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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-11-15 11:14:39 -0500
committerIngo Molnar <mingo@elte.hu>2011-11-17 06:20:22 -0500
commit391e43da797a96aeb65410281891f6d0b0e9611c (patch)
tree0ce6784525a5a8f75b377170cf1a7d60abccea29 /kernel/sched/sched.h
parent029632fbb7b7c9d85063cc9eb470de6c54873df3 (diff)
sched: Move all scheduler bits into kernel/sched/
There's too many sched*.[ch] files in kernel/, give them their own directory. (No code changed, other than Makefile glue added.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched/sched.h')
-rw-r--r--kernel/sched/sched.h1064
1 files changed, 1064 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
new file mode 100644
index 000000000000..c2e780234c31
--- /dev/null
+++ b/kernel/sched/sched.h
@@ -0,0 +1,1064 @@
1
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 * default timeslice is 100 msecs (used only for SCHED_RR tasks).
41 * Timeslices get refilled after they expire.
42 */
43#define DEF_TIMESLICE (100 * HZ / 1000)
44
45/*
46 * single value that denotes runtime == period, ie unlimited time.
47 */
48#define RUNTIME_INF ((u64)~0ULL)
49
50static inline int rt_policy(int policy)
51{
52 if (policy == SCHED_FIFO || policy == SCHED_RR)
53 return 1;
54 return 0;
55}
56
57static inline int task_has_rt_policy(struct task_struct *p)
58{
59 return rt_policy(p->policy);
60}
61
62/*
63 * This is the priority-queue data structure of the RT scheduling class:
64 */
65struct rt_prio_array {
66 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
67 struct list_head queue[MAX_RT_PRIO];
68};
69
70struct rt_bandwidth {
71 /* nests inside the rq lock: */
72 raw_spinlock_t rt_runtime_lock;
73 ktime_t rt_period;
74 u64 rt_runtime;
75 struct hrtimer rt_period_timer;
76};
77
78extern struct mutex sched_domains_mutex;
79
80#ifdef CONFIG_CGROUP_SCHED
81
82#include <linux/cgroup.h>
83
84struct cfs_rq;
85struct rt_rq;
86
87static LIST_HEAD(task_groups);
88
89struct cfs_bandwidth {
90#ifdef CONFIG_CFS_BANDWIDTH
91 raw_spinlock_t lock;
92 ktime_t period;
93 u64 quota, runtime;
94 s64 hierarchal_quota;
95 u64 runtime_expires;
96
97 int idle, timer_active;
98 struct hrtimer period_timer, slack_timer;
99 struct list_head throttled_cfs_rq;
100
101 /* statistics */
102 int nr_periods, nr_throttled;
103 u64 throttled_time;
104#endif
105};
106
107/* task group related information */
108struct task_group {
109 struct cgroup_subsys_state css;
110
111#ifdef CONFIG_FAIR_GROUP_SCHED
112 /* schedulable entities of this group on each cpu */
113 struct sched_entity **se;
114 /* runqueue "owned" by this group on each cpu */
115 struct cfs_rq **cfs_rq;
116 unsigned long shares;
117
118 atomic_t load_weight;
119#endif
120
121#ifdef CONFIG_RT_GROUP_SCHED
122 struct sched_rt_entity **rt_se;
123 struct rt_rq **rt_rq;
124
125 struct rt_bandwidth rt_bandwidth;
126#endif
127
128 struct rcu_head rcu;
129 struct list_head list;
130
131 struct task_group *parent;
132 struct list_head siblings;
133 struct list_head children;
134
135#ifdef CONFIG_SCHED_AUTOGROUP
136 struct autogroup *autogroup;
137#endif
138
139 struct cfs_bandwidth cfs_bandwidth;
140};
141
142#ifdef CONFIG_FAIR_GROUP_SCHED
143#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
144
145/*
146 * A weight of 0 or 1 can cause arithmetics problems.
147 * A weight of a cfs_rq is the sum of weights of which entities
148 * are queued on this cfs_rq, so a weight of a entity should not be
149 * too large, so as the shares value of a task group.
150 * (The default weight is 1024 - so there's no practical
151 * limitation from this.)
152 */
153#define MIN_SHARES (1UL << 1)
154#define MAX_SHARES (1UL << 18)
155#endif
156
157/* Default task group.
158 * Every task in system belong to this group at bootup.
159 */
160extern struct task_group root_task_group;
161
162typedef int (*tg_visitor)(struct task_group *, void *);
163
164extern int walk_tg_tree_from(struct task_group *from,
165 tg_visitor down, tg_visitor up, void *data);
166
167/*
168 * Iterate the full tree, calling @down when first entering a node and @up when
169 * leaving it for the final time.
170 *
171 * Caller must hold rcu_lock or sufficient equivalent.
172 */
173static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
174{
175 return walk_tg_tree_from(&root_task_group, down, up, data);
176}
177
178extern int tg_nop(struct task_group *tg, void *data);
179
180extern void free_fair_sched_group(struct task_group *tg);
181extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
182extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
183extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
184 struct sched_entity *se, int cpu,
185 struct sched_entity *parent);
186extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
187extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
188
189extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
190extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
191extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
192
193extern void free_rt_sched_group(struct task_group *tg);
194extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
195extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
196 struct sched_rt_entity *rt_se, int cpu,
197 struct sched_rt_entity *parent);
198
199#else /* CONFIG_CGROUP_SCHED */
200
201struct cfs_bandwidth { };
202
203#endif /* CONFIG_CGROUP_SCHED */
204
205/* CFS-related fields in a runqueue */
206struct cfs_rq {
207 struct load_weight load;
208 unsigned long nr_running, h_nr_running;
209
210 u64 exec_clock;
211 u64 min_vruntime;
212#ifndef CONFIG_64BIT
213 u64 min_vruntime_copy;
214#endif
215
216 struct rb_root tasks_timeline;
217 struct rb_node *rb_leftmost;
218
219 struct list_head tasks;
220 struct list_head *balance_iterator;
221
222 /*
223 * 'curr' points to currently running entity on this cfs_rq.
224 * It is set to NULL otherwise (i.e when none are currently running).
225 */
226 struct sched_entity *curr, *next, *last, *skip;
227
228#ifdef CONFIG_SCHED_DEBUG
229 unsigned int nr_spread_over;
230#endif
231
232#ifdef CONFIG_FAIR_GROUP_SCHED
233 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
234
235 /*
236 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
237 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
238 * (like users, containers etc.)
239 *
240 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
241 * list is used during load balance.
242 */
243 int on_list;
244 struct list_head leaf_cfs_rq_list;
245 struct task_group *tg; /* group that "owns" this runqueue */
246
247#ifdef CONFIG_SMP
248 /*
249 * the part of load.weight contributed by tasks
250 */
251 unsigned long task_weight;
252
253 /*
254 * h_load = weight * f(tg)
255 *
256 * Where f(tg) is the recursive weight fraction assigned to
257 * this group.
258 */
259 unsigned long h_load;
260
261 /*
262 * Maintaining per-cpu shares distribution for group scheduling
263 *
264 * load_stamp is the last time we updated the load average
265 * load_last is the last time we updated the load average and saw load
266 * load_unacc_exec_time is currently unaccounted execution time
267 */
268 u64 load_avg;
269 u64 load_period;
270 u64 load_stamp, load_last, load_unacc_exec_time;
271
272 unsigned long load_contribution;
273#endif /* CONFIG_SMP */
274#ifdef CONFIG_CFS_BANDWIDTH
275 int runtime_enabled;
276 u64 runtime_expires;
277 s64 runtime_remaining;
278
279 u64 throttled_timestamp;
280 int throttled, throttle_count;
281 struct list_head throttled_list;
282#endif /* CONFIG_CFS_BANDWIDTH */
283#endif /* CONFIG_FAIR_GROUP_SCHED */
284};
285
286static inline int rt_bandwidth_enabled(void)
287{
288 return sysctl_sched_rt_runtime >= 0;
289}
290
291/* Real-Time classes' related field in a runqueue: */
292struct rt_rq {
293 struct rt_prio_array active;
294 unsigned long rt_nr_running;
295#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
296 struct {
297 int curr; /* highest queued rt task prio */
298#ifdef CONFIG_SMP
299 int next; /* next highest */
300#endif
301 } highest_prio;
302#endif
303#ifdef CONFIG_SMP
304 unsigned long rt_nr_migratory;
305 unsigned long rt_nr_total;
306 int overloaded;
307 struct plist_head pushable_tasks;
308#endif
309 int rt_throttled;
310 u64 rt_time;
311 u64 rt_runtime;
312 /* Nests inside the rq lock: */
313 raw_spinlock_t rt_runtime_lock;
314
315#ifdef CONFIG_RT_GROUP_SCHED
316 unsigned long rt_nr_boosted;
317
318 struct rq *rq;
319 struct list_head leaf_rt_rq_list;
320 struct task_group *tg;
321#endif
322};
323
324#ifdef CONFIG_SMP
325
326/*
327 * We add the notion of a root-domain which will be used to define per-domain
328 * variables. Each exclusive cpuset essentially defines an island domain by
329 * fully partitioning the member cpus from any other cpuset. Whenever a new
330 * exclusive cpuset is created, we also create and attach a new root-domain
331 * object.
332 *
333 */
334struct root_domain {
335 atomic_t refcount;
336 atomic_t rto_count;
337 struct rcu_head rcu;
338 cpumask_var_t span;
339 cpumask_var_t online;
340
341 /*
342 * The "RT overload" flag: it gets set if a CPU has more than
343 * one runnable RT task.
344 */
345 cpumask_var_t rto_mask;
346 struct cpupri cpupri;
347};
348
349extern struct root_domain def_root_domain;
350
351#endif /* CONFIG_SMP */
352
353/*
354 * This is the main, per-CPU runqueue data structure.
355 *
356 * Locking rule: those places that want to lock multiple runqueues
357 * (such as the load balancing or the thread migration code), lock
358 * acquire operations must be ordered by ascending &runqueue.
359 */
360struct rq {
361 /* runqueue lock: */
362 raw_spinlock_t lock;
363
364 /*
365 * nr_running and cpu_load should be in the same cacheline because
366 * remote CPUs use both these fields when doing load calculation.
367 */
368 unsigned long nr_running;
369 #define CPU_LOAD_IDX_MAX 5
370 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
371 unsigned long last_load_update_tick;
372#ifdef CONFIG_NO_HZ
373 u64 nohz_stamp;
374 unsigned char nohz_balance_kick;
375#endif
376 int skip_clock_update;
377
378 /* capture load from *all* tasks on this cpu: */
379 struct load_weight load;
380 unsigned long nr_load_updates;
381 u64 nr_switches;
382
383 struct cfs_rq cfs;
384 struct rt_rq rt;
385
386#ifdef CONFIG_FAIR_GROUP_SCHED
387 /* list of leaf cfs_rq on this cpu: */
388 struct list_head leaf_cfs_rq_list;
389#endif
390#ifdef CONFIG_RT_GROUP_SCHED
391 struct list_head leaf_rt_rq_list;
392#endif
393
394 /*
395 * This is part of a global counter where only the total sum
396 * over all CPUs matters. A task can increase this counter on
397 * one CPU and if it got migrated afterwards it may decrease
398 * it on another CPU. Always updated under the runqueue lock:
399 */
400 unsigned long nr_uninterruptible;
401
402 struct task_struct *curr, *idle, *stop;
403 unsigned long next_balance;
404 struct mm_struct *prev_mm;
405
406 u64 clock;
407 u64 clock_task;
408
409 atomic_t nr_iowait;
410
411#ifdef CONFIG_SMP
412 struct root_domain *rd;
413 struct sched_domain *sd;
414
415 unsigned long cpu_power;
416
417 unsigned char idle_balance;
418 /* For active balancing */
419 int post_schedule;
420 int active_balance;
421 int push_cpu;
422 struct cpu_stop_work active_balance_work;
423 /* cpu of this runqueue: */
424 int cpu;
425 int online;
426
427 u64 rt_avg;
428 u64 age_stamp;
429 u64 idle_stamp;
430 u64 avg_idle;
431#endif
432
433#ifdef CONFIG_IRQ_TIME_ACCOUNTING
434 u64 prev_irq_time;
435#endif
436#ifdef CONFIG_PARAVIRT
437 u64 prev_steal_time;
438#endif
439#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
440 u64 prev_steal_time_rq;
441#endif
442
443 /* calc_load related fields */
444 unsigned long calc_load_update;
445 long calc_load_active;
446
447#ifdef CONFIG_SCHED_HRTICK
448#ifdef CONFIG_SMP
449 int hrtick_csd_pending;
450 struct call_single_data hrtick_csd;
451#endif
452 struct hrtimer hrtick_timer;
453#endif
454
455#ifdef CONFIG_SCHEDSTATS
456 /* latency stats */
457 struct sched_info rq_sched_info;
458 unsigned long long rq_cpu_time;
459 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
460
461 /* sys_sched_yield() stats */
462 unsigned int yld_count;
463
464 /* schedule() stats */
465 unsigned int sched_switch;
466 unsigned int sched_count;
467 unsigned int sched_goidle;
468
469 /* try_to_wake_up() stats */
470 unsigned int ttwu_count;
471 unsigned int ttwu_local;
472#endif
473
474#ifdef CONFIG_SMP
475 struct llist_head wake_list;
476#endif
477};
478
479static inline int cpu_of(struct rq *rq)
480{
481#ifdef CONFIG_SMP
482 return rq->cpu;
483#else
484 return 0;
485#endif
486}
487
488DECLARE_PER_CPU(struct rq, runqueues);
489
490#define rcu_dereference_check_sched_domain(p) \
491 rcu_dereference_check((p), \
492 lockdep_is_held(&sched_domains_mutex))
493
494/*
495 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
496 * See detach_destroy_domains: synchronize_sched for details.
497 *
498 * The domain tree of any CPU may only be accessed from within
499 * preempt-disabled sections.
500 */
501#define for_each_domain(cpu, __sd) \
502 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
503
504#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
505#define this_rq() (&__get_cpu_var(runqueues))
506#define task_rq(p) cpu_rq(task_cpu(p))
507#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
508#define raw_rq() (&__raw_get_cpu_var(runqueues))
509
510#include "stats.h"
511#include "auto_group.h"
512
513#ifdef CONFIG_CGROUP_SCHED
514
515/*
516 * Return the group to which this tasks belongs.
517 *
518 * We use task_subsys_state_check() and extend the RCU verification with
519 * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each
520 * task it moves into the cgroup. Therefore by holding either of those locks,
521 * we pin the task to the current cgroup.
522 */
523static inline struct task_group *task_group(struct task_struct *p)
524{
525 struct task_group *tg;
526 struct cgroup_subsys_state *css;
527
528 css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
529 lockdep_is_held(&p->pi_lock) ||
530 lockdep_is_held(&task_rq(p)->lock));
531 tg = container_of(css, struct task_group, css);
532
533 return autogroup_task_group(p, tg);
534}
535
536/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
537static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
538{
539#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
540 struct task_group *tg = task_group(p);
541#endif
542
543#ifdef CONFIG_FAIR_GROUP_SCHED
544 p->se.cfs_rq = tg->cfs_rq[cpu];
545 p->se.parent = tg->se[cpu];
546#endif
547
548#ifdef CONFIG_RT_GROUP_SCHED
549 p->rt.rt_rq = tg->rt_rq[cpu];
550 p->rt.parent = tg->rt_se[cpu];
551#endif
552}
553
554#else /* CONFIG_CGROUP_SCHED */
555
556static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
557static inline struct task_group *task_group(struct task_struct *p)
558{
559 return NULL;
560}
561
562#endif /* CONFIG_CGROUP_SCHED */
563
564static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
565{
566 set_task_rq(p, cpu);
567#ifdef CONFIG_SMP
568 /*
569 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
570 * successfuly executed on another CPU. We must ensure that updates of
571 * per-task data have been completed by this moment.
572 */
573 smp_wmb();
574 task_thread_info(p)->cpu = cpu;
575#endif
576}
577
578/*
579 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
580 */
581#ifdef CONFIG_SCHED_DEBUG
582# define const_debug __read_mostly
583#else
584# define const_debug const
585#endif
586
587extern const_debug unsigned int sysctl_sched_features;
588
589#define SCHED_FEAT(name, enabled) \
590 __SCHED_FEAT_##name ,
591
592enum {
593#include "features.h"
594};
595
596#undef SCHED_FEAT
597
598#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
599
600static inline u64 global_rt_period(void)
601{
602 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
603}
604
605static inline u64 global_rt_runtime(void)
606{
607 if (sysctl_sched_rt_runtime < 0)
608 return RUNTIME_INF;
609
610 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
611}
612
613
614
615static inline int task_current(struct rq *rq, struct task_struct *p)
616{
617 return rq->curr == p;
618}
619
620static inline int task_running(struct rq *rq, struct task_struct *p)
621{
622#ifdef CONFIG_SMP
623 return p->on_cpu;
624#else
625 return task_current(rq, p);
626#endif
627}
628
629
630#ifndef prepare_arch_switch
631# define prepare_arch_switch(next) do { } while (0)
632#endif
633#ifndef finish_arch_switch
634# define finish_arch_switch(prev) do { } while (0)
635#endif
636
637#ifndef __ARCH_WANT_UNLOCKED_CTXSW
638static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
639{
640#ifdef CONFIG_SMP
641 /*
642 * We can optimise this out completely for !SMP, because the
643 * SMP rebalancing from interrupt is the only thing that cares
644 * here.
645 */
646 next->on_cpu = 1;
647#endif
648}
649
650static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
651{
652#ifdef CONFIG_SMP
653 /*
654 * After ->on_cpu is cleared, the task can be moved to a different CPU.
655 * We must ensure this doesn't happen until the switch is completely
656 * finished.
657 */
658 smp_wmb();
659 prev->on_cpu = 0;
660#endif
661#ifdef CONFIG_DEBUG_SPINLOCK
662 /* this is a valid case when another task releases the spinlock */
663 rq->lock.owner = current;
664#endif
665 /*
666 * If we are tracking spinlock dependencies then we have to
667 * fix up the runqueue lock - which gets 'carried over' from
668 * prev into current:
669 */
670 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
671
672 raw_spin_unlock_irq(&rq->lock);
673}
674
675#else /* __ARCH_WANT_UNLOCKED_CTXSW */
676static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
677{
678#ifdef CONFIG_SMP
679 /*
680 * We can optimise this out completely for !SMP, because the
681 * SMP rebalancing from interrupt is the only thing that cares
682 * here.
683 */
684 next->on_cpu = 1;
685#endif
686#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
687 raw_spin_unlock_irq(&rq->lock);
688#else
689 raw_spin_unlock(&rq->lock);
690#endif
691}
692
693static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
694{
695#ifdef CONFIG_SMP
696 /*
697 * After ->on_cpu is cleared, the task can be moved to a different CPU.
698 * We must ensure this doesn't happen until the switch is completely
699 * finished.
700 */
701 smp_wmb();
702 prev->on_cpu = 0;
703#endif
704#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
705 local_irq_enable();
706#endif
707}
708#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
709
710
711static inline void update_load_add(struct load_weight *lw, unsigned long inc)
712{
713 lw->weight += inc;
714 lw->inv_weight = 0;
715}
716
717static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
718{
719 lw->weight -= dec;
720 lw->inv_weight = 0;
721}
722
723static inline void update_load_set(struct load_weight *lw, unsigned long w)
724{
725 lw->weight = w;
726 lw->inv_weight = 0;
727}
728
729/*
730 * To aid in avoiding the subversion of "niceness" due to uneven distribution
731 * of tasks with abnormal "nice" values across CPUs the contribution that
732 * each task makes to its run queue's load is weighted according to its
733 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
734 * scaled version of the new time slice allocation that they receive on time
735 * slice expiry etc.
736 */
737
738#define WEIGHT_IDLEPRIO 3
739#define WMULT_IDLEPRIO 1431655765
740
741/*
742 * Nice levels are multiplicative, with a gentle 10% change for every
743 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
744 * nice 1, it will get ~10% less CPU time than another CPU-bound task
745 * that remained on nice 0.
746 *
747 * The "10% effect" is relative and cumulative: from _any_ nice level,
748 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
749 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
750 * If a task goes up by ~10% and another task goes down by ~10% then
751 * the relative distance between them is ~25%.)
752 */
753static const int prio_to_weight[40] = {
754 /* -20 */ 88761, 71755, 56483, 46273, 36291,
755 /* -15 */ 29154, 23254, 18705, 14949, 11916,
756 /* -10 */ 9548, 7620, 6100, 4904, 3906,
757 /* -5 */ 3121, 2501, 1991, 1586, 1277,
758 /* 0 */ 1024, 820, 655, 526, 423,
759 /* 5 */ 335, 272, 215, 172, 137,
760 /* 10 */ 110, 87, 70, 56, 45,
761 /* 15 */ 36, 29, 23, 18, 15,
762};
763
764/*
765 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
766 *
767 * In cases where the weight does not change often, we can use the
768 * precalculated inverse to speed up arithmetics by turning divisions
769 * into multiplications:
770 */
771static const u32 prio_to_wmult[40] = {
772 /* -20 */ 48388, 59856, 76040, 92818, 118348,
773 /* -15 */ 147320, 184698, 229616, 287308, 360437,
774 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
775 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
776 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
777 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
778 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
779 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
780};
781
782/* Time spent by the tasks of the cpu accounting group executing in ... */
783enum cpuacct_stat_index {
784 CPUACCT_STAT_USER, /* ... user mode */
785 CPUACCT_STAT_SYSTEM, /* ... kernel mode */
786
787 CPUACCT_STAT_NSTATS,
788};
789
790
791#define sched_class_highest (&stop_sched_class)
792#define for_each_class(class) \
793 for (class = sched_class_highest; class; class = class->next)
794
795extern const struct sched_class stop_sched_class;
796extern const struct sched_class rt_sched_class;
797extern const struct sched_class fair_sched_class;
798extern const struct sched_class idle_sched_class;
799
800
801#ifdef CONFIG_SMP
802
803extern void trigger_load_balance(struct rq *rq, int cpu);
804extern void idle_balance(int this_cpu, struct rq *this_rq);
805
806#else /* CONFIG_SMP */
807
808static inline void idle_balance(int cpu, struct rq *rq)
809{
810}
811
812#endif
813
814extern void sysrq_sched_debug_show(void);
815extern void sched_init_granularity(void);
816extern void update_max_interval(void);
817extern void update_group_power(struct sched_domain *sd, int cpu);
818extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu);
819extern void init_sched_rt_class(void);
820extern void init_sched_fair_class(void);
821
822extern void resched_task(struct task_struct *p);
823extern void resched_cpu(int cpu);
824
825extern struct rt_bandwidth def_rt_bandwidth;
826extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
827
828extern void update_cpu_load(struct rq *this_rq);
829
830#ifdef CONFIG_CGROUP_CPUACCT
831extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
832extern void cpuacct_update_stats(struct task_struct *tsk,
833 enum cpuacct_stat_index idx, cputime_t val);
834#else
835static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
836static inline void cpuacct_update_stats(struct task_struct *tsk,
837 enum cpuacct_stat_index idx, cputime_t val) {}
838#endif
839
840static inline void inc_nr_running(struct rq *rq)
841{
842 rq->nr_running++;
843}
844
845static inline void dec_nr_running(struct rq *rq)
846{
847 rq->nr_running--;
848}
849
850extern void update_rq_clock(struct rq *rq);
851
852extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
853extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
854
855extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
856
857extern const_debug unsigned int sysctl_sched_time_avg;
858extern const_debug unsigned int sysctl_sched_nr_migrate;
859extern const_debug unsigned int sysctl_sched_migration_cost;
860
861static inline u64 sched_avg_period(void)
862{
863 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
864}
865
866void calc_load_account_idle(struct rq *this_rq);
867
868#ifdef CONFIG_SCHED_HRTICK
869
870/*
871 * Use hrtick when:
872 * - enabled by features
873 * - hrtimer is actually high res
874 */
875static inline int hrtick_enabled(struct rq *rq)
876{
877 if (!sched_feat(HRTICK))
878 return 0;
879 if (!cpu_active(cpu_of(rq)))
880 return 0;
881 return hrtimer_is_hres_active(&rq->hrtick_timer);
882}
883
884void hrtick_start(struct rq *rq, u64 delay);
885
886#endif /* CONFIG_SCHED_HRTICK */
887
888#ifdef CONFIG_SMP
889extern void sched_avg_update(struct rq *rq);
890static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
891{
892 rq->rt_avg += rt_delta;
893 sched_avg_update(rq);
894}
895#else
896static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
897static inline void sched_avg_update(struct rq *rq) { }
898#endif
899
900extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
901
902#ifdef CONFIG_SMP
903#ifdef CONFIG_PREEMPT
904
905static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
906
907/*
908 * fair double_lock_balance: Safely acquires both rq->locks in a fair
909 * way at the expense of forcing extra atomic operations in all
910 * invocations. This assures that the double_lock is acquired using the
911 * same underlying policy as the spinlock_t on this architecture, which
912 * reduces latency compared to the unfair variant below. However, it
913 * also adds more overhead and therefore may reduce throughput.
914 */
915static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
916 __releases(this_rq->lock)
917 __acquires(busiest->lock)
918 __acquires(this_rq->lock)
919{
920 raw_spin_unlock(&this_rq->lock);
921 double_rq_lock(this_rq, busiest);
922
923 return 1;
924}
925
926#else
927/*
928 * Unfair double_lock_balance: Optimizes throughput at the expense of
929 * latency by eliminating extra atomic operations when the locks are
930 * already in proper order on entry. This favors lower cpu-ids and will
931 * grant the double lock to lower cpus over higher ids under contention,
932 * regardless of entry order into the function.
933 */
934static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
935 __releases(this_rq->lock)
936 __acquires(busiest->lock)
937 __acquires(this_rq->lock)
938{
939 int ret = 0;
940
941 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
942 if (busiest < this_rq) {
943 raw_spin_unlock(&this_rq->lock);
944 raw_spin_lock(&busiest->lock);
945 raw_spin_lock_nested(&this_rq->lock,
946 SINGLE_DEPTH_NESTING);
947 ret = 1;
948 } else
949 raw_spin_lock_nested(&busiest->lock,
950 SINGLE_DEPTH_NESTING);
951 }
952 return ret;
953}
954
955#endif /* CONFIG_PREEMPT */
956
957/*
958 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
959 */
960static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
961{
962 if (unlikely(!irqs_disabled())) {
963 /* printk() doesn't work good under rq->lock */
964 raw_spin_unlock(&this_rq->lock);
965 BUG_ON(1);
966 }
967
968 return _double_lock_balance(this_rq, busiest);
969}
970
971static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
972 __releases(busiest->lock)
973{
974 raw_spin_unlock(&busiest->lock);
975 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
976}
977
978/*
979 * double_rq_lock - safely lock two runqueues
980 *
981 * Note this does not disable interrupts like task_rq_lock,
982 * you need to do so manually before calling.
983 */
984static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
985 __acquires(rq1->lock)
986 __acquires(rq2->lock)
987{
988 BUG_ON(!irqs_disabled());
989 if (rq1 == rq2) {
990 raw_spin_lock(&rq1->lock);
991 __acquire(rq2->lock); /* Fake it out ;) */
992 } else {
993 if (rq1 < rq2) {
994 raw_spin_lock(&rq1->lock);
995 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
996 } else {
997 raw_spin_lock(&rq2->lock);
998 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
999 }
1000 }
1001}
1002
1003/*
1004 * double_rq_unlock - safely unlock two runqueues
1005 *
1006 * Note this does not restore interrupts like task_rq_unlock,
1007 * you need to do so manually after calling.
1008 */
1009static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1010 __releases(rq1->lock)
1011 __releases(rq2->lock)
1012{
1013 raw_spin_unlock(&rq1->lock);
1014 if (rq1 != rq2)
1015 raw_spin_unlock(&rq2->lock);
1016 else
1017 __release(rq2->lock);
1018}
1019
1020#else /* CONFIG_SMP */
1021
1022/*
1023 * double_rq_lock - safely lock two runqueues
1024 *
1025 * Note this does not disable interrupts like task_rq_lock,
1026 * you need to do so manually before calling.
1027 */
1028static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1029 __acquires(rq1->lock)
1030 __acquires(rq2->lock)
1031{
1032 BUG_ON(!irqs_disabled());
1033 BUG_ON(rq1 != rq2);
1034 raw_spin_lock(&rq1->lock);
1035 __acquire(rq2->lock); /* Fake it out ;) */
1036}
1037
1038/*
1039 * double_rq_unlock - safely unlock two runqueues
1040 *
1041 * Note this does not restore interrupts like task_rq_unlock,
1042 * you need to do so manually after calling.
1043 */
1044static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1045 __releases(rq1->lock)
1046 __releases(rq2->lock)
1047{
1048 BUG_ON(rq1 != rq2);
1049 raw_spin_unlock(&rq1->lock);
1050 __release(rq2->lock);
1051}
1052
1053#endif
1054
1055extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1056extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1057extern void print_cfs_stats(struct seq_file *m, int cpu);
1058extern void print_rt_stats(struct seq_file *m, int cpu);
1059
1060extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1061extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1062extern void unthrottle_offline_cfs_rqs(struct rq *rq);
1063
1064extern void account_cfs_bandwidth_used(int enabled, int was_enabled);