Merge branch 'drm-next-4.6' of git://people.freedesktop.org/~agd5f/linux into drm...
[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/binfmts.h>
7 #include <linux/mutex.h>
8 #include <linux/spinlock.h>
9 #include <linux/stop_machine.h>
10 #include <linux/irq_work.h>
11 #include <linux/tick.h>
12 #include <linux/slab.h>
13
14 #include "cpupri.h"
15 #include "cpudeadline.h"
16 #include "cpuacct.h"
17
18 struct rq;
19 struct cpuidle_state;
20
21 /* task_struct::on_rq states: */
22 #define TASK_ON_RQ_QUEUED 1
23 #define TASK_ON_RQ_MIGRATING 2
24
25 extern __read_mostly int scheduler_running;
26
27 extern unsigned long calc_load_update;
28 extern atomic_long_t calc_load_tasks;
29
30 extern void calc_global_load_tick(struct rq *this_rq);
31 extern long calc_load_fold_active(struct rq *this_rq);
32
33 #ifdef CONFIG_SMP
34 extern void update_cpu_load_active(struct rq *this_rq);
35 #else
36 static inline void update_cpu_load_active(struct rq *this_rq) { }
37 #endif
38
39 /*
40 * Helpers for converting nanosecond timing to jiffy resolution
41 */
42 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
43
44 /*
45 * Increase resolution of nice-level calculations for 64-bit architectures.
46 * The extra resolution improves shares distribution and load balancing of
47 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
48 * hierarchies, especially on larger systems. This is not a user-visible change
49 * and does not change the user-interface for setting shares/weights.
50 *
51 * We increase resolution only if we have enough bits to allow this increased
52 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
53 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
54 * increased costs.
55 */
56 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
57 # define SCHED_LOAD_RESOLUTION 10
58 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
59 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
60 #else
61 # define SCHED_LOAD_RESOLUTION 0
62 # define scale_load(w) (w)
63 # define scale_load_down(w) (w)
64 #endif
65
66 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
67 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
68
69 #define NICE_0_LOAD SCHED_LOAD_SCALE
70 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
71
72 /*
73 * Single value that decides SCHED_DEADLINE internal math precision.
74 * 10 -> just above 1us
75 * 9 -> just above 0.5us
76 */
77 #define DL_SCALE (10)
78
79 /*
80 * These are the 'tuning knobs' of the scheduler:
81 */
82
83 /*
84 * single value that denotes runtime == period, ie unlimited time.
85 */
86 #define RUNTIME_INF ((u64)~0ULL)
87
88 static inline int idle_policy(int policy)
89 {
90 return policy == SCHED_IDLE;
91 }
92 static inline int fair_policy(int policy)
93 {
94 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
95 }
96
97 static inline int rt_policy(int policy)
98 {
99 return policy == SCHED_FIFO || policy == SCHED_RR;
100 }
101
102 static inline int dl_policy(int policy)
103 {
104 return policy == SCHED_DEADLINE;
105 }
106 static inline bool valid_policy(int policy)
107 {
108 return idle_policy(policy) || fair_policy(policy) ||
109 rt_policy(policy) || dl_policy(policy);
110 }
111
112 static inline int task_has_rt_policy(struct task_struct *p)
113 {
114 return rt_policy(p->policy);
115 }
116
117 static inline int task_has_dl_policy(struct task_struct *p)
118 {
119 return dl_policy(p->policy);
120 }
121
122 /*
123 * Tells if entity @a should preempt entity @b.
124 */
125 static inline bool
126 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
127 {
128 return dl_time_before(a->deadline, b->deadline);
129 }
130
131 /*
132 * This is the priority-queue data structure of the RT scheduling class:
133 */
134 struct rt_prio_array {
135 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
136 struct list_head queue[MAX_RT_PRIO];
137 };
138
139 struct rt_bandwidth {
140 /* nests inside the rq lock: */
141 raw_spinlock_t rt_runtime_lock;
142 ktime_t rt_period;
143 u64 rt_runtime;
144 struct hrtimer rt_period_timer;
145 unsigned int rt_period_active;
146 };
147
148 void __dl_clear_params(struct task_struct *p);
149
150 /*
151 * To keep the bandwidth of -deadline tasks and groups under control
152 * we need some place where:
153 * - store the maximum -deadline bandwidth of the system (the group);
154 * - cache the fraction of that bandwidth that is currently allocated.
155 *
156 * This is all done in the data structure below. It is similar to the
157 * one used for RT-throttling (rt_bandwidth), with the main difference
158 * that, since here we are only interested in admission control, we
159 * do not decrease any runtime while the group "executes", neither we
160 * need a timer to replenish it.
161 *
162 * With respect to SMP, the bandwidth is given on a per-CPU basis,
163 * meaning that:
164 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
165 * - dl_total_bw array contains, in the i-eth element, the currently
166 * allocated bandwidth on the i-eth CPU.
167 * Moreover, groups consume bandwidth on each CPU, while tasks only
168 * consume bandwidth on the CPU they're running on.
169 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
170 * that will be shown the next time the proc or cgroup controls will
171 * be red. It on its turn can be changed by writing on its own
172 * control.
173 */
174 struct dl_bandwidth {
175 raw_spinlock_t dl_runtime_lock;
176 u64 dl_runtime;
177 u64 dl_period;
178 };
179
180 static inline int dl_bandwidth_enabled(void)
181 {
182 return sysctl_sched_rt_runtime >= 0;
183 }
184
185 extern struct dl_bw *dl_bw_of(int i);
186
187 struct dl_bw {
188 raw_spinlock_t lock;
189 u64 bw, total_bw;
190 };
191
192 static inline
193 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
194 {
195 dl_b->total_bw -= tsk_bw;
196 }
197
198 static inline
199 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
200 {
201 dl_b->total_bw += tsk_bw;
202 }
203
204 static inline
205 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
206 {
207 return dl_b->bw != -1 &&
208 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
209 }
210
211 extern struct mutex sched_domains_mutex;
212
213 #ifdef CONFIG_CGROUP_SCHED
214
215 #include <linux/cgroup.h>
216
217 struct cfs_rq;
218 struct rt_rq;
219
220 extern struct list_head task_groups;
221
222 struct cfs_bandwidth {
223 #ifdef CONFIG_CFS_BANDWIDTH
224 raw_spinlock_t lock;
225 ktime_t period;
226 u64 quota, runtime;
227 s64 hierarchical_quota;
228 u64 runtime_expires;
229
230 int idle, period_active;
231 struct hrtimer period_timer, slack_timer;
232 struct list_head throttled_cfs_rq;
233
234 /* statistics */
235 int nr_periods, nr_throttled;
236 u64 throttled_time;
237 #endif
238 };
239
240 /* task group related information */
241 struct task_group {
242 struct cgroup_subsys_state css;
243
244 #ifdef CONFIG_FAIR_GROUP_SCHED
245 /* schedulable entities of this group on each cpu */
246 struct sched_entity **se;
247 /* runqueue "owned" by this group on each cpu */
248 struct cfs_rq **cfs_rq;
249 unsigned long shares;
250
251 #ifdef CONFIG_SMP
252 /*
253 * load_avg can be heavily contended at clock tick time, so put
254 * it in its own cacheline separated from the fields above which
255 * will also be accessed at each tick.
256 */
257 atomic_long_t load_avg ____cacheline_aligned;
258 #endif
259 #endif
260
261 #ifdef CONFIG_RT_GROUP_SCHED
262 struct sched_rt_entity **rt_se;
263 struct rt_rq **rt_rq;
264
265 struct rt_bandwidth rt_bandwidth;
266 #endif
267
268 struct rcu_head rcu;
269 struct list_head list;
270
271 struct task_group *parent;
272 struct list_head siblings;
273 struct list_head children;
274
275 #ifdef CONFIG_SCHED_AUTOGROUP
276 struct autogroup *autogroup;
277 #endif
278
279 struct cfs_bandwidth cfs_bandwidth;
280 };
281
282 #ifdef CONFIG_FAIR_GROUP_SCHED
283 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
284
285 /*
286 * A weight of 0 or 1 can cause arithmetics problems.
287 * A weight of a cfs_rq is the sum of weights of which entities
288 * are queued on this cfs_rq, so a weight of a entity should not be
289 * too large, so as the shares value of a task group.
290 * (The default weight is 1024 - so there's no practical
291 * limitation from this.)
292 */
293 #define MIN_SHARES (1UL << 1)
294 #define MAX_SHARES (1UL << 18)
295 #endif
296
297 typedef int (*tg_visitor)(struct task_group *, void *);
298
299 extern int walk_tg_tree_from(struct task_group *from,
300 tg_visitor down, tg_visitor up, void *data);
301
302 /*
303 * Iterate the full tree, calling @down when first entering a node and @up when
304 * leaving it for the final time.
305 *
306 * Caller must hold rcu_lock or sufficient equivalent.
307 */
308 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
309 {
310 return walk_tg_tree_from(&root_task_group, down, up, data);
311 }
312
313 extern int tg_nop(struct task_group *tg, void *data);
314
315 extern void free_fair_sched_group(struct task_group *tg);
316 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
317 extern void unregister_fair_sched_group(struct task_group *tg);
318 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
319 struct sched_entity *se, int cpu,
320 struct sched_entity *parent);
321 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
322
323 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
324 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
325 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
326
327 extern void free_rt_sched_group(struct task_group *tg);
328 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
329 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
330 struct sched_rt_entity *rt_se, int cpu,
331 struct sched_rt_entity *parent);
332
333 extern struct task_group *sched_create_group(struct task_group *parent);
334 extern void sched_online_group(struct task_group *tg,
335 struct task_group *parent);
336 extern void sched_destroy_group(struct task_group *tg);
337 extern void sched_offline_group(struct task_group *tg);
338
339 extern void sched_move_task(struct task_struct *tsk);
340
341 #ifdef CONFIG_FAIR_GROUP_SCHED
342 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
343
344 #ifdef CONFIG_SMP
345 extern void set_task_rq_fair(struct sched_entity *se,
346 struct cfs_rq *prev, struct cfs_rq *next);
347 #else /* !CONFIG_SMP */
348 static inline void set_task_rq_fair(struct sched_entity *se,
349 struct cfs_rq *prev, struct cfs_rq *next) { }
350 #endif /* CONFIG_SMP */
351 #endif /* CONFIG_FAIR_GROUP_SCHED */
352
353 #else /* CONFIG_CGROUP_SCHED */
354
355 struct cfs_bandwidth { };
356
357 #endif /* CONFIG_CGROUP_SCHED */
358
359 /* CFS-related fields in a runqueue */
360 struct cfs_rq {
361 struct load_weight load;
362 unsigned int nr_running, h_nr_running;
363
364 u64 exec_clock;
365 u64 min_vruntime;
366 #ifndef CONFIG_64BIT
367 u64 min_vruntime_copy;
368 #endif
369
370 struct rb_root tasks_timeline;
371 struct rb_node *rb_leftmost;
372
373 /*
374 * 'curr' points to currently running entity on this cfs_rq.
375 * It is set to NULL otherwise (i.e when none are currently running).
376 */
377 struct sched_entity *curr, *next, *last, *skip;
378
379 #ifdef CONFIG_SCHED_DEBUG
380 unsigned int nr_spread_over;
381 #endif
382
383 #ifdef CONFIG_SMP
384 /*
385 * CFS load tracking
386 */
387 struct sched_avg avg;
388 u64 runnable_load_sum;
389 unsigned long runnable_load_avg;
390 #ifdef CONFIG_FAIR_GROUP_SCHED
391 unsigned long tg_load_avg_contrib;
392 #endif
393 atomic_long_t removed_load_avg, removed_util_avg;
394 #ifndef CONFIG_64BIT
395 u64 load_last_update_time_copy;
396 #endif
397
398 #ifdef CONFIG_FAIR_GROUP_SCHED
399 /*
400 * h_load = weight * f(tg)
401 *
402 * Where f(tg) is the recursive weight fraction assigned to
403 * this group.
404 */
405 unsigned long h_load;
406 u64 last_h_load_update;
407 struct sched_entity *h_load_next;
408 #endif /* CONFIG_FAIR_GROUP_SCHED */
409 #endif /* CONFIG_SMP */
410
411 #ifdef CONFIG_FAIR_GROUP_SCHED
412 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
413
414 /*
415 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
416 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
417 * (like users, containers etc.)
418 *
419 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
420 * list is used during load balance.
421 */
422 int on_list;
423 struct list_head leaf_cfs_rq_list;
424 struct task_group *tg; /* group that "owns" this runqueue */
425
426 #ifdef CONFIG_CFS_BANDWIDTH
427 int runtime_enabled;
428 u64 runtime_expires;
429 s64 runtime_remaining;
430
431 u64 throttled_clock, throttled_clock_task;
432 u64 throttled_clock_task_time;
433 int throttled, throttle_count;
434 struct list_head throttled_list;
435 #endif /* CONFIG_CFS_BANDWIDTH */
436 #endif /* CONFIG_FAIR_GROUP_SCHED */
437 };
438
439 static inline int rt_bandwidth_enabled(void)
440 {
441 return sysctl_sched_rt_runtime >= 0;
442 }
443
444 /* RT IPI pull logic requires IRQ_WORK */
445 #ifdef CONFIG_IRQ_WORK
446 # define HAVE_RT_PUSH_IPI
447 #endif
448
449 /* Real-Time classes' related field in a runqueue: */
450 struct rt_rq {
451 struct rt_prio_array active;
452 unsigned int rt_nr_running;
453 unsigned int rr_nr_running;
454 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
455 struct {
456 int curr; /* highest queued rt task prio */
457 #ifdef CONFIG_SMP
458 int next; /* next highest */
459 #endif
460 } highest_prio;
461 #endif
462 #ifdef CONFIG_SMP
463 unsigned long rt_nr_migratory;
464 unsigned long rt_nr_total;
465 int overloaded;
466 struct plist_head pushable_tasks;
467 #ifdef HAVE_RT_PUSH_IPI
468 int push_flags;
469 int push_cpu;
470 struct irq_work push_work;
471 raw_spinlock_t push_lock;
472 #endif
473 #endif /* CONFIG_SMP */
474 int rt_queued;
475
476 int rt_throttled;
477 u64 rt_time;
478 u64 rt_runtime;
479 /* Nests inside the rq lock: */
480 raw_spinlock_t rt_runtime_lock;
481
482 #ifdef CONFIG_RT_GROUP_SCHED
483 unsigned long rt_nr_boosted;
484
485 struct rq *rq;
486 struct task_group *tg;
487 #endif
488 };
489
490 /* Deadline class' related fields in a runqueue */
491 struct dl_rq {
492 /* runqueue is an rbtree, ordered by deadline */
493 struct rb_root rb_root;
494 struct rb_node *rb_leftmost;
495
496 unsigned long dl_nr_running;
497
498 #ifdef CONFIG_SMP
499 /*
500 * Deadline values of the currently executing and the
501 * earliest ready task on this rq. Caching these facilitates
502 * the decision wether or not a ready but not running task
503 * should migrate somewhere else.
504 */
505 struct {
506 u64 curr;
507 u64 next;
508 } earliest_dl;
509
510 unsigned long dl_nr_migratory;
511 int overloaded;
512
513 /*
514 * Tasks on this rq that can be pushed away. They are kept in
515 * an rb-tree, ordered by tasks' deadlines, with caching
516 * of the leftmost (earliest deadline) element.
517 */
518 struct rb_root pushable_dl_tasks_root;
519 struct rb_node *pushable_dl_tasks_leftmost;
520 #else
521 struct dl_bw dl_bw;
522 #endif
523 };
524
525 #ifdef CONFIG_SMP
526
527 /*
528 * We add the notion of a root-domain which will be used to define per-domain
529 * variables. Each exclusive cpuset essentially defines an island domain by
530 * fully partitioning the member cpus from any other cpuset. Whenever a new
531 * exclusive cpuset is created, we also create and attach a new root-domain
532 * object.
533 *
534 */
535 struct root_domain {
536 atomic_t refcount;
537 atomic_t rto_count;
538 struct rcu_head rcu;
539 cpumask_var_t span;
540 cpumask_var_t online;
541
542 /* Indicate more than one runnable task for any CPU */
543 bool overload;
544
545 /*
546 * The bit corresponding to a CPU gets set here if such CPU has more
547 * than one runnable -deadline task (as it is below for RT tasks).
548 */
549 cpumask_var_t dlo_mask;
550 atomic_t dlo_count;
551 struct dl_bw dl_bw;
552 struct cpudl cpudl;
553
554 /*
555 * The "RT overload" flag: it gets set if a CPU has more than
556 * one runnable RT task.
557 */
558 cpumask_var_t rto_mask;
559 struct cpupri cpupri;
560 };
561
562 extern struct root_domain def_root_domain;
563
564 #endif /* CONFIG_SMP */
565
566 /*
567 * This is the main, per-CPU runqueue data structure.
568 *
569 * Locking rule: those places that want to lock multiple runqueues
570 * (such as the load balancing or the thread migration code), lock
571 * acquire operations must be ordered by ascending &runqueue.
572 */
573 struct rq {
574 /* runqueue lock: */
575 raw_spinlock_t lock;
576
577 /*
578 * nr_running and cpu_load should be in the same cacheline because
579 * remote CPUs use both these fields when doing load calculation.
580 */
581 unsigned int nr_running;
582 #ifdef CONFIG_NUMA_BALANCING
583 unsigned int nr_numa_running;
584 unsigned int nr_preferred_running;
585 #endif
586 #define CPU_LOAD_IDX_MAX 5
587 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
588 unsigned long last_load_update_tick;
589 #ifdef CONFIG_NO_HZ_COMMON
590 u64 nohz_stamp;
591 unsigned long nohz_flags;
592 #endif
593 #ifdef CONFIG_NO_HZ_FULL
594 unsigned long last_sched_tick;
595 #endif
596 /* capture load from *all* tasks on this cpu: */
597 struct load_weight load;
598 unsigned long nr_load_updates;
599 u64 nr_switches;
600
601 struct cfs_rq cfs;
602 struct rt_rq rt;
603 struct dl_rq dl;
604
605 #ifdef CONFIG_FAIR_GROUP_SCHED
606 /* list of leaf cfs_rq on this cpu: */
607 struct list_head leaf_cfs_rq_list;
608 #endif /* CONFIG_FAIR_GROUP_SCHED */
609
610 /*
611 * This is part of a global counter where only the total sum
612 * over all CPUs matters. A task can increase this counter on
613 * one CPU and if it got migrated afterwards it may decrease
614 * it on another CPU. Always updated under the runqueue lock:
615 */
616 unsigned long nr_uninterruptible;
617
618 struct task_struct *curr, *idle, *stop;
619 unsigned long next_balance;
620 struct mm_struct *prev_mm;
621
622 unsigned int clock_skip_update;
623 u64 clock;
624 u64 clock_task;
625
626 atomic_t nr_iowait;
627
628 #ifdef CONFIG_SMP
629 struct root_domain *rd;
630 struct sched_domain *sd;
631
632 unsigned long cpu_capacity;
633 unsigned long cpu_capacity_orig;
634
635 struct callback_head *balance_callback;
636
637 unsigned char idle_balance;
638 /* For active balancing */
639 int active_balance;
640 int push_cpu;
641 struct cpu_stop_work active_balance_work;
642 /* cpu of this runqueue: */
643 int cpu;
644 int online;
645
646 struct list_head cfs_tasks;
647
648 u64 rt_avg;
649 u64 age_stamp;
650 u64 idle_stamp;
651 u64 avg_idle;
652
653 /* This is used to determine avg_idle's max value */
654 u64 max_idle_balance_cost;
655 #endif
656
657 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
658 u64 prev_irq_time;
659 #endif
660 #ifdef CONFIG_PARAVIRT
661 u64 prev_steal_time;
662 #endif
663 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
664 u64 prev_steal_time_rq;
665 #endif
666
667 /* calc_load related fields */
668 unsigned long calc_load_update;
669 long calc_load_active;
670
671 #ifdef CONFIG_SCHED_HRTICK
672 #ifdef CONFIG_SMP
673 int hrtick_csd_pending;
674 struct call_single_data hrtick_csd;
675 #endif
676 struct hrtimer hrtick_timer;
677 #endif
678
679 #ifdef CONFIG_SCHEDSTATS
680 /* latency stats */
681 struct sched_info rq_sched_info;
682 unsigned long long rq_cpu_time;
683 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
684
685 /* sys_sched_yield() stats */
686 unsigned int yld_count;
687
688 /* schedule() stats */
689 unsigned int sched_count;
690 unsigned int sched_goidle;
691
692 /* try_to_wake_up() stats */
693 unsigned int ttwu_count;
694 unsigned int ttwu_local;
695 #endif
696
697 #ifdef CONFIG_SMP
698 struct llist_head wake_list;
699 #endif
700
701 #ifdef CONFIG_CPU_IDLE
702 /* Must be inspected within a rcu lock section */
703 struct cpuidle_state *idle_state;
704 #endif
705 };
706
707 static inline int cpu_of(struct rq *rq)
708 {
709 #ifdef CONFIG_SMP
710 return rq->cpu;
711 #else
712 return 0;
713 #endif
714 }
715
716 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
717
718 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
719 #define this_rq() this_cpu_ptr(&runqueues)
720 #define task_rq(p) cpu_rq(task_cpu(p))
721 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
722 #define raw_rq() raw_cpu_ptr(&runqueues)
723
724 static inline u64 __rq_clock_broken(struct rq *rq)
725 {
726 return READ_ONCE(rq->clock);
727 }
728
729 static inline u64 rq_clock(struct rq *rq)
730 {
731 lockdep_assert_held(&rq->lock);
732 return rq->clock;
733 }
734
735 static inline u64 rq_clock_task(struct rq *rq)
736 {
737 lockdep_assert_held(&rq->lock);
738 return rq->clock_task;
739 }
740
741 #define RQCF_REQ_SKIP 0x01
742 #define RQCF_ACT_SKIP 0x02
743
744 static inline void rq_clock_skip_update(struct rq *rq, bool skip)
745 {
746 lockdep_assert_held(&rq->lock);
747 if (skip)
748 rq->clock_skip_update |= RQCF_REQ_SKIP;
749 else
750 rq->clock_skip_update &= ~RQCF_REQ_SKIP;
751 }
752
753 #ifdef CONFIG_NUMA
754 enum numa_topology_type {
755 NUMA_DIRECT,
756 NUMA_GLUELESS_MESH,
757 NUMA_BACKPLANE,
758 };
759 extern enum numa_topology_type sched_numa_topology_type;
760 extern int sched_max_numa_distance;
761 extern bool find_numa_distance(int distance);
762 #endif
763
764 #ifdef CONFIG_NUMA_BALANCING
765 /* The regions in numa_faults array from task_struct */
766 enum numa_faults_stats {
767 NUMA_MEM = 0,
768 NUMA_CPU,
769 NUMA_MEMBUF,
770 NUMA_CPUBUF
771 };
772 extern void sched_setnuma(struct task_struct *p, int node);
773 extern int migrate_task_to(struct task_struct *p, int cpu);
774 extern int migrate_swap(struct task_struct *, struct task_struct *);
775 #endif /* CONFIG_NUMA_BALANCING */
776
777 #ifdef CONFIG_SMP
778
779 static inline void
780 queue_balance_callback(struct rq *rq,
781 struct callback_head *head,
782 void (*func)(struct rq *rq))
783 {
784 lockdep_assert_held(&rq->lock);
785
786 if (unlikely(head->next))
787 return;
788
789 head->func = (void (*)(struct callback_head *))func;
790 head->next = rq->balance_callback;
791 rq->balance_callback = head;
792 }
793
794 extern void sched_ttwu_pending(void);
795
796 #define rcu_dereference_check_sched_domain(p) \
797 rcu_dereference_check((p), \
798 lockdep_is_held(&sched_domains_mutex))
799
800 /*
801 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
802 * See detach_destroy_domains: synchronize_sched for details.
803 *
804 * The domain tree of any CPU may only be accessed from within
805 * preempt-disabled sections.
806 */
807 #define for_each_domain(cpu, __sd) \
808 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
809 __sd; __sd = __sd->parent)
810
811 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
812
813 /**
814 * highest_flag_domain - Return highest sched_domain containing flag.
815 * @cpu: The cpu whose highest level of sched domain is to
816 * be returned.
817 * @flag: The flag to check for the highest sched_domain
818 * for the given cpu.
819 *
820 * Returns the highest sched_domain of a cpu which contains the given flag.
821 */
822 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
823 {
824 struct sched_domain *sd, *hsd = NULL;
825
826 for_each_domain(cpu, sd) {
827 if (!(sd->flags & flag))
828 break;
829 hsd = sd;
830 }
831
832 return hsd;
833 }
834
835 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
836 {
837 struct sched_domain *sd;
838
839 for_each_domain(cpu, sd) {
840 if (sd->flags & flag)
841 break;
842 }
843
844 return sd;
845 }
846
847 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
848 DECLARE_PER_CPU(int, sd_llc_size);
849 DECLARE_PER_CPU(int, sd_llc_id);
850 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
851 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
852 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
853
854 struct sched_group_capacity {
855 atomic_t ref;
856 /*
857 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
858 * for a single CPU.
859 */
860 unsigned int capacity;
861 unsigned long next_update;
862 int imbalance; /* XXX unrelated to capacity but shared group state */
863 /*
864 * Number of busy cpus in this group.
865 */
866 atomic_t nr_busy_cpus;
867
868 unsigned long cpumask[0]; /* iteration mask */
869 };
870
871 struct sched_group {
872 struct sched_group *next; /* Must be a circular list */
873 atomic_t ref;
874
875 unsigned int group_weight;
876 struct sched_group_capacity *sgc;
877
878 /*
879 * The CPUs this group covers.
880 *
881 * NOTE: this field is variable length. (Allocated dynamically
882 * by attaching extra space to the end of the structure,
883 * depending on how many CPUs the kernel has booted up with)
884 */
885 unsigned long cpumask[0];
886 };
887
888 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
889 {
890 return to_cpumask(sg->cpumask);
891 }
892
893 /*
894 * cpumask masking which cpus in the group are allowed to iterate up the domain
895 * tree.
896 */
897 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
898 {
899 return to_cpumask(sg->sgc->cpumask);
900 }
901
902 /**
903 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
904 * @group: The group whose first cpu is to be returned.
905 */
906 static inline unsigned int group_first_cpu(struct sched_group *group)
907 {
908 return cpumask_first(sched_group_cpus(group));
909 }
910
911 extern int group_balance_cpu(struct sched_group *sg);
912
913 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
914 void register_sched_domain_sysctl(void);
915 void unregister_sched_domain_sysctl(void);
916 #else
917 static inline void register_sched_domain_sysctl(void)
918 {
919 }
920 static inline void unregister_sched_domain_sysctl(void)
921 {
922 }
923 #endif
924
925 #else
926
927 static inline void sched_ttwu_pending(void) { }
928
929 #endif /* CONFIG_SMP */
930
931 #include "stats.h"
932 #include "auto_group.h"
933
934 #ifdef CONFIG_CGROUP_SCHED
935
936 /*
937 * Return the group to which this tasks belongs.
938 *
939 * We cannot use task_css() and friends because the cgroup subsystem
940 * changes that value before the cgroup_subsys::attach() method is called,
941 * therefore we cannot pin it and might observe the wrong value.
942 *
943 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
944 * core changes this before calling sched_move_task().
945 *
946 * Instead we use a 'copy' which is updated from sched_move_task() while
947 * holding both task_struct::pi_lock and rq::lock.
948 */
949 static inline struct task_group *task_group(struct task_struct *p)
950 {
951 return p->sched_task_group;
952 }
953
954 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
955 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
956 {
957 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
958 struct task_group *tg = task_group(p);
959 #endif
960
961 #ifdef CONFIG_FAIR_GROUP_SCHED
962 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
963 p->se.cfs_rq = tg->cfs_rq[cpu];
964 p->se.parent = tg->se[cpu];
965 #endif
966
967 #ifdef CONFIG_RT_GROUP_SCHED
968 p->rt.rt_rq = tg->rt_rq[cpu];
969 p->rt.parent = tg->rt_se[cpu];
970 #endif
971 }
972
973 #else /* CONFIG_CGROUP_SCHED */
974
975 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
976 static inline struct task_group *task_group(struct task_struct *p)
977 {
978 return NULL;
979 }
980
981 #endif /* CONFIG_CGROUP_SCHED */
982
983 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
984 {
985 set_task_rq(p, cpu);
986 #ifdef CONFIG_SMP
987 /*
988 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
989 * successfuly executed on another CPU. We must ensure that updates of
990 * per-task data have been completed by this moment.
991 */
992 smp_wmb();
993 task_thread_info(p)->cpu = cpu;
994 p->wake_cpu = cpu;
995 #endif
996 }
997
998 /*
999 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
1000 */
1001 #ifdef CONFIG_SCHED_DEBUG
1002 # include <linux/static_key.h>
1003 # define const_debug __read_mostly
1004 #else
1005 # define const_debug const
1006 #endif
1007
1008 extern const_debug unsigned int sysctl_sched_features;
1009
1010 #define SCHED_FEAT(name, enabled) \
1011 __SCHED_FEAT_##name ,
1012
1013 enum {
1014 #include "features.h"
1015 __SCHED_FEAT_NR,
1016 };
1017
1018 #undef SCHED_FEAT
1019
1020 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
1021 #define SCHED_FEAT(name, enabled) \
1022 static __always_inline bool static_branch_##name(struct static_key *key) \
1023 { \
1024 return static_key_##enabled(key); \
1025 }
1026
1027 #include "features.h"
1028
1029 #undef SCHED_FEAT
1030
1031 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1032 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1033 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1034 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1035 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1036
1037 extern struct static_key_false sched_numa_balancing;
1038 extern struct static_key_false sched_schedstats;
1039
1040 static inline u64 global_rt_period(void)
1041 {
1042 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1043 }
1044
1045 static inline u64 global_rt_runtime(void)
1046 {
1047 if (sysctl_sched_rt_runtime < 0)
1048 return RUNTIME_INF;
1049
1050 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1051 }
1052
1053 static inline int task_current(struct rq *rq, struct task_struct *p)
1054 {
1055 return rq->curr == p;
1056 }
1057
1058 static inline int task_running(struct rq *rq, struct task_struct *p)
1059 {
1060 #ifdef CONFIG_SMP
1061 return p->on_cpu;
1062 #else
1063 return task_current(rq, p);
1064 #endif
1065 }
1066
1067 static inline int task_on_rq_queued(struct task_struct *p)
1068 {
1069 return p->on_rq == TASK_ON_RQ_QUEUED;
1070 }
1071
1072 static inline int task_on_rq_migrating(struct task_struct *p)
1073 {
1074 return p->on_rq == TASK_ON_RQ_MIGRATING;
1075 }
1076
1077 #ifndef prepare_arch_switch
1078 # define prepare_arch_switch(next) do { } while (0)
1079 #endif
1080 #ifndef finish_arch_post_lock_switch
1081 # define finish_arch_post_lock_switch() do { } while (0)
1082 #endif
1083
1084 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1085 {
1086 #ifdef CONFIG_SMP
1087 /*
1088 * We can optimise this out completely for !SMP, because the
1089 * SMP rebalancing from interrupt is the only thing that cares
1090 * here.
1091 */
1092 next->on_cpu = 1;
1093 #endif
1094 }
1095
1096 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1097 {
1098 #ifdef CONFIG_SMP
1099 /*
1100 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1101 * We must ensure this doesn't happen until the switch is completely
1102 * finished.
1103 *
1104 * In particular, the load of prev->state in finish_task_switch() must
1105 * happen before this.
1106 *
1107 * Pairs with the smp_cond_acquire() in try_to_wake_up().
1108 */
1109 smp_store_release(&prev->on_cpu, 0);
1110 #endif
1111 #ifdef CONFIG_DEBUG_SPINLOCK
1112 /* this is a valid case when another task releases the spinlock */
1113 rq->lock.owner = current;
1114 #endif
1115 /*
1116 * If we are tracking spinlock dependencies then we have to
1117 * fix up the runqueue lock - which gets 'carried over' from
1118 * prev into current:
1119 */
1120 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
1121
1122 raw_spin_unlock_irq(&rq->lock);
1123 }
1124
1125 /*
1126 * wake flags
1127 */
1128 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1129 #define WF_FORK 0x02 /* child wakeup after fork */
1130 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1131
1132 /*
1133 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1134 * of tasks with abnormal "nice" values across CPUs the contribution that
1135 * each task makes to its run queue's load is weighted according to its
1136 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1137 * scaled version of the new time slice allocation that they receive on time
1138 * slice expiry etc.
1139 */
1140
1141 #define WEIGHT_IDLEPRIO 3
1142 #define WMULT_IDLEPRIO 1431655765
1143
1144 extern const int sched_prio_to_weight[40];
1145 extern const u32 sched_prio_to_wmult[40];
1146
1147 /*
1148 * {de,en}queue flags:
1149 *
1150 * DEQUEUE_SLEEP - task is no longer runnable
1151 * ENQUEUE_WAKEUP - task just became runnable
1152 *
1153 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
1154 * are in a known state which allows modification. Such pairs
1155 * should preserve as much state as possible.
1156 *
1157 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
1158 * in the runqueue.
1159 *
1160 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
1161 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
1162 * ENQUEUE_WAKING - sched_class::task_waking was called
1163 *
1164 */
1165
1166 #define DEQUEUE_SLEEP 0x01
1167 #define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
1168 #define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
1169
1170 #define ENQUEUE_WAKEUP 0x01
1171 #define ENQUEUE_RESTORE 0x02
1172 #define ENQUEUE_MOVE 0x04
1173
1174 #define ENQUEUE_HEAD 0x08
1175 #define ENQUEUE_REPLENISH 0x10
1176 #ifdef CONFIG_SMP
1177 #define ENQUEUE_WAKING 0x20
1178 #else
1179 #define ENQUEUE_WAKING 0x00
1180 #endif
1181
1182 #define RETRY_TASK ((void *)-1UL)
1183
1184 struct sched_class {
1185 const struct sched_class *next;
1186
1187 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1188 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1189 void (*yield_task) (struct rq *rq);
1190 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1191
1192 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1193
1194 /*
1195 * It is the responsibility of the pick_next_task() method that will
1196 * return the next task to call put_prev_task() on the @prev task or
1197 * something equivalent.
1198 *
1199 * May return RETRY_TASK when it finds a higher prio class has runnable
1200 * tasks.
1201 */
1202 struct task_struct * (*pick_next_task) (struct rq *rq,
1203 struct task_struct *prev);
1204 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1205
1206 #ifdef CONFIG_SMP
1207 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1208 void (*migrate_task_rq)(struct task_struct *p);
1209
1210 void (*task_waking) (struct task_struct *task);
1211 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1212
1213 void (*set_cpus_allowed)(struct task_struct *p,
1214 const struct cpumask *newmask);
1215
1216 void (*rq_online)(struct rq *rq);
1217 void (*rq_offline)(struct rq *rq);
1218 #endif
1219
1220 void (*set_curr_task) (struct rq *rq);
1221 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1222 void (*task_fork) (struct task_struct *p);
1223 void (*task_dead) (struct task_struct *p);
1224
1225 /*
1226 * The switched_from() call is allowed to drop rq->lock, therefore we
1227 * cannot assume the switched_from/switched_to pair is serliazed by
1228 * rq->lock. They are however serialized by p->pi_lock.
1229 */
1230 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1231 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1232 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1233 int oldprio);
1234
1235 unsigned int (*get_rr_interval) (struct rq *rq,
1236 struct task_struct *task);
1237
1238 void (*update_curr) (struct rq *rq);
1239
1240 #ifdef CONFIG_FAIR_GROUP_SCHED
1241 void (*task_move_group) (struct task_struct *p);
1242 #endif
1243 };
1244
1245 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1246 {
1247 prev->sched_class->put_prev_task(rq, prev);
1248 }
1249
1250 #define sched_class_highest (&stop_sched_class)
1251 #define for_each_class(class) \
1252 for (class = sched_class_highest; class; class = class->next)
1253
1254 extern const struct sched_class stop_sched_class;
1255 extern const struct sched_class dl_sched_class;
1256 extern const struct sched_class rt_sched_class;
1257 extern const struct sched_class fair_sched_class;
1258 extern const struct sched_class idle_sched_class;
1259
1260
1261 #ifdef CONFIG_SMP
1262
1263 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1264
1265 extern void trigger_load_balance(struct rq *rq);
1266
1267 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1268
1269 #endif
1270
1271 #ifdef CONFIG_CPU_IDLE
1272 static inline void idle_set_state(struct rq *rq,
1273 struct cpuidle_state *idle_state)
1274 {
1275 rq->idle_state = idle_state;
1276 }
1277
1278 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1279 {
1280 WARN_ON(!rcu_read_lock_held());
1281 return rq->idle_state;
1282 }
1283 #else
1284 static inline void idle_set_state(struct rq *rq,
1285 struct cpuidle_state *idle_state)
1286 {
1287 }
1288
1289 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1290 {
1291 return NULL;
1292 }
1293 #endif
1294
1295 extern void sysrq_sched_debug_show(void);
1296 extern void sched_init_granularity(void);
1297 extern void update_max_interval(void);
1298
1299 extern void init_sched_dl_class(void);
1300 extern void init_sched_rt_class(void);
1301 extern void init_sched_fair_class(void);
1302
1303 extern void resched_curr(struct rq *rq);
1304 extern void resched_cpu(int cpu);
1305
1306 extern struct rt_bandwidth def_rt_bandwidth;
1307 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1308
1309 extern struct dl_bandwidth def_dl_bandwidth;
1310 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1311 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1312
1313 unsigned long to_ratio(u64 period, u64 runtime);
1314
1315 extern void init_entity_runnable_average(struct sched_entity *se);
1316
1317 #ifdef CONFIG_NO_HZ_FULL
1318 extern bool sched_can_stop_tick(struct rq *rq);
1319
1320 /*
1321 * Tick may be needed by tasks in the runqueue depending on their policy and
1322 * requirements. If tick is needed, lets send the target an IPI to kick it out of
1323 * nohz mode if necessary.
1324 */
1325 static inline void sched_update_tick_dependency(struct rq *rq)
1326 {
1327 int cpu;
1328
1329 if (!tick_nohz_full_enabled())
1330 return;
1331
1332 cpu = cpu_of(rq);
1333
1334 if (!tick_nohz_full_cpu(cpu))
1335 return;
1336
1337 if (sched_can_stop_tick(rq))
1338 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
1339 else
1340 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
1341 }
1342 #else
1343 static inline void sched_update_tick_dependency(struct rq *rq) { }
1344 #endif
1345
1346 static inline void add_nr_running(struct rq *rq, unsigned count)
1347 {
1348 unsigned prev_nr = rq->nr_running;
1349
1350 rq->nr_running = prev_nr + count;
1351
1352 if (prev_nr < 2 && rq->nr_running >= 2) {
1353 #ifdef CONFIG_SMP
1354 if (!rq->rd->overload)
1355 rq->rd->overload = true;
1356 #endif
1357 }
1358
1359 sched_update_tick_dependency(rq);
1360 }
1361
1362 static inline void sub_nr_running(struct rq *rq, unsigned count)
1363 {
1364 rq->nr_running -= count;
1365 /* Check if we still need preemption */
1366 sched_update_tick_dependency(rq);
1367 }
1368
1369 static inline void rq_last_tick_reset(struct rq *rq)
1370 {
1371 #ifdef CONFIG_NO_HZ_FULL
1372 rq->last_sched_tick = jiffies;
1373 #endif
1374 }
1375
1376 extern void update_rq_clock(struct rq *rq);
1377
1378 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1379 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1380
1381 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1382
1383 extern const_debug unsigned int sysctl_sched_time_avg;
1384 extern const_debug unsigned int sysctl_sched_nr_migrate;
1385 extern const_debug unsigned int sysctl_sched_migration_cost;
1386
1387 static inline u64 sched_avg_period(void)
1388 {
1389 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1390 }
1391
1392 #ifdef CONFIG_SCHED_HRTICK
1393
1394 /*
1395 * Use hrtick when:
1396 * - enabled by features
1397 * - hrtimer is actually high res
1398 */
1399 static inline int hrtick_enabled(struct rq *rq)
1400 {
1401 if (!sched_feat(HRTICK))
1402 return 0;
1403 if (!cpu_active(cpu_of(rq)))
1404 return 0;
1405 return hrtimer_is_hres_active(&rq->hrtick_timer);
1406 }
1407
1408 void hrtick_start(struct rq *rq, u64 delay);
1409
1410 #else
1411
1412 static inline int hrtick_enabled(struct rq *rq)
1413 {
1414 return 0;
1415 }
1416
1417 #endif /* CONFIG_SCHED_HRTICK */
1418
1419 #ifdef CONFIG_SMP
1420 extern void sched_avg_update(struct rq *rq);
1421
1422 #ifndef arch_scale_freq_capacity
1423 static __always_inline
1424 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
1425 {
1426 return SCHED_CAPACITY_SCALE;
1427 }
1428 #endif
1429
1430 #ifndef arch_scale_cpu_capacity
1431 static __always_inline
1432 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
1433 {
1434 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1435 return sd->smt_gain / sd->span_weight;
1436
1437 return SCHED_CAPACITY_SCALE;
1438 }
1439 #endif
1440
1441 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1442 {
1443 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1444 sched_avg_update(rq);
1445 }
1446 #else
1447 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1448 static inline void sched_avg_update(struct rq *rq) { }
1449 #endif
1450
1451 /*
1452 * __task_rq_lock - lock the rq @p resides on.
1453 */
1454 static inline struct rq *__task_rq_lock(struct task_struct *p)
1455 __acquires(rq->lock)
1456 {
1457 struct rq *rq;
1458
1459 lockdep_assert_held(&p->pi_lock);
1460
1461 for (;;) {
1462 rq = task_rq(p);
1463 raw_spin_lock(&rq->lock);
1464 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1465 lockdep_pin_lock(&rq->lock);
1466 return rq;
1467 }
1468 raw_spin_unlock(&rq->lock);
1469
1470 while (unlikely(task_on_rq_migrating(p)))
1471 cpu_relax();
1472 }
1473 }
1474
1475 /*
1476 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
1477 */
1478 static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
1479 __acquires(p->pi_lock)
1480 __acquires(rq->lock)
1481 {
1482 struct rq *rq;
1483
1484 for (;;) {
1485 raw_spin_lock_irqsave(&p->pi_lock, *flags);
1486 rq = task_rq(p);
1487 raw_spin_lock(&rq->lock);
1488 /*
1489 * move_queued_task() task_rq_lock()
1490 *
1491 * ACQUIRE (rq->lock)
1492 * [S] ->on_rq = MIGRATING [L] rq = task_rq()
1493 * WMB (__set_task_cpu()) ACQUIRE (rq->lock);
1494 * [S] ->cpu = new_cpu [L] task_rq()
1495 * [L] ->on_rq
1496 * RELEASE (rq->lock)
1497 *
1498 * If we observe the old cpu in task_rq_lock, the acquire of
1499 * the old rq->lock will fully serialize against the stores.
1500 *
1501 * If we observe the new cpu in task_rq_lock, the acquire will
1502 * pair with the WMB to ensure we must then also see migrating.
1503 */
1504 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1505 lockdep_pin_lock(&rq->lock);
1506 return rq;
1507 }
1508 raw_spin_unlock(&rq->lock);
1509 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1510
1511 while (unlikely(task_on_rq_migrating(p)))
1512 cpu_relax();
1513 }
1514 }
1515
1516 static inline void __task_rq_unlock(struct rq *rq)
1517 __releases(rq->lock)
1518 {
1519 lockdep_unpin_lock(&rq->lock);
1520 raw_spin_unlock(&rq->lock);
1521 }
1522
1523 static inline void
1524 task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
1525 __releases(rq->lock)
1526 __releases(p->pi_lock)
1527 {
1528 lockdep_unpin_lock(&rq->lock);
1529 raw_spin_unlock(&rq->lock);
1530 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1531 }
1532
1533 #ifdef CONFIG_SMP
1534 #ifdef CONFIG_PREEMPT
1535
1536 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1537
1538 /*
1539 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1540 * way at the expense of forcing extra atomic operations in all
1541 * invocations. This assures that the double_lock is acquired using the
1542 * same underlying policy as the spinlock_t on this architecture, which
1543 * reduces latency compared to the unfair variant below. However, it
1544 * also adds more overhead and therefore may reduce throughput.
1545 */
1546 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1547 __releases(this_rq->lock)
1548 __acquires(busiest->lock)
1549 __acquires(this_rq->lock)
1550 {
1551 raw_spin_unlock(&this_rq->lock);
1552 double_rq_lock(this_rq, busiest);
1553
1554 return 1;
1555 }
1556
1557 #else
1558 /*
1559 * Unfair double_lock_balance: Optimizes throughput at the expense of
1560 * latency by eliminating extra atomic operations when the locks are
1561 * already in proper order on entry. This favors lower cpu-ids and will
1562 * grant the double lock to lower cpus over higher ids under contention,
1563 * regardless of entry order into the function.
1564 */
1565 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1566 __releases(this_rq->lock)
1567 __acquires(busiest->lock)
1568 __acquires(this_rq->lock)
1569 {
1570 int ret = 0;
1571
1572 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1573 if (busiest < this_rq) {
1574 raw_spin_unlock(&this_rq->lock);
1575 raw_spin_lock(&busiest->lock);
1576 raw_spin_lock_nested(&this_rq->lock,
1577 SINGLE_DEPTH_NESTING);
1578 ret = 1;
1579 } else
1580 raw_spin_lock_nested(&busiest->lock,
1581 SINGLE_DEPTH_NESTING);
1582 }
1583 return ret;
1584 }
1585
1586 #endif /* CONFIG_PREEMPT */
1587
1588 /*
1589 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1590 */
1591 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1592 {
1593 if (unlikely(!irqs_disabled())) {
1594 /* printk() doesn't work good under rq->lock */
1595 raw_spin_unlock(&this_rq->lock);
1596 BUG_ON(1);
1597 }
1598
1599 return _double_lock_balance(this_rq, busiest);
1600 }
1601
1602 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1603 __releases(busiest->lock)
1604 {
1605 raw_spin_unlock(&busiest->lock);
1606 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1607 }
1608
1609 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1610 {
1611 if (l1 > l2)
1612 swap(l1, l2);
1613
1614 spin_lock(l1);
1615 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1616 }
1617
1618 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1619 {
1620 if (l1 > l2)
1621 swap(l1, l2);
1622
1623 spin_lock_irq(l1);
1624 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1625 }
1626
1627 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1628 {
1629 if (l1 > l2)
1630 swap(l1, l2);
1631
1632 raw_spin_lock(l1);
1633 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1634 }
1635
1636 /*
1637 * double_rq_lock - safely lock two runqueues
1638 *
1639 * Note this does not disable interrupts like task_rq_lock,
1640 * you need to do so manually before calling.
1641 */
1642 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1643 __acquires(rq1->lock)
1644 __acquires(rq2->lock)
1645 {
1646 BUG_ON(!irqs_disabled());
1647 if (rq1 == rq2) {
1648 raw_spin_lock(&rq1->lock);
1649 __acquire(rq2->lock); /* Fake it out ;) */
1650 } else {
1651 if (rq1 < rq2) {
1652 raw_spin_lock(&rq1->lock);
1653 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1654 } else {
1655 raw_spin_lock(&rq2->lock);
1656 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1657 }
1658 }
1659 }
1660
1661 /*
1662 * double_rq_unlock - safely unlock two runqueues
1663 *
1664 * Note this does not restore interrupts like task_rq_unlock,
1665 * you need to do so manually after calling.
1666 */
1667 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1668 __releases(rq1->lock)
1669 __releases(rq2->lock)
1670 {
1671 raw_spin_unlock(&rq1->lock);
1672 if (rq1 != rq2)
1673 raw_spin_unlock(&rq2->lock);
1674 else
1675 __release(rq2->lock);
1676 }
1677
1678 #else /* CONFIG_SMP */
1679
1680 /*
1681 * double_rq_lock - safely lock two runqueues
1682 *
1683 * Note this does not disable interrupts like task_rq_lock,
1684 * you need to do so manually before calling.
1685 */
1686 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1687 __acquires(rq1->lock)
1688 __acquires(rq2->lock)
1689 {
1690 BUG_ON(!irqs_disabled());
1691 BUG_ON(rq1 != rq2);
1692 raw_spin_lock(&rq1->lock);
1693 __acquire(rq2->lock); /* Fake it out ;) */
1694 }
1695
1696 /*
1697 * double_rq_unlock - safely unlock two runqueues
1698 *
1699 * Note this does not restore interrupts like task_rq_unlock,
1700 * you need to do so manually after calling.
1701 */
1702 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1703 __releases(rq1->lock)
1704 __releases(rq2->lock)
1705 {
1706 BUG_ON(rq1 != rq2);
1707 raw_spin_unlock(&rq1->lock);
1708 __release(rq2->lock);
1709 }
1710
1711 #endif
1712
1713 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1714 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1715
1716 #ifdef CONFIG_SCHED_DEBUG
1717 extern void print_cfs_stats(struct seq_file *m, int cpu);
1718 extern void print_rt_stats(struct seq_file *m, int cpu);
1719 extern void print_dl_stats(struct seq_file *m, int cpu);
1720 extern void
1721 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1722
1723 #ifdef CONFIG_NUMA_BALANCING
1724 extern void
1725 show_numa_stats(struct task_struct *p, struct seq_file *m);
1726 extern void
1727 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1728 unsigned long tpf, unsigned long gsf, unsigned long gpf);
1729 #endif /* CONFIG_NUMA_BALANCING */
1730 #endif /* CONFIG_SCHED_DEBUG */
1731
1732 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1733 extern void init_rt_rq(struct rt_rq *rt_rq);
1734 extern void init_dl_rq(struct dl_rq *dl_rq);
1735
1736 extern void cfs_bandwidth_usage_inc(void);
1737 extern void cfs_bandwidth_usage_dec(void);
1738
1739 #ifdef CONFIG_NO_HZ_COMMON
1740 enum rq_nohz_flag_bits {
1741 NOHZ_TICK_STOPPED,
1742 NOHZ_BALANCE_KICK,
1743 };
1744
1745 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1746 #endif
1747
1748 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1749
1750 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1751 DECLARE_PER_CPU(u64, cpu_softirq_time);
1752
1753 #ifndef CONFIG_64BIT
1754 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1755
1756 static inline void irq_time_write_begin(void)
1757 {
1758 __this_cpu_inc(irq_time_seq.sequence);
1759 smp_wmb();
1760 }
1761
1762 static inline void irq_time_write_end(void)
1763 {
1764 smp_wmb();
1765 __this_cpu_inc(irq_time_seq.sequence);
1766 }
1767
1768 static inline u64 irq_time_read(int cpu)
1769 {
1770 u64 irq_time;
1771 unsigned seq;
1772
1773 do {
1774 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1775 irq_time = per_cpu(cpu_softirq_time, cpu) +
1776 per_cpu(cpu_hardirq_time, cpu);
1777 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1778
1779 return irq_time;
1780 }
1781 #else /* CONFIG_64BIT */
1782 static inline void irq_time_write_begin(void)
1783 {
1784 }
1785
1786 static inline void irq_time_write_end(void)
1787 {
1788 }
1789
1790 static inline u64 irq_time_read(int cpu)
1791 {
1792 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1793 }
1794 #endif /* CONFIG_64BIT */
1795 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
1796
1797 #ifdef CONFIG_CPU_FREQ
1798 DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
1799
1800 /**
1801 * cpufreq_update_util - Take a note about CPU utilization changes.
1802 * @time: Current time.
1803 * @util: Current utilization.
1804 * @max: Utilization ceiling.
1805 *
1806 * This function is called by the scheduler on every invocation of
1807 * update_load_avg() on the CPU whose utilization is being updated.
1808 *
1809 * It can only be called from RCU-sched read-side critical sections.
1810 */
1811 static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
1812 {
1813 struct update_util_data *data;
1814
1815 data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
1816 if (data)
1817 data->func(data, time, util, max);
1818 }
1819
1820 /**
1821 * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
1822 * @time: Current time.
1823 *
1824 * The way cpufreq is currently arranged requires it to evaluate the CPU
1825 * performance state (frequency/voltage) on a regular basis to prevent it from
1826 * being stuck in a completely inadequate performance level for too long.
1827 * That is not guaranteed to happen if the updates are only triggered from CFS,
1828 * though, because they may not be coming in if RT or deadline tasks are active
1829 * all the time (or there are RT and DL tasks only).
1830 *
1831 * As a workaround for that issue, this function is called by the RT and DL
1832 * sched classes to trigger extra cpufreq updates to prevent it from stalling,
1833 * but that really is a band-aid. Going forward it should be replaced with
1834 * solutions targeted more specifically at RT and DL tasks.
1835 */
1836 static inline void cpufreq_trigger_update(u64 time)
1837 {
1838 cpufreq_update_util(time, ULONG_MAX, 0);
1839 }
1840 #else
1841 static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
1842 static inline void cpufreq_trigger_update(u64 time) {}
1843 #endif /* CONFIG_CPU_FREQ */
1844
1845 static inline void account_reset_rq(struct rq *rq)
1846 {
1847 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1848 rq->prev_irq_time = 0;
1849 #endif
1850 #ifdef CONFIG_PARAVIRT
1851 rq->prev_steal_time = 0;
1852 #endif
1853 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
1854 rq->prev_steal_time_rq = 0;
1855 #endif
1856 }
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