sched/core: Move the sched_to_prio[] arrays out of line
[deliverable/linux.git] / kernel / sched / sched.h
1
2 #include <linux/sched.h>
3 #include <linux/sched/sysctl.h>
4 #include <linux/sched/rt.h>
5 #include <linux/sched/deadline.h>
6 #include <linux/mutex.h>
7 #include <linux/spinlock.h>
8 #include <linux/stop_machine.h>
9 #include <linux/irq_work.h>
10 #include <linux/tick.h>
11 #include <linux/slab.h>
12
13 #include "cpupri.h"
14 #include "cpudeadline.h"
15 #include "cpuacct.h"
16
17 struct rq;
18 struct cpuidle_state;
19
20 /* task_struct::on_rq states: */
21 #define TASK_ON_RQ_QUEUED 1
22 #define TASK_ON_RQ_MIGRATING 2
23
24 extern __read_mostly int scheduler_running;
25
26 extern unsigned long calc_load_update;
27 extern atomic_long_t calc_load_tasks;
28
29 extern void calc_global_load_tick(struct rq *this_rq);
30 extern long calc_load_fold_active(struct rq *this_rq);
31
32 #ifdef CONFIG_SMP
33 extern void update_cpu_load_active(struct rq *this_rq);
34 #else
35 static inline void update_cpu_load_active(struct rq *this_rq) { }
36 #endif
37
38 /*
39 * Helpers for converting nanosecond timing to jiffy resolution
40 */
41 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
42
43 /*
44 * Increase resolution of nice-level calculations for 64-bit architectures.
45 * The extra resolution improves shares distribution and load balancing of
46 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
47 * hierarchies, especially on larger systems. This is not a user-visible change
48 * and does not change the user-interface for setting shares/weights.
49 *
50 * We increase resolution only if we have enough bits to allow this increased
51 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
52 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
53 * increased costs.
54 */
55 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
56 # define SCHED_LOAD_RESOLUTION 10
57 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
58 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
59 #else
60 # define SCHED_LOAD_RESOLUTION 0
61 # define scale_load(w) (w)
62 # define scale_load_down(w) (w)
63 #endif
64
65 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
66 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
67
68 #define NICE_0_LOAD SCHED_LOAD_SCALE
69 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
70
71 /*
72 * Single value that decides SCHED_DEADLINE internal math precision.
73 * 10 -> just above 1us
74 * 9 -> just above 0.5us
75 */
76 #define DL_SCALE (10)
77
78 /*
79 * These are the 'tuning knobs' of the scheduler:
80 */
81
82 /*
83 * single value that denotes runtime == period, ie unlimited time.
84 */
85 #define RUNTIME_INF ((u64)~0ULL)
86
87 static inline int idle_policy(int policy)
88 {
89 return policy == SCHED_IDLE;
90 }
91 static inline int fair_policy(int policy)
92 {
93 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
94 }
95
96 static inline int rt_policy(int policy)
97 {
98 return policy == SCHED_FIFO || policy == SCHED_RR;
99 }
100
101 static inline int dl_policy(int policy)
102 {
103 return policy == SCHED_DEADLINE;
104 }
105 static inline bool valid_policy(int policy)
106 {
107 return idle_policy(policy) || fair_policy(policy) ||
108 rt_policy(policy) || dl_policy(policy);
109 }
110
111 static inline int task_has_rt_policy(struct task_struct *p)
112 {
113 return rt_policy(p->policy);
114 }
115
116 static inline int task_has_dl_policy(struct task_struct *p)
117 {
118 return dl_policy(p->policy);
119 }
120
121 /*
122 * Tells if entity @a should preempt entity @b.
123 */
124 static inline bool
125 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
126 {
127 return dl_time_before(a->deadline, b->deadline);
128 }
129
130 /*
131 * This is the priority-queue data structure of the RT scheduling class:
132 */
133 struct rt_prio_array {
134 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
135 struct list_head queue[MAX_RT_PRIO];
136 };
137
138 struct rt_bandwidth {
139 /* nests inside the rq lock: */
140 raw_spinlock_t rt_runtime_lock;
141 ktime_t rt_period;
142 u64 rt_runtime;
143 struct hrtimer rt_period_timer;
144 unsigned int rt_period_active;
145 };
146
147 void __dl_clear_params(struct task_struct *p);
148
149 /*
150 * To keep the bandwidth of -deadline tasks and groups under control
151 * we need some place where:
152 * - store the maximum -deadline bandwidth of the system (the group);
153 * - cache the fraction of that bandwidth that is currently allocated.
154 *
155 * This is all done in the data structure below. It is similar to the
156 * one used for RT-throttling (rt_bandwidth), with the main difference
157 * that, since here we are only interested in admission control, we
158 * do not decrease any runtime while the group "executes", neither we
159 * need a timer to replenish it.
160 *
161 * With respect to SMP, the bandwidth is given on a per-CPU basis,
162 * meaning that:
163 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
164 * - dl_total_bw array contains, in the i-eth element, the currently
165 * allocated bandwidth on the i-eth CPU.
166 * Moreover, groups consume bandwidth on each CPU, while tasks only
167 * consume bandwidth on the CPU they're running on.
168 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
169 * that will be shown the next time the proc or cgroup controls will
170 * be red. It on its turn can be changed by writing on its own
171 * control.
172 */
173 struct dl_bandwidth {
174 raw_spinlock_t dl_runtime_lock;
175 u64 dl_runtime;
176 u64 dl_period;
177 };
178
179 static inline int dl_bandwidth_enabled(void)
180 {
181 return sysctl_sched_rt_runtime >= 0;
182 }
183
184 extern struct dl_bw *dl_bw_of(int i);
185
186 struct dl_bw {
187 raw_spinlock_t lock;
188 u64 bw, total_bw;
189 };
190
191 static inline
192 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
193 {
194 dl_b->total_bw -= tsk_bw;
195 }
196
197 static inline
198 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
199 {
200 dl_b->total_bw += tsk_bw;
201 }
202
203 static inline
204 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
205 {
206 return dl_b->bw != -1 &&
207 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
208 }
209
210 extern struct mutex sched_domains_mutex;
211
212 #ifdef CONFIG_CGROUP_SCHED
213
214 #include <linux/cgroup.h>
215
216 struct cfs_rq;
217 struct rt_rq;
218
219 extern struct list_head task_groups;
220
221 struct cfs_bandwidth {
222 #ifdef CONFIG_CFS_BANDWIDTH
223 raw_spinlock_t lock;
224 ktime_t period;
225 u64 quota, runtime;
226 s64 hierarchical_quota;
227 u64 runtime_expires;
228
229 int idle, period_active;
230 struct hrtimer period_timer, slack_timer;
231 struct list_head throttled_cfs_rq;
232
233 /* statistics */
234 int nr_periods, nr_throttled;
235 u64 throttled_time;
236 #endif
237 };
238
239 /* task group related information */
240 struct task_group {
241 struct cgroup_subsys_state css;
242
243 #ifdef CONFIG_FAIR_GROUP_SCHED
244 /* schedulable entities of this group on each cpu */
245 struct sched_entity **se;
246 /* runqueue "owned" by this group on each cpu */
247 struct cfs_rq **cfs_rq;
248 unsigned long shares;
249
250 #ifdef CONFIG_SMP
251 atomic_long_t load_avg;
252 #endif
253 #endif
254
255 #ifdef CONFIG_RT_GROUP_SCHED
256 struct sched_rt_entity **rt_se;
257 struct rt_rq **rt_rq;
258
259 struct rt_bandwidth rt_bandwidth;
260 #endif
261
262 struct rcu_head rcu;
263 struct list_head list;
264
265 struct task_group *parent;
266 struct list_head siblings;
267 struct list_head children;
268
269 #ifdef CONFIG_SCHED_AUTOGROUP
270 struct autogroup *autogroup;
271 #endif
272
273 struct cfs_bandwidth cfs_bandwidth;
274 };
275
276 #ifdef CONFIG_FAIR_GROUP_SCHED
277 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
278
279 /*
280 * A weight of 0 or 1 can cause arithmetics problems.
281 * A weight of a cfs_rq is the sum of weights of which entities
282 * are queued on this cfs_rq, so a weight of a entity should not be
283 * too large, so as the shares value of a task group.
284 * (The default weight is 1024 - so there's no practical
285 * limitation from this.)
286 */
287 #define MIN_SHARES (1UL << 1)
288 #define MAX_SHARES (1UL << 18)
289 #endif
290
291 typedef int (*tg_visitor)(struct task_group *, void *);
292
293 extern int walk_tg_tree_from(struct task_group *from,
294 tg_visitor down, tg_visitor up, void *data);
295
296 /*
297 * Iterate the full tree, calling @down when first entering a node and @up when
298 * leaving it for the final time.
299 *
300 * Caller must hold rcu_lock or sufficient equivalent.
301 */
302 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
303 {
304 return walk_tg_tree_from(&root_task_group, down, up, data);
305 }
306
307 extern int tg_nop(struct task_group *tg, void *data);
308
309 extern void free_fair_sched_group(struct task_group *tg);
310 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
311 extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
312 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
313 struct sched_entity *se, int cpu,
314 struct sched_entity *parent);
315 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
316 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
317
318 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
319 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
320 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
321
322 extern void free_rt_sched_group(struct task_group *tg);
323 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
324 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
325 struct sched_rt_entity *rt_se, int cpu,
326 struct sched_rt_entity *parent);
327
328 extern struct task_group *sched_create_group(struct task_group *parent);
329 extern void sched_online_group(struct task_group *tg,
330 struct task_group *parent);
331 extern void sched_destroy_group(struct task_group *tg);
332 extern void sched_offline_group(struct task_group *tg);
333
334 extern void sched_move_task(struct task_struct *tsk);
335
336 #ifdef CONFIG_FAIR_GROUP_SCHED
337 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
338
339 #ifdef CONFIG_SMP
340 extern void set_task_rq_fair(struct sched_entity *se,
341 struct cfs_rq *prev, struct cfs_rq *next);
342 #else /* !CONFIG_SMP */
343 static inline void set_task_rq_fair(struct sched_entity *se,
344 struct cfs_rq *prev, struct cfs_rq *next) { }
345 #endif /* CONFIG_SMP */
346 #endif /* CONFIG_FAIR_GROUP_SCHED */
347
348 #else /* CONFIG_CGROUP_SCHED */
349
350 struct cfs_bandwidth { };
351
352 #endif /* CONFIG_CGROUP_SCHED */
353
354 /* CFS-related fields in a runqueue */
355 struct cfs_rq {
356 struct load_weight load;
357 unsigned int nr_running, h_nr_running;
358
359 u64 exec_clock;
360 u64 min_vruntime;
361 #ifndef CONFIG_64BIT
362 u64 min_vruntime_copy;
363 #endif
364
365 struct rb_root tasks_timeline;
366 struct rb_node *rb_leftmost;
367
368 /*
369 * 'curr' points to currently running entity on this cfs_rq.
370 * It is set to NULL otherwise (i.e when none are currently running).
371 */
372 struct sched_entity *curr, *next, *last, *skip;
373
374 #ifdef CONFIG_SCHED_DEBUG
375 unsigned int nr_spread_over;
376 #endif
377
378 #ifdef CONFIG_SMP
379 /*
380 * CFS load tracking
381 */
382 struct sched_avg avg;
383 u64 runnable_load_sum;
384 unsigned long runnable_load_avg;
385 #ifdef CONFIG_FAIR_GROUP_SCHED
386 unsigned long tg_load_avg_contrib;
387 #endif
388 atomic_long_t removed_load_avg, removed_util_avg;
389 #ifndef CONFIG_64BIT
390 u64 load_last_update_time_copy;
391 #endif
392
393 #ifdef CONFIG_FAIR_GROUP_SCHED
394 /*
395 * h_load = weight * f(tg)
396 *
397 * Where f(tg) is the recursive weight fraction assigned to
398 * this group.
399 */
400 unsigned long h_load;
401 u64 last_h_load_update;
402 struct sched_entity *h_load_next;
403 #endif /* CONFIG_FAIR_GROUP_SCHED */
404 #endif /* CONFIG_SMP */
405
406 #ifdef CONFIG_FAIR_GROUP_SCHED
407 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
408
409 /*
410 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
411 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
412 * (like users, containers etc.)
413 *
414 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
415 * list is used during load balance.
416 */
417 int on_list;
418 struct list_head leaf_cfs_rq_list;
419 struct task_group *tg; /* group that "owns" this runqueue */
420
421 #ifdef CONFIG_CFS_BANDWIDTH
422 int runtime_enabled;
423 u64 runtime_expires;
424 s64 runtime_remaining;
425
426 u64 throttled_clock, throttled_clock_task;
427 u64 throttled_clock_task_time;
428 int throttled, throttle_count;
429 struct list_head throttled_list;
430 #endif /* CONFIG_CFS_BANDWIDTH */
431 #endif /* CONFIG_FAIR_GROUP_SCHED */
432 };
433
434 static inline int rt_bandwidth_enabled(void)
435 {
436 return sysctl_sched_rt_runtime >= 0;
437 }
438
439 /* RT IPI pull logic requires IRQ_WORK */
440 #ifdef CONFIG_IRQ_WORK
441 # define HAVE_RT_PUSH_IPI
442 #endif
443
444 /* Real-Time classes' related field in a runqueue: */
445 struct rt_rq {
446 struct rt_prio_array active;
447 unsigned int rt_nr_running;
448 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
449 struct {
450 int curr; /* highest queued rt task prio */
451 #ifdef CONFIG_SMP
452 int next; /* next highest */
453 #endif
454 } highest_prio;
455 #endif
456 #ifdef CONFIG_SMP
457 unsigned long rt_nr_migratory;
458 unsigned long rt_nr_total;
459 int overloaded;
460 struct plist_head pushable_tasks;
461 #ifdef HAVE_RT_PUSH_IPI
462 int push_flags;
463 int push_cpu;
464 struct irq_work push_work;
465 raw_spinlock_t push_lock;
466 #endif
467 #endif /* CONFIG_SMP */
468 int rt_queued;
469
470 int rt_throttled;
471 u64 rt_time;
472 u64 rt_runtime;
473 /* Nests inside the rq lock: */
474 raw_spinlock_t rt_runtime_lock;
475
476 #ifdef CONFIG_RT_GROUP_SCHED
477 unsigned long rt_nr_boosted;
478
479 struct rq *rq;
480 struct task_group *tg;
481 #endif
482 };
483
484 /* Deadline class' related fields in a runqueue */
485 struct dl_rq {
486 /* runqueue is an rbtree, ordered by deadline */
487 struct rb_root rb_root;
488 struct rb_node *rb_leftmost;
489
490 unsigned long dl_nr_running;
491
492 #ifdef CONFIG_SMP
493 /*
494 * Deadline values of the currently executing and the
495 * earliest ready task on this rq. Caching these facilitates
496 * the decision wether or not a ready but not running task
497 * should migrate somewhere else.
498 */
499 struct {
500 u64 curr;
501 u64 next;
502 } earliest_dl;
503
504 unsigned long dl_nr_migratory;
505 int overloaded;
506
507 /*
508 * Tasks on this rq that can be pushed away. They are kept in
509 * an rb-tree, ordered by tasks' deadlines, with caching
510 * of the leftmost (earliest deadline) element.
511 */
512 struct rb_root pushable_dl_tasks_root;
513 struct rb_node *pushable_dl_tasks_leftmost;
514 #else
515 struct dl_bw dl_bw;
516 #endif
517 };
518
519 #ifdef CONFIG_SMP
520
521 /*
522 * We add the notion of a root-domain which will be used to define per-domain
523 * variables. Each exclusive cpuset essentially defines an island domain by
524 * fully partitioning the member cpus from any other cpuset. Whenever a new
525 * exclusive cpuset is created, we also create and attach a new root-domain
526 * object.
527 *
528 */
529 struct root_domain {
530 atomic_t refcount;
531 atomic_t rto_count;
532 struct rcu_head rcu;
533 cpumask_var_t span;
534 cpumask_var_t online;
535
536 /* Indicate more than one runnable task for any CPU */
537 bool overload;
538
539 /*
540 * The bit corresponding to a CPU gets set here if such CPU has more
541 * than one runnable -deadline task (as it is below for RT tasks).
542 */
543 cpumask_var_t dlo_mask;
544 atomic_t dlo_count;
545 struct dl_bw dl_bw;
546 struct cpudl cpudl;
547
548 /*
549 * The "RT overload" flag: it gets set if a CPU has more than
550 * one runnable RT task.
551 */
552 cpumask_var_t rto_mask;
553 struct cpupri cpupri;
554 };
555
556 extern struct root_domain def_root_domain;
557
558 #endif /* CONFIG_SMP */
559
560 /*
561 * This is the main, per-CPU runqueue data structure.
562 *
563 * Locking rule: those places that want to lock multiple runqueues
564 * (such as the load balancing or the thread migration code), lock
565 * acquire operations must be ordered by ascending &runqueue.
566 */
567 struct rq {
568 /* runqueue lock: */
569 raw_spinlock_t lock;
570
571 /*
572 * nr_running and cpu_load should be in the same cacheline because
573 * remote CPUs use both these fields when doing load calculation.
574 */
575 unsigned int nr_running;
576 #ifdef CONFIG_NUMA_BALANCING
577 unsigned int nr_numa_running;
578 unsigned int nr_preferred_running;
579 #endif
580 #define CPU_LOAD_IDX_MAX 5
581 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
582 unsigned long last_load_update_tick;
583 #ifdef CONFIG_NO_HZ_COMMON
584 u64 nohz_stamp;
585 unsigned long nohz_flags;
586 #endif
587 #ifdef CONFIG_NO_HZ_FULL
588 unsigned long last_sched_tick;
589 #endif
590 /* capture load from *all* tasks on this cpu: */
591 struct load_weight load;
592 unsigned long nr_load_updates;
593 u64 nr_switches;
594
595 struct cfs_rq cfs;
596 struct rt_rq rt;
597 struct dl_rq dl;
598
599 #ifdef CONFIG_FAIR_GROUP_SCHED
600 /* list of leaf cfs_rq on this cpu: */
601 struct list_head leaf_cfs_rq_list;
602 #endif /* CONFIG_FAIR_GROUP_SCHED */
603
604 /*
605 * This is part of a global counter where only the total sum
606 * over all CPUs matters. A task can increase this counter on
607 * one CPU and if it got migrated afterwards it may decrease
608 * it on another CPU. Always updated under the runqueue lock:
609 */
610 unsigned long nr_uninterruptible;
611
612 struct task_struct *curr, *idle, *stop;
613 unsigned long next_balance;
614 struct mm_struct *prev_mm;
615
616 unsigned int clock_skip_update;
617 u64 clock;
618 u64 clock_task;
619
620 atomic_t nr_iowait;
621
622 #ifdef CONFIG_SMP
623 struct root_domain *rd;
624 struct sched_domain *sd;
625
626 unsigned long cpu_capacity;
627 unsigned long cpu_capacity_orig;
628
629 struct callback_head *balance_callback;
630
631 unsigned char idle_balance;
632 /* For active balancing */
633 int active_balance;
634 int push_cpu;
635 struct cpu_stop_work active_balance_work;
636 /* cpu of this runqueue: */
637 int cpu;
638 int online;
639
640 struct list_head cfs_tasks;
641
642 u64 rt_avg;
643 u64 age_stamp;
644 u64 idle_stamp;
645 u64 avg_idle;
646
647 /* This is used to determine avg_idle's max value */
648 u64 max_idle_balance_cost;
649 #endif
650
651 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
652 u64 prev_irq_time;
653 #endif
654 #ifdef CONFIG_PARAVIRT
655 u64 prev_steal_time;
656 #endif
657 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
658 u64 prev_steal_time_rq;
659 #endif
660
661 /* calc_load related fields */
662 unsigned long calc_load_update;
663 long calc_load_active;
664
665 #ifdef CONFIG_SCHED_HRTICK
666 #ifdef CONFIG_SMP
667 int hrtick_csd_pending;
668 struct call_single_data hrtick_csd;
669 #endif
670 struct hrtimer hrtick_timer;
671 #endif
672
673 #ifdef CONFIG_SCHEDSTATS
674 /* latency stats */
675 struct sched_info rq_sched_info;
676 unsigned long long rq_cpu_time;
677 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
678
679 /* sys_sched_yield() stats */
680 unsigned int yld_count;
681
682 /* schedule() stats */
683 unsigned int sched_count;
684 unsigned int sched_goidle;
685
686 /* try_to_wake_up() stats */
687 unsigned int ttwu_count;
688 unsigned int ttwu_local;
689 #endif
690
691 #ifdef CONFIG_SMP
692 struct llist_head wake_list;
693 #endif
694
695 #ifdef CONFIG_CPU_IDLE
696 /* Must be inspected within a rcu lock section */
697 struct cpuidle_state *idle_state;
698 #endif
699 };
700
701 static inline int cpu_of(struct rq *rq)
702 {
703 #ifdef CONFIG_SMP
704 return rq->cpu;
705 #else
706 return 0;
707 #endif
708 }
709
710 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
711
712 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
713 #define this_rq() this_cpu_ptr(&runqueues)
714 #define task_rq(p) cpu_rq(task_cpu(p))
715 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
716 #define raw_rq() raw_cpu_ptr(&runqueues)
717
718 static inline u64 __rq_clock_broken(struct rq *rq)
719 {
720 return READ_ONCE(rq->clock);
721 }
722
723 static inline u64 rq_clock(struct rq *rq)
724 {
725 lockdep_assert_held(&rq->lock);
726 return rq->clock;
727 }
728
729 static inline u64 rq_clock_task(struct rq *rq)
730 {
731 lockdep_assert_held(&rq->lock);
732 return rq->clock_task;
733 }
734
735 #define RQCF_REQ_SKIP 0x01
736 #define RQCF_ACT_SKIP 0x02
737
738 static inline void rq_clock_skip_update(struct rq *rq, bool skip)
739 {
740 lockdep_assert_held(&rq->lock);
741 if (skip)
742 rq->clock_skip_update |= RQCF_REQ_SKIP;
743 else
744 rq->clock_skip_update &= ~RQCF_REQ_SKIP;
745 }
746
747 #ifdef CONFIG_NUMA
748 enum numa_topology_type {
749 NUMA_DIRECT,
750 NUMA_GLUELESS_MESH,
751 NUMA_BACKPLANE,
752 };
753 extern enum numa_topology_type sched_numa_topology_type;
754 extern int sched_max_numa_distance;
755 extern bool find_numa_distance(int distance);
756 #endif
757
758 #ifdef CONFIG_NUMA_BALANCING
759 /* The regions in numa_faults array from task_struct */
760 enum numa_faults_stats {
761 NUMA_MEM = 0,
762 NUMA_CPU,
763 NUMA_MEMBUF,
764 NUMA_CPUBUF
765 };
766 extern void sched_setnuma(struct task_struct *p, int node);
767 extern int migrate_task_to(struct task_struct *p, int cpu);
768 extern int migrate_swap(struct task_struct *, struct task_struct *);
769 #endif /* CONFIG_NUMA_BALANCING */
770
771 #ifdef CONFIG_SMP
772
773 static inline void
774 queue_balance_callback(struct rq *rq,
775 struct callback_head *head,
776 void (*func)(struct rq *rq))
777 {
778 lockdep_assert_held(&rq->lock);
779
780 if (unlikely(head->next))
781 return;
782
783 head->func = (void (*)(struct callback_head *))func;
784 head->next = rq->balance_callback;
785 rq->balance_callback = head;
786 }
787
788 extern void sched_ttwu_pending(void);
789
790 #define rcu_dereference_check_sched_domain(p) \
791 rcu_dereference_check((p), \
792 lockdep_is_held(&sched_domains_mutex))
793
794 /*
795 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
796 * See detach_destroy_domains: synchronize_sched for details.
797 *
798 * The domain tree of any CPU may only be accessed from within
799 * preempt-disabled sections.
800 */
801 #define for_each_domain(cpu, __sd) \
802 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
803 __sd; __sd = __sd->parent)
804
805 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
806
807 /**
808 * highest_flag_domain - Return highest sched_domain containing flag.
809 * @cpu: The cpu whose highest level of sched domain is to
810 * be returned.
811 * @flag: The flag to check for the highest sched_domain
812 * for the given cpu.
813 *
814 * Returns the highest sched_domain of a cpu which contains the given flag.
815 */
816 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
817 {
818 struct sched_domain *sd, *hsd = NULL;
819
820 for_each_domain(cpu, sd) {
821 if (!(sd->flags & flag))
822 break;
823 hsd = sd;
824 }
825
826 return hsd;
827 }
828
829 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
830 {
831 struct sched_domain *sd;
832
833 for_each_domain(cpu, sd) {
834 if (sd->flags & flag)
835 break;
836 }
837
838 return sd;
839 }
840
841 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
842 DECLARE_PER_CPU(int, sd_llc_size);
843 DECLARE_PER_CPU(int, sd_llc_id);
844 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
845 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
846 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
847
848 struct sched_group_capacity {
849 atomic_t ref;
850 /*
851 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
852 * for a single CPU.
853 */
854 unsigned int capacity;
855 unsigned long next_update;
856 int imbalance; /* XXX unrelated to capacity but shared group state */
857 /*
858 * Number of busy cpus in this group.
859 */
860 atomic_t nr_busy_cpus;
861
862 unsigned long cpumask[0]; /* iteration mask */
863 };
864
865 struct sched_group {
866 struct sched_group *next; /* Must be a circular list */
867 atomic_t ref;
868
869 unsigned int group_weight;
870 struct sched_group_capacity *sgc;
871
872 /*
873 * The CPUs this group covers.
874 *
875 * NOTE: this field is variable length. (Allocated dynamically
876 * by attaching extra space to the end of the structure,
877 * depending on how many CPUs the kernel has booted up with)
878 */
879 unsigned long cpumask[0];
880 };
881
882 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
883 {
884 return to_cpumask(sg->cpumask);
885 }
886
887 /*
888 * cpumask masking which cpus in the group are allowed to iterate up the domain
889 * tree.
890 */
891 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
892 {
893 return to_cpumask(sg->sgc->cpumask);
894 }
895
896 /**
897 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
898 * @group: The group whose first cpu is to be returned.
899 */
900 static inline unsigned int group_first_cpu(struct sched_group *group)
901 {
902 return cpumask_first(sched_group_cpus(group));
903 }
904
905 extern int group_balance_cpu(struct sched_group *sg);
906
907 #else
908
909 static inline void sched_ttwu_pending(void) { }
910
911 #endif /* CONFIG_SMP */
912
913 #include "stats.h"
914 #include "auto_group.h"
915
916 #ifdef CONFIG_CGROUP_SCHED
917
918 /*
919 * Return the group to which this tasks belongs.
920 *
921 * We cannot use task_css() and friends because the cgroup subsystem
922 * changes that value before the cgroup_subsys::attach() method is called,
923 * therefore we cannot pin it and might observe the wrong value.
924 *
925 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
926 * core changes this before calling sched_move_task().
927 *
928 * Instead we use a 'copy' which is updated from sched_move_task() while
929 * holding both task_struct::pi_lock and rq::lock.
930 */
931 static inline struct task_group *task_group(struct task_struct *p)
932 {
933 return p->sched_task_group;
934 }
935
936 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
937 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
938 {
939 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
940 struct task_group *tg = task_group(p);
941 #endif
942
943 #ifdef CONFIG_FAIR_GROUP_SCHED
944 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
945 p->se.cfs_rq = tg->cfs_rq[cpu];
946 p->se.parent = tg->se[cpu];
947 #endif
948
949 #ifdef CONFIG_RT_GROUP_SCHED
950 p->rt.rt_rq = tg->rt_rq[cpu];
951 p->rt.parent = tg->rt_se[cpu];
952 #endif
953 }
954
955 #else /* CONFIG_CGROUP_SCHED */
956
957 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
958 static inline struct task_group *task_group(struct task_struct *p)
959 {
960 return NULL;
961 }
962
963 #endif /* CONFIG_CGROUP_SCHED */
964
965 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
966 {
967 set_task_rq(p, cpu);
968 #ifdef CONFIG_SMP
969 /*
970 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
971 * successfuly executed on another CPU. We must ensure that updates of
972 * per-task data have been completed by this moment.
973 */
974 smp_wmb();
975 task_thread_info(p)->cpu = cpu;
976 p->wake_cpu = cpu;
977 #endif
978 }
979
980 /*
981 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
982 */
983 #ifdef CONFIG_SCHED_DEBUG
984 # include <linux/static_key.h>
985 # define const_debug __read_mostly
986 #else
987 # define const_debug const
988 #endif
989
990 extern const_debug unsigned int sysctl_sched_features;
991
992 #define SCHED_FEAT(name, enabled) \
993 __SCHED_FEAT_##name ,
994
995 enum {
996 #include "features.h"
997 __SCHED_FEAT_NR,
998 };
999
1000 #undef SCHED_FEAT
1001
1002 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
1003 #define SCHED_FEAT(name, enabled) \
1004 static __always_inline bool static_branch_##name(struct static_key *key) \
1005 { \
1006 return static_key_##enabled(key); \
1007 }
1008
1009 #include "features.h"
1010
1011 #undef SCHED_FEAT
1012
1013 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1014 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1015 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1016 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1017 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1018
1019 extern struct static_key_false sched_numa_balancing;
1020
1021 static inline u64 global_rt_period(void)
1022 {
1023 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1024 }
1025
1026 static inline u64 global_rt_runtime(void)
1027 {
1028 if (sysctl_sched_rt_runtime < 0)
1029 return RUNTIME_INF;
1030
1031 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1032 }
1033
1034 static inline int task_current(struct rq *rq, struct task_struct *p)
1035 {
1036 return rq->curr == p;
1037 }
1038
1039 static inline int task_running(struct rq *rq, struct task_struct *p)
1040 {
1041 #ifdef CONFIG_SMP
1042 return p->on_cpu;
1043 #else
1044 return task_current(rq, p);
1045 #endif
1046 }
1047
1048 static inline int task_on_rq_queued(struct task_struct *p)
1049 {
1050 return p->on_rq == TASK_ON_RQ_QUEUED;
1051 }
1052
1053 static inline int task_on_rq_migrating(struct task_struct *p)
1054 {
1055 return p->on_rq == TASK_ON_RQ_MIGRATING;
1056 }
1057
1058 #ifndef prepare_arch_switch
1059 # define prepare_arch_switch(next) do { } while (0)
1060 #endif
1061 #ifndef finish_arch_post_lock_switch
1062 # define finish_arch_post_lock_switch() do { } while (0)
1063 #endif
1064
1065 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1066 {
1067 #ifdef CONFIG_SMP
1068 /*
1069 * We can optimise this out completely for !SMP, because the
1070 * SMP rebalancing from interrupt is the only thing that cares
1071 * here.
1072 */
1073 next->on_cpu = 1;
1074 #endif
1075 }
1076
1077 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1078 {
1079 #ifdef CONFIG_SMP
1080 /*
1081 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1082 * We must ensure this doesn't happen until the switch is completely
1083 * finished.
1084 *
1085 * In particular, the load of prev->state in finish_task_switch() must
1086 * happen before this.
1087 *
1088 * Pairs with the control dependency and rmb in try_to_wake_up().
1089 */
1090 smp_store_release(&prev->on_cpu, 0);
1091 #endif
1092 #ifdef CONFIG_DEBUG_SPINLOCK
1093 /* this is a valid case when another task releases the spinlock */
1094 rq->lock.owner = current;
1095 #endif
1096 /*
1097 * If we are tracking spinlock dependencies then we have to
1098 * fix up the runqueue lock - which gets 'carried over' from
1099 * prev into current:
1100 */
1101 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
1102
1103 raw_spin_unlock_irq(&rq->lock);
1104 }
1105
1106 /*
1107 * wake flags
1108 */
1109 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1110 #define WF_FORK 0x02 /* child wakeup after fork */
1111 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1112
1113 /*
1114 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1115 * of tasks with abnormal "nice" values across CPUs the contribution that
1116 * each task makes to its run queue's load is weighted according to its
1117 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1118 * scaled version of the new time slice allocation that they receive on time
1119 * slice expiry etc.
1120 */
1121
1122 #define WEIGHT_IDLEPRIO 3
1123 #define WMULT_IDLEPRIO 1431655765
1124
1125 extern const int sched_prio_to_weight[40];
1126 extern const u32 sched_prio_to_wmult[40];
1127
1128 #define ENQUEUE_WAKEUP 0x01
1129 #define ENQUEUE_HEAD 0x02
1130 #ifdef CONFIG_SMP
1131 #define ENQUEUE_WAKING 0x04 /* sched_class::task_waking was called */
1132 #else
1133 #define ENQUEUE_WAKING 0x00
1134 #endif
1135 #define ENQUEUE_REPLENISH 0x08
1136 #define ENQUEUE_RESTORE 0x10
1137
1138 #define DEQUEUE_SLEEP 0x01
1139 #define DEQUEUE_SAVE 0x02
1140
1141 #define RETRY_TASK ((void *)-1UL)
1142
1143 struct sched_class {
1144 const struct sched_class *next;
1145
1146 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1147 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1148 void (*yield_task) (struct rq *rq);
1149 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1150
1151 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1152
1153 /*
1154 * It is the responsibility of the pick_next_task() method that will
1155 * return the next task to call put_prev_task() on the @prev task or
1156 * something equivalent.
1157 *
1158 * May return RETRY_TASK when it finds a higher prio class has runnable
1159 * tasks.
1160 */
1161 struct task_struct * (*pick_next_task) (struct rq *rq,
1162 struct task_struct *prev);
1163 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1164
1165 #ifdef CONFIG_SMP
1166 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1167 void (*migrate_task_rq)(struct task_struct *p);
1168
1169 void (*task_waking) (struct task_struct *task);
1170 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1171
1172 void (*set_cpus_allowed)(struct task_struct *p,
1173 const struct cpumask *newmask);
1174
1175 void (*rq_online)(struct rq *rq);
1176 void (*rq_offline)(struct rq *rq);
1177 #endif
1178
1179 void (*set_curr_task) (struct rq *rq);
1180 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1181 void (*task_fork) (struct task_struct *p);
1182 void (*task_dead) (struct task_struct *p);
1183
1184 /*
1185 * The switched_from() call is allowed to drop rq->lock, therefore we
1186 * cannot assume the switched_from/switched_to pair is serliazed by
1187 * rq->lock. They are however serialized by p->pi_lock.
1188 */
1189 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1190 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1191 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1192 int oldprio);
1193
1194 unsigned int (*get_rr_interval) (struct rq *rq,
1195 struct task_struct *task);
1196
1197 void (*update_curr) (struct rq *rq);
1198
1199 #ifdef CONFIG_FAIR_GROUP_SCHED
1200 void (*task_move_group) (struct task_struct *p);
1201 #endif
1202 };
1203
1204 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1205 {
1206 prev->sched_class->put_prev_task(rq, prev);
1207 }
1208
1209 #define sched_class_highest (&stop_sched_class)
1210 #define for_each_class(class) \
1211 for (class = sched_class_highest; class; class = class->next)
1212
1213 extern const struct sched_class stop_sched_class;
1214 extern const struct sched_class dl_sched_class;
1215 extern const struct sched_class rt_sched_class;
1216 extern const struct sched_class fair_sched_class;
1217 extern const struct sched_class idle_sched_class;
1218
1219
1220 #ifdef CONFIG_SMP
1221
1222 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1223
1224 extern void trigger_load_balance(struct rq *rq);
1225
1226 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1227
1228 #endif
1229
1230 #ifdef CONFIG_CPU_IDLE
1231 static inline void idle_set_state(struct rq *rq,
1232 struct cpuidle_state *idle_state)
1233 {
1234 rq->idle_state = idle_state;
1235 }
1236
1237 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1238 {
1239 WARN_ON(!rcu_read_lock_held());
1240 return rq->idle_state;
1241 }
1242 #else
1243 static inline void idle_set_state(struct rq *rq,
1244 struct cpuidle_state *idle_state)
1245 {
1246 }
1247
1248 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1249 {
1250 return NULL;
1251 }
1252 #endif
1253
1254 extern void sysrq_sched_debug_show(void);
1255 extern void sched_init_granularity(void);
1256 extern void update_max_interval(void);
1257
1258 extern void init_sched_dl_class(void);
1259 extern void init_sched_rt_class(void);
1260 extern void init_sched_fair_class(void);
1261
1262 extern void resched_curr(struct rq *rq);
1263 extern void resched_cpu(int cpu);
1264
1265 extern struct rt_bandwidth def_rt_bandwidth;
1266 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1267
1268 extern struct dl_bandwidth def_dl_bandwidth;
1269 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1270 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1271
1272 unsigned long to_ratio(u64 period, u64 runtime);
1273
1274 extern void init_entity_runnable_average(struct sched_entity *se);
1275
1276 static inline void add_nr_running(struct rq *rq, unsigned count)
1277 {
1278 unsigned prev_nr = rq->nr_running;
1279
1280 rq->nr_running = prev_nr + count;
1281
1282 if (prev_nr < 2 && rq->nr_running >= 2) {
1283 #ifdef CONFIG_SMP
1284 if (!rq->rd->overload)
1285 rq->rd->overload = true;
1286 #endif
1287
1288 #ifdef CONFIG_NO_HZ_FULL
1289 if (tick_nohz_full_cpu(rq->cpu)) {
1290 /*
1291 * Tick is needed if more than one task runs on a CPU.
1292 * Send the target an IPI to kick it out of nohz mode.
1293 *
1294 * We assume that IPI implies full memory barrier and the
1295 * new value of rq->nr_running is visible on reception
1296 * from the target.
1297 */
1298 tick_nohz_full_kick_cpu(rq->cpu);
1299 }
1300 #endif
1301 }
1302 }
1303
1304 static inline void sub_nr_running(struct rq *rq, unsigned count)
1305 {
1306 rq->nr_running -= count;
1307 }
1308
1309 static inline void rq_last_tick_reset(struct rq *rq)
1310 {
1311 #ifdef CONFIG_NO_HZ_FULL
1312 rq->last_sched_tick = jiffies;
1313 #endif
1314 }
1315
1316 extern void update_rq_clock(struct rq *rq);
1317
1318 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1319 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1320
1321 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1322
1323 extern const_debug unsigned int sysctl_sched_time_avg;
1324 extern const_debug unsigned int sysctl_sched_nr_migrate;
1325 extern const_debug unsigned int sysctl_sched_migration_cost;
1326
1327 static inline u64 sched_avg_period(void)
1328 {
1329 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1330 }
1331
1332 #ifdef CONFIG_SCHED_HRTICK
1333
1334 /*
1335 * Use hrtick when:
1336 * - enabled by features
1337 * - hrtimer is actually high res
1338 */
1339 static inline int hrtick_enabled(struct rq *rq)
1340 {
1341 if (!sched_feat(HRTICK))
1342 return 0;
1343 if (!cpu_active(cpu_of(rq)))
1344 return 0;
1345 return hrtimer_is_hres_active(&rq->hrtick_timer);
1346 }
1347
1348 void hrtick_start(struct rq *rq, u64 delay);
1349
1350 #else
1351
1352 static inline int hrtick_enabled(struct rq *rq)
1353 {
1354 return 0;
1355 }
1356
1357 #endif /* CONFIG_SCHED_HRTICK */
1358
1359 #ifdef CONFIG_SMP
1360 extern void sched_avg_update(struct rq *rq);
1361
1362 #ifndef arch_scale_freq_capacity
1363 static __always_inline
1364 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
1365 {
1366 return SCHED_CAPACITY_SCALE;
1367 }
1368 #endif
1369
1370 #ifndef arch_scale_cpu_capacity
1371 static __always_inline
1372 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
1373 {
1374 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1375 return sd->smt_gain / sd->span_weight;
1376
1377 return SCHED_CAPACITY_SCALE;
1378 }
1379 #endif
1380
1381 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1382 {
1383 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1384 sched_avg_update(rq);
1385 }
1386 #else
1387 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1388 static inline void sched_avg_update(struct rq *rq) { }
1389 #endif
1390
1391 /*
1392 * __task_rq_lock - lock the rq @p resides on.
1393 */
1394 static inline struct rq *__task_rq_lock(struct task_struct *p)
1395 __acquires(rq->lock)
1396 {
1397 struct rq *rq;
1398
1399 lockdep_assert_held(&p->pi_lock);
1400
1401 for (;;) {
1402 rq = task_rq(p);
1403 raw_spin_lock(&rq->lock);
1404 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1405 lockdep_pin_lock(&rq->lock);
1406 return rq;
1407 }
1408 raw_spin_unlock(&rq->lock);
1409
1410 while (unlikely(task_on_rq_migrating(p)))
1411 cpu_relax();
1412 }
1413 }
1414
1415 /*
1416 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
1417 */
1418 static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
1419 __acquires(p->pi_lock)
1420 __acquires(rq->lock)
1421 {
1422 struct rq *rq;
1423
1424 for (;;) {
1425 raw_spin_lock_irqsave(&p->pi_lock, *flags);
1426 rq = task_rq(p);
1427 raw_spin_lock(&rq->lock);
1428 /*
1429 * move_queued_task() task_rq_lock()
1430 *
1431 * ACQUIRE (rq->lock)
1432 * [S] ->on_rq = MIGRATING [L] rq = task_rq()
1433 * WMB (__set_task_cpu()) ACQUIRE (rq->lock);
1434 * [S] ->cpu = new_cpu [L] task_rq()
1435 * [L] ->on_rq
1436 * RELEASE (rq->lock)
1437 *
1438 * If we observe the old cpu in task_rq_lock, the acquire of
1439 * the old rq->lock will fully serialize against the stores.
1440 *
1441 * If we observe the new cpu in task_rq_lock, the acquire will
1442 * pair with the WMB to ensure we must then also see migrating.
1443 */
1444 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1445 lockdep_pin_lock(&rq->lock);
1446 return rq;
1447 }
1448 raw_spin_unlock(&rq->lock);
1449 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1450
1451 while (unlikely(task_on_rq_migrating(p)))
1452 cpu_relax();
1453 }
1454 }
1455
1456 static inline void __task_rq_unlock(struct rq *rq)
1457 __releases(rq->lock)
1458 {
1459 lockdep_unpin_lock(&rq->lock);
1460 raw_spin_unlock(&rq->lock);
1461 }
1462
1463 static inline void
1464 task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
1465 __releases(rq->lock)
1466 __releases(p->pi_lock)
1467 {
1468 lockdep_unpin_lock(&rq->lock);
1469 raw_spin_unlock(&rq->lock);
1470 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1471 }
1472
1473 #ifdef CONFIG_SMP
1474 #ifdef CONFIG_PREEMPT
1475
1476 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1477
1478 /*
1479 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1480 * way at the expense of forcing extra atomic operations in all
1481 * invocations. This assures that the double_lock is acquired using the
1482 * same underlying policy as the spinlock_t on this architecture, which
1483 * reduces latency compared to the unfair variant below. However, it
1484 * also adds more overhead and therefore may reduce throughput.
1485 */
1486 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1487 __releases(this_rq->lock)
1488 __acquires(busiest->lock)
1489 __acquires(this_rq->lock)
1490 {
1491 raw_spin_unlock(&this_rq->lock);
1492 double_rq_lock(this_rq, busiest);
1493
1494 return 1;
1495 }
1496
1497 #else
1498 /*
1499 * Unfair double_lock_balance: Optimizes throughput at the expense of
1500 * latency by eliminating extra atomic operations when the locks are
1501 * already in proper order on entry. This favors lower cpu-ids and will
1502 * grant the double lock to lower cpus over higher ids under contention,
1503 * regardless of entry order into the function.
1504 */
1505 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1506 __releases(this_rq->lock)
1507 __acquires(busiest->lock)
1508 __acquires(this_rq->lock)
1509 {
1510 int ret = 0;
1511
1512 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1513 if (busiest < this_rq) {
1514 raw_spin_unlock(&this_rq->lock);
1515 raw_spin_lock(&busiest->lock);
1516 raw_spin_lock_nested(&this_rq->lock,
1517 SINGLE_DEPTH_NESTING);
1518 ret = 1;
1519 } else
1520 raw_spin_lock_nested(&busiest->lock,
1521 SINGLE_DEPTH_NESTING);
1522 }
1523 return ret;
1524 }
1525
1526 #endif /* CONFIG_PREEMPT */
1527
1528 /*
1529 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1530 */
1531 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1532 {
1533 if (unlikely(!irqs_disabled())) {
1534 /* printk() doesn't work good under rq->lock */
1535 raw_spin_unlock(&this_rq->lock);
1536 BUG_ON(1);
1537 }
1538
1539 return _double_lock_balance(this_rq, busiest);
1540 }
1541
1542 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1543 __releases(busiest->lock)
1544 {
1545 raw_spin_unlock(&busiest->lock);
1546 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1547 }
1548
1549 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1550 {
1551 if (l1 > l2)
1552 swap(l1, l2);
1553
1554 spin_lock(l1);
1555 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1556 }
1557
1558 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1559 {
1560 if (l1 > l2)
1561 swap(l1, l2);
1562
1563 spin_lock_irq(l1);
1564 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1565 }
1566
1567 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1568 {
1569 if (l1 > l2)
1570 swap(l1, l2);
1571
1572 raw_spin_lock(l1);
1573 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1574 }
1575
1576 /*
1577 * double_rq_lock - safely lock two runqueues
1578 *
1579 * Note this does not disable interrupts like task_rq_lock,
1580 * you need to do so manually before calling.
1581 */
1582 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1583 __acquires(rq1->lock)
1584 __acquires(rq2->lock)
1585 {
1586 BUG_ON(!irqs_disabled());
1587 if (rq1 == rq2) {
1588 raw_spin_lock(&rq1->lock);
1589 __acquire(rq2->lock); /* Fake it out ;) */
1590 } else {
1591 if (rq1 < rq2) {
1592 raw_spin_lock(&rq1->lock);
1593 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1594 } else {
1595 raw_spin_lock(&rq2->lock);
1596 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1597 }
1598 }
1599 }
1600
1601 /*
1602 * double_rq_unlock - safely unlock two runqueues
1603 *
1604 * Note this does not restore interrupts like task_rq_unlock,
1605 * you need to do so manually after calling.
1606 */
1607 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1608 __releases(rq1->lock)
1609 __releases(rq2->lock)
1610 {
1611 raw_spin_unlock(&rq1->lock);
1612 if (rq1 != rq2)
1613 raw_spin_unlock(&rq2->lock);
1614 else
1615 __release(rq2->lock);
1616 }
1617
1618 #else /* CONFIG_SMP */
1619
1620 /*
1621 * double_rq_lock - safely lock two runqueues
1622 *
1623 * Note this does not disable interrupts like task_rq_lock,
1624 * you need to do so manually before calling.
1625 */
1626 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1627 __acquires(rq1->lock)
1628 __acquires(rq2->lock)
1629 {
1630 BUG_ON(!irqs_disabled());
1631 BUG_ON(rq1 != rq2);
1632 raw_spin_lock(&rq1->lock);
1633 __acquire(rq2->lock); /* Fake it out ;) */
1634 }
1635
1636 /*
1637 * double_rq_unlock - safely unlock two runqueues
1638 *
1639 * Note this does not restore interrupts like task_rq_unlock,
1640 * you need to do so manually after calling.
1641 */
1642 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1643 __releases(rq1->lock)
1644 __releases(rq2->lock)
1645 {
1646 BUG_ON(rq1 != rq2);
1647 raw_spin_unlock(&rq1->lock);
1648 __release(rq2->lock);
1649 }
1650
1651 #endif
1652
1653 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1654 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1655
1656 #ifdef CONFIG_SCHED_DEBUG
1657 extern void print_cfs_stats(struct seq_file *m, int cpu);
1658 extern void print_rt_stats(struct seq_file *m, int cpu);
1659 extern void print_dl_stats(struct seq_file *m, int cpu);
1660 extern void
1661 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1662
1663 #ifdef CONFIG_NUMA_BALANCING
1664 extern void
1665 show_numa_stats(struct task_struct *p, struct seq_file *m);
1666 extern void
1667 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1668 unsigned long tpf, unsigned long gsf, unsigned long gpf);
1669 #endif /* CONFIG_NUMA_BALANCING */
1670 #endif /* CONFIG_SCHED_DEBUG */
1671
1672 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1673 extern void init_rt_rq(struct rt_rq *rt_rq);
1674 extern void init_dl_rq(struct dl_rq *dl_rq);
1675
1676 extern void cfs_bandwidth_usage_inc(void);
1677 extern void cfs_bandwidth_usage_dec(void);
1678
1679 #ifdef CONFIG_NO_HZ_COMMON
1680 enum rq_nohz_flag_bits {
1681 NOHZ_TICK_STOPPED,
1682 NOHZ_BALANCE_KICK,
1683 };
1684
1685 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1686 #endif
1687
1688 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1689
1690 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1691 DECLARE_PER_CPU(u64, cpu_softirq_time);
1692
1693 #ifndef CONFIG_64BIT
1694 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1695
1696 static inline void irq_time_write_begin(void)
1697 {
1698 __this_cpu_inc(irq_time_seq.sequence);
1699 smp_wmb();
1700 }
1701
1702 static inline void irq_time_write_end(void)
1703 {
1704 smp_wmb();
1705 __this_cpu_inc(irq_time_seq.sequence);
1706 }
1707
1708 static inline u64 irq_time_read(int cpu)
1709 {
1710 u64 irq_time;
1711 unsigned seq;
1712
1713 do {
1714 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1715 irq_time = per_cpu(cpu_softirq_time, cpu) +
1716 per_cpu(cpu_hardirq_time, cpu);
1717 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1718
1719 return irq_time;
1720 }
1721 #else /* CONFIG_64BIT */
1722 static inline void irq_time_write_begin(void)
1723 {
1724 }
1725
1726 static inline void irq_time_write_end(void)
1727 {
1728 }
1729
1730 static inline u64 irq_time_read(int cpu)
1731 {
1732 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1733 }
1734 #endif /* CONFIG_64BIT */
1735 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
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