ | |
18a3885f PZ |
3923 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3924 | sds->busiest->cpu_power; | |
2e6f44ae | 3925 | if (sds->max_load > tmp) |
18a3885f | 3926 | pwr_move += sds->busiest->cpu_power * |
2e6f44ae GS |
3927 | min(sds->busiest_load_per_task, sds->max_load - tmp); |
3928 | ||
3929 | /* Amount of load we'd add */ | |
18a3885f | 3930 | if (sds->max_load * sds->busiest->cpu_power < |
2e6f44ae | 3931 | sds->busiest_load_per_task * SCHED_LOAD_SCALE) |
18a3885f PZ |
3932 | tmp = (sds->max_load * sds->busiest->cpu_power) / |
3933 | sds->this->cpu_power; | |
2e6f44ae | 3934 | else |
18a3885f PZ |
3935 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3936 | sds->this->cpu_power; | |
3937 | pwr_move += sds->this->cpu_power * | |
2e6f44ae GS |
3938 | min(sds->this_load_per_task, sds->this_load + tmp); |
3939 | pwr_move /= SCHED_LOAD_SCALE; | |
3940 | ||
3941 | /* Move if we gain throughput */ | |
3942 | if (pwr_move > pwr_now) | |
3943 | *imbalance = sds->busiest_load_per_task; | |
3944 | } | |
dbc523a3 GS |
3945 | |
3946 | /** | |
3947 | * calculate_imbalance - Calculate the amount of imbalance present within the | |
3948 | * groups of a given sched_domain during load balance. | |
3949 | * @sds: statistics of the sched_domain whose imbalance is to be calculated. | |
3950 | * @this_cpu: Cpu for which currently load balance is being performed. | |
3951 | * @imbalance: The variable to store the imbalance. | |
3952 | */ | |
3953 | static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, | |
3954 | unsigned long *imbalance) | |
3955 | { | |
3956 | unsigned long max_pull; | |
2dd73a4f PW |
3957 | /* |
3958 | * In the presence of smp nice balancing, certain scenarios can have | |
3959 | * max load less than avg load(as we skip the groups at or below | |
3960 | * its cpu_power, while calculating max_load..) | |
3961 | */ | |
dbc523a3 | 3962 | if (sds->max_load < sds->avg_load) { |
2dd73a4f | 3963 | *imbalance = 0; |
dbc523a3 | 3964 | return fix_small_imbalance(sds, this_cpu, imbalance); |
2dd73a4f | 3965 | } |
0c117f1b SS |
3966 | |
3967 | /* Don't want to pull so many tasks that a group would go idle */ | |
dbc523a3 GS |
3968 | max_pull = min(sds->max_load - sds->avg_load, |
3969 | sds->max_load - sds->busiest_load_per_task); | |
0c117f1b | 3970 | |
1da177e4 | 3971 | /* How much load to actually move to equalise the imbalance */ |
18a3885f PZ |
3972 | *imbalance = min(max_pull * sds->busiest->cpu_power, |
3973 | (sds->avg_load - sds->this_load) * sds->this->cpu_power) | |
1da177e4 LT |
3974 | / SCHED_LOAD_SCALE; |
3975 | ||
2dd73a4f PW |
3976 | /* |
3977 | * if *imbalance is less than the average load per runnable task | |
3978 | * there is no gaurantee that any tasks will be moved so we'll have | |
3979 | * a think about bumping its value to force at least one task to be | |
3980 | * moved | |
3981 | */ | |
dbc523a3 GS |
3982 | if (*imbalance < sds->busiest_load_per_task) |
3983 | return fix_small_imbalance(sds, this_cpu, imbalance); | |
1da177e4 | 3984 | |
dbc523a3 | 3985 | } |
37abe198 | 3986 | /******* find_busiest_group() helpers end here *********************/ |
1da177e4 | 3987 | |
b7bb4c9b GS |
3988 | /** |
3989 | * find_busiest_group - Returns the busiest group within the sched_domain | |
3990 | * if there is an imbalance. If there isn't an imbalance, and | |
3991 | * the user has opted for power-savings, it returns a group whose | |
3992 | * CPUs can be put to idle by rebalancing those tasks elsewhere, if | |
3993 | * such a group exists. | |
3994 | * | |
3995 | * Also calculates the amount of weighted load which should be moved | |
3996 | * to restore balance. | |
3997 | * | |
3998 | * @sd: The sched_domain whose busiest group is to be returned. | |
3999 | * @this_cpu: The cpu for which load balancing is currently being performed. | |
4000 | * @imbalance: Variable which stores amount of weighted load which should | |
4001 | * be moved to restore balance/put a group to idle. | |
4002 | * @idle: The idle status of this_cpu. | |
4003 | * @sd_idle: The idleness of sd | |
4004 | * @cpus: The set of CPUs under consideration for load-balancing. | |
4005 | * @balance: Pointer to a variable indicating if this_cpu | |
4006 | * is the appropriate cpu to perform load balancing at this_level. | |
4007 | * | |
4008 | * Returns: - the busiest group if imbalance exists. | |
4009 | * - If no imbalance and user has opted for power-savings balance, | |
4010 | * return the least loaded group whose CPUs can be | |
4011 | * put to idle by rebalancing its tasks onto our group. | |
37abe198 GS |
4012 | */ |
4013 | static struct sched_group * | |
4014 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
4015 | unsigned long *imbalance, enum cpu_idle_type idle, | |
4016 | int *sd_idle, const struct cpumask *cpus, int *balance) | |
4017 | { | |
4018 | struct sd_lb_stats sds; | |
1da177e4 | 4019 | |
37abe198 | 4020 | memset(&sds, 0, sizeof(sds)); |
1da177e4 | 4021 | |
37abe198 GS |
4022 | /* |
4023 | * Compute the various statistics relavent for load balancing at | |
4024 | * this level. | |
4025 | */ | |
4026 | update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus, | |
4027 | balance, &sds); | |
4028 | ||
b7bb4c9b GS |
4029 | /* Cases where imbalance does not exist from POV of this_cpu */ |
4030 | /* 1) this_cpu is not the appropriate cpu to perform load balancing | |
4031 | * at this level. | |
4032 | * 2) There is no busy sibling group to pull from. | |
4033 | * 3) This group is the busiest group. | |
4034 | * 4) This group is more busy than the avg busieness at this | |
4035 | * sched_domain. | |
4036 | * 5) The imbalance is within the specified limit. | |
4037 | * 6) Any rebalance would lead to ping-pong | |
4038 | */ | |
37abe198 GS |
4039 | if (balance && !(*balance)) |
4040 | goto ret; | |
1da177e4 | 4041 | |
b7bb4c9b GS |
4042 | if (!sds.busiest || sds.busiest_nr_running == 0) |
4043 | goto out_balanced; | |
1da177e4 | 4044 | |
b7bb4c9b | 4045 | if (sds.this_load >= sds.max_load) |
1da177e4 | 4046 | goto out_balanced; |
1da177e4 | 4047 | |
222d656d | 4048 | sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr; |
1da177e4 | 4049 | |
b7bb4c9b GS |
4050 | if (sds.this_load >= sds.avg_load) |
4051 | goto out_balanced; | |
4052 | ||
4053 | if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load) | |
1da177e4 LT |
4054 | goto out_balanced; |
4055 | ||
222d656d GS |
4056 | sds.busiest_load_per_task /= sds.busiest_nr_running; |
4057 | if (sds.group_imb) | |
4058 | sds.busiest_load_per_task = | |
4059 | min(sds.busiest_load_per_task, sds.avg_load); | |
908a7c1b | 4060 | |
1da177e4 LT |
4061 | /* |
4062 | * We're trying to get all the cpus to the average_load, so we don't | |
4063 | * want to push ourselves above the average load, nor do we wish to | |
4064 | * reduce the max loaded cpu below the average load, as either of these | |
4065 | * actions would just result in more rebalancing later, and ping-pong | |
4066 | * tasks around. Thus we look for the minimum possible imbalance. | |
4067 | * Negative imbalances (*we* are more loaded than anyone else) will | |
4068 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 4069 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
4070 | * appear as very large values with unsigned longs. |
4071 | */ | |
222d656d | 4072 | if (sds.max_load <= sds.busiest_load_per_task) |
2dd73a4f PW |
4073 | goto out_balanced; |
4074 | ||
dbc523a3 GS |
4075 | /* Looks like there is an imbalance. Compute it */ |
4076 | calculate_imbalance(&sds, this_cpu, imbalance); | |
222d656d | 4077 | return sds.busiest; |
1da177e4 LT |
4078 | |
4079 | out_balanced: | |
c071df18 GS |
4080 | /* |
4081 | * There is no obvious imbalance. But check if we can do some balancing | |
4082 | * to save power. | |
4083 | */ | |
4084 | if (check_power_save_busiest_group(&sds, this_cpu, imbalance)) | |
4085 | return sds.busiest; | |
783609c6 | 4086 | ret: |
1da177e4 LT |
4087 | *imbalance = 0; |
4088 | return NULL; | |
4089 | } | |
4090 | ||
4091 | /* | |
4092 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
4093 | */ | |
70b97a7f | 4094 | static struct rq * |
d15bcfdb | 4095 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
96f874e2 | 4096 | unsigned long imbalance, const struct cpumask *cpus) |
1da177e4 | 4097 | { |
70b97a7f | 4098 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 4099 | unsigned long max_load = 0; |
1da177e4 LT |
4100 | int i; |
4101 | ||
758b2cdc | 4102 | for_each_cpu(i, sched_group_cpus(group)) { |
bdb94aa5 PZ |
4103 | unsigned long power = power_of(i); |
4104 | unsigned long capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); | |
dd41f596 | 4105 | unsigned long wl; |
0a2966b4 | 4106 | |
96f874e2 | 4107 | if (!cpumask_test_cpu(i, cpus)) |
0a2966b4 CL |
4108 | continue; |
4109 | ||
48f24c4d | 4110 | rq = cpu_rq(i); |
bdb94aa5 PZ |
4111 | wl = weighted_cpuload(i) * SCHED_LOAD_SCALE; |
4112 | wl /= power; | |
2dd73a4f | 4113 | |
bdb94aa5 | 4114 | if (capacity && rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 4115 | continue; |
1da177e4 | 4116 | |
dd41f596 IM |
4117 | if (wl > max_load) { |
4118 | max_load = wl; | |
48f24c4d | 4119 | busiest = rq; |
1da177e4 LT |
4120 | } |
4121 | } | |
4122 | ||
4123 | return busiest; | |
4124 | } | |
4125 | ||
77391d71 NP |
4126 | /* |
4127 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
4128 | * so long as it is large enough. | |
4129 | */ | |
4130 | #define MAX_PINNED_INTERVAL 512 | |
4131 | ||
df7c8e84 RR |
4132 | /* Working cpumask for load_balance and load_balance_newidle. */ |
4133 | static DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); | |
4134 | ||
1da177e4 LT |
4135 | /* |
4136 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4137 | * tasks if there is an imbalance. | |
1da177e4 | 4138 | */ |
70b97a7f | 4139 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 4140 | struct sched_domain *sd, enum cpu_idle_type idle, |
df7c8e84 | 4141 | int *balance) |
1da177e4 | 4142 | { |
43010659 | 4143 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 4144 | struct sched_group *group; |
1da177e4 | 4145 | unsigned long imbalance; |
70b97a7f | 4146 | struct rq *busiest; |
fe2eea3f | 4147 | unsigned long flags; |
df7c8e84 | 4148 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
5969fe06 | 4149 | |
6ad4c188 | 4150 | cpumask_copy(cpus, cpu_active_mask); |
7c16ec58 | 4151 | |
89c4710e SS |
4152 | /* |
4153 | * When power savings policy is enabled for the parent domain, idle | |
4154 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 4155 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 4156 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 4157 | */ |
d15bcfdb | 4158 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4159 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4160 | sd_idle = 1; |
1da177e4 | 4161 | |
2d72376b | 4162 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 4163 | |
0a2966b4 | 4164 | redo: |
c8cba857 | 4165 | update_shares(sd); |
0a2966b4 | 4166 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 4167 | cpus, balance); |
783609c6 | 4168 | |
06066714 | 4169 | if (*balance == 0) |
783609c6 | 4170 | goto out_balanced; |
783609c6 | 4171 | |
1da177e4 LT |
4172 | if (!group) { |
4173 | schedstat_inc(sd, lb_nobusyg[idle]); | |
4174 | goto out_balanced; | |
4175 | } | |
4176 | ||
7c16ec58 | 4177 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
4178 | if (!busiest) { |
4179 | schedstat_inc(sd, lb_nobusyq[idle]); | |
4180 | goto out_balanced; | |
4181 | } | |
4182 | ||
db935dbd | 4183 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
4184 | |
4185 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
4186 | ||
43010659 | 4187 | ld_moved = 0; |
1da177e4 LT |
4188 | if (busiest->nr_running > 1) { |
4189 | /* | |
4190 | * Attempt to move tasks. If find_busiest_group has found | |
4191 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 4192 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
4193 | * correctly treated as an imbalance. |
4194 | */ | |
fe2eea3f | 4195 | local_irq_save(flags); |
e17224bf | 4196 | double_rq_lock(this_rq, busiest); |
43010659 | 4197 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 4198 | imbalance, sd, idle, &all_pinned); |
e17224bf | 4199 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 4200 | local_irq_restore(flags); |
81026794 | 4201 | |
46cb4b7c SS |
4202 | /* |
4203 | * some other cpu did the load balance for us. | |
4204 | */ | |
43010659 | 4205 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
4206 | resched_cpu(this_cpu); |
4207 | ||
81026794 | 4208 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 4209 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4210 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4211 | if (!cpumask_empty(cpus)) | |
0a2966b4 | 4212 | goto redo; |
81026794 | 4213 | goto out_balanced; |
0a2966b4 | 4214 | } |
1da177e4 | 4215 | } |
81026794 | 4216 | |
43010659 | 4217 | if (!ld_moved) { |
1da177e4 LT |
4218 | schedstat_inc(sd, lb_failed[idle]); |
4219 | sd->nr_balance_failed++; | |
4220 | ||
4221 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 4222 | |
05fa785c | 4223 | raw_spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
4224 | |
4225 | /* don't kick the migration_thread, if the curr | |
4226 | * task on busiest cpu can't be moved to this_cpu | |
4227 | */ | |
96f874e2 RR |
4228 | if (!cpumask_test_cpu(this_cpu, |
4229 | &busiest->curr->cpus_allowed)) { | |
05fa785c TG |
4230 | raw_spin_unlock_irqrestore(&busiest->lock, |
4231 | flags); | |
fa3b6ddc SS |
4232 | all_pinned = 1; |
4233 | goto out_one_pinned; | |
4234 | } | |
4235 | ||
1da177e4 LT |
4236 | if (!busiest->active_balance) { |
4237 | busiest->active_balance = 1; | |
4238 | busiest->push_cpu = this_cpu; | |
81026794 | 4239 | active_balance = 1; |
1da177e4 | 4240 | } |
05fa785c | 4241 | raw_spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 4242 | if (active_balance) |
1da177e4 LT |
4243 | wake_up_process(busiest->migration_thread); |
4244 | ||
4245 | /* | |
4246 | * We've kicked active balancing, reset the failure | |
4247 | * counter. | |
4248 | */ | |
39507451 | 4249 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 4250 | } |
81026794 | 4251 | } else |
1da177e4 LT |
4252 | sd->nr_balance_failed = 0; |
4253 | ||
81026794 | 4254 | if (likely(!active_balance)) { |
1da177e4 LT |
4255 | /* We were unbalanced, so reset the balancing interval */ |
4256 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
4257 | } else { |
4258 | /* | |
4259 | * If we've begun active balancing, start to back off. This | |
4260 | * case may not be covered by the all_pinned logic if there | |
4261 | * is only 1 task on the busy runqueue (because we don't call | |
4262 | * move_tasks). | |
4263 | */ | |
4264 | if (sd->balance_interval < sd->max_interval) | |
4265 | sd->balance_interval *= 2; | |
1da177e4 LT |
4266 | } |
4267 | ||
43010659 | 4268 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4269 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4270 | ld_moved = -1; |
4271 | ||
4272 | goto out; | |
1da177e4 LT |
4273 | |
4274 | out_balanced: | |
1da177e4 LT |
4275 | schedstat_inc(sd, lb_balanced[idle]); |
4276 | ||
16cfb1c0 | 4277 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
4278 | |
4279 | out_one_pinned: | |
1da177e4 | 4280 | /* tune up the balancing interval */ |
77391d71 NP |
4281 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
4282 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
4283 | sd->balance_interval *= 2; |
4284 | ||
48f24c4d | 4285 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4286 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4287 | ld_moved = -1; |
4288 | else | |
4289 | ld_moved = 0; | |
4290 | out: | |
c8cba857 PZ |
4291 | if (ld_moved) |
4292 | update_shares(sd); | |
c09595f6 | 4293 | return ld_moved; |
1da177e4 LT |
4294 | } |
4295 | ||
4296 | /* | |
4297 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4298 | * tasks if there is an imbalance. | |
4299 | * | |
d15bcfdb | 4300 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
4301 | * this_rq is locked. |
4302 | */ | |
48f24c4d | 4303 | static int |
df7c8e84 | 4304 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) |
1da177e4 LT |
4305 | { |
4306 | struct sched_group *group; | |
70b97a7f | 4307 | struct rq *busiest = NULL; |
1da177e4 | 4308 | unsigned long imbalance; |
43010659 | 4309 | int ld_moved = 0; |
5969fe06 | 4310 | int sd_idle = 0; |
969bb4e4 | 4311 | int all_pinned = 0; |
df7c8e84 | 4312 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
7c16ec58 | 4313 | |
6ad4c188 | 4314 | cpumask_copy(cpus, cpu_active_mask); |
5969fe06 | 4315 | |
89c4710e SS |
4316 | /* |
4317 | * When power savings policy is enabled for the parent domain, idle | |
4318 | * sibling can pick up load irrespective of busy siblings. In this case, | |
4319 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 4320 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
4321 | */ |
4322 | if (sd->flags & SD_SHARE_CPUPOWER && | |
4323 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4324 | sd_idle = 1; |
1da177e4 | 4325 | |
2d72376b | 4326 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 4327 | redo: |
3e5459b4 | 4328 | update_shares_locked(this_rq, sd); |
d15bcfdb | 4329 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 4330 | &sd_idle, cpus, NULL); |
1da177e4 | 4331 | if (!group) { |
d15bcfdb | 4332 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4333 | goto out_balanced; |
1da177e4 LT |
4334 | } |
4335 | ||
7c16ec58 | 4336 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 4337 | if (!busiest) { |
d15bcfdb | 4338 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4339 | goto out_balanced; |
1da177e4 LT |
4340 | } |
4341 | ||
db935dbd NP |
4342 | BUG_ON(busiest == this_rq); |
4343 | ||
d15bcfdb | 4344 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 4345 | |
43010659 | 4346 | ld_moved = 0; |
d6d5cfaf NP |
4347 | if (busiest->nr_running > 1) { |
4348 | /* Attempt to move tasks */ | |
4349 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
4350 | /* this_rq->clock is already updated */ |
4351 | update_rq_clock(busiest); | |
43010659 | 4352 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
4353 | imbalance, sd, CPU_NEWLY_IDLE, |
4354 | &all_pinned); | |
1b12bbc7 | 4355 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 4356 | |
969bb4e4 | 4357 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4358 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4359 | if (!cpumask_empty(cpus)) | |
0a2966b4 CL |
4360 | goto redo; |
4361 | } | |
d6d5cfaf NP |
4362 | } |
4363 | ||
43010659 | 4364 | if (!ld_moved) { |
36dffab6 | 4365 | int active_balance = 0; |
ad273b32 | 4366 | |
d15bcfdb | 4367 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
4368 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
4369 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4370 | return -1; |
ad273b32 VS |
4371 | |
4372 | if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) | |
4373 | return -1; | |
4374 | ||
4375 | if (sd->nr_balance_failed++ < 2) | |
4376 | return -1; | |
4377 | ||
4378 | /* | |
4379 | * The only task running in a non-idle cpu can be moved to this | |
4380 | * cpu in an attempt to completely freeup the other CPU | |
4381 | * package. The same method used to move task in load_balance() | |
4382 | * have been extended for load_balance_newidle() to speedup | |
4383 | * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) | |
4384 | * | |
4385 | * The package power saving logic comes from | |
4386 | * find_busiest_group(). If there are no imbalance, then | |
4387 | * f_b_g() will return NULL. However when sched_mc={1,2} then | |
4388 | * f_b_g() will select a group from which a running task may be | |
4389 | * pulled to this cpu in order to make the other package idle. | |
4390 | * If there is no opportunity to make a package idle and if | |
4391 | * there are no imbalance, then f_b_g() will return NULL and no | |
4392 | * action will be taken in load_balance_newidle(). | |
4393 | * | |
4394 | * Under normal task pull operation due to imbalance, there | |
4395 | * will be more than one task in the source run queue and | |
4396 | * move_tasks() will succeed. ld_moved will be true and this | |
4397 | * active balance code will not be triggered. | |
4398 | */ | |
4399 | ||
4400 | /* Lock busiest in correct order while this_rq is held */ | |
4401 | double_lock_balance(this_rq, busiest); | |
4402 | ||
4403 | /* | |
4404 | * don't kick the migration_thread, if the curr | |
4405 | * task on busiest cpu can't be moved to this_cpu | |
4406 | */ | |
6ca09dfc | 4407 | if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
ad273b32 VS |
4408 | double_unlock_balance(this_rq, busiest); |
4409 | all_pinned = 1; | |
4410 | return ld_moved; | |
4411 | } | |
4412 | ||
4413 | if (!busiest->active_balance) { | |
4414 | busiest->active_balance = 1; | |
4415 | busiest->push_cpu = this_cpu; | |
4416 | active_balance = 1; | |
4417 | } | |
4418 | ||
4419 | double_unlock_balance(this_rq, busiest); | |
da8d5089 PZ |
4420 | /* |
4421 | * Should not call ttwu while holding a rq->lock | |
4422 | */ | |
05fa785c | 4423 | raw_spin_unlock(&this_rq->lock); |
ad273b32 VS |
4424 | if (active_balance) |
4425 | wake_up_process(busiest->migration_thread); | |
05fa785c | 4426 | raw_spin_lock(&this_rq->lock); |
ad273b32 | 4427 | |
5969fe06 | 4428 | } else |
16cfb1c0 | 4429 | sd->nr_balance_failed = 0; |
1da177e4 | 4430 | |
3e5459b4 | 4431 | update_shares_locked(this_rq, sd); |
43010659 | 4432 | return ld_moved; |
16cfb1c0 NP |
4433 | |
4434 | out_balanced: | |
d15bcfdb | 4435 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 4436 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4437 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4438 | return -1; |
16cfb1c0 | 4439 | sd->nr_balance_failed = 0; |
48f24c4d | 4440 | |
16cfb1c0 | 4441 | return 0; |
1da177e4 LT |
4442 | } |
4443 | ||
4444 | /* | |
4445 | * idle_balance is called by schedule() if this_cpu is about to become | |
4446 | * idle. Attempts to pull tasks from other CPUs. | |
4447 | */ | |
70b97a7f | 4448 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
4449 | { |
4450 | struct sched_domain *sd; | |
efbe027e | 4451 | int pulled_task = 0; |
dd41f596 | 4452 | unsigned long next_balance = jiffies + HZ; |
1da177e4 | 4453 | |
1b9508f6 MG |
4454 | this_rq->idle_stamp = this_rq->clock; |
4455 | ||
4456 | if (this_rq->avg_idle < sysctl_sched_migration_cost) | |
4457 | return; | |
4458 | ||
1da177e4 | 4459 | for_each_domain(this_cpu, sd) { |
92c4ca5c CL |
4460 | unsigned long interval; |
4461 | ||
4462 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
4463 | continue; | |
4464 | ||
4465 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 4466 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 | 4467 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
df7c8e84 | 4468 | sd); |
92c4ca5c CL |
4469 | |
4470 | interval = msecs_to_jiffies(sd->balance_interval); | |
4471 | if (time_after(next_balance, sd->last_balance + interval)) | |
4472 | next_balance = sd->last_balance + interval; | |
1b9508f6 MG |
4473 | if (pulled_task) { |
4474 | this_rq->idle_stamp = 0; | |
92c4ca5c | 4475 | break; |
1b9508f6 | 4476 | } |
1da177e4 | 4477 | } |
dd41f596 | 4478 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
4479 | /* |
4480 | * We are going idle. next_balance may be set based on | |
4481 | * a busy processor. So reset next_balance. | |
4482 | */ | |
4483 | this_rq->next_balance = next_balance; | |
dd41f596 | 4484 | } |
1da177e4 LT |
4485 | } |
4486 | ||
4487 | /* | |
4488 | * active_load_balance is run by migration threads. It pushes running tasks | |
4489 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
4490 | * running on each physical CPU where possible, and avoids physical / | |
4491 | * logical imbalances. | |
4492 | * | |
4493 | * Called with busiest_rq locked. | |
4494 | */ | |
70b97a7f | 4495 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 4496 | { |
39507451 | 4497 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
4498 | struct sched_domain *sd; |
4499 | struct rq *target_rq; | |
39507451 | 4500 | |
48f24c4d | 4501 | /* Is there any task to move? */ |
39507451 | 4502 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
4503 | return; |
4504 | ||
4505 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
4506 | |
4507 | /* | |
39507451 | 4508 | * This condition is "impossible", if it occurs |
41a2d6cf | 4509 | * we need to fix it. Originally reported by |
39507451 | 4510 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 4511 | */ |
39507451 | 4512 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 4513 | |
39507451 NP |
4514 | /* move a task from busiest_rq to target_rq */ |
4515 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
4516 | update_rq_clock(busiest_rq); |
4517 | update_rq_clock(target_rq); | |
39507451 NP |
4518 | |
4519 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 4520 | for_each_domain(target_cpu, sd) { |
39507451 | 4521 | if ((sd->flags & SD_LOAD_BALANCE) && |
758b2cdc | 4522 | cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
39507451 | 4523 | break; |
c96d145e | 4524 | } |
39507451 | 4525 | |
48f24c4d | 4526 | if (likely(sd)) { |
2d72376b | 4527 | schedstat_inc(sd, alb_count); |
39507451 | 4528 | |
43010659 PW |
4529 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
4530 | sd, CPU_IDLE)) | |
48f24c4d IM |
4531 | schedstat_inc(sd, alb_pushed); |
4532 | else | |
4533 | schedstat_inc(sd, alb_failed); | |
4534 | } | |
1b12bbc7 | 4535 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
4536 | } |
4537 | ||
46cb4b7c SS |
4538 | #ifdef CONFIG_NO_HZ |
4539 | static struct { | |
4540 | atomic_t load_balancer; | |
7d1e6a9b | 4541 | cpumask_var_t cpu_mask; |
f711f609 | 4542 | cpumask_var_t ilb_grp_nohz_mask; |
46cb4b7c SS |
4543 | } nohz ____cacheline_aligned = { |
4544 | .load_balancer = ATOMIC_INIT(-1), | |
46cb4b7c SS |
4545 | }; |
4546 | ||
eea08f32 AB |
4547 | int get_nohz_load_balancer(void) |
4548 | { | |
4549 | return atomic_read(&nohz.load_balancer); | |
4550 | } | |
4551 | ||
f711f609 GS |
4552 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
4553 | /** | |
4554 | * lowest_flag_domain - Return lowest sched_domain containing flag. | |
4555 | * @cpu: The cpu whose lowest level of sched domain is to | |
4556 | * be returned. | |
4557 | * @flag: The flag to check for the lowest sched_domain | |
4558 | * for the given cpu. | |
4559 | * | |
4560 | * Returns the lowest sched_domain of a cpu which contains the given flag. | |
4561 | */ | |
4562 | static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) | |
4563 | { | |
4564 | struct sched_domain *sd; | |
4565 | ||
4566 | for_each_domain(cpu, sd) | |
4567 | if (sd && (sd->flags & flag)) | |
4568 | break; | |
4569 | ||
4570 | return sd; | |
4571 | } | |
4572 | ||
4573 | /** | |
4574 | * for_each_flag_domain - Iterates over sched_domains containing the flag. | |
4575 | * @cpu: The cpu whose domains we're iterating over. | |
4576 | * @sd: variable holding the value of the power_savings_sd | |
4577 | * for cpu. | |
4578 | * @flag: The flag to filter the sched_domains to be iterated. | |
4579 | * | |
4580 | * Iterates over all the scheduler domains for a given cpu that has the 'flag' | |
4581 | * set, starting from the lowest sched_domain to the highest. | |
4582 | */ | |
4583 | #define for_each_flag_domain(cpu, sd, flag) \ | |
4584 | for (sd = lowest_flag_domain(cpu, flag); \ | |
4585 | (sd && (sd->flags & flag)); sd = sd->parent) | |
4586 | ||
4587 | /** | |
4588 | * is_semi_idle_group - Checks if the given sched_group is semi-idle. | |
4589 | * @ilb_group: group to be checked for semi-idleness | |
4590 | * | |
4591 | * Returns: 1 if the group is semi-idle. 0 otherwise. | |
4592 | * | |
4593 | * We define a sched_group to be semi idle if it has atleast one idle-CPU | |
4594 | * and atleast one non-idle CPU. This helper function checks if the given | |
4595 | * sched_group is semi-idle or not. | |
4596 | */ | |
4597 | static inline int is_semi_idle_group(struct sched_group *ilb_group) | |
4598 | { | |
4599 | cpumask_and(nohz.ilb_grp_nohz_mask, nohz.cpu_mask, | |
4600 | sched_group_cpus(ilb_group)); | |
4601 | ||
4602 | /* | |
4603 | * A sched_group is semi-idle when it has atleast one busy cpu | |
4604 | * and atleast one idle cpu. | |
4605 | */ | |
4606 | if (cpumask_empty(nohz.ilb_grp_nohz_mask)) | |
4607 | return 0; | |
4608 | ||
4609 | if (cpumask_equal(nohz.ilb_grp_nohz_mask, sched_group_cpus(ilb_group))) | |
4610 | return 0; | |
4611 | ||
4612 | return 1; | |
4613 | } | |
4614 | /** | |
4615 | * find_new_ilb - Finds the optimum idle load balancer for nomination. | |
4616 | * @cpu: The cpu which is nominating a new idle_load_balancer. | |
4617 | * | |
4618 | * Returns: Returns the id of the idle load balancer if it exists, | |
4619 | * Else, returns >= nr_cpu_ids. | |
4620 | * | |
4621 | * This algorithm picks the idle load balancer such that it belongs to a | |
4622 | * semi-idle powersavings sched_domain. The idea is to try and avoid | |
4623 | * completely idle packages/cores just for the purpose of idle load balancing | |
4624 | * when there are other idle cpu's which are better suited for that job. | |
4625 | */ | |
4626 | static int find_new_ilb(int cpu) | |
4627 | { | |
4628 | struct sched_domain *sd; | |
4629 | struct sched_group *ilb_group; | |
4630 | ||
4631 | /* | |
4632 | * Have idle load balancer selection from semi-idle packages only | |
4633 | * when power-aware load balancing is enabled | |
4634 | */ | |
4635 | if (!(sched_smt_power_savings || sched_mc_power_savings)) | |
4636 | goto out_done; | |
4637 | ||
4638 | /* | |
4639 | * Optimize for the case when we have no idle CPUs or only one | |
4640 | * idle CPU. Don't walk the sched_domain hierarchy in such cases | |
4641 | */ | |
4642 | if (cpumask_weight(nohz.cpu_mask) < 2) | |
4643 | goto out_done; | |
4644 | ||
4645 | for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) { | |
4646 | ilb_group = sd->groups; | |
4647 | ||
4648 | do { | |
4649 | if (is_semi_idle_group(ilb_group)) | |
4650 | return cpumask_first(nohz.ilb_grp_nohz_mask); | |
4651 | ||
4652 | ilb_group = ilb_group->next; | |
4653 | ||
4654 | } while (ilb_group != sd->groups); | |
4655 | } | |
4656 | ||
4657 | out_done: | |
4658 | return cpumask_first(nohz.cpu_mask); | |
4659 | } | |
4660 | #else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */ | |
4661 | static inline int find_new_ilb(int call_cpu) | |
4662 | { | |
6e29ec57 | 4663 | return cpumask_first(nohz.cpu_mask); |
f711f609 GS |
4664 | } |
4665 | #endif | |
4666 | ||
7835b98b | 4667 | /* |
46cb4b7c SS |
4668 | * This routine will try to nominate the ilb (idle load balancing) |
4669 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
4670 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
4671 | * go into this tickless mode, then there will be no ilb owner (as there is | |
4672 | * no need for one) and all the cpus will sleep till the next wakeup event | |
4673 | * arrives... | |
4674 | * | |
4675 | * For the ilb owner, tick is not stopped. And this tick will be used | |
4676 | * for idle load balancing. ilb owner will still be part of | |
4677 | * nohz.cpu_mask.. | |
7835b98b | 4678 | * |
46cb4b7c SS |
4679 | * While stopping the tick, this cpu will become the ilb owner if there |
4680 | * is no other owner. And will be the owner till that cpu becomes busy | |
4681 | * or if all cpus in the system stop their ticks at which point | |
4682 | * there is no need for ilb owner. | |
4683 | * | |
4684 | * When the ilb owner becomes busy, it nominates another owner, during the | |
4685 | * next busy scheduler_tick() | |
4686 | */ | |
4687 | int select_nohz_load_balancer(int stop_tick) | |
4688 | { | |
4689 | int cpu = smp_processor_id(); | |
4690 | ||
4691 | if (stop_tick) { | |
46cb4b7c SS |
4692 | cpu_rq(cpu)->in_nohz_recently = 1; |
4693 | ||
483b4ee6 SS |
4694 | if (!cpu_active(cpu)) { |
4695 | if (atomic_read(&nohz.load_balancer) != cpu) | |
4696 | return 0; | |
4697 | ||
4698 | /* | |
4699 | * If we are going offline and still the leader, | |
4700 | * give up! | |
4701 | */ | |
46cb4b7c SS |
4702 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) |
4703 | BUG(); | |
483b4ee6 | 4704 | |
46cb4b7c SS |
4705 | return 0; |
4706 | } | |
4707 | ||
483b4ee6 SS |
4708 | cpumask_set_cpu(cpu, nohz.cpu_mask); |
4709 | ||
46cb4b7c | 4710 | /* time for ilb owner also to sleep */ |
6ad4c188 | 4711 | if (cpumask_weight(nohz.cpu_mask) == num_active_cpus()) { |
46cb4b7c SS |
4712 | if (atomic_read(&nohz.load_balancer) == cpu) |
4713 | atomic_set(&nohz.load_balancer, -1); | |
4714 | return 0; | |
4715 | } | |
4716 | ||
4717 | if (atomic_read(&nohz.load_balancer) == -1) { | |
4718 | /* make me the ilb owner */ | |
4719 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
4720 | return 1; | |
e790fb0b GS |
4721 | } else if (atomic_read(&nohz.load_balancer) == cpu) { |
4722 | int new_ilb; | |
4723 | ||
4724 | if (!(sched_smt_power_savings || | |
4725 | sched_mc_power_savings)) | |
4726 | return 1; | |
4727 | /* | |
4728 | * Check to see if there is a more power-efficient | |
4729 | * ilb. | |
4730 | */ | |
4731 | new_ilb = find_new_ilb(cpu); | |
4732 | if (new_ilb < nr_cpu_ids && new_ilb != cpu) { | |
4733 | atomic_set(&nohz.load_balancer, -1); | |
4734 | resched_cpu(new_ilb); | |
4735 | return 0; | |
4736 | } | |
46cb4b7c | 4737 | return 1; |
e790fb0b | 4738 | } |
46cb4b7c | 4739 | } else { |
7d1e6a9b | 4740 | if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4741 | return 0; |
4742 | ||
7d1e6a9b | 4743 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4744 | |
4745 | if (atomic_read(&nohz.load_balancer) == cpu) | |
4746 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
4747 | BUG(); | |
4748 | } | |
4749 | return 0; | |
4750 | } | |
4751 | #endif | |
4752 | ||
4753 | static DEFINE_SPINLOCK(balancing); | |
4754 | ||
4755 | /* | |
7835b98b CL |
4756 | * It checks each scheduling domain to see if it is due to be balanced, |
4757 | * and initiates a balancing operation if so. | |
4758 | * | |
4759 | * Balancing parameters are set up in arch_init_sched_domains. | |
4760 | */ | |
a9957449 | 4761 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 4762 | { |
46cb4b7c SS |
4763 | int balance = 1; |
4764 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
4765 | unsigned long interval; |
4766 | struct sched_domain *sd; | |
46cb4b7c | 4767 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 4768 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 4769 | int update_next_balance = 0; |
d07355f5 | 4770 | int need_serialize; |
1da177e4 | 4771 | |
46cb4b7c | 4772 | for_each_domain(cpu, sd) { |
1da177e4 LT |
4773 | if (!(sd->flags & SD_LOAD_BALANCE)) |
4774 | continue; | |
4775 | ||
4776 | interval = sd->balance_interval; | |
d15bcfdb | 4777 | if (idle != CPU_IDLE) |
1da177e4 LT |
4778 | interval *= sd->busy_factor; |
4779 | ||
4780 | /* scale ms to jiffies */ | |
4781 | interval = msecs_to_jiffies(interval); | |
4782 | if (unlikely(!interval)) | |
4783 | interval = 1; | |
dd41f596 IM |
4784 | if (interval > HZ*NR_CPUS/10) |
4785 | interval = HZ*NR_CPUS/10; | |
4786 | ||
d07355f5 | 4787 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 4788 | |
d07355f5 | 4789 | if (need_serialize) { |
08c183f3 CL |
4790 | if (!spin_trylock(&balancing)) |
4791 | goto out; | |
4792 | } | |
4793 | ||
c9819f45 | 4794 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
df7c8e84 | 4795 | if (load_balance(cpu, rq, sd, idle, &balance)) { |
fa3b6ddc SS |
4796 | /* |
4797 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
4798 | * longer idle, or one of our SMT siblings is |
4799 | * not idle. | |
4800 | */ | |
d15bcfdb | 4801 | idle = CPU_NOT_IDLE; |
1da177e4 | 4802 | } |
1bd77f2d | 4803 | sd->last_balance = jiffies; |
1da177e4 | 4804 | } |
d07355f5 | 4805 | if (need_serialize) |
08c183f3 CL |
4806 | spin_unlock(&balancing); |
4807 | out: | |
f549da84 | 4808 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 4809 | next_balance = sd->last_balance + interval; |
f549da84 SS |
4810 | update_next_balance = 1; |
4811 | } | |
783609c6 SS |
4812 | |
4813 | /* | |
4814 | * Stop the load balance at this level. There is another | |
4815 | * CPU in our sched group which is doing load balancing more | |
4816 | * actively. | |
4817 | */ | |
4818 | if (!balance) | |
4819 | break; | |
1da177e4 | 4820 | } |
f549da84 SS |
4821 | |
4822 | /* | |
4823 | * next_balance will be updated only when there is a need. | |
4824 | * When the cpu is attached to null domain for ex, it will not be | |
4825 | * updated. | |
4826 | */ | |
4827 | if (likely(update_next_balance)) | |
4828 | rq->next_balance = next_balance; | |
46cb4b7c SS |
4829 | } |
4830 | ||
4831 | /* | |
4832 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
4833 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
4834 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
4835 | */ | |
4836 | static void run_rebalance_domains(struct softirq_action *h) | |
4837 | { | |
dd41f596 IM |
4838 | int this_cpu = smp_processor_id(); |
4839 | struct rq *this_rq = cpu_rq(this_cpu); | |
4840 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
4841 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 4842 | |
dd41f596 | 4843 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
4844 | |
4845 | #ifdef CONFIG_NO_HZ | |
4846 | /* | |
4847 | * If this cpu is the owner for idle load balancing, then do the | |
4848 | * balancing on behalf of the other idle cpus whose ticks are | |
4849 | * stopped. | |
4850 | */ | |
dd41f596 IM |
4851 | if (this_rq->idle_at_tick && |
4852 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
4853 | struct rq *rq; |
4854 | int balance_cpu; | |
4855 | ||
7d1e6a9b RR |
4856 | for_each_cpu(balance_cpu, nohz.cpu_mask) { |
4857 | if (balance_cpu == this_cpu) | |
4858 | continue; | |
4859 | ||
46cb4b7c SS |
4860 | /* |
4861 | * If this cpu gets work to do, stop the load balancing | |
4862 | * work being done for other cpus. Next load | |
4863 | * balancing owner will pick it up. | |
4864 | */ | |
4865 | if (need_resched()) | |
4866 | break; | |
4867 | ||
de0cf899 | 4868 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
4869 | |
4870 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
4871 | if (time_after(this_rq->next_balance, rq->next_balance)) |
4872 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
4873 | } |
4874 | } | |
4875 | #endif | |
4876 | } | |
4877 | ||
8a0be9ef FW |
4878 | static inline int on_null_domain(int cpu) |
4879 | { | |
4880 | return !rcu_dereference(cpu_rq(cpu)->sd); | |
4881 | } | |
4882 | ||
46cb4b7c SS |
4883 | /* |
4884 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
4885 | * | |
4886 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
4887 | * idle load balancing owner or decide to stop the periodic load balancing, | |
4888 | * if the whole system is idle. | |
4889 | */ | |
dd41f596 | 4890 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 4891 | { |
46cb4b7c SS |
4892 | #ifdef CONFIG_NO_HZ |
4893 | /* | |
4894 | * If we were in the nohz mode recently and busy at the current | |
4895 | * scheduler tick, then check if we need to nominate new idle | |
4896 | * load balancer. | |
4897 | */ | |
4898 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
4899 | rq->in_nohz_recently = 0; | |
4900 | ||
4901 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
7d1e6a9b | 4902 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4903 | atomic_set(&nohz.load_balancer, -1); |
4904 | } | |
4905 | ||
4906 | if (atomic_read(&nohz.load_balancer) == -1) { | |
f711f609 | 4907 | int ilb = find_new_ilb(cpu); |
46cb4b7c | 4908 | |
434d53b0 | 4909 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
4910 | resched_cpu(ilb); |
4911 | } | |
4912 | } | |
4913 | ||
4914 | /* | |
4915 | * If this cpu is idle and doing idle load balancing for all the | |
4916 | * cpus with ticks stopped, is it time for that to stop? | |
4917 | */ | |
4918 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
7d1e6a9b | 4919 | cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4920 | resched_cpu(cpu); |
4921 | return; | |
4922 | } | |
4923 | ||
4924 | /* | |
4925 | * If this cpu is idle and the idle load balancing is done by | |
4926 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4927 | */ | |
4928 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
7d1e6a9b | 4929 | cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4930 | return; |
4931 | #endif | |
8a0be9ef FW |
4932 | /* Don't need to rebalance while attached to NULL domain */ |
4933 | if (time_after_eq(jiffies, rq->next_balance) && | |
4934 | likely(!on_null_domain(cpu))) | |
46cb4b7c | 4935 | raise_softirq(SCHED_SOFTIRQ); |
1da177e4 | 4936 | } |
dd41f596 IM |
4937 | |
4938 | #else /* CONFIG_SMP */ | |
4939 | ||
1da177e4 LT |
4940 | /* |
4941 | * on UP we do not need to balance between CPUs: | |
4942 | */ | |
70b97a7f | 4943 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4944 | { |
4945 | } | |
dd41f596 | 4946 | |
1da177e4 LT |
4947 | #endif |
4948 | ||
1da177e4 LT |
4949 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4950 | ||
4951 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4952 | ||
4953 | /* | |
c5f8d995 | 4954 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 4955 | * @p in case that task is currently running. |
c5f8d995 HS |
4956 | * |
4957 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 4958 | */ |
c5f8d995 HS |
4959 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
4960 | { | |
4961 | u64 ns = 0; | |
4962 | ||
4963 | if (task_current(rq, p)) { | |
4964 | update_rq_clock(rq); | |
4965 | ns = rq->clock - p->se.exec_start; | |
4966 | if ((s64)ns < 0) | |
4967 | ns = 0; | |
4968 | } | |
4969 | ||
4970 | return ns; | |
4971 | } | |
4972 | ||
bb34d92f | 4973 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4974 | { |
1da177e4 | 4975 | unsigned long flags; |
41b86e9c | 4976 | struct rq *rq; |
bb34d92f | 4977 | u64 ns = 0; |
48f24c4d | 4978 | |
41b86e9c | 4979 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
4980 | ns = do_task_delta_exec(p, rq); |
4981 | task_rq_unlock(rq, &flags); | |
1508487e | 4982 | |
c5f8d995 HS |
4983 | return ns; |
4984 | } | |
f06febc9 | 4985 | |
c5f8d995 HS |
4986 | /* |
4987 | * Return accounted runtime for the task. | |
4988 | * In case the task is currently running, return the runtime plus current's | |
4989 | * pending runtime that have not been accounted yet. | |
4990 | */ | |
4991 | unsigned long long task_sched_runtime(struct task_struct *p) | |
4992 | { | |
4993 | unsigned long flags; | |
4994 | struct rq *rq; | |
4995 | u64 ns = 0; | |
4996 | ||
4997 | rq = task_rq_lock(p, &flags); | |
4998 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
4999 | task_rq_unlock(rq, &flags); | |
5000 | ||
5001 | return ns; | |
5002 | } | |
48f24c4d | 5003 | |
c5f8d995 HS |
5004 | /* |
5005 | * Return sum_exec_runtime for the thread group. | |
5006 | * In case the task is currently running, return the sum plus current's | |
5007 | * pending runtime that have not been accounted yet. | |
5008 | * | |
5009 | * Note that the thread group might have other running tasks as well, | |
5010 | * so the return value not includes other pending runtime that other | |
5011 | * running tasks might have. | |
5012 | */ | |
5013 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
5014 | { | |
5015 | struct task_cputime totals; | |
5016 | unsigned long flags; | |
5017 | struct rq *rq; | |
5018 | u64 ns; | |
5019 | ||
5020 | rq = task_rq_lock(p, &flags); | |
5021 | thread_group_cputime(p, &totals); | |
5022 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 5023 | task_rq_unlock(rq, &flags); |
48f24c4d | 5024 | |
1da177e4 LT |
5025 | return ns; |
5026 | } | |
5027 | ||
1da177e4 LT |
5028 | /* |
5029 | * Account user cpu time to a process. | |
5030 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 5031 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 5032 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 5033 | */ |
457533a7 MS |
5034 | void account_user_time(struct task_struct *p, cputime_t cputime, |
5035 | cputime_t cputime_scaled) | |
1da177e4 LT |
5036 | { |
5037 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
5038 | cputime64_t tmp; | |
5039 | ||
457533a7 | 5040 | /* Add user time to process. */ |
1da177e4 | 5041 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 5042 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 5043 | account_group_user_time(p, cputime); |
1da177e4 LT |
5044 | |
5045 | /* Add user time to cpustat. */ | |
5046 | tmp = cputime_to_cputime64(cputime); | |
5047 | if (TASK_NICE(p) > 0) | |
5048 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
5049 | else | |
5050 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
5051 | |
5052 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
5053 | /* Account for user time used */ |
5054 | acct_update_integrals(p); | |
1da177e4 LT |
5055 | } |
5056 | ||
94886b84 LV |
5057 | /* |
5058 | * Account guest cpu time to a process. | |
5059 | * @p: the process that the cpu time gets accounted to | |
5060 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 5061 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 5062 | */ |
457533a7 MS |
5063 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
5064 | cputime_t cputime_scaled) | |
94886b84 LV |
5065 | { |
5066 | cputime64_t tmp; | |
5067 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
5068 | ||
5069 | tmp = cputime_to_cputime64(cputime); | |
5070 | ||
457533a7 | 5071 | /* Add guest time to process. */ |
94886b84 | 5072 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 5073 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 5074 | account_group_user_time(p, cputime); |
94886b84 LV |
5075 | p->gtime = cputime_add(p->gtime, cputime); |
5076 | ||
457533a7 | 5077 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
5078 | if (TASK_NICE(p) > 0) { |
5079 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
5080 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
5081 | } else { | |
5082 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
5083 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
5084 | } | |
94886b84 LV |
5085 | } |
5086 | ||
1da177e4 LT |
5087 | /* |
5088 | * Account system cpu time to a process. | |
5089 | * @p: the process that the cpu time gets accounted to | |
5090 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
5091 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 5092 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
5093 | */ |
5094 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 5095 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
5096 | { |
5097 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
5098 | cputime64_t tmp; |
5099 | ||
983ed7a6 | 5100 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 5101 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
5102 | return; |
5103 | } | |
94886b84 | 5104 | |
457533a7 | 5105 | /* Add system time to process. */ |
1da177e4 | 5106 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 5107 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 5108 | account_group_system_time(p, cputime); |
1da177e4 LT |
5109 | |
5110 | /* Add system time to cpustat. */ | |
5111 | tmp = cputime_to_cputime64(cputime); | |
5112 | if (hardirq_count() - hardirq_offset) | |
5113 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
5114 | else if (softirq_count()) | |
5115 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 5116 | else |
79741dd3 MS |
5117 | cpustat->system = cputime64_add(cpustat->system, tmp); |
5118 | ||
ef12fefa BR |
5119 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
5120 | ||
1da177e4 LT |
5121 | /* Account for system time used */ |
5122 | acct_update_integrals(p); | |
1da177e4 LT |
5123 | } |
5124 | ||
c66f08be | 5125 | /* |
1da177e4 | 5126 | * Account for involuntary wait time. |
1da177e4 | 5127 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 5128 | */ |
79741dd3 | 5129 | void account_steal_time(cputime_t cputime) |
c66f08be | 5130 | { |
79741dd3 MS |
5131 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
5132 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
5133 | ||
5134 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
5135 | } |
5136 | ||
1da177e4 | 5137 | /* |
79741dd3 MS |
5138 | * Account for idle time. |
5139 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 5140 | */ |
79741dd3 | 5141 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
5142 | { |
5143 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 5144 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 5145 | struct rq *rq = this_rq(); |
1da177e4 | 5146 | |
79741dd3 MS |
5147 | if (atomic_read(&rq->nr_iowait) > 0) |
5148 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
5149 | else | |
5150 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
5151 | } |
5152 | ||
79741dd3 MS |
5153 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
5154 | ||
5155 | /* | |
5156 | * Account a single tick of cpu time. | |
5157 | * @p: the process that the cpu time gets accounted to | |
5158 | * @user_tick: indicates if the tick is a user or a system tick | |
5159 | */ | |
5160 | void account_process_tick(struct task_struct *p, int user_tick) | |
5161 | { | |
a42548a1 | 5162 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
5163 | struct rq *rq = this_rq(); |
5164 | ||
5165 | if (user_tick) | |
a42548a1 | 5166 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 5167 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 5168 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
5169 | one_jiffy_scaled); |
5170 | else | |
a42548a1 | 5171 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
5172 | } |
5173 | ||
5174 | /* | |
5175 | * Account multiple ticks of steal time. | |
5176 | * @p: the process from which the cpu time has been stolen | |
5177 | * @ticks: number of stolen ticks | |
5178 | */ | |
5179 | void account_steal_ticks(unsigned long ticks) | |
5180 | { | |
5181 | account_steal_time(jiffies_to_cputime(ticks)); | |
5182 | } | |
5183 | ||
5184 | /* | |
5185 | * Account multiple ticks of idle time. | |
5186 | * @ticks: number of stolen ticks | |
5187 | */ | |
5188 | void account_idle_ticks(unsigned long ticks) | |
5189 | { | |
5190 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
5191 | } |
5192 | ||
79741dd3 MS |
5193 | #endif |
5194 | ||
49048622 BS |
5195 | /* |
5196 | * Use precise platform statistics if available: | |
5197 | */ | |
5198 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 5199 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5200 | { |
d99ca3b9 HS |
5201 | *ut = p->utime; |
5202 | *st = p->stime; | |
49048622 BS |
5203 | } |
5204 | ||
0cf55e1e | 5205 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5206 | { |
0cf55e1e HS |
5207 | struct task_cputime cputime; |
5208 | ||
5209 | thread_group_cputime(p, &cputime); | |
5210 | ||
5211 | *ut = cputime.utime; | |
5212 | *st = cputime.stime; | |
49048622 BS |
5213 | } |
5214 | #else | |
761b1d26 HS |
5215 | |
5216 | #ifndef nsecs_to_cputime | |
b7b20df9 | 5217 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
5218 | #endif |
5219 | ||
d180c5bc | 5220 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5221 | { |
d99ca3b9 | 5222 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
5223 | |
5224 | /* | |
5225 | * Use CFS's precise accounting: | |
5226 | */ | |
d180c5bc | 5227 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
5228 | |
5229 | if (total) { | |
d180c5bc HS |
5230 | u64 temp; |
5231 | ||
5232 | temp = (u64)(rtime * utime); | |
49048622 | 5233 | do_div(temp, total); |
d180c5bc HS |
5234 | utime = (cputime_t)temp; |
5235 | } else | |
5236 | utime = rtime; | |
49048622 | 5237 | |
d180c5bc HS |
5238 | /* |
5239 | * Compare with previous values, to keep monotonicity: | |
5240 | */ | |
761b1d26 | 5241 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 5242 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 5243 | |
d99ca3b9 HS |
5244 | *ut = p->prev_utime; |
5245 | *st = p->prev_stime; | |
49048622 BS |
5246 | } |
5247 | ||
0cf55e1e HS |
5248 | /* |
5249 | * Must be called with siglock held. | |
5250 | */ | |
5251 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 5252 | { |
0cf55e1e HS |
5253 | struct signal_struct *sig = p->signal; |
5254 | struct task_cputime cputime; | |
5255 | cputime_t rtime, utime, total; | |
49048622 | 5256 | |
0cf55e1e | 5257 | thread_group_cputime(p, &cputime); |
49048622 | 5258 | |
0cf55e1e HS |
5259 | total = cputime_add(cputime.utime, cputime.stime); |
5260 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 5261 | |
0cf55e1e HS |
5262 | if (total) { |
5263 | u64 temp; | |
49048622 | 5264 | |
0cf55e1e HS |
5265 | temp = (u64)(rtime * cputime.utime); |
5266 | do_div(temp, total); | |
5267 | utime = (cputime_t)temp; | |
5268 | } else | |
5269 | utime = rtime; | |
5270 | ||
5271 | sig->prev_utime = max(sig->prev_utime, utime); | |
5272 | sig->prev_stime = max(sig->prev_stime, | |
5273 | cputime_sub(rtime, sig->prev_utime)); | |
5274 | ||
5275 | *ut = sig->prev_utime; | |
5276 | *st = sig->prev_stime; | |
49048622 | 5277 | } |
49048622 | 5278 | #endif |
49048622 | 5279 | |
7835b98b CL |
5280 | /* |
5281 | * This function gets called by the timer code, with HZ frequency. | |
5282 | * We call it with interrupts disabled. | |
5283 | * | |
5284 | * It also gets called by the fork code, when changing the parent's | |
5285 | * timeslices. | |
5286 | */ | |
5287 | void scheduler_tick(void) | |
5288 | { | |
7835b98b CL |
5289 | int cpu = smp_processor_id(); |
5290 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 5291 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
5292 | |
5293 | sched_clock_tick(); | |
dd41f596 | 5294 | |
05fa785c | 5295 | raw_spin_lock(&rq->lock); |
3e51f33f | 5296 | update_rq_clock(rq); |
f1a438d8 | 5297 | update_cpu_load(rq); |
fa85ae24 | 5298 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 5299 | raw_spin_unlock(&rq->lock); |
7835b98b | 5300 | |
cdd6c482 | 5301 | perf_event_task_tick(curr, cpu); |
e220d2dc | 5302 | |
e418e1c2 | 5303 | #ifdef CONFIG_SMP |
dd41f596 IM |
5304 | rq->idle_at_tick = idle_cpu(cpu); |
5305 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 5306 | #endif |
1da177e4 LT |
5307 | } |
5308 | ||
132380a0 | 5309 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
5310 | { |
5311 | if (in_lock_functions(addr)) { | |
5312 | addr = CALLER_ADDR2; | |
5313 | if (in_lock_functions(addr)) | |
5314 | addr = CALLER_ADDR3; | |
5315 | } | |
5316 | return addr; | |
5317 | } | |
1da177e4 | 5318 | |
7e49fcce SR |
5319 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
5320 | defined(CONFIG_PREEMPT_TRACER)) | |
5321 | ||
43627582 | 5322 | void __kprobes add_preempt_count(int val) |
1da177e4 | 5323 | { |
6cd8a4bb | 5324 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5325 | /* |
5326 | * Underflow? | |
5327 | */ | |
9a11b49a IM |
5328 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
5329 | return; | |
6cd8a4bb | 5330 | #endif |
1da177e4 | 5331 | preempt_count() += val; |
6cd8a4bb | 5332 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5333 | /* |
5334 | * Spinlock count overflowing soon? | |
5335 | */ | |
33859f7f MOS |
5336 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
5337 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
5338 | #endif |
5339 | if (preempt_count() == val) | |
5340 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5341 | } |
5342 | EXPORT_SYMBOL(add_preempt_count); | |
5343 | ||
43627582 | 5344 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 5345 | { |
6cd8a4bb | 5346 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5347 | /* |
5348 | * Underflow? | |
5349 | */ | |
01e3eb82 | 5350 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 5351 | return; |
1da177e4 LT |
5352 | /* |
5353 | * Is the spinlock portion underflowing? | |
5354 | */ | |
9a11b49a IM |
5355 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
5356 | !(preempt_count() & PREEMPT_MASK))) | |
5357 | return; | |
6cd8a4bb | 5358 | #endif |
9a11b49a | 5359 | |
6cd8a4bb SR |
5360 | if (preempt_count() == val) |
5361 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5362 | preempt_count() -= val; |
5363 | } | |
5364 | EXPORT_SYMBOL(sub_preempt_count); | |
5365 | ||
5366 | #endif | |
5367 | ||
5368 | /* | |
dd41f596 | 5369 | * Print scheduling while atomic bug: |
1da177e4 | 5370 | */ |
dd41f596 | 5371 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 5372 | { |
838225b4 SS |
5373 | struct pt_regs *regs = get_irq_regs(); |
5374 | ||
3df0fc5b PZ |
5375 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
5376 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 5377 | |
dd41f596 | 5378 | debug_show_held_locks(prev); |
e21f5b15 | 5379 | print_modules(); |
dd41f596 IM |
5380 | if (irqs_disabled()) |
5381 | print_irqtrace_events(prev); | |
838225b4 SS |
5382 | |
5383 | if (regs) | |
5384 | show_regs(regs); | |
5385 | else | |
5386 | dump_stack(); | |
dd41f596 | 5387 | } |
1da177e4 | 5388 | |
dd41f596 IM |
5389 | /* |
5390 | * Various schedule()-time debugging checks and statistics: | |
5391 | */ | |
5392 | static inline void schedule_debug(struct task_struct *prev) | |
5393 | { | |
1da177e4 | 5394 | /* |
41a2d6cf | 5395 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
5396 | * schedule() atomically, we ignore that path for now. |
5397 | * Otherwise, whine if we are scheduling when we should not be. | |
5398 | */ | |
3f33a7ce | 5399 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
5400 | __schedule_bug(prev); |
5401 | ||
1da177e4 LT |
5402 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
5403 | ||
2d72376b | 5404 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
5405 | #ifdef CONFIG_SCHEDSTATS |
5406 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
5407 | schedstat_inc(this_rq(), bkl_count); |
5408 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
5409 | } |
5410 | #endif | |
dd41f596 IM |
5411 | } |
5412 | ||
6cecd084 | 5413 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 5414 | { |
6cecd084 PZ |
5415 | if (prev->state == TASK_RUNNING) { |
5416 | u64 runtime = prev->se.sum_exec_runtime; | |
df1c99d4 | 5417 | |
6cecd084 PZ |
5418 | runtime -= prev->se.prev_sum_exec_runtime; |
5419 | runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); | |
df1c99d4 MG |
5420 | |
5421 | /* | |
5422 | * In order to avoid avg_overlap growing stale when we are | |
5423 | * indeed overlapping and hence not getting put to sleep, grow | |
5424 | * the avg_overlap on preemption. | |
5425 | * | |
5426 | * We use the average preemption runtime because that | |
5427 | * correlates to the amount of cache footprint a task can | |
5428 | * build up. | |
5429 | */ | |
6cecd084 | 5430 | update_avg(&prev->se.avg_overlap, runtime); |
df1c99d4 | 5431 | } |
6cecd084 | 5432 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
5433 | } |
5434 | ||
dd41f596 IM |
5435 | /* |
5436 | * Pick up the highest-prio task: | |
5437 | */ | |
5438 | static inline struct task_struct * | |
b67802ea | 5439 | pick_next_task(struct rq *rq) |
dd41f596 | 5440 | { |
5522d5d5 | 5441 | const struct sched_class *class; |
dd41f596 | 5442 | struct task_struct *p; |
1da177e4 LT |
5443 | |
5444 | /* | |
dd41f596 IM |
5445 | * Optimization: we know that if all tasks are in |
5446 | * the fair class we can call that function directly: | |
1da177e4 | 5447 | */ |
dd41f596 | 5448 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 5449 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
5450 | if (likely(p)) |
5451 | return p; | |
1da177e4 LT |
5452 | } |
5453 | ||
dd41f596 IM |
5454 | class = sched_class_highest; |
5455 | for ( ; ; ) { | |
fb8d4724 | 5456 | p = class->pick_next_task(rq); |
dd41f596 IM |
5457 | if (p) |
5458 | return p; | |
5459 | /* | |
5460 | * Will never be NULL as the idle class always | |
5461 | * returns a non-NULL p: | |
5462 | */ | |
5463 | class = class->next; | |
5464 | } | |
5465 | } | |
1da177e4 | 5466 | |
dd41f596 IM |
5467 | /* |
5468 | * schedule() is the main scheduler function. | |
5469 | */ | |
ff743345 | 5470 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
5471 | { |
5472 | struct task_struct *prev, *next; | |
67ca7bde | 5473 | unsigned long *switch_count; |
dd41f596 | 5474 | struct rq *rq; |
31656519 | 5475 | int cpu; |
dd41f596 | 5476 | |
ff743345 PZ |
5477 | need_resched: |
5478 | preempt_disable(); | |
dd41f596 IM |
5479 | cpu = smp_processor_id(); |
5480 | rq = cpu_rq(cpu); | |
d6714c22 | 5481 | rcu_sched_qs(cpu); |
dd41f596 IM |
5482 | prev = rq->curr; |
5483 | switch_count = &prev->nivcsw; | |
5484 | ||
5485 | release_kernel_lock(prev); | |
5486 | need_resched_nonpreemptible: | |
5487 | ||
5488 | schedule_debug(prev); | |
1da177e4 | 5489 | |
31656519 | 5490 | if (sched_feat(HRTICK)) |
f333fdc9 | 5491 | hrtick_clear(rq); |
8f4d37ec | 5492 | |
05fa785c | 5493 | raw_spin_lock_irq(&rq->lock); |
3e51f33f | 5494 | update_rq_clock(rq); |
1e819950 | 5495 | clear_tsk_need_resched(prev); |
1da177e4 | 5496 | |
1da177e4 | 5497 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 5498 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 5499 | prev->state = TASK_RUNNING; |
16882c1e | 5500 | else |
2e1cb74a | 5501 | deactivate_task(rq, prev, 1); |
dd41f596 | 5502 | switch_count = &prev->nvcsw; |
1da177e4 LT |
5503 | } |
5504 | ||
3f029d3c | 5505 | pre_schedule(rq, prev); |
f65eda4f | 5506 | |
dd41f596 | 5507 | if (unlikely(!rq->nr_running)) |
1da177e4 | 5508 | idle_balance(cpu, rq); |
1da177e4 | 5509 | |
df1c99d4 | 5510 | put_prev_task(rq, prev); |
b67802ea | 5511 | next = pick_next_task(rq); |
1da177e4 | 5512 | |
1da177e4 | 5513 | if (likely(prev != next)) { |
673a90a1 | 5514 | sched_info_switch(prev, next); |
cdd6c482 | 5515 | perf_event_task_sched_out(prev, next, cpu); |
673a90a1 | 5516 | |
1da177e4 LT |
5517 | rq->nr_switches++; |
5518 | rq->curr = next; | |
5519 | ++*switch_count; | |
5520 | ||
dd41f596 | 5521 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
5522 | /* |
5523 | * the context switch might have flipped the stack from under | |
5524 | * us, hence refresh the local variables. | |
5525 | */ | |
5526 | cpu = smp_processor_id(); | |
5527 | rq = cpu_rq(cpu); | |
1da177e4 | 5528 | } else |
05fa785c | 5529 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5530 | |
3f029d3c | 5531 | post_schedule(rq); |
1da177e4 | 5532 | |
6d558c3a YZ |
5533 | if (unlikely(reacquire_kernel_lock(current) < 0)) { |
5534 | prev = rq->curr; | |
5535 | switch_count = &prev->nivcsw; | |
1da177e4 | 5536 | goto need_resched_nonpreemptible; |
6d558c3a | 5537 | } |
8f4d37ec | 5538 | |
1da177e4 | 5539 | preempt_enable_no_resched(); |
ff743345 | 5540 | if (need_resched()) |
1da177e4 LT |
5541 | goto need_resched; |
5542 | } | |
1da177e4 LT |
5543 | EXPORT_SYMBOL(schedule); |
5544 | ||
c08f7829 | 5545 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
5546 | /* |
5547 | * Look out! "owner" is an entirely speculative pointer | |
5548 | * access and not reliable. | |
5549 | */ | |
5550 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
5551 | { | |
5552 | unsigned int cpu; | |
5553 | struct rq *rq; | |
5554 | ||
5555 | if (!sched_feat(OWNER_SPIN)) | |
5556 | return 0; | |
5557 | ||
5558 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
5559 | /* | |
5560 | * Need to access the cpu field knowing that | |
5561 | * DEBUG_PAGEALLOC could have unmapped it if | |
5562 | * the mutex owner just released it and exited. | |
5563 | */ | |
5564 | if (probe_kernel_address(&owner->cpu, cpu)) | |
5565 | goto out; | |
5566 | #else | |
5567 | cpu = owner->cpu; | |
5568 | #endif | |
5569 | ||
5570 | /* | |
5571 | * Even if the access succeeded (likely case), | |
5572 | * the cpu field may no longer be valid. | |
5573 | */ | |
5574 | if (cpu >= nr_cpumask_bits) | |
5575 | goto out; | |
5576 | ||
5577 | /* | |
5578 | * We need to validate that we can do a | |
5579 | * get_cpu() and that we have the percpu area. | |
5580 | */ | |
5581 | if (!cpu_online(cpu)) | |
5582 | goto out; | |
5583 | ||
5584 | rq = cpu_rq(cpu); | |
5585 | ||
5586 | for (;;) { | |
5587 | /* | |
5588 | * Owner changed, break to re-assess state. | |
5589 | */ | |
5590 | if (lock->owner != owner) | |
5591 | break; | |
5592 | ||
5593 | /* | |
5594 | * Is that owner really running on that cpu? | |
5595 | */ | |
5596 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
5597 | return 0; | |
5598 | ||
5599 | cpu_relax(); | |
5600 | } | |
5601 | out: | |
5602 | return 1; | |
5603 | } | |
5604 | #endif | |
5605 | ||
1da177e4 LT |
5606 | #ifdef CONFIG_PREEMPT |
5607 | /* | |
2ed6e34f | 5608 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 5609 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
5610 | * occur there and call schedule directly. |
5611 | */ | |
5612 | asmlinkage void __sched preempt_schedule(void) | |
5613 | { | |
5614 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5615 | |
1da177e4 LT |
5616 | /* |
5617 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 5618 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 5619 | */ |
beed33a8 | 5620 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
5621 | return; |
5622 | ||
3a5c359a AK |
5623 | do { |
5624 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 5625 | schedule(); |
3a5c359a | 5626 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5627 | |
3a5c359a AK |
5628 | /* |
5629 | * Check again in case we missed a preemption opportunity | |
5630 | * between schedule and now. | |
5631 | */ | |
5632 | barrier(); | |
5ed0cec0 | 5633 | } while (need_resched()); |
1da177e4 | 5634 | } |
1da177e4 LT |
5635 | EXPORT_SYMBOL(preempt_schedule); |
5636 | ||
5637 | /* | |
2ed6e34f | 5638 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
5639 | * off of irq context. |
5640 | * Note, that this is called and return with irqs disabled. This will | |
5641 | * protect us against recursive calling from irq. | |
5642 | */ | |
5643 | asmlinkage void __sched preempt_schedule_irq(void) | |
5644 | { | |
5645 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5646 | |
2ed6e34f | 5647 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
5648 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
5649 | ||
3a5c359a AK |
5650 | do { |
5651 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
5652 | local_irq_enable(); |
5653 | schedule(); | |
5654 | local_irq_disable(); | |
3a5c359a | 5655 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5656 | |
3a5c359a AK |
5657 | /* |
5658 | * Check again in case we missed a preemption opportunity | |
5659 | * between schedule and now. | |
5660 | */ | |
5661 | barrier(); | |
5ed0cec0 | 5662 | } while (need_resched()); |
1da177e4 LT |
5663 | } |
5664 | ||
5665 | #endif /* CONFIG_PREEMPT */ | |
5666 | ||
63859d4f | 5667 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 5668 | void *key) |
1da177e4 | 5669 | { |
63859d4f | 5670 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 5671 | } |
1da177e4 LT |
5672 | EXPORT_SYMBOL(default_wake_function); |
5673 | ||
5674 | /* | |
41a2d6cf IM |
5675 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
5676 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
5677 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
5678 | * | |
5679 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 5680 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
5681 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
5682 | */ | |
78ddb08f | 5683 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 5684 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 5685 | { |
2e45874c | 5686 | wait_queue_t *curr, *next; |
1da177e4 | 5687 | |
2e45874c | 5688 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
5689 | unsigned flags = curr->flags; |
5690 | ||
63859d4f | 5691 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 5692 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
5693 | break; |
5694 | } | |
5695 | } | |
5696 | ||
5697 | /** | |
5698 | * __wake_up - wake up threads blocked on a waitqueue. | |
5699 | * @q: the waitqueue | |
5700 | * @mode: which threads | |
5701 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 5702 | * @key: is directly passed to the wakeup function |
50fa610a DH |
5703 | * |
5704 | * It may be assumed that this function implies a write memory barrier before | |
5705 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5706 | */ |
7ad5b3a5 | 5707 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 5708 | int nr_exclusive, void *key) |
1da177e4 LT |
5709 | { |
5710 | unsigned long flags; | |
5711 | ||
5712 | spin_lock_irqsave(&q->lock, flags); | |
5713 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
5714 | spin_unlock_irqrestore(&q->lock, flags); | |
5715 | } | |
1da177e4 LT |
5716 | EXPORT_SYMBOL(__wake_up); |
5717 | ||
5718 | /* | |
5719 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
5720 | */ | |
7ad5b3a5 | 5721 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
5722 | { |
5723 | __wake_up_common(q, mode, 1, 0, NULL); | |
5724 | } | |
5725 | ||
4ede816a DL |
5726 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
5727 | { | |
5728 | __wake_up_common(q, mode, 1, 0, key); | |
5729 | } | |
5730 | ||
1da177e4 | 5731 | /** |
4ede816a | 5732 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
5733 | * @q: the waitqueue |
5734 | * @mode: which threads | |
5735 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 5736 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
5737 | * |
5738 | * The sync wakeup differs that the waker knows that it will schedule | |
5739 | * away soon, so while the target thread will be woken up, it will not | |
5740 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
5741 | * with each other. This can prevent needless bouncing between CPUs. | |
5742 | * | |
5743 | * On UP it can prevent extra preemption. | |
50fa610a DH |
5744 | * |
5745 | * It may be assumed that this function implies a write memory barrier before | |
5746 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5747 | */ |
4ede816a DL |
5748 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
5749 | int nr_exclusive, void *key) | |
1da177e4 LT |
5750 | { |
5751 | unsigned long flags; | |
7d478721 | 5752 | int wake_flags = WF_SYNC; |
1da177e4 LT |
5753 | |
5754 | if (unlikely(!q)) | |
5755 | return; | |
5756 | ||
5757 | if (unlikely(!nr_exclusive)) | |
7d478721 | 5758 | wake_flags = 0; |
1da177e4 LT |
5759 | |
5760 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 5761 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
5762 | spin_unlock_irqrestore(&q->lock, flags); |
5763 | } | |
4ede816a DL |
5764 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
5765 | ||
5766 | /* | |
5767 | * __wake_up_sync - see __wake_up_sync_key() | |
5768 | */ | |
5769 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
5770 | { | |
5771 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
5772 | } | |
1da177e4 LT |
5773 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
5774 | ||
65eb3dc6 KD |
5775 | /** |
5776 | * complete: - signals a single thread waiting on this completion | |
5777 | * @x: holds the state of this particular completion | |
5778 | * | |
5779 | * This will wake up a single thread waiting on this completion. Threads will be | |
5780 | * awakened in the same order in which they were queued. | |
5781 | * | |
5782 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
5783 | * |
5784 | * It may be assumed that this function implies a write memory barrier before | |
5785 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5786 | */ |
b15136e9 | 5787 | void complete(struct completion *x) |
1da177e4 LT |
5788 | { |
5789 | unsigned long flags; | |
5790 | ||
5791 | spin_lock_irqsave(&x->wait.lock, flags); | |
5792 | x->done++; | |
d9514f6c | 5793 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
5794 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5795 | } | |
5796 | EXPORT_SYMBOL(complete); | |
5797 | ||
65eb3dc6 KD |
5798 | /** |
5799 | * complete_all: - signals all threads waiting on this completion | |
5800 | * @x: holds the state of this particular completion | |
5801 | * | |
5802 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
5803 | * |
5804 | * It may be assumed that this function implies a write memory barrier before | |
5805 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5806 | */ |
b15136e9 | 5807 | void complete_all(struct completion *x) |
1da177e4 LT |
5808 | { |
5809 | unsigned long flags; | |
5810 | ||
5811 | spin_lock_irqsave(&x->wait.lock, flags); | |
5812 | x->done += UINT_MAX/2; | |
d9514f6c | 5813 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
5814 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5815 | } | |
5816 | EXPORT_SYMBOL(complete_all); | |
5817 | ||
8cbbe86d AK |
5818 | static inline long __sched |
5819 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5820 | { |
1da177e4 LT |
5821 | if (!x->done) { |
5822 | DECLARE_WAITQUEUE(wait, current); | |
5823 | ||
5824 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
5825 | __add_wait_queue_tail(&x->wait, &wait); | |
5826 | do { | |
94d3d824 | 5827 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
5828 | timeout = -ERESTARTSYS; |
5829 | break; | |
8cbbe86d AK |
5830 | } |
5831 | __set_current_state(state); | |
1da177e4 LT |
5832 | spin_unlock_irq(&x->wait.lock); |
5833 | timeout = schedule_timeout(timeout); | |
5834 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 5835 | } while (!x->done && timeout); |
1da177e4 | 5836 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
5837 | if (!x->done) |
5838 | return timeout; | |
1da177e4 LT |
5839 | } |
5840 | x->done--; | |
ea71a546 | 5841 | return timeout ?: 1; |
1da177e4 | 5842 | } |
1da177e4 | 5843 | |
8cbbe86d AK |
5844 | static long __sched |
5845 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5846 | { |
1da177e4 LT |
5847 | might_sleep(); |
5848 | ||
5849 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 5850 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 5851 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
5852 | return timeout; |
5853 | } | |
1da177e4 | 5854 | |
65eb3dc6 KD |
5855 | /** |
5856 | * wait_for_completion: - waits for completion of a task | |
5857 | * @x: holds the state of this particular completion | |
5858 | * | |
5859 | * This waits to be signaled for completion of a specific task. It is NOT | |
5860 | * interruptible and there is no timeout. | |
5861 | * | |
5862 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
5863 | * and interrupt capability. Also see complete(). | |
5864 | */ | |
b15136e9 | 5865 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
5866 | { |
5867 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 5868 | } |
8cbbe86d | 5869 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 5870 | |
65eb3dc6 KD |
5871 | /** |
5872 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
5873 | * @x: holds the state of this particular completion | |
5874 | * @timeout: timeout value in jiffies | |
5875 | * | |
5876 | * This waits for either a completion of a specific task to be signaled or for a | |
5877 | * specified timeout to expire. The timeout is in jiffies. It is not | |
5878 | * interruptible. | |
5879 | */ | |
b15136e9 | 5880 | unsigned long __sched |
8cbbe86d | 5881 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 5882 | { |
8cbbe86d | 5883 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 5884 | } |
8cbbe86d | 5885 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 5886 | |
65eb3dc6 KD |
5887 | /** |
5888 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
5889 | * @x: holds the state of this particular completion | |
5890 | * | |
5891 | * This waits for completion of a specific task to be signaled. It is | |
5892 | * interruptible. | |
5893 | */ | |
8cbbe86d | 5894 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 5895 | { |
51e97990 AK |
5896 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
5897 | if (t == -ERESTARTSYS) | |
5898 | return t; | |
5899 | return 0; | |
0fec171c | 5900 | } |
8cbbe86d | 5901 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 5902 | |
65eb3dc6 KD |
5903 | /** |
5904 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
5905 | * @x: holds the state of this particular completion | |
5906 | * @timeout: timeout value in jiffies | |
5907 | * | |
5908 | * This waits for either a completion of a specific task to be signaled or for a | |
5909 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
5910 | */ | |
b15136e9 | 5911 | unsigned long __sched |
8cbbe86d AK |
5912 | wait_for_completion_interruptible_timeout(struct completion *x, |
5913 | unsigned long timeout) | |
0fec171c | 5914 | { |
8cbbe86d | 5915 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 5916 | } |
8cbbe86d | 5917 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 5918 | |
65eb3dc6 KD |
5919 | /** |
5920 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
5921 | * @x: holds the state of this particular completion | |
5922 | * | |
5923 | * This waits to be signaled for completion of a specific task. It can be | |
5924 | * interrupted by a kill signal. | |
5925 | */ | |
009e577e MW |
5926 | int __sched wait_for_completion_killable(struct completion *x) |
5927 | { | |
5928 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
5929 | if (t == -ERESTARTSYS) | |
5930 | return t; | |
5931 | return 0; | |
5932 | } | |
5933 | EXPORT_SYMBOL(wait_for_completion_killable); | |
5934 | ||
be4de352 DC |
5935 | /** |
5936 | * try_wait_for_completion - try to decrement a completion without blocking | |
5937 | * @x: completion structure | |
5938 | * | |
5939 | * Returns: 0 if a decrement cannot be done without blocking | |
5940 | * 1 if a decrement succeeded. | |
5941 | * | |
5942 | * If a completion is being used as a counting completion, | |
5943 | * attempt to decrement the counter without blocking. This | |
5944 | * enables us to avoid waiting if the resource the completion | |
5945 | * is protecting is not available. | |
5946 | */ | |
5947 | bool try_wait_for_completion(struct completion *x) | |
5948 | { | |
7539a3b3 | 5949 | unsigned long flags; |
be4de352 DC |
5950 | int ret = 1; |
5951 | ||
7539a3b3 | 5952 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
5953 | if (!x->done) |
5954 | ret = 0; | |
5955 | else | |
5956 | x->done--; | |
7539a3b3 | 5957 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
5958 | return ret; |
5959 | } | |
5960 | EXPORT_SYMBOL(try_wait_for_completion); | |
5961 | ||
5962 | /** | |
5963 | * completion_done - Test to see if a completion has any waiters | |
5964 | * @x: completion structure | |
5965 | * | |
5966 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
5967 | * 1 if there are no waiters. | |
5968 | * | |
5969 | */ | |
5970 | bool completion_done(struct completion *x) | |
5971 | { | |
7539a3b3 | 5972 | unsigned long flags; |
be4de352 DC |
5973 | int ret = 1; |
5974 | ||
7539a3b3 | 5975 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
5976 | if (!x->done) |
5977 | ret = 0; | |
7539a3b3 | 5978 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
5979 | return ret; |
5980 | } | |
5981 | EXPORT_SYMBOL(completion_done); | |
5982 | ||
8cbbe86d AK |
5983 | static long __sched |
5984 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 5985 | { |
0fec171c IM |
5986 | unsigned long flags; |
5987 | wait_queue_t wait; | |
5988 | ||
5989 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 5990 | |
8cbbe86d | 5991 | __set_current_state(state); |
1da177e4 | 5992 | |
8cbbe86d AK |
5993 | spin_lock_irqsave(&q->lock, flags); |
5994 | __add_wait_queue(q, &wait); | |
5995 | spin_unlock(&q->lock); | |
5996 | timeout = schedule_timeout(timeout); | |
5997 | spin_lock_irq(&q->lock); | |
5998 | __remove_wait_queue(q, &wait); | |
5999 | spin_unlock_irqrestore(&q->lock, flags); | |
6000 | ||
6001 | return timeout; | |
6002 | } | |
6003 | ||
6004 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
6005 | { | |
6006 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 6007 | } |
1da177e4 LT |
6008 | EXPORT_SYMBOL(interruptible_sleep_on); |
6009 | ||
0fec171c | 6010 | long __sched |
95cdf3b7 | 6011 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 6012 | { |
8cbbe86d | 6013 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 6014 | } |
1da177e4 LT |
6015 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
6016 | ||
0fec171c | 6017 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 6018 | { |
8cbbe86d | 6019 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 6020 | } |
1da177e4 LT |
6021 | EXPORT_SYMBOL(sleep_on); |
6022 | ||
0fec171c | 6023 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 6024 | { |
8cbbe86d | 6025 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 6026 | } |
1da177e4 LT |
6027 | EXPORT_SYMBOL(sleep_on_timeout); |
6028 | ||
b29739f9 IM |
6029 | #ifdef CONFIG_RT_MUTEXES |
6030 | ||
6031 | /* | |
6032 | * rt_mutex_setprio - set the current priority of a task | |
6033 | * @p: task | |
6034 | * @prio: prio value (kernel-internal form) | |
6035 | * | |
6036 | * This function changes the 'effective' priority of a task. It does | |
6037 | * not touch ->normal_prio like __setscheduler(). | |
6038 | * | |
6039 | * Used by the rt_mutex code to implement priority inheritance logic. | |
6040 | */ | |
36c8b586 | 6041 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
6042 | { |
6043 | unsigned long flags; | |
83b699ed | 6044 | int oldprio, on_rq, running; |
70b97a7f | 6045 | struct rq *rq; |
cb469845 | 6046 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
6047 | |
6048 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
6049 | ||
6050 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 6051 | update_rq_clock(rq); |
b29739f9 | 6052 | |
d5f9f942 | 6053 | oldprio = p->prio; |
dd41f596 | 6054 | on_rq = p->se.on_rq; |
051a1d1a | 6055 | running = task_current(rq, p); |
0e1f3483 | 6056 | if (on_rq) |
69be72c1 | 6057 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
6058 | if (running) |
6059 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
6060 | |
6061 | if (rt_prio(prio)) | |
6062 | p->sched_class = &rt_sched_class; | |
6063 | else | |
6064 | p->sched_class = &fair_sched_class; | |
6065 | ||
b29739f9 IM |
6066 | p->prio = prio; |
6067 | ||
0e1f3483 HS |
6068 | if (running) |
6069 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 6070 | if (on_rq) { |
8159f87e | 6071 | enqueue_task(rq, p, 0); |
cb469845 SR |
6072 | |
6073 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
6074 | } |
6075 | task_rq_unlock(rq, &flags); | |
6076 | } | |
6077 | ||
6078 | #endif | |
6079 | ||
36c8b586 | 6080 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 6081 | { |
dd41f596 | 6082 | int old_prio, delta, on_rq; |
1da177e4 | 6083 | unsigned long flags; |
70b97a7f | 6084 | struct rq *rq; |
1da177e4 LT |
6085 | |
6086 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
6087 | return; | |
6088 | /* | |
6089 | * We have to be careful, if called from sys_setpriority(), | |
6090 | * the task might be in the middle of scheduling on another CPU. | |
6091 | */ | |
6092 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 6093 | update_rq_clock(rq); |
1da177e4 LT |
6094 | /* |
6095 | * The RT priorities are set via sched_setscheduler(), but we still | |
6096 | * allow the 'normal' nice value to be set - but as expected | |
6097 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 6098 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 6099 | */ |
e05606d3 | 6100 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
6101 | p->static_prio = NICE_TO_PRIO(nice); |
6102 | goto out_unlock; | |
6103 | } | |
dd41f596 | 6104 | on_rq = p->se.on_rq; |
c09595f6 | 6105 | if (on_rq) |
69be72c1 | 6106 | dequeue_task(rq, p, 0); |
1da177e4 | 6107 | |
1da177e4 | 6108 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 6109 | set_load_weight(p); |
b29739f9 IM |
6110 | old_prio = p->prio; |
6111 | p->prio = effective_prio(p); | |
6112 | delta = p->prio - old_prio; | |
1da177e4 | 6113 | |
dd41f596 | 6114 | if (on_rq) { |
8159f87e | 6115 | enqueue_task(rq, p, 0); |
1da177e4 | 6116 | /* |
d5f9f942 AM |
6117 | * If the task increased its priority or is running and |
6118 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 6119 | */ |
d5f9f942 | 6120 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
6121 | resched_task(rq->curr); |
6122 | } | |
6123 | out_unlock: | |
6124 | task_rq_unlock(rq, &flags); | |
6125 | } | |
1da177e4 LT |
6126 | EXPORT_SYMBOL(set_user_nice); |
6127 | ||
e43379f1 MM |
6128 | /* |
6129 | * can_nice - check if a task can reduce its nice value | |
6130 | * @p: task | |
6131 | * @nice: nice value | |
6132 | */ | |
36c8b586 | 6133 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 6134 | { |
024f4747 MM |
6135 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
6136 | int nice_rlim = 20 - nice; | |
48f24c4d | 6137 | |
e43379f1 MM |
6138 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
6139 | capable(CAP_SYS_NICE)); | |
6140 | } | |
6141 | ||
1da177e4 LT |
6142 | #ifdef __ARCH_WANT_SYS_NICE |
6143 | ||
6144 | /* | |
6145 | * sys_nice - change the priority of the current process. | |
6146 | * @increment: priority increment | |
6147 | * | |
6148 | * sys_setpriority is a more generic, but much slower function that | |
6149 | * does similar things. | |
6150 | */ | |
5add95d4 | 6151 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 6152 | { |
48f24c4d | 6153 | long nice, retval; |
1da177e4 LT |
6154 | |
6155 | /* | |
6156 | * Setpriority might change our priority at the same moment. | |
6157 | * We don't have to worry. Conceptually one call occurs first | |
6158 | * and we have a single winner. | |
6159 | */ | |
e43379f1 MM |
6160 | if (increment < -40) |
6161 | increment = -40; | |
1da177e4 LT |
6162 | if (increment > 40) |
6163 | increment = 40; | |
6164 | ||
2b8f836f | 6165 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
6166 | if (nice < -20) |
6167 | nice = -20; | |
6168 | if (nice > 19) | |
6169 | nice = 19; | |
6170 | ||
e43379f1 MM |
6171 | if (increment < 0 && !can_nice(current, nice)) |
6172 | return -EPERM; | |
6173 | ||
1da177e4 LT |
6174 | retval = security_task_setnice(current, nice); |
6175 | if (retval) | |
6176 | return retval; | |
6177 | ||
6178 | set_user_nice(current, nice); | |
6179 | return 0; | |
6180 | } | |
6181 | ||
6182 | #endif | |
6183 | ||
6184 | /** | |
6185 | * task_prio - return the priority value of a given task. | |
6186 | * @p: the task in question. | |
6187 | * | |
6188 | * This is the priority value as seen by users in /proc. | |
6189 | * RT tasks are offset by -200. Normal tasks are centered | |
6190 | * around 0, value goes from -16 to +15. | |
6191 | */ | |
36c8b586 | 6192 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
6193 | { |
6194 | return p->prio - MAX_RT_PRIO; | |
6195 | } | |
6196 | ||
6197 | /** | |
6198 | * task_nice - return the nice value of a given task. | |
6199 | * @p: the task in question. | |
6200 | */ | |
36c8b586 | 6201 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
6202 | { |
6203 | return TASK_NICE(p); | |
6204 | } | |
150d8bed | 6205 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
6206 | |
6207 | /** | |
6208 | * idle_cpu - is a given cpu idle currently? | |
6209 | * @cpu: the processor in question. | |
6210 | */ | |
6211 | int idle_cpu(int cpu) | |
6212 | { | |
6213 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
6214 | } | |
6215 | ||
1da177e4 LT |
6216 | /** |
6217 | * idle_task - return the idle task for a given cpu. | |
6218 | * @cpu: the processor in question. | |
6219 | */ | |
36c8b586 | 6220 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
6221 | { |
6222 | return cpu_rq(cpu)->idle; | |
6223 | } | |
6224 | ||
6225 | /** | |
6226 | * find_process_by_pid - find a process with a matching PID value. | |
6227 | * @pid: the pid in question. | |
6228 | */ | |
a9957449 | 6229 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 6230 | { |
228ebcbe | 6231 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
6232 | } |
6233 | ||
6234 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
6235 | static void |
6236 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 6237 | { |
dd41f596 | 6238 | BUG_ON(p->se.on_rq); |
48f24c4d | 6239 | |
1da177e4 LT |
6240 | p->policy = policy; |
6241 | p->rt_priority = prio; | |
b29739f9 IM |
6242 | p->normal_prio = normal_prio(p); |
6243 | /* we are holding p->pi_lock already */ | |
6244 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
6245 | if (rt_prio(p->prio)) |
6246 | p->sched_class = &rt_sched_class; | |
6247 | else | |
6248 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 6249 | set_load_weight(p); |
1da177e4 LT |
6250 | } |
6251 | ||
c69e8d9c DH |
6252 | /* |
6253 | * check the target process has a UID that matches the current process's | |
6254 | */ | |
6255 | static bool check_same_owner(struct task_struct *p) | |
6256 | { | |
6257 | const struct cred *cred = current_cred(), *pcred; | |
6258 | bool match; | |
6259 | ||
6260 | rcu_read_lock(); | |
6261 | pcred = __task_cred(p); | |
6262 | match = (cred->euid == pcred->euid || | |
6263 | cred->euid == pcred->uid); | |
6264 | rcu_read_unlock(); | |
6265 | return match; | |
6266 | } | |
6267 | ||
961ccddd RR |
6268 | static int __sched_setscheduler(struct task_struct *p, int policy, |
6269 | struct sched_param *param, bool user) | |
1da177e4 | 6270 | { |
83b699ed | 6271 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 6272 | unsigned long flags; |
cb469845 | 6273 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 6274 | struct rq *rq; |
ca94c442 | 6275 | int reset_on_fork; |
1da177e4 | 6276 | |
66e5393a SR |
6277 | /* may grab non-irq protected spin_locks */ |
6278 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
6279 | recheck: |
6280 | /* double check policy once rq lock held */ | |
ca94c442 LP |
6281 | if (policy < 0) { |
6282 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 6283 | policy = oldpolicy = p->policy; |
ca94c442 LP |
6284 | } else { |
6285 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
6286 | policy &= ~SCHED_RESET_ON_FORK; | |
6287 | ||
6288 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
6289 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
6290 | policy != SCHED_IDLE) | |
6291 | return -EINVAL; | |
6292 | } | |
6293 | ||
1da177e4 LT |
6294 | /* |
6295 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
6296 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
6297 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
6298 | */ |
6299 | if (param->sched_priority < 0 || | |
95cdf3b7 | 6300 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 6301 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 6302 | return -EINVAL; |
e05606d3 | 6303 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
6304 | return -EINVAL; |
6305 | ||
37e4ab3f OC |
6306 | /* |
6307 | * Allow unprivileged RT tasks to decrease priority: | |
6308 | */ | |
961ccddd | 6309 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 6310 | if (rt_policy(policy)) { |
8dc3e909 | 6311 | unsigned long rlim_rtprio; |
8dc3e909 ON |
6312 | |
6313 | if (!lock_task_sighand(p, &flags)) | |
6314 | return -ESRCH; | |
6315 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
6316 | unlock_task_sighand(p, &flags); | |
6317 | ||
6318 | /* can't set/change the rt policy */ | |
6319 | if (policy != p->policy && !rlim_rtprio) | |
6320 | return -EPERM; | |
6321 | ||
6322 | /* can't increase priority */ | |
6323 | if (param->sched_priority > p->rt_priority && | |
6324 | param->sched_priority > rlim_rtprio) | |
6325 | return -EPERM; | |
6326 | } | |
dd41f596 IM |
6327 | /* |
6328 | * Like positive nice levels, dont allow tasks to | |
6329 | * move out of SCHED_IDLE either: | |
6330 | */ | |
6331 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
6332 | return -EPERM; | |
5fe1d75f | 6333 | |
37e4ab3f | 6334 | /* can't change other user's priorities */ |
c69e8d9c | 6335 | if (!check_same_owner(p)) |
37e4ab3f | 6336 | return -EPERM; |
ca94c442 LP |
6337 | |
6338 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
6339 | if (p->sched_reset_on_fork && !reset_on_fork) | |
6340 | return -EPERM; | |
37e4ab3f | 6341 | } |
1da177e4 | 6342 | |
725aad24 | 6343 | if (user) { |
b68aa230 | 6344 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
6345 | /* |
6346 | * Do not allow realtime tasks into groups that have no runtime | |
6347 | * assigned. | |
6348 | */ | |
9a7e0b18 PZ |
6349 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
6350 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 6351 | return -EPERM; |
b68aa230 PZ |
6352 | #endif |
6353 | ||
725aad24 JF |
6354 | retval = security_task_setscheduler(p, policy, param); |
6355 | if (retval) | |
6356 | return retval; | |
6357 | } | |
6358 | ||
b29739f9 IM |
6359 | /* |
6360 | * make sure no PI-waiters arrive (or leave) while we are | |
6361 | * changing the priority of the task: | |
6362 | */ | |
1d615482 | 6363 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
6364 | /* |
6365 | * To be able to change p->policy safely, the apropriate | |
6366 | * runqueue lock must be held. | |
6367 | */ | |
b29739f9 | 6368 | rq = __task_rq_lock(p); |
1da177e4 LT |
6369 | /* recheck policy now with rq lock held */ |
6370 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
6371 | policy = oldpolicy = -1; | |
b29739f9 | 6372 | __task_rq_unlock(rq); |
1d615482 | 6373 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
6374 | goto recheck; |
6375 | } | |
2daa3577 | 6376 | update_rq_clock(rq); |
dd41f596 | 6377 | on_rq = p->se.on_rq; |
051a1d1a | 6378 | running = task_current(rq, p); |
0e1f3483 | 6379 | if (on_rq) |
2e1cb74a | 6380 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
6381 | if (running) |
6382 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 6383 | |
ca94c442 LP |
6384 | p->sched_reset_on_fork = reset_on_fork; |
6385 | ||
1da177e4 | 6386 | oldprio = p->prio; |
dd41f596 | 6387 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 6388 | |
0e1f3483 HS |
6389 | if (running) |
6390 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
6391 | if (on_rq) { |
6392 | activate_task(rq, p, 0); | |
cb469845 SR |
6393 | |
6394 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 6395 | } |
b29739f9 | 6396 | __task_rq_unlock(rq); |
1d615482 | 6397 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 6398 | |
95e02ca9 TG |
6399 | rt_mutex_adjust_pi(p); |
6400 | ||
1da177e4 LT |
6401 | return 0; |
6402 | } | |
961ccddd RR |
6403 | |
6404 | /** | |
6405 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
6406 | * @p: the task in question. | |
6407 | * @policy: new policy. | |
6408 | * @param: structure containing the new RT priority. | |
6409 | * | |
6410 | * NOTE that the task may be already dead. | |
6411 | */ | |
6412 | int sched_setscheduler(struct task_struct *p, int policy, | |
6413 | struct sched_param *param) | |
6414 | { | |
6415 | return __sched_setscheduler(p, policy, param, true); | |
6416 | } | |
1da177e4 LT |
6417 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
6418 | ||
961ccddd RR |
6419 | /** |
6420 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
6421 | * @p: the task in question. | |
6422 | * @policy: new policy. | |
6423 | * @param: structure containing the new RT priority. | |
6424 | * | |
6425 | * Just like sched_setscheduler, only don't bother checking if the | |
6426 | * current context has permission. For example, this is needed in | |
6427 | * stop_machine(): we create temporary high priority worker threads, | |
6428 | * but our caller might not have that capability. | |
6429 | */ | |
6430 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
6431 | struct sched_param *param) | |
6432 | { | |
6433 | return __sched_setscheduler(p, policy, param, false); | |
6434 | } | |
6435 | ||
95cdf3b7 IM |
6436 | static int |
6437 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 6438 | { |
1da177e4 LT |
6439 | struct sched_param lparam; |
6440 | struct task_struct *p; | |
36c8b586 | 6441 | int retval; |
1da177e4 LT |
6442 | |
6443 | if (!param || pid < 0) | |
6444 | return -EINVAL; | |
6445 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
6446 | return -EFAULT; | |
5fe1d75f ON |
6447 | |
6448 | rcu_read_lock(); | |
6449 | retval = -ESRCH; | |
1da177e4 | 6450 | p = find_process_by_pid(pid); |
5fe1d75f ON |
6451 | if (p != NULL) |
6452 | retval = sched_setscheduler(p, policy, &lparam); | |
6453 | rcu_read_unlock(); | |
36c8b586 | 6454 | |
1da177e4 LT |
6455 | return retval; |
6456 | } | |
6457 | ||
6458 | /** | |
6459 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
6460 | * @pid: the pid in question. | |
6461 | * @policy: new policy. | |
6462 | * @param: structure containing the new RT priority. | |
6463 | */ | |
5add95d4 HC |
6464 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
6465 | struct sched_param __user *, param) | |
1da177e4 | 6466 | { |
c21761f1 JB |
6467 | /* negative values for policy are not valid */ |
6468 | if (policy < 0) | |
6469 | return -EINVAL; | |
6470 | ||
1da177e4 LT |
6471 | return do_sched_setscheduler(pid, policy, param); |
6472 | } | |
6473 | ||
6474 | /** | |
6475 | * sys_sched_setparam - set/change the RT priority of a thread | |
6476 | * @pid: the pid in question. | |
6477 | * @param: structure containing the new RT priority. | |
6478 | */ | |
5add95d4 | 6479 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6480 | { |
6481 | return do_sched_setscheduler(pid, -1, param); | |
6482 | } | |
6483 | ||
6484 | /** | |
6485 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
6486 | * @pid: the pid in question. | |
6487 | */ | |
5add95d4 | 6488 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 6489 | { |
36c8b586 | 6490 | struct task_struct *p; |
3a5c359a | 6491 | int retval; |
1da177e4 LT |
6492 | |
6493 | if (pid < 0) | |
3a5c359a | 6494 | return -EINVAL; |
1da177e4 LT |
6495 | |
6496 | retval = -ESRCH; | |
5fe85be0 | 6497 | rcu_read_lock(); |
1da177e4 LT |
6498 | p = find_process_by_pid(pid); |
6499 | if (p) { | |
6500 | retval = security_task_getscheduler(p); | |
6501 | if (!retval) | |
ca94c442 LP |
6502 | retval = p->policy |
6503 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 6504 | } |
5fe85be0 | 6505 | rcu_read_unlock(); |
1da177e4 LT |
6506 | return retval; |
6507 | } | |
6508 | ||
6509 | /** | |
ca94c442 | 6510 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
6511 | * @pid: the pid in question. |
6512 | * @param: structure containing the RT priority. | |
6513 | */ | |
5add95d4 | 6514 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6515 | { |
6516 | struct sched_param lp; | |
36c8b586 | 6517 | struct task_struct *p; |
3a5c359a | 6518 | int retval; |
1da177e4 LT |
6519 | |
6520 | if (!param || pid < 0) | |
3a5c359a | 6521 | return -EINVAL; |
1da177e4 | 6522 | |
5fe85be0 | 6523 | rcu_read_lock(); |
1da177e4 LT |
6524 | p = find_process_by_pid(pid); |
6525 | retval = -ESRCH; | |
6526 | if (!p) | |
6527 | goto out_unlock; | |
6528 | ||
6529 | retval = security_task_getscheduler(p); | |
6530 | if (retval) | |
6531 | goto out_unlock; | |
6532 | ||
6533 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 6534 | rcu_read_unlock(); |
1da177e4 LT |
6535 | |
6536 | /* | |
6537 | * This one might sleep, we cannot do it with a spinlock held ... | |
6538 | */ | |
6539 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
6540 | ||
1da177e4 LT |
6541 | return retval; |
6542 | ||
6543 | out_unlock: | |
5fe85be0 | 6544 | rcu_read_unlock(); |
1da177e4 LT |
6545 | return retval; |
6546 | } | |
6547 | ||
96f874e2 | 6548 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 6549 | { |
5a16f3d3 | 6550 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
6551 | struct task_struct *p; |
6552 | int retval; | |
1da177e4 | 6553 | |
95402b38 | 6554 | get_online_cpus(); |
23f5d142 | 6555 | rcu_read_lock(); |
1da177e4 LT |
6556 | |
6557 | p = find_process_by_pid(pid); | |
6558 | if (!p) { | |
23f5d142 | 6559 | rcu_read_unlock(); |
95402b38 | 6560 | put_online_cpus(); |
1da177e4 LT |
6561 | return -ESRCH; |
6562 | } | |
6563 | ||
23f5d142 | 6564 | /* Prevent p going away */ |
1da177e4 | 6565 | get_task_struct(p); |
23f5d142 | 6566 | rcu_read_unlock(); |
1da177e4 | 6567 | |
5a16f3d3 RR |
6568 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
6569 | retval = -ENOMEM; | |
6570 | goto out_put_task; | |
6571 | } | |
6572 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
6573 | retval = -ENOMEM; | |
6574 | goto out_free_cpus_allowed; | |
6575 | } | |
1da177e4 | 6576 | retval = -EPERM; |
c69e8d9c | 6577 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
6578 | goto out_unlock; |
6579 | ||
e7834f8f DQ |
6580 | retval = security_task_setscheduler(p, 0, NULL); |
6581 | if (retval) | |
6582 | goto out_unlock; | |
6583 | ||
5a16f3d3 RR |
6584 | cpuset_cpus_allowed(p, cpus_allowed); |
6585 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 6586 | again: |
5a16f3d3 | 6587 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 6588 | |
8707d8b8 | 6589 | if (!retval) { |
5a16f3d3 RR |
6590 | cpuset_cpus_allowed(p, cpus_allowed); |
6591 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
6592 | /* |
6593 | * We must have raced with a concurrent cpuset | |
6594 | * update. Just reset the cpus_allowed to the | |
6595 | * cpuset's cpus_allowed | |
6596 | */ | |
5a16f3d3 | 6597 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
6598 | goto again; |
6599 | } | |
6600 | } | |
1da177e4 | 6601 | out_unlock: |
5a16f3d3 RR |
6602 | free_cpumask_var(new_mask); |
6603 | out_free_cpus_allowed: | |
6604 | free_cpumask_var(cpus_allowed); | |
6605 | out_put_task: | |
1da177e4 | 6606 | put_task_struct(p); |
95402b38 | 6607 | put_online_cpus(); |
1da177e4 LT |
6608 | return retval; |
6609 | } | |
6610 | ||
6611 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 6612 | struct cpumask *new_mask) |
1da177e4 | 6613 | { |
96f874e2 RR |
6614 | if (len < cpumask_size()) |
6615 | cpumask_clear(new_mask); | |
6616 | else if (len > cpumask_size()) | |
6617 | len = cpumask_size(); | |
6618 | ||
1da177e4 LT |
6619 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
6620 | } | |
6621 | ||
6622 | /** | |
6623 | * sys_sched_setaffinity - set the cpu affinity of a process | |
6624 | * @pid: pid of the process | |
6625 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6626 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
6627 | */ | |
5add95d4 HC |
6628 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
6629 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 6630 | { |
5a16f3d3 | 6631 | cpumask_var_t new_mask; |
1da177e4 LT |
6632 | int retval; |
6633 | ||
5a16f3d3 RR |
6634 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
6635 | return -ENOMEM; | |
1da177e4 | 6636 | |
5a16f3d3 RR |
6637 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
6638 | if (retval == 0) | |
6639 | retval = sched_setaffinity(pid, new_mask); | |
6640 | free_cpumask_var(new_mask); | |
6641 | return retval; | |
1da177e4 LT |
6642 | } |
6643 | ||
96f874e2 | 6644 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 6645 | { |
36c8b586 | 6646 | struct task_struct *p; |
31605683 TG |
6647 | unsigned long flags; |
6648 | struct rq *rq; | |
1da177e4 | 6649 | int retval; |
1da177e4 | 6650 | |
95402b38 | 6651 | get_online_cpus(); |
23f5d142 | 6652 | rcu_read_lock(); |
1da177e4 LT |
6653 | |
6654 | retval = -ESRCH; | |
6655 | p = find_process_by_pid(pid); | |
6656 | if (!p) | |
6657 | goto out_unlock; | |
6658 | ||
e7834f8f DQ |
6659 | retval = security_task_getscheduler(p); |
6660 | if (retval) | |
6661 | goto out_unlock; | |
6662 | ||
31605683 | 6663 | rq = task_rq_lock(p, &flags); |
96f874e2 | 6664 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 6665 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
6666 | |
6667 | out_unlock: | |
23f5d142 | 6668 | rcu_read_unlock(); |
95402b38 | 6669 | put_online_cpus(); |
1da177e4 | 6670 | |
9531b62f | 6671 | return retval; |
1da177e4 LT |
6672 | } |
6673 | ||
6674 | /** | |
6675 | * sys_sched_getaffinity - get the cpu affinity of a process | |
6676 | * @pid: pid of the process | |
6677 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6678 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
6679 | */ | |
5add95d4 HC |
6680 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
6681 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
6682 | { |
6683 | int ret; | |
f17c8607 | 6684 | cpumask_var_t mask; |
1da177e4 | 6685 | |
f17c8607 | 6686 | if (len < cpumask_size()) |
1da177e4 LT |
6687 | return -EINVAL; |
6688 | ||
f17c8607 RR |
6689 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
6690 | return -ENOMEM; | |
1da177e4 | 6691 | |
f17c8607 RR |
6692 | ret = sched_getaffinity(pid, mask); |
6693 | if (ret == 0) { | |
6694 | if (copy_to_user(user_mask_ptr, mask, cpumask_size())) | |
6695 | ret = -EFAULT; | |
6696 | else | |
6697 | ret = cpumask_size(); | |
6698 | } | |
6699 | free_cpumask_var(mask); | |
1da177e4 | 6700 | |
f17c8607 | 6701 | return ret; |
1da177e4 LT |
6702 | } |
6703 | ||
6704 | /** | |
6705 | * sys_sched_yield - yield the current processor to other threads. | |
6706 | * | |
dd41f596 IM |
6707 | * This function yields the current CPU to other tasks. If there are no |
6708 | * other threads running on this CPU then this function will return. | |
1da177e4 | 6709 | */ |
5add95d4 | 6710 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 6711 | { |
70b97a7f | 6712 | struct rq *rq = this_rq_lock(); |
1da177e4 | 6713 | |
2d72376b | 6714 | schedstat_inc(rq, yld_count); |
4530d7ab | 6715 | current->sched_class->yield_task(rq); |
1da177e4 LT |
6716 | |
6717 | /* | |
6718 | * Since we are going to call schedule() anyway, there's | |
6719 | * no need to preempt or enable interrupts: | |
6720 | */ | |
6721 | __release(rq->lock); | |
8a25d5de | 6722 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 6723 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
6724 | preempt_enable_no_resched(); |
6725 | ||
6726 | schedule(); | |
6727 | ||
6728 | return 0; | |
6729 | } | |
6730 | ||
d86ee480 PZ |
6731 | static inline int should_resched(void) |
6732 | { | |
6733 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
6734 | } | |
6735 | ||
e7b38404 | 6736 | static void __cond_resched(void) |
1da177e4 | 6737 | { |
e7aaaa69 FW |
6738 | add_preempt_count(PREEMPT_ACTIVE); |
6739 | schedule(); | |
6740 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
6741 | } |
6742 | ||
02b67cc3 | 6743 | int __sched _cond_resched(void) |
1da177e4 | 6744 | { |
d86ee480 | 6745 | if (should_resched()) { |
1da177e4 LT |
6746 | __cond_resched(); |
6747 | return 1; | |
6748 | } | |
6749 | return 0; | |
6750 | } | |
02b67cc3 | 6751 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
6752 | |
6753 | /* | |
613afbf8 | 6754 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
6755 | * call schedule, and on return reacquire the lock. |
6756 | * | |
41a2d6cf | 6757 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
6758 | * operations here to prevent schedule() from being called twice (once via |
6759 | * spin_unlock(), once by hand). | |
6760 | */ | |
613afbf8 | 6761 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 6762 | { |
d86ee480 | 6763 | int resched = should_resched(); |
6df3cecb JK |
6764 | int ret = 0; |
6765 | ||
f607c668 PZ |
6766 | lockdep_assert_held(lock); |
6767 | ||
95c354fe | 6768 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 6769 | spin_unlock(lock); |
d86ee480 | 6770 | if (resched) |
95c354fe NP |
6771 | __cond_resched(); |
6772 | else | |
6773 | cpu_relax(); | |
6df3cecb | 6774 | ret = 1; |
1da177e4 | 6775 | spin_lock(lock); |
1da177e4 | 6776 | } |
6df3cecb | 6777 | return ret; |
1da177e4 | 6778 | } |
613afbf8 | 6779 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 6780 | |
613afbf8 | 6781 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
6782 | { |
6783 | BUG_ON(!in_softirq()); | |
6784 | ||
d86ee480 | 6785 | if (should_resched()) { |
98d82567 | 6786 | local_bh_enable(); |
1da177e4 LT |
6787 | __cond_resched(); |
6788 | local_bh_disable(); | |
6789 | return 1; | |
6790 | } | |
6791 | return 0; | |
6792 | } | |
613afbf8 | 6793 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 6794 | |
1da177e4 LT |
6795 | /** |
6796 | * yield - yield the current processor to other threads. | |
6797 | * | |
72fd4a35 | 6798 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
6799 | * thread runnable and calls sys_sched_yield(). |
6800 | */ | |
6801 | void __sched yield(void) | |
6802 | { | |
6803 | set_current_state(TASK_RUNNING); | |
6804 | sys_sched_yield(); | |
6805 | } | |
1da177e4 LT |
6806 | EXPORT_SYMBOL(yield); |
6807 | ||
6808 | /* | |
41a2d6cf | 6809 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 6810 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
6811 | */ |
6812 | void __sched io_schedule(void) | |
6813 | { | |
54d35f29 | 6814 | struct rq *rq = raw_rq(); |
1da177e4 | 6815 | |
0ff92245 | 6816 | delayacct_blkio_start(); |
1da177e4 | 6817 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6818 | current->in_iowait = 1; |
1da177e4 | 6819 | schedule(); |
8f0dfc34 | 6820 | current->in_iowait = 0; |
1da177e4 | 6821 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6822 | delayacct_blkio_end(); |
1da177e4 | 6823 | } |
1da177e4 LT |
6824 | EXPORT_SYMBOL(io_schedule); |
6825 | ||
6826 | long __sched io_schedule_timeout(long timeout) | |
6827 | { | |
54d35f29 | 6828 | struct rq *rq = raw_rq(); |
1da177e4 LT |
6829 | long ret; |
6830 | ||
0ff92245 | 6831 | delayacct_blkio_start(); |
1da177e4 | 6832 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6833 | current->in_iowait = 1; |
1da177e4 | 6834 | ret = schedule_timeout(timeout); |
8f0dfc34 | 6835 | current->in_iowait = 0; |
1da177e4 | 6836 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6837 | delayacct_blkio_end(); |
1da177e4 LT |
6838 | return ret; |
6839 | } | |
6840 | ||
6841 | /** | |
6842 | * sys_sched_get_priority_max - return maximum RT priority. | |
6843 | * @policy: scheduling class. | |
6844 | * | |
6845 | * this syscall returns the maximum rt_priority that can be used | |
6846 | * by a given scheduling class. | |
6847 | */ | |
5add95d4 | 6848 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
6849 | { |
6850 | int ret = -EINVAL; | |
6851 | ||
6852 | switch (policy) { | |
6853 | case SCHED_FIFO: | |
6854 | case SCHED_RR: | |
6855 | ret = MAX_USER_RT_PRIO-1; | |
6856 | break; | |
6857 | case SCHED_NORMAL: | |
b0a9499c | 6858 | case SCHED_BATCH: |
dd41f596 | 6859 | case SCHED_IDLE: |
1da177e4 LT |
6860 | ret = 0; |
6861 | break; | |
6862 | } | |
6863 | return ret; | |
6864 | } | |
6865 | ||
6866 | /** | |
6867 | * sys_sched_get_priority_min - return minimum RT priority. | |
6868 | * @policy: scheduling class. | |
6869 | * | |
6870 | * this syscall returns the minimum rt_priority that can be used | |
6871 | * by a given scheduling class. | |
6872 | */ | |
5add95d4 | 6873 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
6874 | { |
6875 | int ret = -EINVAL; | |
6876 | ||
6877 | switch (policy) { | |
6878 | case SCHED_FIFO: | |
6879 | case SCHED_RR: | |
6880 | ret = 1; | |
6881 | break; | |
6882 | case SCHED_NORMAL: | |
b0a9499c | 6883 | case SCHED_BATCH: |
dd41f596 | 6884 | case SCHED_IDLE: |
1da177e4 LT |
6885 | ret = 0; |
6886 | } | |
6887 | return ret; | |
6888 | } | |
6889 | ||
6890 | /** | |
6891 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
6892 | * @pid: pid of the process. | |
6893 | * @interval: userspace pointer to the timeslice value. | |
6894 | * | |
6895 | * this syscall writes the default timeslice value of a given process | |
6896 | * into the user-space timespec buffer. A value of '0' means infinity. | |
6897 | */ | |
17da2bd9 | 6898 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 6899 | struct timespec __user *, interval) |
1da177e4 | 6900 | { |
36c8b586 | 6901 | struct task_struct *p; |
a4ec24b4 | 6902 | unsigned int time_slice; |
dba091b9 TG |
6903 | unsigned long flags; |
6904 | struct rq *rq; | |
3a5c359a | 6905 | int retval; |
1da177e4 | 6906 | struct timespec t; |
1da177e4 LT |
6907 | |
6908 | if (pid < 0) | |
3a5c359a | 6909 | return -EINVAL; |
1da177e4 LT |
6910 | |
6911 | retval = -ESRCH; | |
1a551ae7 | 6912 | rcu_read_lock(); |
1da177e4 LT |
6913 | p = find_process_by_pid(pid); |
6914 | if (!p) | |
6915 | goto out_unlock; | |
6916 | ||
6917 | retval = security_task_getscheduler(p); | |
6918 | if (retval) | |
6919 | goto out_unlock; | |
6920 | ||
dba091b9 TG |
6921 | rq = task_rq_lock(p, &flags); |
6922 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
6923 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 6924 | |
1a551ae7 | 6925 | rcu_read_unlock(); |
a4ec24b4 | 6926 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 6927 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 6928 | return retval; |
3a5c359a | 6929 | |
1da177e4 | 6930 | out_unlock: |
1a551ae7 | 6931 | rcu_read_unlock(); |
1da177e4 LT |
6932 | return retval; |
6933 | } | |
6934 | ||
7c731e0a | 6935 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 6936 | |
82a1fcb9 | 6937 | void sched_show_task(struct task_struct *p) |
1da177e4 | 6938 | { |
1da177e4 | 6939 | unsigned long free = 0; |
36c8b586 | 6940 | unsigned state; |
1da177e4 | 6941 | |
1da177e4 | 6942 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 6943 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 6944 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 6945 | #if BITS_PER_LONG == 32 |
1da177e4 | 6946 | if (state == TASK_RUNNING) |
3df0fc5b | 6947 | printk(KERN_CONT " running "); |
1da177e4 | 6948 | else |
3df0fc5b | 6949 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6950 | #else |
6951 | if (state == TASK_RUNNING) | |
3df0fc5b | 6952 | printk(KERN_CONT " running task "); |
1da177e4 | 6953 | else |
3df0fc5b | 6954 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6955 | #endif |
6956 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6957 | free = stack_not_used(p); |
1da177e4 | 6958 | #endif |
3df0fc5b | 6959 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
6960 | task_pid_nr(p), task_pid_nr(p->real_parent), |
6961 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 6962 | |
5fb5e6de | 6963 | show_stack(p, NULL); |
1da177e4 LT |
6964 | } |
6965 | ||
e59e2ae2 | 6966 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6967 | { |
36c8b586 | 6968 | struct task_struct *g, *p; |
1da177e4 | 6969 | |
4bd77321 | 6970 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
6971 | printk(KERN_INFO |
6972 | " task PC stack pid father\n"); | |
1da177e4 | 6973 | #else |
3df0fc5b PZ |
6974 | printk(KERN_INFO |
6975 | " task PC stack pid father\n"); | |
1da177e4 LT |
6976 | #endif |
6977 | read_lock(&tasklist_lock); | |
6978 | do_each_thread(g, p) { | |
6979 | /* | |
6980 | * reset the NMI-timeout, listing all files on a slow | |
6981 | * console might take alot of time: | |
6982 | */ | |
6983 | touch_nmi_watchdog(); | |
39bc89fd | 6984 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6985 | sched_show_task(p); |
1da177e4 LT |
6986 | } while_each_thread(g, p); |
6987 | ||
04c9167f JF |
6988 | touch_all_softlockup_watchdogs(); |
6989 | ||
dd41f596 IM |
6990 | #ifdef CONFIG_SCHED_DEBUG |
6991 | sysrq_sched_debug_show(); | |
6992 | #endif | |
1da177e4 | 6993 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
6994 | /* |
6995 | * Only show locks if all tasks are dumped: | |
6996 | */ | |
93335a21 | 6997 | if (!state_filter) |
e59e2ae2 | 6998 | debug_show_all_locks(); |
1da177e4 LT |
6999 | } |
7000 | ||
1df21055 IM |
7001 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
7002 | { | |
dd41f596 | 7003 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
7004 | } |
7005 | ||
f340c0d1 IM |
7006 | /** |
7007 | * init_idle - set up an idle thread for a given CPU | |
7008 | * @idle: task in question | |
7009 | * @cpu: cpu the idle task belongs to | |
7010 | * | |
7011 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
7012 | * flag, to make booting more robust. | |
7013 | */ | |
5c1e1767 | 7014 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 7015 | { |
70b97a7f | 7016 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
7017 | unsigned long flags; |
7018 | ||
05fa785c | 7019 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 7020 | |
dd41f596 | 7021 | __sched_fork(idle); |
06b83b5f | 7022 | idle->state = TASK_RUNNING; |
dd41f596 IM |
7023 | idle->se.exec_start = sched_clock(); |
7024 | ||
96f874e2 | 7025 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 7026 | __set_task_cpu(idle, cpu); |
1da177e4 | 7027 | |
1da177e4 | 7028 | rq->curr = rq->idle = idle; |
4866cde0 NP |
7029 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
7030 | idle->oncpu = 1; | |
7031 | #endif | |
05fa785c | 7032 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
7033 | |
7034 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
7035 | #if defined(CONFIG_PREEMPT) |
7036 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
7037 | #else | |
a1261f54 | 7038 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 7039 | #endif |
dd41f596 IM |
7040 | /* |
7041 | * The idle tasks have their own, simple scheduling class: | |
7042 | */ | |
7043 | idle->sched_class = &idle_sched_class; | |
fb52607a | 7044 | ftrace_graph_init_task(idle); |
1da177e4 LT |
7045 | } |
7046 | ||
7047 | /* | |
7048 | * In a system that switches off the HZ timer nohz_cpu_mask | |
7049 | * indicates which cpus entered this state. This is used | |
7050 | * in the rcu update to wait only for active cpus. For system | |
7051 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 7052 | * always be CPU_BITS_NONE. |
1da177e4 | 7053 | */ |
6a7b3dc3 | 7054 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 7055 | |
19978ca6 IM |
7056 | /* |
7057 | * Increase the granularity value when there are more CPUs, | |
7058 | * because with more CPUs the 'effective latency' as visible | |
7059 | * to users decreases. But the relationship is not linear, | |
7060 | * so pick a second-best guess by going with the log2 of the | |
7061 | * number of CPUs. | |
7062 | * | |
7063 | * This idea comes from the SD scheduler of Con Kolivas: | |
7064 | */ | |
acb4a848 | 7065 | static int get_update_sysctl_factor(void) |
19978ca6 | 7066 | { |
4ca3ef71 | 7067 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
7068 | unsigned int factor; |
7069 | ||
7070 | switch (sysctl_sched_tunable_scaling) { | |
7071 | case SCHED_TUNABLESCALING_NONE: | |
7072 | factor = 1; | |
7073 | break; | |
7074 | case SCHED_TUNABLESCALING_LINEAR: | |
7075 | factor = cpus; | |
7076 | break; | |
7077 | case SCHED_TUNABLESCALING_LOG: | |
7078 | default: | |
7079 | factor = 1 + ilog2(cpus); | |
7080 | break; | |
7081 | } | |
19978ca6 | 7082 | |
acb4a848 CE |
7083 | return factor; |
7084 | } | |
19978ca6 | 7085 | |
acb4a848 CE |
7086 | static void update_sysctl(void) |
7087 | { | |
7088 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 7089 | |
0bcdcf28 CE |
7090 | #define SET_SYSCTL(name) \ |
7091 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
7092 | SET_SYSCTL(sched_min_granularity); | |
7093 | SET_SYSCTL(sched_latency); | |
7094 | SET_SYSCTL(sched_wakeup_granularity); | |
7095 | SET_SYSCTL(sched_shares_ratelimit); | |
7096 | #undef SET_SYSCTL | |
7097 | } | |
55cd5340 | 7098 | |
0bcdcf28 CE |
7099 | static inline void sched_init_granularity(void) |
7100 | { | |
7101 | update_sysctl(); | |
19978ca6 IM |
7102 | } |
7103 | ||
1da177e4 LT |
7104 | #ifdef CONFIG_SMP |
7105 | /* | |
7106 | * This is how migration works: | |
7107 | * | |
70b97a7f | 7108 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
7109 | * runqueue and wake up that CPU's migration thread. |
7110 | * 2) we down() the locked semaphore => thread blocks. | |
7111 | * 3) migration thread wakes up (implicitly it forces the migrated | |
7112 | * thread off the CPU) | |
7113 | * 4) it gets the migration request and checks whether the migrated | |
7114 | * task is still in the wrong runqueue. | |
7115 | * 5) if it's in the wrong runqueue then the migration thread removes | |
7116 | * it and puts it into the right queue. | |
7117 | * 6) migration thread up()s the semaphore. | |
7118 | * 7) we wake up and the migration is done. | |
7119 | */ | |
7120 | ||
7121 | /* | |
7122 | * Change a given task's CPU affinity. Migrate the thread to a | |
7123 | * proper CPU and schedule it away if the CPU it's executing on | |
7124 | * is removed from the allowed bitmask. | |
7125 | * | |
7126 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 7127 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
7128 | * call is not atomic; no spinlocks may be held. |
7129 | */ | |
96f874e2 | 7130 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 7131 | { |
70b97a7f | 7132 | struct migration_req req; |
1da177e4 | 7133 | unsigned long flags; |
70b97a7f | 7134 | struct rq *rq; |
48f24c4d | 7135 | int ret = 0; |
1da177e4 | 7136 | |
e2912009 PZ |
7137 | /* |
7138 | * Since we rely on wake-ups to migrate sleeping tasks, don't change | |
7139 | * the ->cpus_allowed mask from under waking tasks, which would be | |
7140 | * possible when we change rq->lock in ttwu(), so synchronize against | |
7141 | * TASK_WAKING to avoid that. | |
7142 | */ | |
7143 | again: | |
7144 | while (p->state == TASK_WAKING) | |
7145 | cpu_relax(); | |
7146 | ||
1da177e4 | 7147 | rq = task_rq_lock(p, &flags); |
e2912009 PZ |
7148 | |
7149 | if (p->state == TASK_WAKING) { | |
7150 | task_rq_unlock(rq, &flags); | |
7151 | goto again; | |
7152 | } | |
7153 | ||
6ad4c188 | 7154 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
7155 | ret = -EINVAL; |
7156 | goto out; | |
7157 | } | |
7158 | ||
9985b0ba | 7159 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 7160 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
7161 | ret = -EINVAL; |
7162 | goto out; | |
7163 | } | |
7164 | ||
73fe6aae | 7165 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 7166 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 7167 | else { |
96f874e2 RR |
7168 | cpumask_copy(&p->cpus_allowed, new_mask); |
7169 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
7170 | } |
7171 | ||
1da177e4 | 7172 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 7173 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
7174 | goto out; |
7175 | ||
6ad4c188 | 7176 | if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) { |
1da177e4 | 7177 | /* Need help from migration thread: drop lock and wait. */ |
693525e3 PZ |
7178 | struct task_struct *mt = rq->migration_thread; |
7179 | ||
7180 | get_task_struct(mt); | |
1da177e4 LT |
7181 | task_rq_unlock(rq, &flags); |
7182 | wake_up_process(rq->migration_thread); | |
693525e3 | 7183 | put_task_struct(mt); |
1da177e4 LT |
7184 | wait_for_completion(&req.done); |
7185 | tlb_migrate_finish(p->mm); | |
7186 | return 0; | |
7187 | } | |
7188 | out: | |
7189 | task_rq_unlock(rq, &flags); | |
48f24c4d | 7190 | |
1da177e4 LT |
7191 | return ret; |
7192 | } | |
cd8ba7cd | 7193 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
7194 | |
7195 | /* | |
41a2d6cf | 7196 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
7197 | * this because either it can't run here any more (set_cpus_allowed() |
7198 | * away from this CPU, or CPU going down), or because we're | |
7199 | * attempting to rebalance this task on exec (sched_exec). | |
7200 | * | |
7201 | * So we race with normal scheduler movements, but that's OK, as long | |
7202 | * as the task is no longer on this CPU. | |
efc30814 KK |
7203 | * |
7204 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 7205 | */ |
efc30814 | 7206 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 7207 | { |
70b97a7f | 7208 | struct rq *rq_dest, *rq_src; |
e2912009 | 7209 | int ret = 0; |
1da177e4 | 7210 | |
e761b772 | 7211 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 7212 | return ret; |
1da177e4 LT |
7213 | |
7214 | rq_src = cpu_rq(src_cpu); | |
7215 | rq_dest = cpu_rq(dest_cpu); | |
7216 | ||
7217 | double_rq_lock(rq_src, rq_dest); | |
7218 | /* Already moved. */ | |
7219 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 7220 | goto done; |
1da177e4 | 7221 | /* Affinity changed (again). */ |
96f874e2 | 7222 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 7223 | goto fail; |
1da177e4 | 7224 | |
e2912009 PZ |
7225 | /* |
7226 | * If we're not on a rq, the next wake-up will ensure we're | |
7227 | * placed properly. | |
7228 | */ | |
7229 | if (p->se.on_rq) { | |
2e1cb74a | 7230 | deactivate_task(rq_src, p, 0); |
e2912009 | 7231 | set_task_cpu(p, dest_cpu); |
dd41f596 | 7232 | activate_task(rq_dest, p, 0); |
15afe09b | 7233 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 7234 | } |
b1e38734 | 7235 | done: |
efc30814 | 7236 | ret = 1; |
b1e38734 | 7237 | fail: |
1da177e4 | 7238 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 7239 | return ret; |
1da177e4 LT |
7240 | } |
7241 | ||
03b042bf PM |
7242 | #define RCU_MIGRATION_IDLE 0 |
7243 | #define RCU_MIGRATION_NEED_QS 1 | |
7244 | #define RCU_MIGRATION_GOT_QS 2 | |
7245 | #define RCU_MIGRATION_MUST_SYNC 3 | |
7246 | ||
1da177e4 LT |
7247 | /* |
7248 | * migration_thread - this is a highprio system thread that performs | |
7249 | * thread migration by bumping thread off CPU then 'pushing' onto | |
7250 | * another runqueue. | |
7251 | */ | |
95cdf3b7 | 7252 | static int migration_thread(void *data) |
1da177e4 | 7253 | { |
03b042bf | 7254 | int badcpu; |
1da177e4 | 7255 | int cpu = (long)data; |
70b97a7f | 7256 | struct rq *rq; |
1da177e4 LT |
7257 | |
7258 | rq = cpu_rq(cpu); | |
7259 | BUG_ON(rq->migration_thread != current); | |
7260 | ||
7261 | set_current_state(TASK_INTERRUPTIBLE); | |
7262 | while (!kthread_should_stop()) { | |
70b97a7f | 7263 | struct migration_req *req; |
1da177e4 | 7264 | struct list_head *head; |
1da177e4 | 7265 | |
05fa785c | 7266 | raw_spin_lock_irq(&rq->lock); |
1da177e4 LT |
7267 | |
7268 | if (cpu_is_offline(cpu)) { | |
05fa785c | 7269 | raw_spin_unlock_irq(&rq->lock); |
371cbb38 | 7270 | break; |
1da177e4 LT |
7271 | } |
7272 | ||
7273 | if (rq->active_balance) { | |
7274 | active_load_balance(rq, cpu); | |
7275 | rq->active_balance = 0; | |
7276 | } | |
7277 | ||
7278 | head = &rq->migration_queue; | |
7279 | ||
7280 | if (list_empty(head)) { | |
05fa785c | 7281 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
7282 | schedule(); |
7283 | set_current_state(TASK_INTERRUPTIBLE); | |
7284 | continue; | |
7285 | } | |
70b97a7f | 7286 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
7287 | list_del_init(head->next); |
7288 | ||
03b042bf | 7289 | if (req->task != NULL) { |
05fa785c | 7290 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7291 | __migrate_task(req->task, cpu, req->dest_cpu); |
7292 | } else if (likely(cpu == (badcpu = smp_processor_id()))) { | |
7293 | req->dest_cpu = RCU_MIGRATION_GOT_QS; | |
05fa785c | 7294 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7295 | } else { |
7296 | req->dest_cpu = RCU_MIGRATION_MUST_SYNC; | |
05fa785c | 7297 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7298 | WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); |
7299 | } | |
674311d5 | 7300 | local_irq_enable(); |
1da177e4 LT |
7301 | |
7302 | complete(&req->done); | |
7303 | } | |
7304 | __set_current_state(TASK_RUNNING); | |
1da177e4 | 7305 | |
1da177e4 LT |
7306 | return 0; |
7307 | } | |
7308 | ||
7309 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
7310 | |
7311 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
7312 | { | |
7313 | int ret; | |
7314 | ||
7315 | local_irq_disable(); | |
7316 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
7317 | local_irq_enable(); | |
7318 | return ret; | |
7319 | } | |
7320 | ||
054b9108 | 7321 | /* |
3a4fa0a2 | 7322 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 7323 | */ |
48f24c4d | 7324 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 7325 | { |
70b97a7f | 7326 | int dest_cpu; |
e76bd8d9 RR |
7327 | |
7328 | again: | |
5da9a0fb | 7329 | dest_cpu = select_fallback_rq(dead_cpu, p); |
e76bd8d9 | 7330 | |
e76bd8d9 RR |
7331 | /* It can have affinity changed while we were choosing. */ |
7332 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
7333 | goto again; | |
1da177e4 LT |
7334 | } |
7335 | ||
7336 | /* | |
7337 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
7338 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
7339 | * for performance reasons the counter is not stricly tracking tasks to | |
7340 | * their home CPUs. So we just add the counter to another CPU's counter, | |
7341 | * to keep the global sum constant after CPU-down: | |
7342 | */ | |
70b97a7f | 7343 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 7344 | { |
6ad4c188 | 7345 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
7346 | unsigned long flags; |
7347 | ||
7348 | local_irq_save(flags); | |
7349 | double_rq_lock(rq_src, rq_dest); | |
7350 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
7351 | rq_src->nr_uninterruptible = 0; | |
7352 | double_rq_unlock(rq_src, rq_dest); | |
7353 | local_irq_restore(flags); | |
7354 | } | |
7355 | ||
7356 | /* Run through task list and migrate tasks from the dead cpu. */ | |
7357 | static void migrate_live_tasks(int src_cpu) | |
7358 | { | |
48f24c4d | 7359 | struct task_struct *p, *t; |
1da177e4 | 7360 | |
f7b4cddc | 7361 | read_lock(&tasklist_lock); |
1da177e4 | 7362 | |
48f24c4d IM |
7363 | do_each_thread(t, p) { |
7364 | if (p == current) | |
1da177e4 LT |
7365 | continue; |
7366 | ||
48f24c4d IM |
7367 | if (task_cpu(p) == src_cpu) |
7368 | move_task_off_dead_cpu(src_cpu, p); | |
7369 | } while_each_thread(t, p); | |
1da177e4 | 7370 | |
f7b4cddc | 7371 | read_unlock(&tasklist_lock); |
1da177e4 LT |
7372 | } |
7373 | ||
dd41f596 IM |
7374 | /* |
7375 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
7376 | * It does so by boosting its priority to highest possible. |
7377 | * Used by CPU offline code. | |
1da177e4 LT |
7378 | */ |
7379 | void sched_idle_next(void) | |
7380 | { | |
48f24c4d | 7381 | int this_cpu = smp_processor_id(); |
70b97a7f | 7382 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
7383 | struct task_struct *p = rq->idle; |
7384 | unsigned long flags; | |
7385 | ||
7386 | /* cpu has to be offline */ | |
48f24c4d | 7387 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 7388 | |
48f24c4d IM |
7389 | /* |
7390 | * Strictly not necessary since rest of the CPUs are stopped by now | |
7391 | * and interrupts disabled on the current cpu. | |
1da177e4 | 7392 | */ |
05fa785c | 7393 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 7394 | |
dd41f596 | 7395 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 7396 | |
94bc9a7b DA |
7397 | update_rq_clock(rq); |
7398 | activate_task(rq, p, 0); | |
1da177e4 | 7399 | |
05fa785c | 7400 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
7401 | } |
7402 | ||
48f24c4d IM |
7403 | /* |
7404 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
7405 | * offline. |
7406 | */ | |
7407 | void idle_task_exit(void) | |
7408 | { | |
7409 | struct mm_struct *mm = current->active_mm; | |
7410 | ||
7411 | BUG_ON(cpu_online(smp_processor_id())); | |
7412 | ||
7413 | if (mm != &init_mm) | |
7414 | switch_mm(mm, &init_mm, current); | |
7415 | mmdrop(mm); | |
7416 | } | |
7417 | ||
054b9108 | 7418 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 7419 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 7420 | { |
70b97a7f | 7421 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
7422 | |
7423 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 7424 | BUG_ON(!p->exit_state); |
1da177e4 LT |
7425 | |
7426 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 7427 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 7428 | |
48f24c4d | 7429 | get_task_struct(p); |
1da177e4 LT |
7430 | |
7431 | /* | |
7432 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 7433 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
7434 | * fine. |
7435 | */ | |
05fa785c | 7436 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 7437 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 7438 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7439 | |
48f24c4d | 7440 | put_task_struct(p); |
1da177e4 LT |
7441 | } |
7442 | ||
7443 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
7444 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
7445 | { | |
70b97a7f | 7446 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 7447 | struct task_struct *next; |
48f24c4d | 7448 | |
dd41f596 IM |
7449 | for ( ; ; ) { |
7450 | if (!rq->nr_running) | |
7451 | break; | |
a8e504d2 | 7452 | update_rq_clock(rq); |
b67802ea | 7453 | next = pick_next_task(rq); |
dd41f596 IM |
7454 | if (!next) |
7455 | break; | |
79c53799 | 7456 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 7457 | migrate_dead(dead_cpu, next); |
e692ab53 | 7458 | |
1da177e4 LT |
7459 | } |
7460 | } | |
dce48a84 TG |
7461 | |
7462 | /* | |
7463 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
7464 | */ | |
7465 | static void calc_global_load_remove(struct rq *rq) | |
7466 | { | |
7467 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 7468 | rq->calc_load_active = 0; |
dce48a84 | 7469 | } |
1da177e4 LT |
7470 | #endif /* CONFIG_HOTPLUG_CPU */ |
7471 | ||
e692ab53 NP |
7472 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
7473 | ||
7474 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
7475 | { |
7476 | .procname = "sched_domain", | |
c57baf1e | 7477 | .mode = 0555, |
e0361851 | 7478 | }, |
56992309 | 7479 | {} |
e692ab53 NP |
7480 | }; |
7481 | ||
7482 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
7483 | { |
7484 | .procname = "kernel", | |
c57baf1e | 7485 | .mode = 0555, |
e0361851 AD |
7486 | .child = sd_ctl_dir, |
7487 | }, | |
56992309 | 7488 | {} |
e692ab53 NP |
7489 | }; |
7490 | ||
7491 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
7492 | { | |
7493 | struct ctl_table *entry = | |
5cf9f062 | 7494 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 7495 | |
e692ab53 NP |
7496 | return entry; |
7497 | } | |
7498 | ||
6382bc90 MM |
7499 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
7500 | { | |
cd790076 | 7501 | struct ctl_table *entry; |
6382bc90 | 7502 | |
cd790076 MM |
7503 | /* |
7504 | * In the intermediate directories, both the child directory and | |
7505 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 7506 | * will always be set. In the lowest directory the names are |
cd790076 MM |
7507 | * static strings and all have proc handlers. |
7508 | */ | |
7509 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
7510 | if (entry->child) |
7511 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
7512 | if (entry->proc_handler == NULL) |
7513 | kfree(entry->procname); | |
7514 | } | |
6382bc90 MM |
7515 | |
7516 | kfree(*tablep); | |
7517 | *tablep = NULL; | |
7518 | } | |
7519 | ||
e692ab53 | 7520 | static void |
e0361851 | 7521 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
7522 | const char *procname, void *data, int maxlen, |
7523 | mode_t mode, proc_handler *proc_handler) | |
7524 | { | |
e692ab53 NP |
7525 | entry->procname = procname; |
7526 | entry->data = data; | |
7527 | entry->maxlen = maxlen; | |
7528 | entry->mode = mode; | |
7529 | entry->proc_handler = proc_handler; | |
7530 | } | |
7531 | ||
7532 | static struct ctl_table * | |
7533 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
7534 | { | |
a5d8c348 | 7535 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 7536 | |
ad1cdc1d MM |
7537 | if (table == NULL) |
7538 | return NULL; | |
7539 | ||
e0361851 | 7540 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 7541 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7542 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 7543 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7544 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 7545 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7546 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 7547 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7548 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 7549 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7550 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 7551 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7552 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 7553 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7554 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 7555 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7556 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 7557 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 7558 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
7559 | &sd->cache_nice_tries, |
7560 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 7561 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 7562 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
7563 | set_table_entry(&table[11], "name", sd->name, |
7564 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
7565 | /* &table[12] is terminator */ | |
e692ab53 NP |
7566 | |
7567 | return table; | |
7568 | } | |
7569 | ||
9a4e7159 | 7570 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
7571 | { |
7572 | struct ctl_table *entry, *table; | |
7573 | struct sched_domain *sd; | |
7574 | int domain_num = 0, i; | |
7575 | char buf[32]; | |
7576 | ||
7577 | for_each_domain(cpu, sd) | |
7578 | domain_num++; | |
7579 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
7580 | if (table == NULL) |
7581 | return NULL; | |
e692ab53 NP |
7582 | |
7583 | i = 0; | |
7584 | for_each_domain(cpu, sd) { | |
7585 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 7586 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7587 | entry->mode = 0555; |
e692ab53 NP |
7588 | entry->child = sd_alloc_ctl_domain_table(sd); |
7589 | entry++; | |
7590 | i++; | |
7591 | } | |
7592 | return table; | |
7593 | } | |
7594 | ||
7595 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 7596 | static void register_sched_domain_sysctl(void) |
e692ab53 | 7597 | { |
6ad4c188 | 7598 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
7599 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
7600 | char buf[32]; | |
7601 | ||
7378547f MM |
7602 | WARN_ON(sd_ctl_dir[0].child); |
7603 | sd_ctl_dir[0].child = entry; | |
7604 | ||
ad1cdc1d MM |
7605 | if (entry == NULL) |
7606 | return; | |
7607 | ||
6ad4c188 | 7608 | for_each_possible_cpu(i) { |
e692ab53 | 7609 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 7610 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7611 | entry->mode = 0555; |
e692ab53 | 7612 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 7613 | entry++; |
e692ab53 | 7614 | } |
7378547f MM |
7615 | |
7616 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
7617 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
7618 | } | |
6382bc90 | 7619 | |
7378547f | 7620 | /* may be called multiple times per register */ |
6382bc90 MM |
7621 | static void unregister_sched_domain_sysctl(void) |
7622 | { | |
7378547f MM |
7623 | if (sd_sysctl_header) |
7624 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 7625 | sd_sysctl_header = NULL; |
7378547f MM |
7626 | if (sd_ctl_dir[0].child) |
7627 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 7628 | } |
e692ab53 | 7629 | #else |
6382bc90 MM |
7630 | static void register_sched_domain_sysctl(void) |
7631 | { | |
7632 | } | |
7633 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
7634 | { |
7635 | } | |
7636 | #endif | |
7637 | ||
1f11eb6a GH |
7638 | static void set_rq_online(struct rq *rq) |
7639 | { | |
7640 | if (!rq->online) { | |
7641 | const struct sched_class *class; | |
7642 | ||
c6c4927b | 7643 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7644 | rq->online = 1; |
7645 | ||
7646 | for_each_class(class) { | |
7647 | if (class->rq_online) | |
7648 | class->rq_online(rq); | |
7649 | } | |
7650 | } | |
7651 | } | |
7652 | ||
7653 | static void set_rq_offline(struct rq *rq) | |
7654 | { | |
7655 | if (rq->online) { | |
7656 | const struct sched_class *class; | |
7657 | ||
7658 | for_each_class(class) { | |
7659 | if (class->rq_offline) | |
7660 | class->rq_offline(rq); | |
7661 | } | |
7662 | ||
c6c4927b | 7663 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7664 | rq->online = 0; |
7665 | } | |
7666 | } | |
7667 | ||
1da177e4 LT |
7668 | /* |
7669 | * migration_call - callback that gets triggered when a CPU is added. | |
7670 | * Here we can start up the necessary migration thread for the new CPU. | |
7671 | */ | |
48f24c4d IM |
7672 | static int __cpuinit |
7673 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 7674 | { |
1da177e4 | 7675 | struct task_struct *p; |
48f24c4d | 7676 | int cpu = (long)hcpu; |
1da177e4 | 7677 | unsigned long flags; |
70b97a7f | 7678 | struct rq *rq; |
1da177e4 LT |
7679 | |
7680 | switch (action) { | |
5be9361c | 7681 | |
1da177e4 | 7682 | case CPU_UP_PREPARE: |
8bb78442 | 7683 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 7684 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
7685 | if (IS_ERR(p)) |
7686 | return NOTIFY_BAD; | |
1da177e4 LT |
7687 | kthread_bind(p, cpu); |
7688 | /* Must be high prio: stop_machine expects to yield to it. */ | |
7689 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 7690 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 | 7691 | task_rq_unlock(rq, &flags); |
371cbb38 | 7692 | get_task_struct(p); |
1da177e4 | 7693 | cpu_rq(cpu)->migration_thread = p; |
a468d389 | 7694 | rq->calc_load_update = calc_load_update; |
1da177e4 | 7695 | break; |
48f24c4d | 7696 | |
1da177e4 | 7697 | case CPU_ONLINE: |
8bb78442 | 7698 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 7699 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 7700 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
7701 | |
7702 | /* Update our root-domain */ | |
7703 | rq = cpu_rq(cpu); | |
05fa785c | 7704 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 7705 | if (rq->rd) { |
c6c4927b | 7706 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
7707 | |
7708 | set_rq_online(rq); | |
1f94ef59 | 7709 | } |
05fa785c | 7710 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 7711 | break; |
48f24c4d | 7712 | |
1da177e4 LT |
7713 | #ifdef CONFIG_HOTPLUG_CPU |
7714 | case CPU_UP_CANCELED: | |
8bb78442 | 7715 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
7716 | if (!cpu_rq(cpu)->migration_thread) |
7717 | break; | |
41a2d6cf | 7718 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 7719 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 7720 | cpumask_any(cpu_online_mask)); |
1da177e4 | 7721 | kthread_stop(cpu_rq(cpu)->migration_thread); |
371cbb38 | 7722 | put_task_struct(cpu_rq(cpu)->migration_thread); |
1da177e4 LT |
7723 | cpu_rq(cpu)->migration_thread = NULL; |
7724 | break; | |
48f24c4d | 7725 | |
1da177e4 | 7726 | case CPU_DEAD: |
8bb78442 | 7727 | case CPU_DEAD_FROZEN: |
470fd646 | 7728 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
7729 | migrate_live_tasks(cpu); |
7730 | rq = cpu_rq(cpu); | |
7731 | kthread_stop(rq->migration_thread); | |
371cbb38 | 7732 | put_task_struct(rq->migration_thread); |
1da177e4 LT |
7733 | rq->migration_thread = NULL; |
7734 | /* Idle task back to normal (off runqueue, low prio) */ | |
05fa785c | 7735 | raw_spin_lock_irq(&rq->lock); |
a8e504d2 | 7736 | update_rq_clock(rq); |
2e1cb74a | 7737 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
7738 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
7739 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 7740 | migrate_dead_tasks(cpu); |
05fa785c | 7741 | raw_spin_unlock_irq(&rq->lock); |
470fd646 | 7742 | cpuset_unlock(); |
1da177e4 LT |
7743 | migrate_nr_uninterruptible(rq); |
7744 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 7745 | calc_global_load_remove(rq); |
41a2d6cf IM |
7746 | /* |
7747 | * No need to migrate the tasks: it was best-effort if | |
7748 | * they didn't take sched_hotcpu_mutex. Just wake up | |
7749 | * the requestors. | |
7750 | */ | |
05fa785c | 7751 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7752 | while (!list_empty(&rq->migration_queue)) { |
70b97a7f IM |
7753 | struct migration_req *req; |
7754 | ||
1da177e4 | 7755 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 7756 | struct migration_req, list); |
1da177e4 | 7757 | list_del_init(&req->list); |
05fa785c | 7758 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 7759 | complete(&req->done); |
05fa785c | 7760 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7761 | } |
05fa785c | 7762 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 7763 | break; |
57d885fe | 7764 | |
08f503b0 GH |
7765 | case CPU_DYING: |
7766 | case CPU_DYING_FROZEN: | |
57d885fe GH |
7767 | /* Update our root-domain */ |
7768 | rq = cpu_rq(cpu); | |
05fa785c | 7769 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 7770 | if (rq->rd) { |
c6c4927b | 7771 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 7772 | set_rq_offline(rq); |
57d885fe | 7773 | } |
05fa785c | 7774 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 7775 | break; |
1da177e4 LT |
7776 | #endif |
7777 | } | |
7778 | return NOTIFY_OK; | |
7779 | } | |
7780 | ||
f38b0820 PM |
7781 | /* |
7782 | * Register at high priority so that task migration (migrate_all_tasks) | |
7783 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 7784 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 7785 | */ |
26c2143b | 7786 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
7787 | .notifier_call = migration_call, |
7788 | .priority = 10 | |
7789 | }; | |
7790 | ||
7babe8db | 7791 | static int __init migration_init(void) |
1da177e4 LT |
7792 | { |
7793 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 7794 | int err; |
48f24c4d IM |
7795 | |
7796 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
7797 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
7798 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
7799 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
7800 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 7801 | |
a004cd42 | 7802 | return 0; |
1da177e4 | 7803 | } |
7babe8db | 7804 | early_initcall(migration_init); |
1da177e4 LT |
7805 | #endif |
7806 | ||
7807 | #ifdef CONFIG_SMP | |
476f3534 | 7808 | |
3e9830dc | 7809 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 7810 | |
f6630114 MT |
7811 | static __read_mostly int sched_domain_debug_enabled; |
7812 | ||
7813 | static int __init sched_domain_debug_setup(char *str) | |
7814 | { | |
7815 | sched_domain_debug_enabled = 1; | |
7816 | ||
7817 | return 0; | |
7818 | } | |
7819 | early_param("sched_debug", sched_domain_debug_setup); | |
7820 | ||
7c16ec58 | 7821 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 7822 | struct cpumask *groupmask) |
1da177e4 | 7823 | { |
4dcf6aff | 7824 | struct sched_group *group = sd->groups; |
434d53b0 | 7825 | char str[256]; |
1da177e4 | 7826 | |
968ea6d8 | 7827 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 7828 | cpumask_clear(groupmask); |
4dcf6aff IM |
7829 | |
7830 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
7831 | ||
7832 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 7833 | printk("does not load-balance\n"); |
4dcf6aff | 7834 | if (sd->parent) |
3df0fc5b PZ |
7835 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
7836 | " has parent"); | |
4dcf6aff | 7837 | return -1; |
41c7ce9a NP |
7838 | } |
7839 | ||
3df0fc5b | 7840 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 7841 | |
758b2cdc | 7842 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
7843 | printk(KERN_ERR "ERROR: domain->span does not contain " |
7844 | "CPU%d\n", cpu); | |
4dcf6aff | 7845 | } |
758b2cdc | 7846 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
7847 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
7848 | " CPU%d\n", cpu); | |
4dcf6aff | 7849 | } |
1da177e4 | 7850 | |
4dcf6aff | 7851 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 7852 | do { |
4dcf6aff | 7853 | if (!group) { |
3df0fc5b PZ |
7854 | printk("\n"); |
7855 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
7856 | break; |
7857 | } | |
7858 | ||
18a3885f | 7859 | if (!group->cpu_power) { |
3df0fc5b PZ |
7860 | printk(KERN_CONT "\n"); |
7861 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
7862 | "set\n"); | |
4dcf6aff IM |
7863 | break; |
7864 | } | |
1da177e4 | 7865 | |
758b2cdc | 7866 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
7867 | printk(KERN_CONT "\n"); |
7868 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
7869 | break; |
7870 | } | |
1da177e4 | 7871 | |
758b2cdc | 7872 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
7873 | printk(KERN_CONT "\n"); |
7874 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
7875 | break; |
7876 | } | |
1da177e4 | 7877 | |
758b2cdc | 7878 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 7879 | |
968ea6d8 | 7880 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 7881 | |
3df0fc5b | 7882 | printk(KERN_CONT " %s", str); |
18a3885f | 7883 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
7884 | printk(KERN_CONT " (cpu_power = %d)", |
7885 | group->cpu_power); | |
381512cf | 7886 | } |
1da177e4 | 7887 | |
4dcf6aff IM |
7888 | group = group->next; |
7889 | } while (group != sd->groups); | |
3df0fc5b | 7890 | printk(KERN_CONT "\n"); |
1da177e4 | 7891 | |
758b2cdc | 7892 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 7893 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 7894 | |
758b2cdc RR |
7895 | if (sd->parent && |
7896 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
7897 | printk(KERN_ERR "ERROR: parent span is not a superset " |
7898 | "of domain->span\n"); | |
4dcf6aff IM |
7899 | return 0; |
7900 | } | |
1da177e4 | 7901 | |
4dcf6aff IM |
7902 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
7903 | { | |
d5dd3db1 | 7904 | cpumask_var_t groupmask; |
4dcf6aff | 7905 | int level = 0; |
1da177e4 | 7906 | |
f6630114 MT |
7907 | if (!sched_domain_debug_enabled) |
7908 | return; | |
7909 | ||
4dcf6aff IM |
7910 | if (!sd) { |
7911 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
7912 | return; | |
7913 | } | |
1da177e4 | 7914 | |
4dcf6aff IM |
7915 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
7916 | ||
d5dd3db1 | 7917 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
7918 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
7919 | return; | |
7920 | } | |
7921 | ||
4dcf6aff | 7922 | for (;;) { |
7c16ec58 | 7923 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 7924 | break; |
1da177e4 LT |
7925 | level++; |
7926 | sd = sd->parent; | |
33859f7f | 7927 | if (!sd) |
4dcf6aff IM |
7928 | break; |
7929 | } | |
d5dd3db1 | 7930 | free_cpumask_var(groupmask); |
1da177e4 | 7931 | } |
6d6bc0ad | 7932 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 7933 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 7934 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 7935 | |
1a20ff27 | 7936 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 7937 | { |
758b2cdc | 7938 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
7939 | return 1; |
7940 | ||
7941 | /* Following flags need at least 2 groups */ | |
7942 | if (sd->flags & (SD_LOAD_BALANCE | | |
7943 | SD_BALANCE_NEWIDLE | | |
7944 | SD_BALANCE_FORK | | |
89c4710e SS |
7945 | SD_BALANCE_EXEC | |
7946 | SD_SHARE_CPUPOWER | | |
7947 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
7948 | if (sd->groups != sd->groups->next) |
7949 | return 0; | |
7950 | } | |
7951 | ||
7952 | /* Following flags don't use groups */ | |
c88d5910 | 7953 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
7954 | return 0; |
7955 | ||
7956 | return 1; | |
7957 | } | |
7958 | ||
48f24c4d IM |
7959 | static int |
7960 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
7961 | { |
7962 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
7963 | ||
7964 | if (sd_degenerate(parent)) | |
7965 | return 1; | |
7966 | ||
758b2cdc | 7967 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
7968 | return 0; |
7969 | ||
245af2c7 SS |
7970 | /* Flags needing groups don't count if only 1 group in parent */ |
7971 | if (parent->groups == parent->groups->next) { | |
7972 | pflags &= ~(SD_LOAD_BALANCE | | |
7973 | SD_BALANCE_NEWIDLE | | |
7974 | SD_BALANCE_FORK | | |
89c4710e SS |
7975 | SD_BALANCE_EXEC | |
7976 | SD_SHARE_CPUPOWER | | |
7977 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
7978 | if (nr_node_ids == 1) |
7979 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
7980 | } |
7981 | if (~cflags & pflags) | |
7982 | return 0; | |
7983 | ||
7984 | return 1; | |
7985 | } | |
7986 | ||
c6c4927b RR |
7987 | static void free_rootdomain(struct root_domain *rd) |
7988 | { | |
047106ad PZ |
7989 | synchronize_sched(); |
7990 | ||
68e74568 RR |
7991 | cpupri_cleanup(&rd->cpupri); |
7992 | ||
c6c4927b RR |
7993 | free_cpumask_var(rd->rto_mask); |
7994 | free_cpumask_var(rd->online); | |
7995 | free_cpumask_var(rd->span); | |
7996 | kfree(rd); | |
7997 | } | |
7998 | ||
57d885fe GH |
7999 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
8000 | { | |
a0490fa3 | 8001 | struct root_domain *old_rd = NULL; |
57d885fe | 8002 | unsigned long flags; |
57d885fe | 8003 | |
05fa785c | 8004 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
8005 | |
8006 | if (rq->rd) { | |
a0490fa3 | 8007 | old_rd = rq->rd; |
57d885fe | 8008 | |
c6c4927b | 8009 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 8010 | set_rq_offline(rq); |
57d885fe | 8011 | |
c6c4927b | 8012 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 8013 | |
a0490fa3 IM |
8014 | /* |
8015 | * If we dont want to free the old_rt yet then | |
8016 | * set old_rd to NULL to skip the freeing later | |
8017 | * in this function: | |
8018 | */ | |
8019 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
8020 | old_rd = NULL; | |
57d885fe GH |
8021 | } |
8022 | ||
8023 | atomic_inc(&rd->refcount); | |
8024 | rq->rd = rd; | |
8025 | ||
c6c4927b | 8026 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 8027 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 8028 | set_rq_online(rq); |
57d885fe | 8029 | |
05fa785c | 8030 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
8031 | |
8032 | if (old_rd) | |
8033 | free_rootdomain(old_rd); | |
57d885fe GH |
8034 | } |
8035 | ||
fd5e1b5d | 8036 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 8037 | { |
36b7b6d4 PE |
8038 | gfp_t gfp = GFP_KERNEL; |
8039 | ||
57d885fe GH |
8040 | memset(rd, 0, sizeof(*rd)); |
8041 | ||
36b7b6d4 PE |
8042 | if (bootmem) |
8043 | gfp = GFP_NOWAIT; | |
c6c4927b | 8044 | |
36b7b6d4 | 8045 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 8046 | goto out; |
36b7b6d4 | 8047 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 8048 | goto free_span; |
36b7b6d4 | 8049 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 8050 | goto free_online; |
6e0534f2 | 8051 | |
0fb53029 | 8052 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 8053 | goto free_rto_mask; |
c6c4927b | 8054 | return 0; |
6e0534f2 | 8055 | |
68e74568 RR |
8056 | free_rto_mask: |
8057 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
8058 | free_online: |
8059 | free_cpumask_var(rd->online); | |
8060 | free_span: | |
8061 | free_cpumask_var(rd->span); | |
0c910d28 | 8062 | out: |
c6c4927b | 8063 | return -ENOMEM; |
57d885fe GH |
8064 | } |
8065 | ||
8066 | static void init_defrootdomain(void) | |
8067 | { | |
c6c4927b RR |
8068 | init_rootdomain(&def_root_domain, true); |
8069 | ||
57d885fe GH |
8070 | atomic_set(&def_root_domain.refcount, 1); |
8071 | } | |
8072 | ||
dc938520 | 8073 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
8074 | { |
8075 | struct root_domain *rd; | |
8076 | ||
8077 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
8078 | if (!rd) | |
8079 | return NULL; | |
8080 | ||
c6c4927b RR |
8081 | if (init_rootdomain(rd, false) != 0) { |
8082 | kfree(rd); | |
8083 | return NULL; | |
8084 | } | |
57d885fe GH |
8085 | |
8086 | return rd; | |
8087 | } | |
8088 | ||
1da177e4 | 8089 | /* |
0eab9146 | 8090 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
8091 | * hold the hotplug lock. |
8092 | */ | |
0eab9146 IM |
8093 | static void |
8094 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 8095 | { |
70b97a7f | 8096 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
8097 | struct sched_domain *tmp; |
8098 | ||
8099 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 8100 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
8101 | struct sched_domain *parent = tmp->parent; |
8102 | if (!parent) | |
8103 | break; | |
f29c9b1c | 8104 | |
1a848870 | 8105 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 8106 | tmp->parent = parent->parent; |
1a848870 SS |
8107 | if (parent->parent) |
8108 | parent->parent->child = tmp; | |
f29c9b1c LZ |
8109 | } else |
8110 | tmp = tmp->parent; | |
245af2c7 SS |
8111 | } |
8112 | ||
1a848870 | 8113 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 8114 | sd = sd->parent; |
1a848870 SS |
8115 | if (sd) |
8116 | sd->child = NULL; | |
8117 | } | |
1da177e4 LT |
8118 | |
8119 | sched_domain_debug(sd, cpu); | |
8120 | ||
57d885fe | 8121 | rq_attach_root(rq, rd); |
674311d5 | 8122 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
8123 | } |
8124 | ||
8125 | /* cpus with isolated domains */ | |
dcc30a35 | 8126 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
8127 | |
8128 | /* Setup the mask of cpus configured for isolated domains */ | |
8129 | static int __init isolated_cpu_setup(char *str) | |
8130 | { | |
bdddd296 | 8131 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 8132 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
8133 | return 1; |
8134 | } | |
8135 | ||
8927f494 | 8136 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
8137 | |
8138 | /* | |
6711cab4 SS |
8139 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
8140 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
8141 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
8142 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
8143 | * |
8144 | * init_sched_build_groups will build a circular linked list of the groups | |
8145 | * covered by the given span, and will set each group's ->cpumask correctly, | |
8146 | * and ->cpu_power to 0. | |
8147 | */ | |
a616058b | 8148 | static void |
96f874e2 RR |
8149 | init_sched_build_groups(const struct cpumask *span, |
8150 | const struct cpumask *cpu_map, | |
8151 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 8152 | struct sched_group **sg, |
96f874e2 RR |
8153 | struct cpumask *tmpmask), |
8154 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
8155 | { |
8156 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
8157 | int i; |
8158 | ||
96f874e2 | 8159 | cpumask_clear(covered); |
7c16ec58 | 8160 | |
abcd083a | 8161 | for_each_cpu(i, span) { |
6711cab4 | 8162 | struct sched_group *sg; |
7c16ec58 | 8163 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
8164 | int j; |
8165 | ||
758b2cdc | 8166 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
8167 | continue; |
8168 | ||
758b2cdc | 8169 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 8170 | sg->cpu_power = 0; |
1da177e4 | 8171 | |
abcd083a | 8172 | for_each_cpu(j, span) { |
7c16ec58 | 8173 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
8174 | continue; |
8175 | ||
96f874e2 | 8176 | cpumask_set_cpu(j, covered); |
758b2cdc | 8177 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
8178 | } |
8179 | if (!first) | |
8180 | first = sg; | |
8181 | if (last) | |
8182 | last->next = sg; | |
8183 | last = sg; | |
8184 | } | |
8185 | last->next = first; | |
8186 | } | |
8187 | ||
9c1cfda2 | 8188 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 8189 | |
9c1cfda2 | 8190 | #ifdef CONFIG_NUMA |
198e2f18 | 8191 | |
9c1cfda2 JH |
8192 | /** |
8193 | * find_next_best_node - find the next node to include in a sched_domain | |
8194 | * @node: node whose sched_domain we're building | |
8195 | * @used_nodes: nodes already in the sched_domain | |
8196 | * | |
41a2d6cf | 8197 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
8198 | * finds the closest node not already in the @used_nodes map. |
8199 | * | |
8200 | * Should use nodemask_t. | |
8201 | */ | |
c5f59f08 | 8202 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
8203 | { |
8204 | int i, n, val, min_val, best_node = 0; | |
8205 | ||
8206 | min_val = INT_MAX; | |
8207 | ||
076ac2af | 8208 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 8209 | /* Start at @node */ |
076ac2af | 8210 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
8211 | |
8212 | if (!nr_cpus_node(n)) | |
8213 | continue; | |
8214 | ||
8215 | /* Skip already used nodes */ | |
c5f59f08 | 8216 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
8217 | continue; |
8218 | ||
8219 | /* Simple min distance search */ | |
8220 | val = node_distance(node, n); | |
8221 | ||
8222 | if (val < min_val) { | |
8223 | min_val = val; | |
8224 | best_node = n; | |
8225 | } | |
8226 | } | |
8227 | ||
c5f59f08 | 8228 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
8229 | return best_node; |
8230 | } | |
8231 | ||
8232 | /** | |
8233 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
8234 | * @node: node whose cpumask we're constructing | |
73486722 | 8235 | * @span: resulting cpumask |
9c1cfda2 | 8236 | * |
41a2d6cf | 8237 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
8238 | * should be one that prevents unnecessary balancing, but also spreads tasks |
8239 | * out optimally. | |
8240 | */ | |
96f874e2 | 8241 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 8242 | { |
c5f59f08 | 8243 | nodemask_t used_nodes; |
48f24c4d | 8244 | int i; |
9c1cfda2 | 8245 | |
6ca09dfc | 8246 | cpumask_clear(span); |
c5f59f08 | 8247 | nodes_clear(used_nodes); |
9c1cfda2 | 8248 | |
6ca09dfc | 8249 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 8250 | node_set(node, used_nodes); |
9c1cfda2 JH |
8251 | |
8252 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 8253 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 8254 | |
6ca09dfc | 8255 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 8256 | } |
9c1cfda2 | 8257 | } |
6d6bc0ad | 8258 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 8259 | |
5c45bf27 | 8260 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 8261 | |
6c99e9ad RR |
8262 | /* |
8263 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
8264 | * |
8265 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
8266 | * and struct sched_domain. ) | |
6c99e9ad RR |
8267 | */ |
8268 | struct static_sched_group { | |
8269 | struct sched_group sg; | |
8270 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
8271 | }; | |
8272 | ||
8273 | struct static_sched_domain { | |
8274 | struct sched_domain sd; | |
8275 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
8276 | }; | |
8277 | ||
49a02c51 AH |
8278 | struct s_data { |
8279 | #ifdef CONFIG_NUMA | |
8280 | int sd_allnodes; | |
8281 | cpumask_var_t domainspan; | |
8282 | cpumask_var_t covered; | |
8283 | cpumask_var_t notcovered; | |
8284 | #endif | |
8285 | cpumask_var_t nodemask; | |
8286 | cpumask_var_t this_sibling_map; | |
8287 | cpumask_var_t this_core_map; | |
8288 | cpumask_var_t send_covered; | |
8289 | cpumask_var_t tmpmask; | |
8290 | struct sched_group **sched_group_nodes; | |
8291 | struct root_domain *rd; | |
8292 | }; | |
8293 | ||
2109b99e AH |
8294 | enum s_alloc { |
8295 | sa_sched_groups = 0, | |
8296 | sa_rootdomain, | |
8297 | sa_tmpmask, | |
8298 | sa_send_covered, | |
8299 | sa_this_core_map, | |
8300 | sa_this_sibling_map, | |
8301 | sa_nodemask, | |
8302 | sa_sched_group_nodes, | |
8303 | #ifdef CONFIG_NUMA | |
8304 | sa_notcovered, | |
8305 | sa_covered, | |
8306 | sa_domainspan, | |
8307 | #endif | |
8308 | sa_none, | |
8309 | }; | |
8310 | ||
9c1cfda2 | 8311 | /* |
48f24c4d | 8312 | * SMT sched-domains: |
9c1cfda2 | 8313 | */ |
1da177e4 | 8314 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 8315 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 8316 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 8317 | |
41a2d6cf | 8318 | static int |
96f874e2 RR |
8319 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
8320 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 8321 | { |
6711cab4 | 8322 | if (sg) |
1871e52c | 8323 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
8324 | return cpu; |
8325 | } | |
6d6bc0ad | 8326 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 8327 | |
48f24c4d IM |
8328 | /* |
8329 | * multi-core sched-domains: | |
8330 | */ | |
1e9f28fa | 8331 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
8332 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
8333 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 8334 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
8335 | |
8336 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 8337 | static int |
96f874e2 RR |
8338 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8339 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 8340 | { |
6711cab4 | 8341 | int group; |
7c16ec58 | 8342 | |
c69fc56d | 8343 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8344 | group = cpumask_first(mask); |
6711cab4 | 8345 | if (sg) |
6c99e9ad | 8346 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 8347 | return group; |
1e9f28fa SS |
8348 | } |
8349 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 8350 | static int |
96f874e2 RR |
8351 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8352 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 8353 | { |
6711cab4 | 8354 | if (sg) |
6c99e9ad | 8355 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
8356 | return cpu; |
8357 | } | |
8358 | #endif | |
8359 | ||
6c99e9ad RR |
8360 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
8361 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 8362 | |
41a2d6cf | 8363 | static int |
96f874e2 RR |
8364 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
8365 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 8366 | { |
6711cab4 | 8367 | int group; |
48f24c4d | 8368 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 8369 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 8370 | group = cpumask_first(mask); |
1e9f28fa | 8371 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 8372 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8373 | group = cpumask_first(mask); |
1da177e4 | 8374 | #else |
6711cab4 | 8375 | group = cpu; |
1da177e4 | 8376 | #endif |
6711cab4 | 8377 | if (sg) |
6c99e9ad | 8378 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 8379 | return group; |
1da177e4 LT |
8380 | } |
8381 | ||
8382 | #ifdef CONFIG_NUMA | |
1da177e4 | 8383 | /* |
9c1cfda2 JH |
8384 | * The init_sched_build_groups can't handle what we want to do with node |
8385 | * groups, so roll our own. Now each node has its own list of groups which | |
8386 | * gets dynamically allocated. | |
1da177e4 | 8387 | */ |
62ea9ceb | 8388 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 8389 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 8390 | |
62ea9ceb | 8391 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 8392 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 8393 | |
96f874e2 RR |
8394 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
8395 | struct sched_group **sg, | |
8396 | struct cpumask *nodemask) | |
9c1cfda2 | 8397 | { |
6711cab4 SS |
8398 | int group; |
8399 | ||
6ca09dfc | 8400 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 8401 | group = cpumask_first(nodemask); |
6711cab4 SS |
8402 | |
8403 | if (sg) | |
6c99e9ad | 8404 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 8405 | return group; |
1da177e4 | 8406 | } |
6711cab4 | 8407 | |
08069033 SS |
8408 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
8409 | { | |
8410 | struct sched_group *sg = group_head; | |
8411 | int j; | |
8412 | ||
8413 | if (!sg) | |
8414 | return; | |
3a5c359a | 8415 | do { |
758b2cdc | 8416 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 8417 | struct sched_domain *sd; |
08069033 | 8418 | |
6c99e9ad | 8419 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 8420 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
8421 | /* |
8422 | * Only add "power" once for each | |
8423 | * physical package. | |
8424 | */ | |
8425 | continue; | |
8426 | } | |
08069033 | 8427 | |
18a3885f | 8428 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
8429 | } |
8430 | sg = sg->next; | |
8431 | } while (sg != group_head); | |
08069033 | 8432 | } |
0601a88d AH |
8433 | |
8434 | static int build_numa_sched_groups(struct s_data *d, | |
8435 | const struct cpumask *cpu_map, int num) | |
8436 | { | |
8437 | struct sched_domain *sd; | |
8438 | struct sched_group *sg, *prev; | |
8439 | int n, j; | |
8440 | ||
8441 | cpumask_clear(d->covered); | |
8442 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
8443 | if (cpumask_empty(d->nodemask)) { | |
8444 | d->sched_group_nodes[num] = NULL; | |
8445 | goto out; | |
8446 | } | |
8447 | ||
8448 | sched_domain_node_span(num, d->domainspan); | |
8449 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
8450 | ||
8451 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8452 | GFP_KERNEL, num); | |
8453 | if (!sg) { | |
3df0fc5b PZ |
8454 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
8455 | num); | |
0601a88d AH |
8456 | return -ENOMEM; |
8457 | } | |
8458 | d->sched_group_nodes[num] = sg; | |
8459 | ||
8460 | for_each_cpu(j, d->nodemask) { | |
8461 | sd = &per_cpu(node_domains, j).sd; | |
8462 | sd->groups = sg; | |
8463 | } | |
8464 | ||
18a3885f | 8465 | sg->cpu_power = 0; |
0601a88d AH |
8466 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
8467 | sg->next = sg; | |
8468 | cpumask_or(d->covered, d->covered, d->nodemask); | |
8469 | ||
8470 | prev = sg; | |
8471 | for (j = 0; j < nr_node_ids; j++) { | |
8472 | n = (num + j) % nr_node_ids; | |
8473 | cpumask_complement(d->notcovered, d->covered); | |
8474 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
8475 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
8476 | if (cpumask_empty(d->tmpmask)) | |
8477 | break; | |
8478 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
8479 | if (cpumask_empty(d->tmpmask)) | |
8480 | continue; | |
8481 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8482 | GFP_KERNEL, num); | |
8483 | if (!sg) { | |
3df0fc5b PZ |
8484 | printk(KERN_WARNING |
8485 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
8486 | return -ENOMEM; |
8487 | } | |
18a3885f | 8488 | sg->cpu_power = 0; |
0601a88d AH |
8489 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
8490 | sg->next = prev->next; | |
8491 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
8492 | prev->next = sg; | |
8493 | prev = sg; | |
8494 | } | |
8495 | out: | |
8496 | return 0; | |
8497 | } | |
6d6bc0ad | 8498 | #endif /* CONFIG_NUMA */ |
1da177e4 | 8499 | |
a616058b | 8500 | #ifdef CONFIG_NUMA |
51888ca2 | 8501 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
8502 | static void free_sched_groups(const struct cpumask *cpu_map, |
8503 | struct cpumask *nodemask) | |
51888ca2 | 8504 | { |
a616058b | 8505 | int cpu, i; |
51888ca2 | 8506 | |
abcd083a | 8507 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
8508 | struct sched_group **sched_group_nodes |
8509 | = sched_group_nodes_bycpu[cpu]; | |
8510 | ||
51888ca2 SV |
8511 | if (!sched_group_nodes) |
8512 | continue; | |
8513 | ||
076ac2af | 8514 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
8515 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
8516 | ||
6ca09dfc | 8517 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 8518 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
8519 | continue; |
8520 | ||
8521 | if (sg == NULL) | |
8522 | continue; | |
8523 | sg = sg->next; | |
8524 | next_sg: | |
8525 | oldsg = sg; | |
8526 | sg = sg->next; | |
8527 | kfree(oldsg); | |
8528 | if (oldsg != sched_group_nodes[i]) | |
8529 | goto next_sg; | |
8530 | } | |
8531 | kfree(sched_group_nodes); | |
8532 | sched_group_nodes_bycpu[cpu] = NULL; | |
8533 | } | |
51888ca2 | 8534 | } |
6d6bc0ad | 8535 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
8536 | static void free_sched_groups(const struct cpumask *cpu_map, |
8537 | struct cpumask *nodemask) | |
a616058b SS |
8538 | { |
8539 | } | |
6d6bc0ad | 8540 | #endif /* CONFIG_NUMA */ |
51888ca2 | 8541 | |
89c4710e SS |
8542 | /* |
8543 | * Initialize sched groups cpu_power. | |
8544 | * | |
8545 | * cpu_power indicates the capacity of sched group, which is used while | |
8546 | * distributing the load between different sched groups in a sched domain. | |
8547 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
8548 | * there are asymmetries in the topology. If there are asymmetries, group | |
8549 | * having more cpu_power will pickup more load compared to the group having | |
8550 | * less cpu_power. | |
89c4710e SS |
8551 | */ |
8552 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
8553 | { | |
8554 | struct sched_domain *child; | |
8555 | struct sched_group *group; | |
f93e65c1 PZ |
8556 | long power; |
8557 | int weight; | |
89c4710e SS |
8558 | |
8559 | WARN_ON(!sd || !sd->groups); | |
8560 | ||
13318a71 | 8561 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
8562 | return; |
8563 | ||
8564 | child = sd->child; | |
8565 | ||
18a3885f | 8566 | sd->groups->cpu_power = 0; |
5517d86b | 8567 | |
f93e65c1 PZ |
8568 | if (!child) { |
8569 | power = SCHED_LOAD_SCALE; | |
8570 | weight = cpumask_weight(sched_domain_span(sd)); | |
8571 | /* | |
8572 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
8573 | * Usually multiple threads get a better yield out of |
8574 | * that one core than a single thread would have, | |
8575 | * reflect that in sd->smt_gain. | |
f93e65c1 | 8576 | */ |
a52bfd73 PZ |
8577 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
8578 | power *= sd->smt_gain; | |
f93e65c1 | 8579 | power /= weight; |
a52bfd73 PZ |
8580 | power >>= SCHED_LOAD_SHIFT; |
8581 | } | |
18a3885f | 8582 | sd->groups->cpu_power += power; |
89c4710e SS |
8583 | return; |
8584 | } | |
8585 | ||
89c4710e | 8586 | /* |
f93e65c1 | 8587 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
8588 | */ |
8589 | group = child->groups; | |
8590 | do { | |
18a3885f | 8591 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
8592 | group = group->next; |
8593 | } while (group != child->groups); | |
8594 | } | |
8595 | ||
7c16ec58 MT |
8596 | /* |
8597 | * Initializers for schedule domains | |
8598 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
8599 | */ | |
8600 | ||
a5d8c348 IM |
8601 | #ifdef CONFIG_SCHED_DEBUG |
8602 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
8603 | #else | |
8604 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
8605 | #endif | |
8606 | ||
7c16ec58 | 8607 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 8608 | |
7c16ec58 MT |
8609 | #define SD_INIT_FUNC(type) \ |
8610 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
8611 | { \ | |
8612 | memset(sd, 0, sizeof(*sd)); \ | |
8613 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 8614 | sd->level = SD_LV_##type; \ |
a5d8c348 | 8615 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
8616 | } |
8617 | ||
8618 | SD_INIT_FUNC(CPU) | |
8619 | #ifdef CONFIG_NUMA | |
8620 | SD_INIT_FUNC(ALLNODES) | |
8621 | SD_INIT_FUNC(NODE) | |
8622 | #endif | |
8623 | #ifdef CONFIG_SCHED_SMT | |
8624 | SD_INIT_FUNC(SIBLING) | |
8625 | #endif | |
8626 | #ifdef CONFIG_SCHED_MC | |
8627 | SD_INIT_FUNC(MC) | |
8628 | #endif | |
8629 | ||
1d3504fc HS |
8630 | static int default_relax_domain_level = -1; |
8631 | ||
8632 | static int __init setup_relax_domain_level(char *str) | |
8633 | { | |
30e0e178 LZ |
8634 | unsigned long val; |
8635 | ||
8636 | val = simple_strtoul(str, NULL, 0); | |
8637 | if (val < SD_LV_MAX) | |
8638 | default_relax_domain_level = val; | |
8639 | ||
1d3504fc HS |
8640 | return 1; |
8641 | } | |
8642 | __setup("relax_domain_level=", setup_relax_domain_level); | |
8643 | ||
8644 | static void set_domain_attribute(struct sched_domain *sd, | |
8645 | struct sched_domain_attr *attr) | |
8646 | { | |
8647 | int request; | |
8648 | ||
8649 | if (!attr || attr->relax_domain_level < 0) { | |
8650 | if (default_relax_domain_level < 0) | |
8651 | return; | |
8652 | else | |
8653 | request = default_relax_domain_level; | |
8654 | } else | |
8655 | request = attr->relax_domain_level; | |
8656 | if (request < sd->level) { | |
8657 | /* turn off idle balance on this domain */ | |
c88d5910 | 8658 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
8659 | } else { |
8660 | /* turn on idle balance on this domain */ | |
c88d5910 | 8661 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
8662 | } |
8663 | } | |
8664 | ||
2109b99e AH |
8665 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
8666 | const struct cpumask *cpu_map) | |
8667 | { | |
8668 | switch (what) { | |
8669 | case sa_sched_groups: | |
8670 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
8671 | d->sched_group_nodes = NULL; | |
8672 | case sa_rootdomain: | |
8673 | free_rootdomain(d->rd); /* fall through */ | |
8674 | case sa_tmpmask: | |
8675 | free_cpumask_var(d->tmpmask); /* fall through */ | |
8676 | case sa_send_covered: | |
8677 | free_cpumask_var(d->send_covered); /* fall through */ | |
8678 | case sa_this_core_map: | |
8679 | free_cpumask_var(d->this_core_map); /* fall through */ | |
8680 | case sa_this_sibling_map: | |
8681 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
8682 | case sa_nodemask: | |
8683 | free_cpumask_var(d->nodemask); /* fall through */ | |
8684 | case sa_sched_group_nodes: | |
d1b55138 | 8685 | #ifdef CONFIG_NUMA |
2109b99e AH |
8686 | kfree(d->sched_group_nodes); /* fall through */ |
8687 | case sa_notcovered: | |
8688 | free_cpumask_var(d->notcovered); /* fall through */ | |
8689 | case sa_covered: | |
8690 | free_cpumask_var(d->covered); /* fall through */ | |
8691 | case sa_domainspan: | |
8692 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 8693 | #endif |
2109b99e AH |
8694 | case sa_none: |
8695 | break; | |
8696 | } | |
8697 | } | |
3404c8d9 | 8698 | |
2109b99e AH |
8699 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
8700 | const struct cpumask *cpu_map) | |
8701 | { | |
3404c8d9 | 8702 | #ifdef CONFIG_NUMA |
2109b99e AH |
8703 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
8704 | return sa_none; | |
8705 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
8706 | return sa_domainspan; | |
8707 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
8708 | return sa_covered; | |
8709 | /* Allocate the per-node list of sched groups */ | |
8710 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
8711 | sizeof(struct sched_group *), GFP_KERNEL); | |
8712 | if (!d->sched_group_nodes) { | |
3df0fc5b | 8713 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 8714 | return sa_notcovered; |
d1b55138 | 8715 | } |
2109b99e | 8716 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 8717 | #endif |
2109b99e AH |
8718 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
8719 | return sa_sched_group_nodes; | |
8720 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
8721 | return sa_nodemask; | |
8722 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
8723 | return sa_this_sibling_map; | |
8724 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
8725 | return sa_this_core_map; | |
8726 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
8727 | return sa_send_covered; | |
8728 | d->rd = alloc_rootdomain(); | |
8729 | if (!d->rd) { | |
3df0fc5b | 8730 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 8731 | return sa_tmpmask; |
57d885fe | 8732 | } |
2109b99e AH |
8733 | return sa_rootdomain; |
8734 | } | |
57d885fe | 8735 | |
7f4588f3 AH |
8736 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
8737 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
8738 | { | |
8739 | struct sched_domain *sd = NULL; | |
7c16ec58 | 8740 | #ifdef CONFIG_NUMA |
7f4588f3 | 8741 | struct sched_domain *parent; |
1da177e4 | 8742 | |
7f4588f3 AH |
8743 | d->sd_allnodes = 0; |
8744 | if (cpumask_weight(cpu_map) > | |
8745 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
8746 | sd = &per_cpu(allnodes_domains, i).sd; | |
8747 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 8748 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
8749 | cpumask_copy(sched_domain_span(sd), cpu_map); |
8750 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8751 | d->sd_allnodes = 1; | |
8752 | } | |
8753 | parent = sd; | |
8754 | ||
8755 | sd = &per_cpu(node_domains, i).sd; | |
8756 | SD_INIT(sd, NODE); | |
8757 | set_domain_attribute(sd, attr); | |
8758 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
8759 | sd->parent = parent; | |
8760 | if (parent) | |
8761 | parent->child = sd; | |
8762 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 8763 | #endif |
7f4588f3 AH |
8764 | return sd; |
8765 | } | |
1da177e4 | 8766 | |
87cce662 AH |
8767 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
8768 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8769 | struct sched_domain *parent, int i) | |
8770 | { | |
8771 | struct sched_domain *sd; | |
8772 | sd = &per_cpu(phys_domains, i).sd; | |
8773 | SD_INIT(sd, CPU); | |
8774 | set_domain_attribute(sd, attr); | |
8775 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
8776 | sd->parent = parent; | |
8777 | if (parent) | |
8778 | parent->child = sd; | |
8779 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8780 | return sd; | |
8781 | } | |
1da177e4 | 8782 | |
410c4081 AH |
8783 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
8784 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8785 | struct sched_domain *parent, int i) | |
8786 | { | |
8787 | struct sched_domain *sd = parent; | |
1e9f28fa | 8788 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
8789 | sd = &per_cpu(core_domains, i).sd; |
8790 | SD_INIT(sd, MC); | |
8791 | set_domain_attribute(sd, attr); | |
8792 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
8793 | sd->parent = parent; | |
8794 | parent->child = sd; | |
8795 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 8796 | #endif |
410c4081 AH |
8797 | return sd; |
8798 | } | |
1e9f28fa | 8799 | |
d8173535 AH |
8800 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
8801 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8802 | struct sched_domain *parent, int i) | |
8803 | { | |
8804 | struct sched_domain *sd = parent; | |
1da177e4 | 8805 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
8806 | sd = &per_cpu(cpu_domains, i).sd; |
8807 | SD_INIT(sd, SIBLING); | |
8808 | set_domain_attribute(sd, attr); | |
8809 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
8810 | sd->parent = parent; | |
8811 | parent->child = sd; | |
8812 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 8813 | #endif |
d8173535 AH |
8814 | return sd; |
8815 | } | |
1da177e4 | 8816 | |
0e8e85c9 AH |
8817 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
8818 | const struct cpumask *cpu_map, int cpu) | |
8819 | { | |
8820 | switch (l) { | |
1da177e4 | 8821 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
8822 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
8823 | cpumask_and(d->this_sibling_map, cpu_map, | |
8824 | topology_thread_cpumask(cpu)); | |
8825 | if (cpu == cpumask_first(d->this_sibling_map)) | |
8826 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
8827 | &cpu_to_cpu_group, | |
8828 | d->send_covered, d->tmpmask); | |
8829 | break; | |
1da177e4 | 8830 | #endif |
1e9f28fa | 8831 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
8832 | case SD_LV_MC: /* set up multi-core groups */ |
8833 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
8834 | if (cpu == cpumask_first(d->this_core_map)) | |
8835 | init_sched_build_groups(d->this_core_map, cpu_map, | |
8836 | &cpu_to_core_group, | |
8837 | d->send_covered, d->tmpmask); | |
8838 | break; | |
1e9f28fa | 8839 | #endif |
86548096 AH |
8840 | case SD_LV_CPU: /* set up physical groups */ |
8841 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
8842 | if (!cpumask_empty(d->nodemask)) | |
8843 | init_sched_build_groups(d->nodemask, cpu_map, | |
8844 | &cpu_to_phys_group, | |
8845 | d->send_covered, d->tmpmask); | |
8846 | break; | |
1da177e4 | 8847 | #ifdef CONFIG_NUMA |
de616e36 AH |
8848 | case SD_LV_ALLNODES: |
8849 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
8850 | d->send_covered, d->tmpmask); | |
8851 | break; | |
8852 | #endif | |
0e8e85c9 AH |
8853 | default: |
8854 | break; | |
7c16ec58 | 8855 | } |
0e8e85c9 | 8856 | } |
9c1cfda2 | 8857 | |
2109b99e AH |
8858 | /* |
8859 | * Build sched domains for a given set of cpus and attach the sched domains | |
8860 | * to the individual cpus | |
8861 | */ | |
8862 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
8863 | struct sched_domain_attr *attr) | |
8864 | { | |
8865 | enum s_alloc alloc_state = sa_none; | |
8866 | struct s_data d; | |
294b0c96 | 8867 | struct sched_domain *sd; |
2109b99e | 8868 | int i; |
7c16ec58 | 8869 | #ifdef CONFIG_NUMA |
2109b99e | 8870 | d.sd_allnodes = 0; |
7c16ec58 | 8871 | #endif |
9c1cfda2 | 8872 | |
2109b99e AH |
8873 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
8874 | if (alloc_state != sa_rootdomain) | |
8875 | goto error; | |
8876 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 8877 | |
1da177e4 | 8878 | /* |
1a20ff27 | 8879 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 8880 | */ |
abcd083a | 8881 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
8882 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
8883 | cpu_map); | |
9761eea8 | 8884 | |
7f4588f3 | 8885 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 8886 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 8887 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 8888 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 8889 | } |
9c1cfda2 | 8890 | |
abcd083a | 8891 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 8892 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 8893 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 8894 | } |
9c1cfda2 | 8895 | |
1da177e4 | 8896 | /* Set up physical groups */ |
86548096 AH |
8897 | for (i = 0; i < nr_node_ids; i++) |
8898 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 8899 | |
1da177e4 LT |
8900 | #ifdef CONFIG_NUMA |
8901 | /* Set up node groups */ | |
de616e36 AH |
8902 | if (d.sd_allnodes) |
8903 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 8904 | |
0601a88d AH |
8905 | for (i = 0; i < nr_node_ids; i++) |
8906 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 8907 | goto error; |
1da177e4 LT |
8908 | #endif |
8909 | ||
8910 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 8911 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 8912 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8913 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 8914 | init_sched_groups_power(i, sd); |
5c45bf27 | 8915 | } |
1da177e4 | 8916 | #endif |
1e9f28fa | 8917 | #ifdef CONFIG_SCHED_MC |
abcd083a | 8918 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8919 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 8920 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
8921 | } |
8922 | #endif | |
1e9f28fa | 8923 | |
abcd083a | 8924 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8925 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 8926 | init_sched_groups_power(i, sd); |
1da177e4 LT |
8927 | } |
8928 | ||
9c1cfda2 | 8929 | #ifdef CONFIG_NUMA |
076ac2af | 8930 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 8931 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 8932 | |
49a02c51 | 8933 | if (d.sd_allnodes) { |
6711cab4 | 8934 | struct sched_group *sg; |
f712c0c7 | 8935 | |
96f874e2 | 8936 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 8937 | d.tmpmask); |
f712c0c7 SS |
8938 | init_numa_sched_groups_power(sg); |
8939 | } | |
9c1cfda2 JH |
8940 | #endif |
8941 | ||
1da177e4 | 8942 | /* Attach the domains */ |
abcd083a | 8943 | for_each_cpu(i, cpu_map) { |
1da177e4 | 8944 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 8945 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 8946 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 8947 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 8948 | #else |
6c99e9ad | 8949 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 8950 | #endif |
49a02c51 | 8951 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 8952 | } |
51888ca2 | 8953 | |
2109b99e AH |
8954 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
8955 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
8956 | return 0; | |
51888ca2 | 8957 | |
51888ca2 | 8958 | error: |
2109b99e AH |
8959 | __free_domain_allocs(&d, alloc_state, cpu_map); |
8960 | return -ENOMEM; | |
1da177e4 | 8961 | } |
029190c5 | 8962 | |
96f874e2 | 8963 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
8964 | { |
8965 | return __build_sched_domains(cpu_map, NULL); | |
8966 | } | |
8967 | ||
acc3f5d7 | 8968 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 8969 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
8970 | static struct sched_domain_attr *dattr_cur; |
8971 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
8972 | |
8973 | /* | |
8974 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
8975 | * cpumask) fails, then fallback to a single sched domain, |
8976 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 8977 | */ |
4212823f | 8978 | static cpumask_var_t fallback_doms; |
029190c5 | 8979 | |
ee79d1bd HC |
8980 | /* |
8981 | * arch_update_cpu_topology lets virtualized architectures update the | |
8982 | * cpu core maps. It is supposed to return 1 if the topology changed | |
8983 | * or 0 if it stayed the same. | |
8984 | */ | |
8985 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 8986 | { |
ee79d1bd | 8987 | return 0; |
22e52b07 HC |
8988 | } |
8989 | ||
acc3f5d7 RR |
8990 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
8991 | { | |
8992 | int i; | |
8993 | cpumask_var_t *doms; | |
8994 | ||
8995 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
8996 | if (!doms) | |
8997 | return NULL; | |
8998 | for (i = 0; i < ndoms; i++) { | |
8999 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
9000 | free_sched_domains(doms, i); | |
9001 | return NULL; | |
9002 | } | |
9003 | } | |
9004 | return doms; | |
9005 | } | |
9006 | ||
9007 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
9008 | { | |
9009 | unsigned int i; | |
9010 | for (i = 0; i < ndoms; i++) | |
9011 | free_cpumask_var(doms[i]); | |
9012 | kfree(doms); | |
9013 | } | |
9014 | ||
1a20ff27 | 9015 | /* |
41a2d6cf | 9016 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
9017 | * For now this just excludes isolated cpus, but could be used to |
9018 | * exclude other special cases in the future. | |
1a20ff27 | 9019 | */ |
96f874e2 | 9020 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 9021 | { |
7378547f MM |
9022 | int err; |
9023 | ||
22e52b07 | 9024 | arch_update_cpu_topology(); |
029190c5 | 9025 | ndoms_cur = 1; |
acc3f5d7 | 9026 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 9027 | if (!doms_cur) |
acc3f5d7 RR |
9028 | doms_cur = &fallback_doms; |
9029 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 9030 | dattr_cur = NULL; |
acc3f5d7 | 9031 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 9032 | register_sched_domain_sysctl(); |
7378547f MM |
9033 | |
9034 | return err; | |
1a20ff27 DG |
9035 | } |
9036 | ||
96f874e2 RR |
9037 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
9038 | struct cpumask *tmpmask) | |
1da177e4 | 9039 | { |
7c16ec58 | 9040 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 9041 | } |
1da177e4 | 9042 | |
1a20ff27 DG |
9043 | /* |
9044 | * Detach sched domains from a group of cpus specified in cpu_map | |
9045 | * These cpus will now be attached to the NULL domain | |
9046 | */ | |
96f874e2 | 9047 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 9048 | { |
96f874e2 RR |
9049 | /* Save because hotplug lock held. */ |
9050 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
9051 | int i; |
9052 | ||
abcd083a | 9053 | for_each_cpu(i, cpu_map) |
57d885fe | 9054 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 9055 | synchronize_sched(); |
96f874e2 | 9056 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
9057 | } |
9058 | ||
1d3504fc HS |
9059 | /* handle null as "default" */ |
9060 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
9061 | struct sched_domain_attr *new, int idx_new) | |
9062 | { | |
9063 | struct sched_domain_attr tmp; | |
9064 | ||
9065 | /* fast path */ | |
9066 | if (!new && !cur) | |
9067 | return 1; | |
9068 | ||
9069 | tmp = SD_ATTR_INIT; | |
9070 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
9071 | new ? (new + idx_new) : &tmp, | |
9072 | sizeof(struct sched_domain_attr)); | |
9073 | } | |
9074 | ||
029190c5 PJ |
9075 | /* |
9076 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 9077 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
9078 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
9079 | * It destroys each deleted domain and builds each new domain. | |
9080 | * | |
acc3f5d7 | 9081 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
9082 | * The masks don't intersect (don't overlap.) We should setup one |
9083 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
9084 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
9085 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
9086 | * it as it is. | |
9087 | * | |
acc3f5d7 RR |
9088 | * The passed in 'doms_new' should be allocated using |
9089 | * alloc_sched_domains. This routine takes ownership of it and will | |
9090 | * free_sched_domains it when done with it. If the caller failed the | |
9091 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
9092 | * and partition_sched_domains() will fallback to the single partition | |
9093 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 9094 | * |
96f874e2 | 9095 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
9096 | * ndoms_new == 0 is a special case for destroying existing domains, |
9097 | * and it will not create the default domain. | |
dfb512ec | 9098 | * |
029190c5 PJ |
9099 | * Call with hotplug lock held |
9100 | */ | |
acc3f5d7 | 9101 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 9102 | struct sched_domain_attr *dattr_new) |
029190c5 | 9103 | { |
dfb512ec | 9104 | int i, j, n; |
d65bd5ec | 9105 | int new_topology; |
029190c5 | 9106 | |
712555ee | 9107 | mutex_lock(&sched_domains_mutex); |
a1835615 | 9108 | |
7378547f MM |
9109 | /* always unregister in case we don't destroy any domains */ |
9110 | unregister_sched_domain_sysctl(); | |
9111 | ||
d65bd5ec HC |
9112 | /* Let architecture update cpu core mappings. */ |
9113 | new_topology = arch_update_cpu_topology(); | |
9114 | ||
dfb512ec | 9115 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
9116 | |
9117 | /* Destroy deleted domains */ | |
9118 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 9119 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 9120 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 9121 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
9122 | goto match1; |
9123 | } | |
9124 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 9125 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
9126 | match1: |
9127 | ; | |
9128 | } | |
9129 | ||
e761b772 MK |
9130 | if (doms_new == NULL) { |
9131 | ndoms_cur = 0; | |
acc3f5d7 | 9132 | doms_new = &fallback_doms; |
6ad4c188 | 9133 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 9134 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
9135 | } |
9136 | ||
029190c5 PJ |
9137 | /* Build new domains */ |
9138 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 9139 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 9140 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 9141 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
9142 | goto match2; |
9143 | } | |
9144 | /* no match - add a new doms_new */ | |
acc3f5d7 | 9145 | __build_sched_domains(doms_new[i], |
1d3504fc | 9146 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
9147 | match2: |
9148 | ; | |
9149 | } | |
9150 | ||
9151 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
9152 | if (doms_cur != &fallback_doms) |
9153 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 9154 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 9155 | doms_cur = doms_new; |
1d3504fc | 9156 | dattr_cur = dattr_new; |
029190c5 | 9157 | ndoms_cur = ndoms_new; |
7378547f MM |
9158 | |
9159 | register_sched_domain_sysctl(); | |
a1835615 | 9160 | |
712555ee | 9161 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
9162 | } |
9163 | ||
5c45bf27 | 9164 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 9165 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 9166 | { |
95402b38 | 9167 | get_online_cpus(); |
dfb512ec MK |
9168 | |
9169 | /* Destroy domains first to force the rebuild */ | |
9170 | partition_sched_domains(0, NULL, NULL); | |
9171 | ||
e761b772 | 9172 | rebuild_sched_domains(); |
95402b38 | 9173 | put_online_cpus(); |
5c45bf27 SS |
9174 | } |
9175 | ||
9176 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
9177 | { | |
afb8a9b7 | 9178 | unsigned int level = 0; |
5c45bf27 | 9179 | |
afb8a9b7 GS |
9180 | if (sscanf(buf, "%u", &level) != 1) |
9181 | return -EINVAL; | |
9182 | ||
9183 | /* | |
9184 | * level is always be positive so don't check for | |
9185 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
9186 | * What happens on 0 or 1 byte write, | |
9187 | * need to check for count as well? | |
9188 | */ | |
9189 | ||
9190 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
9191 | return -EINVAL; |
9192 | ||
9193 | if (smt) | |
afb8a9b7 | 9194 | sched_smt_power_savings = level; |
5c45bf27 | 9195 | else |
afb8a9b7 | 9196 | sched_mc_power_savings = level; |
5c45bf27 | 9197 | |
c70f22d2 | 9198 | arch_reinit_sched_domains(); |
5c45bf27 | 9199 | |
c70f22d2 | 9200 | return count; |
5c45bf27 SS |
9201 | } |
9202 | ||
5c45bf27 | 9203 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
9204 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
9205 | char *page) | |
5c45bf27 SS |
9206 | { |
9207 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
9208 | } | |
f718cd4a | 9209 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 9210 | const char *buf, size_t count) |
5c45bf27 SS |
9211 | { |
9212 | return sched_power_savings_store(buf, count, 0); | |
9213 | } | |
f718cd4a AK |
9214 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
9215 | sched_mc_power_savings_show, | |
9216 | sched_mc_power_savings_store); | |
5c45bf27 SS |
9217 | #endif |
9218 | ||
9219 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
9220 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
9221 | char *page) | |
5c45bf27 SS |
9222 | { |
9223 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
9224 | } | |
f718cd4a | 9225 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 9226 | const char *buf, size_t count) |
5c45bf27 SS |
9227 | { |
9228 | return sched_power_savings_store(buf, count, 1); | |
9229 | } | |
f718cd4a AK |
9230 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
9231 | sched_smt_power_savings_show, | |
6707de00 AB |
9232 | sched_smt_power_savings_store); |
9233 | #endif | |
9234 | ||
39aac648 | 9235 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
9236 | { |
9237 | int err = 0; | |
9238 | ||
9239 | #ifdef CONFIG_SCHED_SMT | |
9240 | if (smt_capable()) | |
9241 | err = sysfs_create_file(&cls->kset.kobj, | |
9242 | &attr_sched_smt_power_savings.attr); | |
9243 | #endif | |
9244 | #ifdef CONFIG_SCHED_MC | |
9245 | if (!err && mc_capable()) | |
9246 | err = sysfs_create_file(&cls->kset.kobj, | |
9247 | &attr_sched_mc_power_savings.attr); | |
9248 | #endif | |
9249 | return err; | |
9250 | } | |
6d6bc0ad | 9251 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 9252 | |
e761b772 | 9253 | #ifndef CONFIG_CPUSETS |
1da177e4 | 9254 | /* |
e761b772 MK |
9255 | * Add online and remove offline CPUs from the scheduler domains. |
9256 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
9257 | */ |
9258 | static int update_sched_domains(struct notifier_block *nfb, | |
9259 | unsigned long action, void *hcpu) | |
e761b772 MK |
9260 | { |
9261 | switch (action) { | |
9262 | case CPU_ONLINE: | |
9263 | case CPU_ONLINE_FROZEN: | |
6ad4c188 PZ |
9264 | case CPU_DOWN_PREPARE: |
9265 | case CPU_DOWN_PREPARE_FROZEN: | |
9266 | case CPU_DOWN_FAILED: | |
9267 | case CPU_DOWN_FAILED_FROZEN: | |
dfb512ec | 9268 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
9269 | return NOTIFY_OK; |
9270 | ||
9271 | default: | |
9272 | return NOTIFY_DONE; | |
9273 | } | |
9274 | } | |
9275 | #endif | |
9276 | ||
9277 | static int update_runtime(struct notifier_block *nfb, | |
9278 | unsigned long action, void *hcpu) | |
1da177e4 | 9279 | { |
7def2be1 PZ |
9280 | int cpu = (int)(long)hcpu; |
9281 | ||
1da177e4 | 9282 | switch (action) { |
1da177e4 | 9283 | case CPU_DOWN_PREPARE: |
8bb78442 | 9284 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 9285 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
9286 | return NOTIFY_OK; |
9287 | ||
1da177e4 | 9288 | case CPU_DOWN_FAILED: |
8bb78442 | 9289 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 9290 | case CPU_ONLINE: |
8bb78442 | 9291 | case CPU_ONLINE_FROZEN: |
7def2be1 | 9292 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
9293 | return NOTIFY_OK; |
9294 | ||
1da177e4 LT |
9295 | default: |
9296 | return NOTIFY_DONE; | |
9297 | } | |
1da177e4 | 9298 | } |
1da177e4 LT |
9299 | |
9300 | void __init sched_init_smp(void) | |
9301 | { | |
dcc30a35 RR |
9302 | cpumask_var_t non_isolated_cpus; |
9303 | ||
9304 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 9305 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 9306 | |
434d53b0 MT |
9307 | #if defined(CONFIG_NUMA) |
9308 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
9309 | GFP_KERNEL); | |
9310 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
9311 | #endif | |
95402b38 | 9312 | get_online_cpus(); |
712555ee | 9313 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 9314 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
9315 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
9316 | if (cpumask_empty(non_isolated_cpus)) | |
9317 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 9318 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 9319 | put_online_cpus(); |
e761b772 MK |
9320 | |
9321 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
9322 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
9323 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
9324 | #endif |
9325 | ||
9326 | /* RT runtime code needs to handle some hotplug events */ | |
9327 | hotcpu_notifier(update_runtime, 0); | |
9328 | ||
b328ca18 | 9329 | init_hrtick(); |
5c1e1767 NP |
9330 | |
9331 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 9332 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 9333 | BUG(); |
19978ca6 | 9334 | sched_init_granularity(); |
dcc30a35 | 9335 | free_cpumask_var(non_isolated_cpus); |
4212823f | 9336 | |
0e3900e6 | 9337 | init_sched_rt_class(); |
1da177e4 LT |
9338 | } |
9339 | #else | |
9340 | void __init sched_init_smp(void) | |
9341 | { | |
19978ca6 | 9342 | sched_init_granularity(); |
1da177e4 LT |
9343 | } |
9344 | #endif /* CONFIG_SMP */ | |
9345 | ||
cd1bb94b AB |
9346 | const_debug unsigned int sysctl_timer_migration = 1; |
9347 | ||
1da177e4 LT |
9348 | int in_sched_functions(unsigned long addr) |
9349 | { | |
1da177e4 LT |
9350 | return in_lock_functions(addr) || |
9351 | (addr >= (unsigned long)__sched_text_start | |
9352 | && addr < (unsigned long)__sched_text_end); | |
9353 | } | |
9354 | ||
a9957449 | 9355 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
9356 | { |
9357 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 9358 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
9359 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9360 | cfs_rq->rq = rq; | |
9361 | #endif | |
67e9fb2a | 9362 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
9363 | } |
9364 | ||
fa85ae24 PZ |
9365 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
9366 | { | |
9367 | struct rt_prio_array *array; | |
9368 | int i; | |
9369 | ||
9370 | array = &rt_rq->active; | |
9371 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
9372 | INIT_LIST_HEAD(array->queue + i); | |
9373 | __clear_bit(i, array->bitmap); | |
9374 | } | |
9375 | /* delimiter for bitsearch: */ | |
9376 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
9377 | ||
052f1dc7 | 9378 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 9379 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 9380 | #ifdef CONFIG_SMP |
e864c499 | 9381 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 9382 | #endif |
48d5e258 | 9383 | #endif |
fa85ae24 PZ |
9384 | #ifdef CONFIG_SMP |
9385 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 9386 | rt_rq->overloaded = 0; |
05fa785c | 9387 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
9388 | #endif |
9389 | ||
9390 | rt_rq->rt_time = 0; | |
9391 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 9392 | rt_rq->rt_runtime = 0; |
0986b11b | 9393 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 9394 | |
052f1dc7 | 9395 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 9396 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
9397 | rt_rq->rq = rq; |
9398 | #endif | |
fa85ae24 PZ |
9399 | } |
9400 | ||
6f505b16 | 9401 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
9402 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
9403 | struct sched_entity *se, int cpu, int add, | |
9404 | struct sched_entity *parent) | |
6f505b16 | 9405 | { |
ec7dc8ac | 9406 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
9407 | tg->cfs_rq[cpu] = cfs_rq; |
9408 | init_cfs_rq(cfs_rq, rq); | |
9409 | cfs_rq->tg = tg; | |
9410 | if (add) | |
9411 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
9412 | ||
9413 | tg->se[cpu] = se; | |
354d60c2 DG |
9414 | /* se could be NULL for init_task_group */ |
9415 | if (!se) | |
9416 | return; | |
9417 | ||
ec7dc8ac DG |
9418 | if (!parent) |
9419 | se->cfs_rq = &rq->cfs; | |
9420 | else | |
9421 | se->cfs_rq = parent->my_q; | |
9422 | ||
6f505b16 PZ |
9423 | se->my_q = cfs_rq; |
9424 | se->load.weight = tg->shares; | |
e05510d0 | 9425 | se->load.inv_weight = 0; |
ec7dc8ac | 9426 | se->parent = parent; |
6f505b16 | 9427 | } |
052f1dc7 | 9428 | #endif |
6f505b16 | 9429 | |
052f1dc7 | 9430 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
9431 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
9432 | struct sched_rt_entity *rt_se, int cpu, int add, | |
9433 | struct sched_rt_entity *parent) | |
6f505b16 | 9434 | { |
ec7dc8ac DG |
9435 | struct rq *rq = cpu_rq(cpu); |
9436 | ||
6f505b16 PZ |
9437 | tg->rt_rq[cpu] = rt_rq; |
9438 | init_rt_rq(rt_rq, rq); | |
9439 | rt_rq->tg = tg; | |
9440 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 9441 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
9442 | if (add) |
9443 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
9444 | ||
9445 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
9446 | if (!rt_se) |
9447 | return; | |
9448 | ||
ec7dc8ac DG |
9449 | if (!parent) |
9450 | rt_se->rt_rq = &rq->rt; | |
9451 | else | |
9452 | rt_se->rt_rq = parent->my_q; | |
9453 | ||
6f505b16 | 9454 | rt_se->my_q = rt_rq; |
ec7dc8ac | 9455 | rt_se->parent = parent; |
6f505b16 PZ |
9456 | INIT_LIST_HEAD(&rt_se->run_list); |
9457 | } | |
9458 | #endif | |
9459 | ||
1da177e4 LT |
9460 | void __init sched_init(void) |
9461 | { | |
dd41f596 | 9462 | int i, j; |
434d53b0 MT |
9463 | unsigned long alloc_size = 0, ptr; |
9464 | ||
9465 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9466 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
9467 | #endif | |
9468 | #ifdef CONFIG_RT_GROUP_SCHED | |
9469 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9470 | #endif |
9471 | #ifdef CONFIG_USER_SCHED | |
9472 | alloc_size *= 2; | |
df7c8e84 RR |
9473 | #endif |
9474 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
8c083f08 | 9475 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 9476 | #endif |
434d53b0 | 9477 | if (alloc_size) { |
36b7b6d4 | 9478 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
9479 | |
9480 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9481 | init_task_group.se = (struct sched_entity **)ptr; | |
9482 | ptr += nr_cpu_ids * sizeof(void **); | |
9483 | ||
9484 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9485 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9486 | |
9487 | #ifdef CONFIG_USER_SCHED | |
9488 | root_task_group.se = (struct sched_entity **)ptr; | |
9489 | ptr += nr_cpu_ids * sizeof(void **); | |
9490 | ||
9491 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9492 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9493 | #endif /* CONFIG_USER_SCHED */ |
9494 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
9495 | #ifdef CONFIG_RT_GROUP_SCHED |
9496 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9497 | ptr += nr_cpu_ids * sizeof(void **); | |
9498 | ||
9499 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
9500 | ptr += nr_cpu_ids * sizeof(void **); |
9501 | ||
9502 | #ifdef CONFIG_USER_SCHED | |
9503 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9504 | ptr += nr_cpu_ids * sizeof(void **); | |
9505 | ||
9506 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
9507 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9508 | #endif /* CONFIG_USER_SCHED */ |
9509 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
df7c8e84 RR |
9510 | #ifdef CONFIG_CPUMASK_OFFSTACK |
9511 | for_each_possible_cpu(i) { | |
9512 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
9513 | ptr += cpumask_size(); | |
9514 | } | |
9515 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 9516 | } |
dd41f596 | 9517 | |
57d885fe GH |
9518 | #ifdef CONFIG_SMP |
9519 | init_defrootdomain(); | |
9520 | #endif | |
9521 | ||
d0b27fa7 PZ |
9522 | init_rt_bandwidth(&def_rt_bandwidth, |
9523 | global_rt_period(), global_rt_runtime()); | |
9524 | ||
9525 | #ifdef CONFIG_RT_GROUP_SCHED | |
9526 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
9527 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
9528 | #ifdef CONFIG_USER_SCHED |
9529 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
9530 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
9531 | #endif /* CONFIG_USER_SCHED */ |
9532 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 9533 | |
052f1dc7 | 9534 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 9535 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
9536 | INIT_LIST_HEAD(&init_task_group.children); |
9537 | ||
9538 | #ifdef CONFIG_USER_SCHED | |
9539 | INIT_LIST_HEAD(&root_task_group.children); | |
9540 | init_task_group.parent = &root_task_group; | |
9541 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
9542 | #endif /* CONFIG_USER_SCHED */ |
9543 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 9544 | |
4a6cc4bd JK |
9545 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
9546 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
9547 | __alignof__(unsigned long)); | |
9548 | #endif | |
0a945022 | 9549 | for_each_possible_cpu(i) { |
70b97a7f | 9550 | struct rq *rq; |
1da177e4 LT |
9551 | |
9552 | rq = cpu_rq(i); | |
05fa785c | 9553 | raw_spin_lock_init(&rq->lock); |
7897986b | 9554 | rq->nr_running = 0; |
dce48a84 TG |
9555 | rq->calc_load_active = 0; |
9556 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 9557 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 9558 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 9559 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 9560 | init_task_group.shares = init_task_group_load; |
6f505b16 | 9561 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
9562 | #ifdef CONFIG_CGROUP_SCHED |
9563 | /* | |
9564 | * How much cpu bandwidth does init_task_group get? | |
9565 | * | |
9566 | * In case of task-groups formed thr' the cgroup filesystem, it | |
9567 | * gets 100% of the cpu resources in the system. This overall | |
9568 | * system cpu resource is divided among the tasks of | |
9569 | * init_task_group and its child task-groups in a fair manner, | |
9570 | * based on each entity's (task or task-group's) weight | |
9571 | * (se->load.weight). | |
9572 | * | |
9573 | * In other words, if init_task_group has 10 tasks of weight | |
9574 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
9575 | * then A0's share of the cpu resource is: | |
9576 | * | |
0d905bca | 9577 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
9578 | * |
9579 | * We achieve this by letting init_task_group's tasks sit | |
9580 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
9581 | */ | |
ec7dc8ac | 9582 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 9583 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
9584 | root_task_group.shares = NICE_0_LOAD; |
9585 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
9586 | /* |
9587 | * In case of task-groups formed thr' the user id of tasks, | |
9588 | * init_task_group represents tasks belonging to root user. | |
9589 | * Hence it forms a sibling of all subsequent groups formed. | |
9590 | * In this case, init_task_group gets only a fraction of overall | |
9591 | * system cpu resource, based on the weight assigned to root | |
9592 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
9593 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
84e9dabf | 9594 | * (init_tg_cfs_rq) and having one entity represent this group of |
354d60c2 DG |
9595 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). |
9596 | */ | |
ec7dc8ac | 9597 | init_tg_cfs_entry(&init_task_group, |
84e9dabf | 9598 | &per_cpu(init_tg_cfs_rq, i), |
eff766a6 PZ |
9599 | &per_cpu(init_sched_entity, i), i, 1, |
9600 | root_task_group.se[i]); | |
6f505b16 | 9601 | |
052f1dc7 | 9602 | #endif |
354d60c2 DG |
9603 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
9604 | ||
9605 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 9606 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9607 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 9608 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 9609 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 9610 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 9611 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 9612 | init_tg_rt_entry(&init_task_group, |
1871e52c | 9613 | &per_cpu(init_rt_rq_var, i), |
eff766a6 PZ |
9614 | &per_cpu(init_sched_rt_entity, i), i, 1, |
9615 | root_task_group.rt_se[i]); | |
354d60c2 | 9616 | #endif |
dd41f596 | 9617 | #endif |
1da177e4 | 9618 | |
dd41f596 IM |
9619 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
9620 | rq->cpu_load[j] = 0; | |
1da177e4 | 9621 | #ifdef CONFIG_SMP |
41c7ce9a | 9622 | rq->sd = NULL; |
57d885fe | 9623 | rq->rd = NULL; |
3f029d3c | 9624 | rq->post_schedule = 0; |
1da177e4 | 9625 | rq->active_balance = 0; |
dd41f596 | 9626 | rq->next_balance = jiffies; |
1da177e4 | 9627 | rq->push_cpu = 0; |
0a2966b4 | 9628 | rq->cpu = i; |
1f11eb6a | 9629 | rq->online = 0; |
1da177e4 | 9630 | rq->migration_thread = NULL; |
eae0c9df MG |
9631 | rq->idle_stamp = 0; |
9632 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
1da177e4 | 9633 | INIT_LIST_HEAD(&rq->migration_queue); |
dc938520 | 9634 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 9635 | #endif |
8f4d37ec | 9636 | init_rq_hrtick(rq); |
1da177e4 | 9637 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
9638 | } |
9639 | ||
2dd73a4f | 9640 | set_load_weight(&init_task); |
b50f60ce | 9641 | |
e107be36 AK |
9642 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
9643 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
9644 | #endif | |
9645 | ||
c9819f45 | 9646 | #ifdef CONFIG_SMP |
962cf36c | 9647 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
9648 | #endif |
9649 | ||
b50f60ce | 9650 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 9651 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
9652 | #endif |
9653 | ||
1da177e4 LT |
9654 | /* |
9655 | * The boot idle thread does lazy MMU switching as well: | |
9656 | */ | |
9657 | atomic_inc(&init_mm.mm_count); | |
9658 | enter_lazy_tlb(&init_mm, current); | |
9659 | ||
9660 | /* | |
9661 | * Make us the idle thread. Technically, schedule() should not be | |
9662 | * called from this thread, however somewhere below it might be, | |
9663 | * but because we are the idle thread, we just pick up running again | |
9664 | * when this runqueue becomes "idle". | |
9665 | */ | |
9666 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
9667 | |
9668 | calc_load_update = jiffies + LOAD_FREQ; | |
9669 | ||
dd41f596 IM |
9670 | /* |
9671 | * During early bootup we pretend to be a normal task: | |
9672 | */ | |
9673 | current->sched_class = &fair_sched_class; | |
6892b75e | 9674 | |
6a7b3dc3 | 9675 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 9676 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 9677 | #ifdef CONFIG_SMP |
7d1e6a9b | 9678 | #ifdef CONFIG_NO_HZ |
49557e62 | 9679 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
4bdddf8f | 9680 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); |
7d1e6a9b | 9681 | #endif |
bdddd296 RR |
9682 | /* May be allocated at isolcpus cmdline parse time */ |
9683 | if (cpu_isolated_map == NULL) | |
9684 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 9685 | #endif /* SMP */ |
6a7b3dc3 | 9686 | |
cdd6c482 | 9687 | perf_event_init(); |
0d905bca | 9688 | |
6892b75e | 9689 | scheduler_running = 1; |
1da177e4 LT |
9690 | } |
9691 | ||
9692 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
9693 | static inline int preempt_count_equals(int preempt_offset) |
9694 | { | |
234da7bc | 9695 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
9696 | |
9697 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
9698 | } | |
9699 | ||
9700 | void __might_sleep(char *file, int line, int preempt_offset) | |
1da177e4 | 9701 | { |
48f24c4d | 9702 | #ifdef in_atomic |
1da177e4 LT |
9703 | static unsigned long prev_jiffy; /* ratelimiting */ |
9704 | ||
e4aafea2 FW |
9705 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
9706 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
9707 | return; |
9708 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
9709 | return; | |
9710 | prev_jiffy = jiffies; | |
9711 | ||
3df0fc5b PZ |
9712 | printk(KERN_ERR |
9713 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
9714 | file, line); | |
9715 | printk(KERN_ERR | |
9716 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
9717 | in_atomic(), irqs_disabled(), | |
9718 | current->pid, current->comm); | |
aef745fc IM |
9719 | |
9720 | debug_show_held_locks(current); | |
9721 | if (irqs_disabled()) | |
9722 | print_irqtrace_events(current); | |
9723 | dump_stack(); | |
1da177e4 LT |
9724 | #endif |
9725 | } | |
9726 | EXPORT_SYMBOL(__might_sleep); | |
9727 | #endif | |
9728 | ||
9729 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
9730 | static void normalize_task(struct rq *rq, struct task_struct *p) |
9731 | { | |
9732 | int on_rq; | |
3e51f33f | 9733 | |
3a5e4dc1 AK |
9734 | update_rq_clock(rq); |
9735 | on_rq = p->se.on_rq; | |
9736 | if (on_rq) | |
9737 | deactivate_task(rq, p, 0); | |
9738 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
9739 | if (on_rq) { | |
9740 | activate_task(rq, p, 0); | |
9741 | resched_task(rq->curr); | |
9742 | } | |
9743 | } | |
9744 | ||
1da177e4 LT |
9745 | void normalize_rt_tasks(void) |
9746 | { | |
a0f98a1c | 9747 | struct task_struct *g, *p; |
1da177e4 | 9748 | unsigned long flags; |
70b97a7f | 9749 | struct rq *rq; |
1da177e4 | 9750 | |
4cf5d77a | 9751 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 9752 | do_each_thread(g, p) { |
178be793 IM |
9753 | /* |
9754 | * Only normalize user tasks: | |
9755 | */ | |
9756 | if (!p->mm) | |
9757 | continue; | |
9758 | ||
6cfb0d5d | 9759 | p->se.exec_start = 0; |
6cfb0d5d | 9760 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 9761 | p->se.wait_start = 0; |
dd41f596 | 9762 | p->se.sleep_start = 0; |
dd41f596 | 9763 | p->se.block_start = 0; |
6cfb0d5d | 9764 | #endif |
dd41f596 IM |
9765 | |
9766 | if (!rt_task(p)) { | |
9767 | /* | |
9768 | * Renice negative nice level userspace | |
9769 | * tasks back to 0: | |
9770 | */ | |
9771 | if (TASK_NICE(p) < 0 && p->mm) | |
9772 | set_user_nice(p, 0); | |
1da177e4 | 9773 | continue; |
dd41f596 | 9774 | } |
1da177e4 | 9775 | |
1d615482 | 9776 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 9777 | rq = __task_rq_lock(p); |
1da177e4 | 9778 | |
178be793 | 9779 | normalize_task(rq, p); |
3a5e4dc1 | 9780 | |
b29739f9 | 9781 | __task_rq_unlock(rq); |
1d615482 | 9782 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
9783 | } while_each_thread(g, p); |
9784 | ||
4cf5d77a | 9785 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
9786 | } |
9787 | ||
9788 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
9789 | |
9790 | #ifdef CONFIG_IA64 | |
9791 | /* | |
9792 | * These functions are only useful for the IA64 MCA handling. | |
9793 | * | |
9794 | * They can only be called when the whole system has been | |
9795 | * stopped - every CPU needs to be quiescent, and no scheduling | |
9796 | * activity can take place. Using them for anything else would | |
9797 | * be a serious bug, and as a result, they aren't even visible | |
9798 | * under any other configuration. | |
9799 | */ | |
9800 | ||
9801 | /** | |
9802 | * curr_task - return the current task for a given cpu. | |
9803 | * @cpu: the processor in question. | |
9804 | * | |
9805 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9806 | */ | |
36c8b586 | 9807 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
9808 | { |
9809 | return cpu_curr(cpu); | |
9810 | } | |
9811 | ||
9812 | /** | |
9813 | * set_curr_task - set the current task for a given cpu. | |
9814 | * @cpu: the processor in question. | |
9815 | * @p: the task pointer to set. | |
9816 | * | |
9817 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
9818 | * are serviced on a separate stack. It allows the architecture to switch the |
9819 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
9820 | * must be called with all CPU's synchronized, and interrupts disabled, the |
9821 | * and caller must save the original value of the current task (see | |
9822 | * curr_task() above) and restore that value before reenabling interrupts and | |
9823 | * re-starting the system. | |
9824 | * | |
9825 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9826 | */ | |
36c8b586 | 9827 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
9828 | { |
9829 | cpu_curr(cpu) = p; | |
9830 | } | |
9831 | ||
9832 | #endif | |
29f59db3 | 9833 | |
bccbe08a PZ |
9834 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9835 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
9836 | { |
9837 | int i; | |
9838 | ||
9839 | for_each_possible_cpu(i) { | |
9840 | if (tg->cfs_rq) | |
9841 | kfree(tg->cfs_rq[i]); | |
9842 | if (tg->se) | |
9843 | kfree(tg->se[i]); | |
6f505b16 PZ |
9844 | } |
9845 | ||
9846 | kfree(tg->cfs_rq); | |
9847 | kfree(tg->se); | |
6f505b16 PZ |
9848 | } |
9849 | ||
ec7dc8ac DG |
9850 | static |
9851 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 9852 | { |
29f59db3 | 9853 | struct cfs_rq *cfs_rq; |
eab17229 | 9854 | struct sched_entity *se; |
9b5b7751 | 9855 | struct rq *rq; |
29f59db3 SV |
9856 | int i; |
9857 | ||
434d53b0 | 9858 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9859 | if (!tg->cfs_rq) |
9860 | goto err; | |
434d53b0 | 9861 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9862 | if (!tg->se) |
9863 | goto err; | |
052f1dc7 PZ |
9864 | |
9865 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
9866 | |
9867 | for_each_possible_cpu(i) { | |
9b5b7751 | 9868 | rq = cpu_rq(i); |
29f59db3 | 9869 | |
eab17229 LZ |
9870 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
9871 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
9872 | if (!cfs_rq) |
9873 | goto err; | |
9874 | ||
eab17229 LZ |
9875 | se = kzalloc_node(sizeof(struct sched_entity), |
9876 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 9877 | if (!se) |
dfc12eb2 | 9878 | goto err_free_rq; |
29f59db3 | 9879 | |
eab17229 | 9880 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
9881 | } |
9882 | ||
9883 | return 1; | |
9884 | ||
dfc12eb2 PC |
9885 | err_free_rq: |
9886 | kfree(cfs_rq); | |
bccbe08a PZ |
9887 | err: |
9888 | return 0; | |
9889 | } | |
9890 | ||
9891 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9892 | { | |
9893 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
9894 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
9895 | } | |
9896 | ||
9897 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9898 | { | |
9899 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
9900 | } | |
6d6bc0ad | 9901 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
9902 | static inline void free_fair_sched_group(struct task_group *tg) |
9903 | { | |
9904 | } | |
9905 | ||
ec7dc8ac DG |
9906 | static inline |
9907 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9908 | { |
9909 | return 1; | |
9910 | } | |
9911 | ||
9912 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9913 | { | |
9914 | } | |
9915 | ||
9916 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9917 | { | |
9918 | } | |
6d6bc0ad | 9919 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
9920 | |
9921 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
9922 | static void free_rt_sched_group(struct task_group *tg) |
9923 | { | |
9924 | int i; | |
9925 | ||
d0b27fa7 PZ |
9926 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
9927 | ||
bccbe08a PZ |
9928 | for_each_possible_cpu(i) { |
9929 | if (tg->rt_rq) | |
9930 | kfree(tg->rt_rq[i]); | |
9931 | if (tg->rt_se) | |
9932 | kfree(tg->rt_se[i]); | |
9933 | } | |
9934 | ||
9935 | kfree(tg->rt_rq); | |
9936 | kfree(tg->rt_se); | |
9937 | } | |
9938 | ||
ec7dc8ac DG |
9939 | static |
9940 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9941 | { |
9942 | struct rt_rq *rt_rq; | |
eab17229 | 9943 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
9944 | struct rq *rq; |
9945 | int i; | |
9946 | ||
434d53b0 | 9947 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9948 | if (!tg->rt_rq) |
9949 | goto err; | |
434d53b0 | 9950 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9951 | if (!tg->rt_se) |
9952 | goto err; | |
9953 | ||
d0b27fa7 PZ |
9954 | init_rt_bandwidth(&tg->rt_bandwidth, |
9955 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
9956 | |
9957 | for_each_possible_cpu(i) { | |
9958 | rq = cpu_rq(i); | |
9959 | ||
eab17229 LZ |
9960 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
9961 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
9962 | if (!rt_rq) |
9963 | goto err; | |
29f59db3 | 9964 | |
eab17229 LZ |
9965 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
9966 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 9967 | if (!rt_se) |
dfc12eb2 | 9968 | goto err_free_rq; |
29f59db3 | 9969 | |
eab17229 | 9970 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
9971 | } |
9972 | ||
bccbe08a PZ |
9973 | return 1; |
9974 | ||
dfc12eb2 PC |
9975 | err_free_rq: |
9976 | kfree(rt_rq); | |
bccbe08a PZ |
9977 | err: |
9978 | return 0; | |
9979 | } | |
9980 | ||
9981 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
9982 | { | |
9983 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
9984 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
9985 | } | |
9986 | ||
9987 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
9988 | { | |
9989 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
9990 | } | |
6d6bc0ad | 9991 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
9992 | static inline void free_rt_sched_group(struct task_group *tg) |
9993 | { | |
9994 | } | |
9995 | ||
ec7dc8ac DG |
9996 | static inline |
9997 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9998 | { |
9999 | return 1; | |
10000 | } | |
10001 | ||
10002 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
10003 | { | |
10004 | } | |
10005 | ||
10006 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
10007 | { | |
10008 | } | |
6d6bc0ad | 10009 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 10010 | |
d0b27fa7 | 10011 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
10012 | static void free_sched_group(struct task_group *tg) |
10013 | { | |
10014 | free_fair_sched_group(tg); | |
10015 | free_rt_sched_group(tg); | |
10016 | kfree(tg); | |
10017 | } | |
10018 | ||
10019 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 10020 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
10021 | { |
10022 | struct task_group *tg; | |
10023 | unsigned long flags; | |
10024 | int i; | |
10025 | ||
10026 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
10027 | if (!tg) | |
10028 | return ERR_PTR(-ENOMEM); | |
10029 | ||
ec7dc8ac | 10030 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
10031 | goto err; |
10032 | ||
ec7dc8ac | 10033 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
10034 | goto err; |
10035 | ||
8ed36996 | 10036 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 10037 | for_each_possible_cpu(i) { |
bccbe08a PZ |
10038 | register_fair_sched_group(tg, i); |
10039 | register_rt_sched_group(tg, i); | |
9b5b7751 | 10040 | } |
6f505b16 | 10041 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
10042 | |
10043 | WARN_ON(!parent); /* root should already exist */ | |
10044 | ||
10045 | tg->parent = parent; | |
f473aa5e | 10046 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 10047 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 10048 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 10049 | |
9b5b7751 | 10050 | return tg; |
29f59db3 SV |
10051 | |
10052 | err: | |
6f505b16 | 10053 | free_sched_group(tg); |
29f59db3 SV |
10054 | return ERR_PTR(-ENOMEM); |
10055 | } | |
10056 | ||
9b5b7751 | 10057 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 10058 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 10059 | { |
29f59db3 | 10060 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 10061 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
10062 | } |
10063 | ||
9b5b7751 | 10064 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 10065 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 10066 | { |
8ed36996 | 10067 | unsigned long flags; |
9b5b7751 | 10068 | int i; |
29f59db3 | 10069 | |
8ed36996 | 10070 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 10071 | for_each_possible_cpu(i) { |
bccbe08a PZ |
10072 | unregister_fair_sched_group(tg, i); |
10073 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 10074 | } |
6f505b16 | 10075 | list_del_rcu(&tg->list); |
f473aa5e | 10076 | list_del_rcu(&tg->siblings); |
8ed36996 | 10077 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 10078 | |
9b5b7751 | 10079 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 10080 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
10081 | } |
10082 | ||
9b5b7751 | 10083 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
10084 | * The caller of this function should have put the task in its new group |
10085 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
10086 | * reflect its new group. | |
9b5b7751 SV |
10087 | */ |
10088 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
10089 | { |
10090 | int on_rq, running; | |
10091 | unsigned long flags; | |
10092 | struct rq *rq; | |
10093 | ||
10094 | rq = task_rq_lock(tsk, &flags); | |
10095 | ||
29f59db3 SV |
10096 | update_rq_clock(rq); |
10097 | ||
051a1d1a | 10098 | running = task_current(rq, tsk); |
29f59db3 SV |
10099 | on_rq = tsk->se.on_rq; |
10100 | ||
0e1f3483 | 10101 | if (on_rq) |
29f59db3 | 10102 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
10103 | if (unlikely(running)) |
10104 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 10105 | |
6f505b16 | 10106 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 10107 | |
810b3817 PZ |
10108 | #ifdef CONFIG_FAIR_GROUP_SCHED |
10109 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 10110 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
10111 | #endif |
10112 | ||
0e1f3483 HS |
10113 | if (unlikely(running)) |
10114 | tsk->sched_class->set_curr_task(rq); | |
10115 | if (on_rq) | |
7074badb | 10116 | enqueue_task(rq, tsk, 0); |
29f59db3 | 10117 | |
29f59db3 SV |
10118 | task_rq_unlock(rq, &flags); |
10119 | } | |
6d6bc0ad | 10120 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 10121 | |
052f1dc7 | 10122 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 10123 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
10124 | { |
10125 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
10126 | int on_rq; |
10127 | ||
29f59db3 | 10128 | on_rq = se->on_rq; |
62fb1851 | 10129 | if (on_rq) |
29f59db3 SV |
10130 | dequeue_entity(cfs_rq, se, 0); |
10131 | ||
10132 | se->load.weight = shares; | |
e05510d0 | 10133 | se->load.inv_weight = 0; |
29f59db3 | 10134 | |
62fb1851 | 10135 | if (on_rq) |
29f59db3 | 10136 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 10137 | } |
62fb1851 | 10138 | |
c09595f6 PZ |
10139 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
10140 | { | |
10141 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
10142 | struct rq *rq = cfs_rq->rq; | |
10143 | unsigned long flags; | |
10144 | ||
05fa785c | 10145 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 10146 | __set_se_shares(se, shares); |
05fa785c | 10147 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
10148 | } |
10149 | ||
8ed36996 PZ |
10150 | static DEFINE_MUTEX(shares_mutex); |
10151 | ||
4cf86d77 | 10152 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
10153 | { |
10154 | int i; | |
8ed36996 | 10155 | unsigned long flags; |
c61935fd | 10156 | |
ec7dc8ac DG |
10157 | /* |
10158 | * We can't change the weight of the root cgroup. | |
10159 | */ | |
10160 | if (!tg->se[0]) | |
10161 | return -EINVAL; | |
10162 | ||
18d95a28 PZ |
10163 | if (shares < MIN_SHARES) |
10164 | shares = MIN_SHARES; | |
cb4ad1ff MX |
10165 | else if (shares > MAX_SHARES) |
10166 | shares = MAX_SHARES; | |
62fb1851 | 10167 | |
8ed36996 | 10168 | mutex_lock(&shares_mutex); |
9b5b7751 | 10169 | if (tg->shares == shares) |
5cb350ba | 10170 | goto done; |
29f59db3 | 10171 | |
8ed36996 | 10172 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10173 | for_each_possible_cpu(i) |
10174 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 10175 | list_del_rcu(&tg->siblings); |
8ed36996 | 10176 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
10177 | |
10178 | /* wait for any ongoing reference to this group to finish */ | |
10179 | synchronize_sched(); | |
10180 | ||
10181 | /* | |
10182 | * Now we are free to modify the group's share on each cpu | |
10183 | * w/o tripping rebalance_share or load_balance_fair. | |
10184 | */ | |
9b5b7751 | 10185 | tg->shares = shares; |
c09595f6 PZ |
10186 | for_each_possible_cpu(i) { |
10187 | /* | |
10188 | * force a rebalance | |
10189 | */ | |
10190 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 10191 | set_se_shares(tg->se[i], shares); |
c09595f6 | 10192 | } |
29f59db3 | 10193 | |
6b2d7700 SV |
10194 | /* |
10195 | * Enable load balance activity on this group, by inserting it back on | |
10196 | * each cpu's rq->leaf_cfs_rq_list. | |
10197 | */ | |
8ed36996 | 10198 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10199 | for_each_possible_cpu(i) |
10200 | register_fair_sched_group(tg, i); | |
f473aa5e | 10201 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 10202 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 10203 | done: |
8ed36996 | 10204 | mutex_unlock(&shares_mutex); |
9b5b7751 | 10205 | return 0; |
29f59db3 SV |
10206 | } |
10207 | ||
5cb350ba DG |
10208 | unsigned long sched_group_shares(struct task_group *tg) |
10209 | { | |
10210 | return tg->shares; | |
10211 | } | |
052f1dc7 | 10212 | #endif |
5cb350ba | 10213 | |
052f1dc7 | 10214 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 10215 | /* |
9f0c1e56 | 10216 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 10217 | */ |
9f0c1e56 PZ |
10218 | static DEFINE_MUTEX(rt_constraints_mutex); |
10219 | ||
10220 | static unsigned long to_ratio(u64 period, u64 runtime) | |
10221 | { | |
10222 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 10223 | return 1ULL << 20; |
9f0c1e56 | 10224 | |
9a7e0b18 | 10225 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
10226 | } |
10227 | ||
9a7e0b18 PZ |
10228 | /* Must be called with tasklist_lock held */ |
10229 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 10230 | { |
9a7e0b18 | 10231 | struct task_struct *g, *p; |
b40b2e8e | 10232 | |
9a7e0b18 PZ |
10233 | do_each_thread(g, p) { |
10234 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
10235 | return 1; | |
10236 | } while_each_thread(g, p); | |
b40b2e8e | 10237 | |
9a7e0b18 PZ |
10238 | return 0; |
10239 | } | |
b40b2e8e | 10240 | |
9a7e0b18 PZ |
10241 | struct rt_schedulable_data { |
10242 | struct task_group *tg; | |
10243 | u64 rt_period; | |
10244 | u64 rt_runtime; | |
10245 | }; | |
b40b2e8e | 10246 | |
9a7e0b18 PZ |
10247 | static int tg_schedulable(struct task_group *tg, void *data) |
10248 | { | |
10249 | struct rt_schedulable_data *d = data; | |
10250 | struct task_group *child; | |
10251 | unsigned long total, sum = 0; | |
10252 | u64 period, runtime; | |
b40b2e8e | 10253 | |
9a7e0b18 PZ |
10254 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
10255 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 10256 | |
9a7e0b18 PZ |
10257 | if (tg == d->tg) { |
10258 | period = d->rt_period; | |
10259 | runtime = d->rt_runtime; | |
b40b2e8e | 10260 | } |
b40b2e8e | 10261 | |
98a4826b PZ |
10262 | #ifdef CONFIG_USER_SCHED |
10263 | if (tg == &root_task_group) { | |
10264 | period = global_rt_period(); | |
10265 | runtime = global_rt_runtime(); | |
10266 | } | |
10267 | #endif | |
10268 | ||
4653f803 PZ |
10269 | /* |
10270 | * Cannot have more runtime than the period. | |
10271 | */ | |
10272 | if (runtime > period && runtime != RUNTIME_INF) | |
10273 | return -EINVAL; | |
6f505b16 | 10274 | |
4653f803 PZ |
10275 | /* |
10276 | * Ensure we don't starve existing RT tasks. | |
10277 | */ | |
9a7e0b18 PZ |
10278 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
10279 | return -EBUSY; | |
6f505b16 | 10280 | |
9a7e0b18 | 10281 | total = to_ratio(period, runtime); |
6f505b16 | 10282 | |
4653f803 PZ |
10283 | /* |
10284 | * Nobody can have more than the global setting allows. | |
10285 | */ | |
10286 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
10287 | return -EINVAL; | |
6f505b16 | 10288 | |
4653f803 PZ |
10289 | /* |
10290 | * The sum of our children's runtime should not exceed our own. | |
10291 | */ | |
9a7e0b18 PZ |
10292 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
10293 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
10294 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 10295 | |
9a7e0b18 PZ |
10296 | if (child == d->tg) { |
10297 | period = d->rt_period; | |
10298 | runtime = d->rt_runtime; | |
10299 | } | |
6f505b16 | 10300 | |
9a7e0b18 | 10301 | sum += to_ratio(period, runtime); |
9f0c1e56 | 10302 | } |
6f505b16 | 10303 | |
9a7e0b18 PZ |
10304 | if (sum > total) |
10305 | return -EINVAL; | |
10306 | ||
10307 | return 0; | |
6f505b16 PZ |
10308 | } |
10309 | ||
9a7e0b18 | 10310 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 10311 | { |
9a7e0b18 PZ |
10312 | struct rt_schedulable_data data = { |
10313 | .tg = tg, | |
10314 | .rt_period = period, | |
10315 | .rt_runtime = runtime, | |
10316 | }; | |
10317 | ||
10318 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
10319 | } |
10320 | ||
d0b27fa7 PZ |
10321 | static int tg_set_bandwidth(struct task_group *tg, |
10322 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 10323 | { |
ac086bc2 | 10324 | int i, err = 0; |
9f0c1e56 | 10325 | |
9f0c1e56 | 10326 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 10327 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
10328 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
10329 | if (err) | |
9f0c1e56 | 10330 | goto unlock; |
ac086bc2 | 10331 | |
0986b11b | 10332 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
10333 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
10334 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
10335 | |
10336 | for_each_possible_cpu(i) { | |
10337 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
10338 | ||
0986b11b | 10339 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10340 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 10341 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10342 | } |
0986b11b | 10343 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 10344 | unlock: |
521f1a24 | 10345 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
10346 | mutex_unlock(&rt_constraints_mutex); |
10347 | ||
10348 | return err; | |
6f505b16 PZ |
10349 | } |
10350 | ||
d0b27fa7 PZ |
10351 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
10352 | { | |
10353 | u64 rt_runtime, rt_period; | |
10354 | ||
10355 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10356 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
10357 | if (rt_runtime_us < 0) | |
10358 | rt_runtime = RUNTIME_INF; | |
10359 | ||
10360 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
10361 | } | |
10362 | ||
9f0c1e56 PZ |
10363 | long sched_group_rt_runtime(struct task_group *tg) |
10364 | { | |
10365 | u64 rt_runtime_us; | |
10366 | ||
d0b27fa7 | 10367 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
10368 | return -1; |
10369 | ||
d0b27fa7 | 10370 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
10371 | do_div(rt_runtime_us, NSEC_PER_USEC); |
10372 | return rt_runtime_us; | |
10373 | } | |
d0b27fa7 PZ |
10374 | |
10375 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
10376 | { | |
10377 | u64 rt_runtime, rt_period; | |
10378 | ||
10379 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
10380 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
10381 | ||
619b0488 R |
10382 | if (rt_period == 0) |
10383 | return -EINVAL; | |
10384 | ||
d0b27fa7 PZ |
10385 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
10386 | } | |
10387 | ||
10388 | long sched_group_rt_period(struct task_group *tg) | |
10389 | { | |
10390 | u64 rt_period_us; | |
10391 | ||
10392 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10393 | do_div(rt_period_us, NSEC_PER_USEC); | |
10394 | return rt_period_us; | |
10395 | } | |
10396 | ||
10397 | static int sched_rt_global_constraints(void) | |
10398 | { | |
4653f803 | 10399 | u64 runtime, period; |
d0b27fa7 PZ |
10400 | int ret = 0; |
10401 | ||
ec5d4989 HS |
10402 | if (sysctl_sched_rt_period <= 0) |
10403 | return -EINVAL; | |
10404 | ||
4653f803 PZ |
10405 | runtime = global_rt_runtime(); |
10406 | period = global_rt_period(); | |
10407 | ||
10408 | /* | |
10409 | * Sanity check on the sysctl variables. | |
10410 | */ | |
10411 | if (runtime > period && runtime != RUNTIME_INF) | |
10412 | return -EINVAL; | |
10b612f4 | 10413 | |
d0b27fa7 | 10414 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 10415 | read_lock(&tasklist_lock); |
4653f803 | 10416 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 10417 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
10418 | mutex_unlock(&rt_constraints_mutex); |
10419 | ||
10420 | return ret; | |
10421 | } | |
54e99124 DG |
10422 | |
10423 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
10424 | { | |
10425 | /* Don't accept realtime tasks when there is no way for them to run */ | |
10426 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
10427 | return 0; | |
10428 | ||
10429 | return 1; | |
10430 | } | |
10431 | ||
6d6bc0ad | 10432 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10433 | static int sched_rt_global_constraints(void) |
10434 | { | |
ac086bc2 PZ |
10435 | unsigned long flags; |
10436 | int i; | |
10437 | ||
ec5d4989 HS |
10438 | if (sysctl_sched_rt_period <= 0) |
10439 | return -EINVAL; | |
10440 | ||
60aa605d PZ |
10441 | /* |
10442 | * There's always some RT tasks in the root group | |
10443 | * -- migration, kstopmachine etc.. | |
10444 | */ | |
10445 | if (sysctl_sched_rt_runtime == 0) | |
10446 | return -EBUSY; | |
10447 | ||
0986b11b | 10448 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
10449 | for_each_possible_cpu(i) { |
10450 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
10451 | ||
0986b11b | 10452 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10453 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 10454 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10455 | } |
0986b11b | 10456 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 10457 | |
d0b27fa7 PZ |
10458 | return 0; |
10459 | } | |
6d6bc0ad | 10460 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10461 | |
10462 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 10463 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
10464 | loff_t *ppos) |
10465 | { | |
10466 | int ret; | |
10467 | int old_period, old_runtime; | |
10468 | static DEFINE_MUTEX(mutex); | |
10469 | ||
10470 | mutex_lock(&mutex); | |
10471 | old_period = sysctl_sched_rt_period; | |
10472 | old_runtime = sysctl_sched_rt_runtime; | |
10473 | ||
8d65af78 | 10474 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
10475 | |
10476 | if (!ret && write) { | |
10477 | ret = sched_rt_global_constraints(); | |
10478 | if (ret) { | |
10479 | sysctl_sched_rt_period = old_period; | |
10480 | sysctl_sched_rt_runtime = old_runtime; | |
10481 | } else { | |
10482 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
10483 | def_rt_bandwidth.rt_period = | |
10484 | ns_to_ktime(global_rt_period()); | |
10485 | } | |
10486 | } | |
10487 | mutex_unlock(&mutex); | |
10488 | ||
10489 | return ret; | |
10490 | } | |
68318b8e | 10491 | |
052f1dc7 | 10492 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
10493 | |
10494 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 10495 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 10496 | { |
2b01dfe3 PM |
10497 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
10498 | struct task_group, css); | |
68318b8e SV |
10499 | } |
10500 | ||
10501 | static struct cgroup_subsys_state * | |
2b01dfe3 | 10502 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 10503 | { |
ec7dc8ac | 10504 | struct task_group *tg, *parent; |
68318b8e | 10505 | |
2b01dfe3 | 10506 | if (!cgrp->parent) { |
68318b8e | 10507 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
10508 | return &init_task_group.css; |
10509 | } | |
10510 | ||
ec7dc8ac DG |
10511 | parent = cgroup_tg(cgrp->parent); |
10512 | tg = sched_create_group(parent); | |
68318b8e SV |
10513 | if (IS_ERR(tg)) |
10514 | return ERR_PTR(-ENOMEM); | |
10515 | ||
68318b8e SV |
10516 | return &tg->css; |
10517 | } | |
10518 | ||
41a2d6cf IM |
10519 | static void |
10520 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 10521 | { |
2b01dfe3 | 10522 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10523 | |
10524 | sched_destroy_group(tg); | |
10525 | } | |
10526 | ||
41a2d6cf | 10527 | static int |
be367d09 | 10528 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 10529 | { |
b68aa230 | 10530 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 10531 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
10532 | return -EINVAL; |
10533 | #else | |
68318b8e SV |
10534 | /* We don't support RT-tasks being in separate groups */ |
10535 | if (tsk->sched_class != &fair_sched_class) | |
10536 | return -EINVAL; | |
b68aa230 | 10537 | #endif |
be367d09 BB |
10538 | return 0; |
10539 | } | |
68318b8e | 10540 | |
be367d09 BB |
10541 | static int |
10542 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
10543 | struct task_struct *tsk, bool threadgroup) | |
10544 | { | |
10545 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
10546 | if (retval) | |
10547 | return retval; | |
10548 | if (threadgroup) { | |
10549 | struct task_struct *c; | |
10550 | rcu_read_lock(); | |
10551 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
10552 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
10553 | if (retval) { | |
10554 | rcu_read_unlock(); | |
10555 | return retval; | |
10556 | } | |
10557 | } | |
10558 | rcu_read_unlock(); | |
10559 | } | |
68318b8e SV |
10560 | return 0; |
10561 | } | |
10562 | ||
10563 | static void | |
2b01dfe3 | 10564 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
10565 | struct cgroup *old_cont, struct task_struct *tsk, |
10566 | bool threadgroup) | |
68318b8e SV |
10567 | { |
10568 | sched_move_task(tsk); | |
be367d09 BB |
10569 | if (threadgroup) { |
10570 | struct task_struct *c; | |
10571 | rcu_read_lock(); | |
10572 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
10573 | sched_move_task(c); | |
10574 | } | |
10575 | rcu_read_unlock(); | |
10576 | } | |
68318b8e SV |
10577 | } |
10578 | ||
052f1dc7 | 10579 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 10580 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 10581 | u64 shareval) |
68318b8e | 10582 | { |
2b01dfe3 | 10583 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
10584 | } |
10585 | ||
f4c753b7 | 10586 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 10587 | { |
2b01dfe3 | 10588 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10589 | |
10590 | return (u64) tg->shares; | |
10591 | } | |
6d6bc0ad | 10592 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 10593 | |
052f1dc7 | 10594 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 10595 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 10596 | s64 val) |
6f505b16 | 10597 | { |
06ecb27c | 10598 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
10599 | } |
10600 | ||
06ecb27c | 10601 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 10602 | { |
06ecb27c | 10603 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 10604 | } |
d0b27fa7 PZ |
10605 | |
10606 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
10607 | u64 rt_period_us) | |
10608 | { | |
10609 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
10610 | } | |
10611 | ||
10612 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
10613 | { | |
10614 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
10615 | } | |
6d6bc0ad | 10616 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 10617 | |
fe5c7cc2 | 10618 | static struct cftype cpu_files[] = { |
052f1dc7 | 10619 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
10620 | { |
10621 | .name = "shares", | |
f4c753b7 PM |
10622 | .read_u64 = cpu_shares_read_u64, |
10623 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 10624 | }, |
052f1dc7 PZ |
10625 | #endif |
10626 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 10627 | { |
9f0c1e56 | 10628 | .name = "rt_runtime_us", |
06ecb27c PM |
10629 | .read_s64 = cpu_rt_runtime_read, |
10630 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 10631 | }, |
d0b27fa7 PZ |
10632 | { |
10633 | .name = "rt_period_us", | |
f4c753b7 PM |
10634 | .read_u64 = cpu_rt_period_read_uint, |
10635 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 10636 | }, |
052f1dc7 | 10637 | #endif |
68318b8e SV |
10638 | }; |
10639 | ||
10640 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
10641 | { | |
fe5c7cc2 | 10642 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
10643 | } |
10644 | ||
10645 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
10646 | .name = "cpu", |
10647 | .create = cpu_cgroup_create, | |
10648 | .destroy = cpu_cgroup_destroy, | |
10649 | .can_attach = cpu_cgroup_can_attach, | |
10650 | .attach = cpu_cgroup_attach, | |
10651 | .populate = cpu_cgroup_populate, | |
10652 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
10653 | .early_init = 1, |
10654 | }; | |
10655 | ||
052f1dc7 | 10656 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
10657 | |
10658 | #ifdef CONFIG_CGROUP_CPUACCT | |
10659 | ||
10660 | /* | |
10661 | * CPU accounting code for task groups. | |
10662 | * | |
10663 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
10664 | * (balbir@in.ibm.com). | |
10665 | */ | |
10666 | ||
934352f2 | 10667 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
10668 | struct cpuacct { |
10669 | struct cgroup_subsys_state css; | |
10670 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
10671 | u64 *cpuusage; | |
ef12fefa | 10672 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 10673 | struct cpuacct *parent; |
d842de87 SV |
10674 | }; |
10675 | ||
10676 | struct cgroup_subsys cpuacct_subsys; | |
10677 | ||
10678 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 10679 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 10680 | { |
32cd756a | 10681 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
10682 | struct cpuacct, css); |
10683 | } | |
10684 | ||
10685 | /* return cpu accounting group to which this task belongs */ | |
10686 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
10687 | { | |
10688 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
10689 | struct cpuacct, css); | |
10690 | } | |
10691 | ||
10692 | /* create a new cpu accounting group */ | |
10693 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 10694 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
10695 | { |
10696 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 10697 | int i; |
d842de87 SV |
10698 | |
10699 | if (!ca) | |
ef12fefa | 10700 | goto out; |
d842de87 SV |
10701 | |
10702 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
10703 | if (!ca->cpuusage) |
10704 | goto out_free_ca; | |
10705 | ||
10706 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
10707 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
10708 | goto out_free_counters; | |
d842de87 | 10709 | |
934352f2 BR |
10710 | if (cgrp->parent) |
10711 | ca->parent = cgroup_ca(cgrp->parent); | |
10712 | ||
d842de87 | 10713 | return &ca->css; |
ef12fefa BR |
10714 | |
10715 | out_free_counters: | |
10716 | while (--i >= 0) | |
10717 | percpu_counter_destroy(&ca->cpustat[i]); | |
10718 | free_percpu(ca->cpuusage); | |
10719 | out_free_ca: | |
10720 | kfree(ca); | |
10721 | out: | |
10722 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
10723 | } |
10724 | ||
10725 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 10726 | static void |
32cd756a | 10727 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10728 | { |
32cd756a | 10729 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 10730 | int i; |
d842de87 | 10731 | |
ef12fefa BR |
10732 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
10733 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
10734 | free_percpu(ca->cpuusage); |
10735 | kfree(ca); | |
10736 | } | |
10737 | ||
720f5498 KC |
10738 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
10739 | { | |
b36128c8 | 10740 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10741 | u64 data; |
10742 | ||
10743 | #ifndef CONFIG_64BIT | |
10744 | /* | |
10745 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
10746 | */ | |
05fa785c | 10747 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 10748 | data = *cpuusage; |
05fa785c | 10749 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
10750 | #else |
10751 | data = *cpuusage; | |
10752 | #endif | |
10753 | ||
10754 | return data; | |
10755 | } | |
10756 | ||
10757 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
10758 | { | |
b36128c8 | 10759 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10760 | |
10761 | #ifndef CONFIG_64BIT | |
10762 | /* | |
10763 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
10764 | */ | |
05fa785c | 10765 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 10766 | *cpuusage = val; |
05fa785c | 10767 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
10768 | #else |
10769 | *cpuusage = val; | |
10770 | #endif | |
10771 | } | |
10772 | ||
d842de87 | 10773 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 10774 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 10775 | { |
32cd756a | 10776 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
10777 | u64 totalcpuusage = 0; |
10778 | int i; | |
10779 | ||
720f5498 KC |
10780 | for_each_present_cpu(i) |
10781 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
10782 | |
10783 | return totalcpuusage; | |
10784 | } | |
10785 | ||
0297b803 DG |
10786 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
10787 | u64 reset) | |
10788 | { | |
10789 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10790 | int err = 0; | |
10791 | int i; | |
10792 | ||
10793 | if (reset) { | |
10794 | err = -EINVAL; | |
10795 | goto out; | |
10796 | } | |
10797 | ||
720f5498 KC |
10798 | for_each_present_cpu(i) |
10799 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 10800 | |
0297b803 DG |
10801 | out: |
10802 | return err; | |
10803 | } | |
10804 | ||
e9515c3c KC |
10805 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
10806 | struct seq_file *m) | |
10807 | { | |
10808 | struct cpuacct *ca = cgroup_ca(cgroup); | |
10809 | u64 percpu; | |
10810 | int i; | |
10811 | ||
10812 | for_each_present_cpu(i) { | |
10813 | percpu = cpuacct_cpuusage_read(ca, i); | |
10814 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
10815 | } | |
10816 | seq_printf(m, "\n"); | |
10817 | return 0; | |
10818 | } | |
10819 | ||
ef12fefa BR |
10820 | static const char *cpuacct_stat_desc[] = { |
10821 | [CPUACCT_STAT_USER] = "user", | |
10822 | [CPUACCT_STAT_SYSTEM] = "system", | |
10823 | }; | |
10824 | ||
10825 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
10826 | struct cgroup_map_cb *cb) | |
10827 | { | |
10828 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10829 | int i; | |
10830 | ||
10831 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
10832 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
10833 | val = cputime64_to_clock_t(val); | |
10834 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
10835 | } | |
10836 | return 0; | |
10837 | } | |
10838 | ||
d842de87 SV |
10839 | static struct cftype files[] = { |
10840 | { | |
10841 | .name = "usage", | |
f4c753b7 PM |
10842 | .read_u64 = cpuusage_read, |
10843 | .write_u64 = cpuusage_write, | |
d842de87 | 10844 | }, |
e9515c3c KC |
10845 | { |
10846 | .name = "usage_percpu", | |
10847 | .read_seq_string = cpuacct_percpu_seq_read, | |
10848 | }, | |
ef12fefa BR |
10849 | { |
10850 | .name = "stat", | |
10851 | .read_map = cpuacct_stats_show, | |
10852 | }, | |
d842de87 SV |
10853 | }; |
10854 | ||
32cd756a | 10855 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10856 | { |
32cd756a | 10857 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
10858 | } |
10859 | ||
10860 | /* | |
10861 | * charge this task's execution time to its accounting group. | |
10862 | * | |
10863 | * called with rq->lock held. | |
10864 | */ | |
10865 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
10866 | { | |
10867 | struct cpuacct *ca; | |
934352f2 | 10868 | int cpu; |
d842de87 | 10869 | |
c40c6f85 | 10870 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
10871 | return; |
10872 | ||
934352f2 | 10873 | cpu = task_cpu(tsk); |
a18b83b7 BR |
10874 | |
10875 | rcu_read_lock(); | |
10876 | ||
d842de87 | 10877 | ca = task_ca(tsk); |
d842de87 | 10878 | |
934352f2 | 10879 | for (; ca; ca = ca->parent) { |
b36128c8 | 10880 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
10881 | *cpuusage += cputime; |
10882 | } | |
a18b83b7 BR |
10883 | |
10884 | rcu_read_unlock(); | |
d842de87 SV |
10885 | } |
10886 | ||
ef12fefa BR |
10887 | /* |
10888 | * Charge the system/user time to the task's accounting group. | |
10889 | */ | |
10890 | static void cpuacct_update_stats(struct task_struct *tsk, | |
10891 | enum cpuacct_stat_index idx, cputime_t val) | |
10892 | { | |
10893 | struct cpuacct *ca; | |
10894 | ||
10895 | if (unlikely(!cpuacct_subsys.active)) | |
10896 | return; | |
10897 | ||
10898 | rcu_read_lock(); | |
10899 | ca = task_ca(tsk); | |
10900 | ||
10901 | do { | |
10902 | percpu_counter_add(&ca->cpustat[idx], val); | |
10903 | ca = ca->parent; | |
10904 | } while (ca); | |
10905 | rcu_read_unlock(); | |
10906 | } | |
10907 | ||
d842de87 SV |
10908 | struct cgroup_subsys cpuacct_subsys = { |
10909 | .name = "cpuacct", | |
10910 | .create = cpuacct_create, | |
10911 | .destroy = cpuacct_destroy, | |
10912 | .populate = cpuacct_populate, | |
10913 | .subsys_id = cpuacct_subsys_id, | |
10914 | }; | |
10915 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
10916 | |
10917 | #ifndef CONFIG_SMP | |
10918 | ||
10919 | int rcu_expedited_torture_stats(char *page) | |
10920 | { | |
10921 | return 0; | |
10922 | } | |
10923 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10924 | ||
10925 | void synchronize_sched_expedited(void) | |
10926 | { | |
10927 | } | |
10928 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
10929 | ||
10930 | #else /* #ifndef CONFIG_SMP */ | |
10931 | ||
10932 | static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); | |
10933 | static DEFINE_MUTEX(rcu_sched_expedited_mutex); | |
10934 | ||
10935 | #define RCU_EXPEDITED_STATE_POST -2 | |
10936 | #define RCU_EXPEDITED_STATE_IDLE -1 | |
10937 | ||
10938 | static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
10939 | ||
10940 | int rcu_expedited_torture_stats(char *page) | |
10941 | { | |
10942 | int cnt = 0; | |
10943 | int cpu; | |
10944 | ||
10945 | cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); | |
10946 | for_each_online_cpu(cpu) { | |
10947 | cnt += sprintf(&page[cnt], " %d:%d", | |
10948 | cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); | |
10949 | } | |
10950 | cnt += sprintf(&page[cnt], "\n"); | |
10951 | return cnt; | |
10952 | } | |
10953 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10954 | ||
10955 | static long synchronize_sched_expedited_count; | |
10956 | ||
10957 | /* | |
10958 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
10959 | * approach to force grace period to end quickly. This consumes | |
10960 | * significant time on all CPUs, and is thus not recommended for | |
10961 | * any sort of common-case code. | |
10962 | * | |
10963 | * Note that it is illegal to call this function while holding any | |
10964 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
10965 | * observe this restriction will result in deadlock. | |
10966 | */ | |
10967 | void synchronize_sched_expedited(void) | |
10968 | { | |
10969 | int cpu; | |
10970 | unsigned long flags; | |
10971 | bool need_full_sync = 0; | |
10972 | struct rq *rq; | |
10973 | struct migration_req *req; | |
10974 | long snap; | |
10975 | int trycount = 0; | |
10976 | ||
10977 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
10978 | snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; | |
10979 | get_online_cpus(); | |
10980 | while (!mutex_trylock(&rcu_sched_expedited_mutex)) { | |
10981 | put_online_cpus(); | |
10982 | if (trycount++ < 10) | |
10983 | udelay(trycount * num_online_cpus()); | |
10984 | else { | |
10985 | synchronize_sched(); | |
10986 | return; | |
10987 | } | |
10988 | if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { | |
10989 | smp_mb(); /* ensure test happens before caller kfree */ | |
10990 | return; | |
10991 | } | |
10992 | get_online_cpus(); | |
10993 | } | |
10994 | rcu_expedited_state = RCU_EXPEDITED_STATE_POST; | |
10995 | for_each_online_cpu(cpu) { | |
10996 | rq = cpu_rq(cpu); | |
10997 | req = &per_cpu(rcu_migration_req, cpu); | |
10998 | init_completion(&req->done); | |
10999 | req->task = NULL; | |
11000 | req->dest_cpu = RCU_MIGRATION_NEED_QS; | |
05fa785c | 11001 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf | 11002 | list_add(&req->list, &rq->migration_queue); |
05fa785c | 11003 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
11004 | wake_up_process(rq->migration_thread); |
11005 | } | |
11006 | for_each_online_cpu(cpu) { | |
11007 | rcu_expedited_state = cpu; | |
11008 | req = &per_cpu(rcu_migration_req, cpu); | |
11009 | rq = cpu_rq(cpu); | |
11010 | wait_for_completion(&req->done); | |
05fa785c | 11011 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf PM |
11012 | if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) |
11013 | need_full_sync = 1; | |
11014 | req->dest_cpu = RCU_MIGRATION_IDLE; | |
05fa785c | 11015 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
11016 | } |
11017 | rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
956539b7 | 11018 | synchronize_sched_expedited_count++; |
03b042bf PM |
11019 | mutex_unlock(&rcu_sched_expedited_mutex); |
11020 | put_online_cpus(); | |
11021 | if (need_full_sync) | |
11022 | synchronize_sched(); | |
11023 | } | |
11024 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
11025 | ||
11026 | #endif /* #else #ifndef CONFIG_SMP */ |