blob: ed2bab54edf1a9425f3d765884c94fa1c3f1ee27 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001
2#include <linux/sched.h>
3#include <linux/mutex.h>
4#include <linux/spinlock.h>
5#include <linux/stop_machine.h>
6
7#include "cpupri.h"
8
9extern __read_mostly int scheduler_running;
10
11/*
12 * Convert user-nice values [ -20 ... 0 ... 19 ]
13 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
14 * and back.
15 */
16#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
17#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
18#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
19
20/*
21 * 'User priority' is the nice value converted to something we
22 * can work with better when scaling various scheduler parameters,
23 * it's a [ 0 ... 39 ] range.
24 */
25#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
26#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
27#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
28
29/*
30 * Helpers for converting nanosecond timing to jiffy resolution
31 */
32#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
33
34#define NICE_0_LOAD SCHED_LOAD_SCALE
35#define NICE_0_SHIFT SCHED_LOAD_SHIFT
36
37/*
38 * These are the 'tuning knobs' of the scheduler:
39 */
40
41/*
42 * single value that denotes runtime == period, ie unlimited time.
43 */
44#define RUNTIME_INF ((u64)~0ULL)
45
46static inline int rt_policy(int policy)
47{
48 if (policy == SCHED_FIFO || policy == SCHED_RR)
49 return 1;
50 return 0;
51}
52
53static inline int task_has_rt_policy(struct task_struct *p)
54{
55 return rt_policy(p->policy);
56}
57
58/*
59 * This is the priority-queue data structure of the RT scheduling class:
60 */
61struct rt_prio_array {
62 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
63 struct list_head queue[MAX_RT_PRIO];
64};
65
66struct rt_bandwidth {
67 /* nests inside the rq lock: */
68 raw_spinlock_t rt_runtime_lock;
69 ktime_t rt_period;
70 u64 rt_runtime;
71 struct hrtimer rt_period_timer;
72};
73
74extern struct mutex sched_domains_mutex;
75
76#ifdef CONFIG_CGROUP_SCHED
77
78#include <linux/cgroup.h>
79
80struct cfs_rq;
81struct rt_rq;
82
83extern struct list_head task_groups;
84
85struct cfs_bandwidth {
86#ifdef CONFIG_CFS_BANDWIDTH
87 raw_spinlock_t lock;
88 ktime_t period;
89 u64 quota, runtime;
90 s64 hierarchal_quota;
91 u64 runtime_expires;
92
93 int idle, timer_active;
94 struct hrtimer period_timer, slack_timer;
95 struct list_head throttled_cfs_rq;
96
97 /* statistics */
98 int nr_periods, nr_throttled;
99 u64 throttled_time;
100#endif
101};
102
103/* task group related information */
104struct task_group {
105 struct cgroup_subsys_state css;
106
107#ifdef CONFIG_FAIR_GROUP_SCHED
108 /* schedulable entities of this group on each cpu */
109 struct sched_entity **se;
110 /* runqueue "owned" by this group on each cpu */
111 struct cfs_rq **cfs_rq;
112 unsigned long shares;
113
114 atomic_t load_weight;
115#endif
116
117#ifdef CONFIG_RT_GROUP_SCHED
118 struct sched_rt_entity **rt_se;
119 struct rt_rq **rt_rq;
120
121 struct rt_bandwidth rt_bandwidth;
122#endif
123
124 struct rcu_head rcu;
125 struct list_head list;
126
127 struct task_group *parent;
128 struct list_head siblings;
129 struct list_head children;
130
131#ifdef CONFIG_SCHED_AUTOGROUP
132 struct autogroup *autogroup;
133#endif
134
135 struct cfs_bandwidth cfs_bandwidth;
136};
137
138#ifdef CONFIG_FAIR_GROUP_SCHED
139#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
140
141/*
142 * A weight of 0 or 1 can cause arithmetics problems.
143 * A weight of a cfs_rq is the sum of weights of which entities
144 * are queued on this cfs_rq, so a weight of a entity should not be
145 * too large, so as the shares value of a task group.
146 * (The default weight is 1024 - so there's no practical
147 * limitation from this.)
148 */
149#define MIN_SHARES (1UL << 1)
150#define MAX_SHARES (1UL << 18)
151#endif
152
153/* Default task group.
154 * Every task in system belong to this group at bootup.
155 */
156extern struct task_group root_task_group;
157
158typedef int (*tg_visitor)(struct task_group *, void *);
159
160extern int walk_tg_tree_from(struct task_group *from,
161 tg_visitor down, tg_visitor up, void *data);
162
163/*
164 * Iterate the full tree, calling @down when first entering a node and @up when
165 * leaving it for the final time.
166 *
167 * Caller must hold rcu_lock or sufficient equivalent.
168 */
169static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
170{
171 return walk_tg_tree_from(&root_task_group, down, up, data);
172}
173
174extern int tg_nop(struct task_group *tg, void *data);
175
176extern void free_fair_sched_group(struct task_group *tg);
177extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
178extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
179extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
180 struct sched_entity *se, int cpu,
181 struct sched_entity *parent);
182extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
183extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
184
185extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
186extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
187extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
188
189extern void free_rt_sched_group(struct task_group *tg);
190extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
191extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
192 struct sched_rt_entity *rt_se, int cpu,
193 struct sched_rt_entity *parent);
194
195#else /* CONFIG_CGROUP_SCHED */
196
197struct cfs_bandwidth { };
198
199#endif /* CONFIG_CGROUP_SCHED */
200
201/* CFS-related fields in a runqueue */
202struct cfs_rq {
203 struct load_weight load;
204 unsigned long nr_running, h_nr_running;
205
206 u64 exec_clock;
207 u64 min_vruntime;
208#ifndef CONFIG_64BIT
209 u64 min_vruntime_copy;
210#endif
211
212 struct rb_root tasks_timeline;
213 struct rb_node *rb_leftmost;
214
215 /*
216 * 'curr' points to currently running entity on this cfs_rq.
217 * It is set to NULL otherwise (i.e when none are currently running).
218 */
219 struct sched_entity *curr, *next, *last, *skip;
220
221#ifdef CONFIG_SCHED_DEBUG
222 unsigned int nr_spread_over;
223#endif
224
225#ifdef CONFIG_FAIR_GROUP_SCHED
226 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
227
228 /*
229 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
230 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
231 * (like users, containers etc.)
232 *
233 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
234 * list is used during load balance.
235 */
236 int on_list;
237 struct list_head leaf_cfs_rq_list;
238 struct task_group *tg; /* group that "owns" this runqueue */
239
240#ifdef CONFIG_SMP
241 /*
242 * h_load = weight * f(tg)
243 *
244 * Where f(tg) is the recursive weight fraction assigned to
245 * this group.
246 */
247 unsigned long h_load;
248
249 /*
250 * Maintaining per-cpu shares distribution for group scheduling
251 *
252 * load_stamp is the last time we updated the load average
253 * load_last is the last time we updated the load average and saw load
254 * load_unacc_exec_time is currently unaccounted execution time
255 */
256 u64 load_avg;
257 u64 load_period;
258 u64 load_stamp, load_last, load_unacc_exec_time;
259
260 unsigned long load_contribution;
261#endif /* CONFIG_SMP */
262#ifdef CONFIG_CFS_BANDWIDTH
263 int runtime_enabled;
264 u64 runtime_expires;
265 s64 runtime_remaining;
266
267 u64 throttled_timestamp;
268 int throttled, throttle_count;
269 struct list_head throttled_list;
270#endif /* CONFIG_CFS_BANDWIDTH */
271#endif /* CONFIG_FAIR_GROUP_SCHED */
272};
273
274static inline int rt_bandwidth_enabled(void)
275{
276 return sysctl_sched_rt_runtime >= 0;
277}
278
279/* Real-Time classes' related field in a runqueue: */
280struct rt_rq {
281 struct rt_prio_array active;
282 unsigned long rt_nr_running;
283#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
284 struct {
285 int curr; /* highest queued rt task prio */
286#ifdef CONFIG_SMP
287 int next; /* next highest */
288#endif
289 } highest_prio;
290#endif
291#ifdef CONFIG_SMP
292 unsigned long rt_nr_migratory;
293 unsigned long rt_nr_total;
294 int overloaded;
295 struct plist_head pushable_tasks;
296#endif
297 int rt_throttled;
298 u64 rt_time;
299 u64 rt_runtime;
300 /* Nests inside the rq lock: */
301 raw_spinlock_t rt_runtime_lock;
302
303#ifdef CONFIG_RT_GROUP_SCHED
304 unsigned long rt_nr_boosted;
305
306 struct rq *rq;
307 struct list_head leaf_rt_rq_list;
308 struct task_group *tg;
309#endif
310};
311
312#ifdef CONFIG_SMP
313
314/*
315 * We add the notion of a root-domain which will be used to define per-domain
316 * variables. Each exclusive cpuset essentially defines an island domain by
317 * fully partitioning the member cpus from any other cpuset. Whenever a new
318 * exclusive cpuset is created, we also create and attach a new root-domain
319 * object.
320 *
321 */
322struct root_domain {
323 atomic_t refcount;
324 atomic_t rto_count;
325 struct rcu_head rcu;
326 cpumask_var_t span;
327 cpumask_var_t online;
328
329 /*
330 * The "RT overload" flag: it gets set if a CPU has more than
331 * one runnable RT task.
332 */
333 cpumask_var_t rto_mask;
334 struct cpupri cpupri;
335};
336
337extern struct root_domain def_root_domain;
338
339#endif /* CONFIG_SMP */
340
341/*
342 * This is the main, per-CPU runqueue data structure.
343 *
344 * Locking rule: those places that want to lock multiple runqueues
345 * (such as the load balancing or the thread migration code), lock
346 * acquire operations must be ordered by ascending &runqueue.
347 */
348struct rq {
349 /* runqueue lock: */
350 raw_spinlock_t lock;
351
352 /*
353 * nr_running and cpu_load should be in the same cacheline because
354 * remote CPUs use both these fields when doing load calculation.
355 */
356 unsigned long nr_running;
357 #define CPU_LOAD_IDX_MAX 5
358 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
359 unsigned long last_load_update_tick;
360#ifdef CONFIG_NO_HZ
361 u64 nohz_stamp;
362 unsigned long nohz_flags;
363#endif
364 int skip_clock_update;
365
366 /* capture load from *all* tasks on this cpu: */
367 struct load_weight load;
368 unsigned long nr_load_updates;
369 u64 nr_switches;
370
371 struct cfs_rq cfs;
372 struct rt_rq rt;
373
374#ifdef CONFIG_FAIR_GROUP_SCHED
375 /* list of leaf cfs_rq on this cpu: */
376 struct list_head leaf_cfs_rq_list;
377#endif
378#ifdef CONFIG_RT_GROUP_SCHED
379 struct list_head leaf_rt_rq_list;
380#endif
381
382 /*
383 * This is part of a global counter where only the total sum
384 * over all CPUs matters. A task can increase this counter on
385 * one CPU and if it got migrated afterwards it may decrease
386 * it on another CPU. Always updated under the runqueue lock:
387 */
388 unsigned long nr_uninterruptible;
389
390 struct task_struct *curr, *idle, *stop;
391 unsigned long next_balance;
392 struct mm_struct *prev_mm;
393
394 u64 clock;
395 u64 clock_task;
396
397 atomic_t nr_iowait;
398
399#ifdef CONFIG_SMP
400 struct root_domain *rd;
401 struct sched_domain *sd;
402
403 unsigned long cpu_power;
404
405 unsigned char idle_balance;
406 /* For active balancing */
407 int post_schedule;
408 int active_balance;
409 int push_cpu;
410 struct cpu_stop_work active_balance_work;
411 /* cpu of this runqueue: */
412 int cpu;
413 int online;
414
415 struct list_head cfs_tasks;
416
417 u64 rt_avg;
418 u64 age_stamp;
419 u64 idle_stamp;
420 u64 avg_idle;
421#endif
422
423#ifdef CONFIG_IRQ_TIME_ACCOUNTING
424 u64 prev_irq_time;
425#endif
426#ifdef CONFIG_PARAVIRT
427 u64 prev_steal_time;
428#endif
429#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
430 u64 prev_steal_time_rq;
431#endif
432
433 /* calc_load related fields */
434 unsigned long calc_load_update;
435 long calc_load_active;
436
437#ifdef CONFIG_SCHED_HRTICK
438#ifdef CONFIG_SMP
439 int hrtick_csd_pending;
440 struct call_single_data hrtick_csd;
441#endif
442 struct hrtimer hrtick_timer;
443#endif
444
445#ifdef CONFIG_SCHEDSTATS
446 /* latency stats */
447 struct sched_info rq_sched_info;
448 unsigned long long rq_cpu_time;
449 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
450
451 /* sys_sched_yield() stats */
452 unsigned int yld_count;
453
454 /* schedule() stats */
455 unsigned int sched_count;
456 unsigned int sched_goidle;
457
458 /* try_to_wake_up() stats */
459 unsigned int ttwu_count;
460 unsigned int ttwu_local;
461#endif
462
463#ifdef CONFIG_SMP
464 struct llist_head wake_list;
465#endif
466};
467
468static inline int cpu_of(struct rq *rq)
469{
470#ifdef CONFIG_SMP
471 return rq->cpu;
472#else
473 return 0;
474#endif
475}
476
477DECLARE_PER_CPU(struct rq, runqueues);
478
479#ifdef CONFIG_STACK_SIZE
480extern struct thread_info * current_kernel_thread;
481#endif
482
483#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
484#define this_rq() (&__get_cpu_var(runqueues))
485#define task_rq(p) cpu_rq(task_cpu(p))
486#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
487#define raw_rq() (&__raw_get_cpu_var(runqueues))
488
489#ifdef CONFIG_SMP
490
491#define rcu_dereference_check_sched_domain(p) \
492 rcu_dereference_check((p), \
493 lockdep_is_held(&sched_domains_mutex))
494
495/*
496 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
497 * See detach_destroy_domains: synchronize_sched for details.
498 *
499 * The domain tree of any CPU may only be accessed from within
500 * preempt-disabled sections.
501 */
502#define for_each_domain(cpu, __sd) \
503 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
504 __sd; __sd = __sd->parent)
505
506#define for_each_lower_domain(sd) for (; sd; sd = sd->child)
507
508/**
509 * highest_flag_domain - Return highest sched_domain containing flag.
510 * @cpu: The cpu whose highest level of sched domain is to
511 * be returned.
512 * @flag: The flag to check for the highest sched_domain
513 * for the given cpu.
514 *
515 * Returns the highest sched_domain of a cpu which contains the given flag.
516 */
517static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
518{
519 struct sched_domain *sd, *hsd = NULL;
520
521 for_each_domain(cpu, sd) {
522 if (!(sd->flags & flag))
523 break;
524 hsd = sd;
525 }
526
527 return hsd;
528}
529
530DECLARE_PER_CPU(struct sched_domain *, sd_llc);
531DECLARE_PER_CPU(int, sd_llc_id);
532
533#endif /* CONFIG_SMP */
534
535#include "stats.h"
536#include "auto_group.h"
537
538#ifdef CONFIG_CGROUP_SCHED
539
540/*
541 * Return the group to which this tasks belongs.
542 *
543 * We cannot use task_subsys_state() and friends because the cgroup
544 * subsystem changes that value before the cgroup_subsys::attach() method
545 * is called, therefore we cannot pin it and might observe the wrong value.
546 *
547 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
548 * core changes this before calling sched_move_task().
549 *
550 * Instead we use a 'copy' which is updated from sched_move_task() while
551 * holding both task_struct::pi_lock and rq::lock.
552 */
553static inline struct task_group *task_group(struct task_struct *p)
554{
555 return p->sched_task_group;
556}
557
558/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
559static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
560{
561#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
562 struct task_group *tg = task_group(p);
563#endif
564
565#ifdef CONFIG_FAIR_GROUP_SCHED
566 p->se.cfs_rq = tg->cfs_rq[cpu];
567 p->se.parent = tg->se[cpu];
568#endif
569
570#ifdef CONFIG_RT_GROUP_SCHED
571 p->rt.rt_rq = tg->rt_rq[cpu];
572 p->rt.parent = tg->rt_se[cpu];
573#endif
574}
575
576#else /* CONFIG_CGROUP_SCHED */
577
578static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
579static inline struct task_group *task_group(struct task_struct *p)
580{
581 return NULL;
582}
583
584#endif /* CONFIG_CGROUP_SCHED */
585
586static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
587{
588 set_task_rq(p, cpu);
589#ifdef CONFIG_SMP
590 /*
591 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
592 * successfuly executed on another CPU. We must ensure that updates of
593 * per-task data have been completed by this moment.
594 */
595 smp_wmb();
596 task_thread_info(p)->cpu = cpu;
597#endif
598}
599
600/*
601 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
602 */
603#ifdef CONFIG_SCHED_DEBUG
604# include <linux/static_key.h>
605# define const_debug __read_mostly
606#else
607# define const_debug const
608#endif
609
610extern const_debug unsigned int sysctl_sched_features;
611
612#define SCHED_FEAT(name, enabled) \
613 __SCHED_FEAT_##name ,
614
615enum {
616#include "features.h"
617 __SCHED_FEAT_NR,
618};
619
620#undef SCHED_FEAT
621
622#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
623static __always_inline bool static_branch__true(struct static_key *key)
624{
625 return static_key_true(key); /* Not out of line branch. */
626}
627
628static __always_inline bool static_branch__false(struct static_key *key)
629{
630 return static_key_false(key); /* Out of line branch. */
631}
632
633#define SCHED_FEAT(name, enabled) \
634static __always_inline bool static_branch_##name(struct static_key *key) \
635{ \
636 return static_branch__##enabled(key); \
637}
638
639#include "features.h"
640
641#undef SCHED_FEAT
642
643extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
644#define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
645#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
646#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
647#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
648
649static inline u64 global_rt_period(void)
650{
651 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
652}
653
654static inline u64 global_rt_runtime(void)
655{
656 if (sysctl_sched_rt_runtime < 0)
657 return RUNTIME_INF;
658
659 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
660}
661
662
663
664static inline int task_current(struct rq *rq, struct task_struct *p)
665{
666 return rq->curr == p;
667}
668
669static inline int task_running(struct rq *rq, struct task_struct *p)
670{
671#ifdef CONFIG_SMP
672 return p->on_cpu;
673#else
674 return task_current(rq, p);
675#endif
676}
677
678
679#ifndef prepare_arch_switch
680# define prepare_arch_switch(next) do { } while (0)
681#endif
682#ifndef finish_arch_switch
683# define finish_arch_switch(prev) do { } while (0)
684#endif
685#ifndef finish_arch_post_lock_switch
686# define finish_arch_post_lock_switch() do { } while (0)
687#endif
688
689#ifndef __ARCH_WANT_UNLOCKED_CTXSW
690static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
691{
692#ifdef CONFIG_SMP
693 /*
694 * We can optimise this out completely for !SMP, because the
695 * SMP rebalancing from interrupt is the only thing that cares
696 * here.
697 */
698 next->on_cpu = 1;
699#endif
700}
701
702static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
703{
704#ifdef CONFIG_SMP
705 /*
706 * After ->on_cpu is cleared, the task can be moved to a different CPU.
707 * We must ensure this doesn't happen until the switch is completely
708 * finished.
709 */
710 smp_wmb();
711 prev->on_cpu = 0;
712#endif
713#ifdef CONFIG_DEBUG_SPINLOCK
714 /* this is a valid case when another task releases the spinlock */
715 rq->lock.owner = current;
716#endif
717 /*
718 * If we are tracking spinlock dependencies then we have to
719 * fix up the runqueue lock - which gets 'carried over' from
720 * prev into current:
721 */
722 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
723
724 raw_spin_unlock_irq(&rq->lock);
725}
726
727#else /* __ARCH_WANT_UNLOCKED_CTXSW */
728static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
729{
730#ifdef CONFIG_SMP
731 /*
732 * We can optimise this out completely for !SMP, because the
733 * SMP rebalancing from interrupt is the only thing that cares
734 * here.
735 */
736 next->on_cpu = 1;
737#endif
738#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
739 raw_spin_unlock_irq(&rq->lock);
740#else
741 raw_spin_unlock(&rq->lock);
742#endif
743}
744
745static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
746{
747#ifdef CONFIG_SMP
748 /*
749 * After ->on_cpu is cleared, the task can be moved to a different CPU.
750 * We must ensure this doesn't happen until the switch is completely
751 * finished.
752 */
753 smp_wmb();
754 prev->on_cpu = 0;
755#endif
756#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
757 local_irq_enable();
758#endif
759}
760#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
761
762
763static inline void update_load_add(struct load_weight *lw, unsigned long inc)
764{
765 lw->weight += inc;
766 lw->inv_weight = 0;
767}
768
769static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
770{
771 lw->weight -= dec;
772 lw->inv_weight = 0;
773}
774
775static inline void update_load_set(struct load_weight *lw, unsigned long w)
776{
777 lw->weight = w;
778 lw->inv_weight = 0;
779}
780
781/*
782 * To aid in avoiding the subversion of "niceness" due to uneven distribution
783 * of tasks with abnormal "nice" values across CPUs the contribution that
784 * each task makes to its run queue's load is weighted according to its
785 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
786 * scaled version of the new time slice allocation that they receive on time
787 * slice expiry etc.
788 */
789
790#define WEIGHT_IDLEPRIO 3
791#define WMULT_IDLEPRIO 1431655765
792
793/*
794 * Nice levels are multiplicative, with a gentle 10% change for every
795 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
796 * nice 1, it will get ~10% less CPU time than another CPU-bound task
797 * that remained on nice 0.
798 *
799 * The "10% effect" is relative and cumulative: from _any_ nice level,
800 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
801 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
802 * If a task goes up by ~10% and another task goes down by ~10% then
803 * the relative distance between them is ~25%.)
804 */
805static const int prio_to_weight[40] = {
806 /* -20 */ 88761, 71755, 56483, 46273, 36291,
807 /* -15 */ 29154, 23254, 18705, 14949, 11916,
808 /* -10 */ 9548, 7620, 6100, 4904, 3906,
809 /* -5 */ 3121, 2501, 1991, 1586, 1277,
810 /* 0 */ 1024, 820, 655, 526, 423,
811 /* 5 */ 335, 272, 215, 172, 137,
812 /* 10 */ 110, 87, 70, 56, 45,
813 /* 15 */ 36, 29, 23, 18, 15,
814};
815
816/*
817 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
818 *
819 * In cases where the weight does not change often, we can use the
820 * precalculated inverse to speed up arithmetics by turning divisions
821 * into multiplications:
822 */
823static const u32 prio_to_wmult[40] = {
824 /* -20 */ 48388, 59856, 76040, 92818, 118348,
825 /* -15 */ 147320, 184698, 229616, 287308, 360437,
826 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
827 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
828 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
829 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
830 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
831 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
832};
833
834/* Time spent by the tasks of the cpu accounting group executing in ... */
835enum cpuacct_stat_index {
836 CPUACCT_STAT_USER, /* ... user mode */
837 CPUACCT_STAT_SYSTEM, /* ... kernel mode */
838
839 CPUACCT_STAT_NSTATS,
840};
841
842
843#define sched_class_highest (&stop_sched_class)
844#define for_each_class(class) \
845 for (class = sched_class_highest; class; class = class->next)
846
847extern const struct sched_class stop_sched_class;
848extern const struct sched_class rt_sched_class;
849extern const struct sched_class fair_sched_class;
850extern const struct sched_class idle_sched_class;
851
852
853#ifdef CONFIG_SMP
854
855extern void trigger_load_balance(struct rq *rq, int cpu);
856extern void idle_balance(int this_cpu, struct rq *this_rq);
857
858#else /* CONFIG_SMP */
859
860static inline void idle_balance(int cpu, struct rq *rq)
861{
862}
863
864#endif
865
866extern void sysrq_sched_debug_show(void);
867extern void sched_init_granularity(void);
868extern void update_max_interval(void);
869extern void update_group_power(struct sched_domain *sd, int cpu);
870extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu);
871extern void init_sched_rt_class(void);
872extern void init_sched_fair_class(void);
873
874extern void resched_task(struct task_struct *p);
875extern void resched_cpu(int cpu);
876
877extern struct rt_bandwidth def_rt_bandwidth;
878extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
879
880extern void update_idle_cpu_load(struct rq *this_rq);
881
882#ifdef CONFIG_CGROUP_CPUACCT
883#include <linux/cgroup.h>
884/* track cpu usage of a group of tasks and its child groups */
885struct cpuacct {
886 struct cgroup_subsys_state css;
887 /* cpuusage holds pointer to a u64-type object on every cpu */
888 u64 __percpu *cpuusage;
889 struct kernel_cpustat __percpu *cpustat;
890};
891
892/* return cpu accounting group corresponding to this container */
893static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
894{
895 return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
896 struct cpuacct, css);
897}
898
899/* return cpu accounting group to which this task belongs */
900static inline struct cpuacct *task_ca(struct task_struct *tsk)
901{
902 return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
903 struct cpuacct, css);
904}
905
906static inline struct cpuacct *parent_ca(struct cpuacct *ca)
907{
908 if (!ca || !ca->css.cgroup->parent)
909 return NULL;
910 return cgroup_ca(ca->css.cgroup->parent);
911}
912
913extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
914#else
915static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
916#endif
917
918static inline void inc_nr_running(struct rq *rq)
919{
920 rq->nr_running++;
921}
922
923static inline void dec_nr_running(struct rq *rq)
924{
925 rq->nr_running--;
926}
927
928extern void update_rq_clock(struct rq *rq);
929
930extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
931extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
932
933extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
934
935extern const_debug unsigned int sysctl_sched_time_avg;
936extern const_debug unsigned int sysctl_sched_nr_migrate;
937extern const_debug unsigned int sysctl_sched_migration_cost;
938
939static inline u64 sched_avg_period(void)
940{
941 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
942}
943
944#ifdef CONFIG_SCHED_HRTICK
945
946/*
947 * Use hrtick when:
948 * - enabled by features
949 * - hrtimer is actually high res
950 */
951static inline int hrtick_enabled(struct rq *rq)
952{
953 if (!sched_feat(HRTICK))
954 return 0;
955 if (!cpu_active(cpu_of(rq)))
956 return 0;
957 return hrtimer_is_hres_active(&rq->hrtick_timer);
958}
959
960void hrtick_start(struct rq *rq, u64 delay);
961
962#else
963
964static inline int hrtick_enabled(struct rq *rq)
965{
966 return 0;
967}
968
969#endif /* CONFIG_SCHED_HRTICK */
970
971#ifdef CONFIG_SMP
972extern void sched_avg_update(struct rq *rq);
973static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
974{
975 rq->rt_avg += rt_delta;
976 sched_avg_update(rq);
977}
978#else
979static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
980static inline void sched_avg_update(struct rq *rq) { }
981#endif
982
983extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
984
985#ifdef CONFIG_SMP
986#ifdef CONFIG_PREEMPT
987
988static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
989
990/*
991 * fair double_lock_balance: Safely acquires both rq->locks in a fair
992 * way at the expense of forcing extra atomic operations in all
993 * invocations. This assures that the double_lock is acquired using the
994 * same underlying policy as the spinlock_t on this architecture, which
995 * reduces latency compared to the unfair variant below. However, it
996 * also adds more overhead and therefore may reduce throughput.
997 */
998static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
999 __releases(this_rq->lock)
1000 __acquires(busiest->lock)
1001 __acquires(this_rq->lock)
1002{
1003 raw_spin_unlock(&this_rq->lock);
1004 double_rq_lock(this_rq, busiest);
1005
1006 return 1;
1007}
1008
1009#else
1010/*
1011 * Unfair double_lock_balance: Optimizes throughput at the expense of
1012 * latency by eliminating extra atomic operations when the locks are
1013 * already in proper order on entry. This favors lower cpu-ids and will
1014 * grant the double lock to lower cpus over higher ids under contention,
1015 * regardless of entry order into the function.
1016 */
1017static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1018 __releases(this_rq->lock)
1019 __acquires(busiest->lock)
1020 __acquires(this_rq->lock)
1021{
1022 int ret = 0;
1023
1024 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1025 if (busiest < this_rq) {
1026 raw_spin_unlock(&this_rq->lock);
1027 raw_spin_lock(&busiest->lock);
1028 raw_spin_lock_nested(&this_rq->lock,
1029 SINGLE_DEPTH_NESTING);
1030 ret = 1;
1031 } else
1032 raw_spin_lock_nested(&busiest->lock,
1033 SINGLE_DEPTH_NESTING);
1034 }
1035 return ret;
1036}
1037
1038#endif /* CONFIG_PREEMPT */
1039
1040/*
1041 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1042 */
1043static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1044{
1045 if (unlikely(!irqs_disabled())) {
1046 /* printk() doesn't work good under rq->lock */
1047 raw_spin_unlock(&this_rq->lock);
1048 BUG_ON(1);
1049 }
1050
1051 return _double_lock_balance(this_rq, busiest);
1052}
1053
1054static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1055 __releases(busiest->lock)
1056{
1057 raw_spin_unlock(&busiest->lock);
1058 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1059}
1060
1061/*
1062 * double_rq_lock - safely lock two runqueues
1063 *
1064 * Note this does not disable interrupts like task_rq_lock,
1065 * you need to do so manually before calling.
1066 */
1067static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1068 __acquires(rq1->lock)
1069 __acquires(rq2->lock)
1070{
1071 BUG_ON(!irqs_disabled());
1072 if (rq1 == rq2) {
1073 raw_spin_lock(&rq1->lock);
1074 __acquire(rq2->lock); /* Fake it out ;) */
1075 } else {
1076 if (rq1 < rq2) {
1077 raw_spin_lock(&rq1->lock);
1078 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1079 } else {
1080 raw_spin_lock(&rq2->lock);
1081 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1082 }
1083 }
1084}
1085
1086/*
1087 * double_rq_unlock - safely unlock two runqueues
1088 *
1089 * Note this does not restore interrupts like task_rq_unlock,
1090 * you need to do so manually after calling.
1091 */
1092static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1093 __releases(rq1->lock)
1094 __releases(rq2->lock)
1095{
1096 raw_spin_unlock(&rq1->lock);
1097 if (rq1 != rq2)
1098 raw_spin_unlock(&rq2->lock);
1099 else
1100 __release(rq2->lock);
1101}
1102
1103#else /* CONFIG_SMP */
1104
1105/*
1106 * double_rq_lock - safely lock two runqueues
1107 *
1108 * Note this does not disable interrupts like task_rq_lock,
1109 * you need to do so manually before calling.
1110 */
1111static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1112 __acquires(rq1->lock)
1113 __acquires(rq2->lock)
1114{
1115 BUG_ON(!irqs_disabled());
1116 BUG_ON(rq1 != rq2);
1117 raw_spin_lock(&rq1->lock);
1118 __acquire(rq2->lock); /* Fake it out ;) */
1119}
1120
1121/*
1122 * double_rq_unlock - safely unlock two runqueues
1123 *
1124 * Note this does not restore interrupts like task_rq_unlock,
1125 * you need to do so manually after calling.
1126 */
1127static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1128 __releases(rq1->lock)
1129 __releases(rq2->lock)
1130{
1131 BUG_ON(rq1 != rq2);
1132 raw_spin_unlock(&rq1->lock);
1133 __release(rq2->lock);
1134}
1135
1136#endif
1137
1138extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1139extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1140extern void print_cfs_stats(struct seq_file *m, int cpu);
1141extern void print_rt_stats(struct seq_file *m, int cpu);
1142
1143extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1144extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1145
1146extern void cfs_bandwidth_usage_inc(void);
1147extern void cfs_bandwidth_usage_dec(void);
1148
1149#ifdef CONFIG_NO_HZ
1150enum rq_nohz_flag_bits {
1151 NOHZ_TICK_STOPPED,
1152 NOHZ_BALANCE_KICK,
1153 NOHZ_IDLE,
1154};
1155
1156#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1157#endif