cfg80211: allow set_interface without type
[linux-2.6/sactl.git] / kernel / sched_fair.c
blobfb8994c6d4bb4bbe90a71f89341baee3cc6e9806
1 /*
2 * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH)
4 * Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 * Interactivity improvements by Mike Galbraith
7 * (C) 2007 Mike Galbraith <efault@gmx.de>
9 * Various enhancements by Dmitry Adamushko.
10 * (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com>
12 * Group scheduling enhancements by Srivatsa Vaddagiri
13 * Copyright IBM Corporation, 2007
14 * Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
16 * Scaled math optimizations by Thomas Gleixner
17 * Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de>
19 * Adaptive scheduling granularity, math enhancements by Peter Zijlstra
20 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
23 #include <linux/latencytop.h>
26 * Targeted preemption latency for CPU-bound tasks:
27 * (default: 20ms * (1 + ilog(ncpus)), units: nanoseconds)
29 * NOTE: this latency value is not the same as the concept of
30 * 'timeslice length' - timeslices in CFS are of variable length
31 * and have no persistent notion like in traditional, time-slice
32 * based scheduling concepts.
34 * (to see the precise effective timeslice length of your workload,
35 * run vmstat and monitor the context-switches (cs) field)
37 unsigned int sysctl_sched_latency = 20000000ULL;
40 * Minimal preemption granularity for CPU-bound tasks:
41 * (default: 4 msec * (1 + ilog(ncpus)), units: nanoseconds)
43 unsigned int sysctl_sched_min_granularity = 4000000ULL;
46 * is kept at sysctl_sched_latency / sysctl_sched_min_granularity
48 static unsigned int sched_nr_latency = 5;
51 * After fork, child runs first. (default) If set to 0 then
52 * parent will (try to) run first.
54 const_debug unsigned int sysctl_sched_child_runs_first = 1;
57 * sys_sched_yield() compat mode
59 * This option switches the agressive yield implementation of the
60 * old scheduler back on.
62 unsigned int __read_mostly sysctl_sched_compat_yield;
65 * SCHED_OTHER wake-up granularity.
66 * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
68 * This option delays the preemption effects of decoupled workloads
69 * and reduces their over-scheduling. Synchronous workloads will still
70 * have immediate wakeup/sleep latencies.
72 unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
74 const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
76 /**************************************************************
77 * CFS operations on generic schedulable entities:
80 static inline struct task_struct *task_of(struct sched_entity *se)
82 return container_of(se, struct task_struct, se);
85 #ifdef CONFIG_FAIR_GROUP_SCHED
87 /* cpu runqueue to which this cfs_rq is attached */
88 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
90 return cfs_rq->rq;
93 /* An entity is a task if it doesn't "own" a runqueue */
94 #define entity_is_task(se) (!se->my_q)
96 /* Walk up scheduling entities hierarchy */
97 #define for_each_sched_entity(se) \
98 for (; se; se = se->parent)
100 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
102 return p->se.cfs_rq;
105 /* runqueue on which this entity is (to be) queued */
106 static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
108 return se->cfs_rq;
111 /* runqueue "owned" by this group */
112 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
114 return grp->my_q;
117 /* Given a group's cfs_rq on one cpu, return its corresponding cfs_rq on
118 * another cpu ('this_cpu')
120 static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu)
122 return cfs_rq->tg->cfs_rq[this_cpu];
125 /* Iterate thr' all leaf cfs_rq's on a runqueue */
126 #define for_each_leaf_cfs_rq(rq, cfs_rq) \
127 list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
129 /* Do the two (enqueued) entities belong to the same group ? */
130 static inline int
131 is_same_group(struct sched_entity *se, struct sched_entity *pse)
133 if (se->cfs_rq == pse->cfs_rq)
134 return 1;
136 return 0;
139 static inline struct sched_entity *parent_entity(struct sched_entity *se)
141 return se->parent;
144 #else /* CONFIG_FAIR_GROUP_SCHED */
146 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
148 return container_of(cfs_rq, struct rq, cfs);
151 #define entity_is_task(se) 1
153 #define for_each_sched_entity(se) \
154 for (; se; se = NULL)
156 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
158 return &task_rq(p)->cfs;
161 static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
163 struct task_struct *p = task_of(se);
164 struct rq *rq = task_rq(p);
166 return &rq->cfs;
169 /* runqueue "owned" by this group */
170 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
172 return NULL;
175 static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu)
177 return &cpu_rq(this_cpu)->cfs;
180 #define for_each_leaf_cfs_rq(rq, cfs_rq) \
181 for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
183 static inline int
184 is_same_group(struct sched_entity *se, struct sched_entity *pse)
186 return 1;
189 static inline struct sched_entity *parent_entity(struct sched_entity *se)
191 return NULL;
194 #endif /* CONFIG_FAIR_GROUP_SCHED */
197 /**************************************************************
198 * Scheduling class tree data structure manipulation methods:
201 static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime)
203 s64 delta = (s64)(vruntime - min_vruntime);
204 if (delta > 0)
205 min_vruntime = vruntime;
207 return min_vruntime;
210 static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
212 s64 delta = (s64)(vruntime - min_vruntime);
213 if (delta < 0)
214 min_vruntime = vruntime;
216 return min_vruntime;
219 static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
221 return se->vruntime - cfs_rq->min_vruntime;
225 * Enqueue an entity into the rb-tree:
227 static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
229 struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
230 struct rb_node *parent = NULL;
231 struct sched_entity *entry;
232 s64 key = entity_key(cfs_rq, se);
233 int leftmost = 1;
236 * Find the right place in the rbtree:
238 while (*link) {
239 parent = *link;
240 entry = rb_entry(parent, struct sched_entity, run_node);
242 * We dont care about collisions. Nodes with
243 * the same key stay together.
245 if (key < entity_key(cfs_rq, entry)) {
246 link = &parent->rb_left;
247 } else {
248 link = &parent->rb_right;
249 leftmost = 0;
254 * Maintain a cache of leftmost tree entries (it is frequently
255 * used):
257 if (leftmost) {
258 cfs_rq->rb_leftmost = &se->run_node;
260 * maintain cfs_rq->min_vruntime to be a monotonic increasing
261 * value tracking the leftmost vruntime in the tree.
263 cfs_rq->min_vruntime =
264 max_vruntime(cfs_rq->min_vruntime, se->vruntime);
267 rb_link_node(&se->run_node, parent, link);
268 rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
271 static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
273 if (cfs_rq->rb_leftmost == &se->run_node) {
274 struct rb_node *next_node;
275 struct sched_entity *next;
277 next_node = rb_next(&se->run_node);
278 cfs_rq->rb_leftmost = next_node;
280 if (next_node) {
281 next = rb_entry(next_node,
282 struct sched_entity, run_node);
283 cfs_rq->min_vruntime =
284 max_vruntime(cfs_rq->min_vruntime,
285 next->vruntime);
289 if (cfs_rq->next == se)
290 cfs_rq->next = NULL;
292 rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
295 static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
297 return cfs_rq->rb_leftmost;
300 static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
302 return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node);
305 static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
307 struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
309 if (!last)
310 return NULL;
312 return rb_entry(last, struct sched_entity, run_node);
315 /**************************************************************
316 * Scheduling class statistics methods:
319 #ifdef CONFIG_SCHED_DEBUG
320 int sched_nr_latency_handler(struct ctl_table *table, int write,
321 struct file *filp, void __user *buffer, size_t *lenp,
322 loff_t *ppos)
324 int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
326 if (ret || !write)
327 return ret;
329 sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
330 sysctl_sched_min_granularity);
332 return 0;
334 #endif
337 * delta *= w / rw
339 static inline unsigned long
340 calc_delta_weight(unsigned long delta, struct sched_entity *se)
342 for_each_sched_entity(se) {
343 delta = calc_delta_mine(delta,
344 se->load.weight, &cfs_rq_of(se)->load);
347 return delta;
351 * delta *= rw / w
353 static inline unsigned long
354 calc_delta_fair(unsigned long delta, struct sched_entity *se)
356 for_each_sched_entity(se) {
357 delta = calc_delta_mine(delta,
358 cfs_rq_of(se)->load.weight, &se->load);
361 return delta;
365 * The idea is to set a period in which each task runs once.
367 * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
368 * this period because otherwise the slices get too small.
370 * p = (nr <= nl) ? l : l*nr/nl
372 static u64 __sched_period(unsigned long nr_running)
374 u64 period = sysctl_sched_latency;
375 unsigned long nr_latency = sched_nr_latency;
377 if (unlikely(nr_running > nr_latency)) {
378 period = sysctl_sched_min_granularity;
379 period *= nr_running;
382 return period;
386 * We calculate the wall-time slice from the period by taking a part
387 * proportional to the weight.
389 * s = p*w/rw
391 static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
393 return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
397 * We calculate the vruntime slice of a to be inserted task
399 * vs = s*rw/w = p
401 static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
403 unsigned long nr_running = cfs_rq->nr_running;
405 if (!se->on_rq)
406 nr_running++;
408 return __sched_period(nr_running);
412 * The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
413 * that it favours >=0 over <0.
415 * -20 |
417 * 0 --------+-------
418 * .'
419 * 19 .'
422 static unsigned long
423 calc_delta_asym(unsigned long delta, struct sched_entity *se)
425 struct load_weight lw = {
426 .weight = NICE_0_LOAD,
427 .inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
430 for_each_sched_entity(se) {
431 struct load_weight *se_lw = &se->load;
432 unsigned long rw = cfs_rq_of(se)->load.weight;
434 #ifdef CONFIG_FAIR_SCHED_GROUP
435 struct cfs_rq *cfs_rq = se->my_q;
436 struct task_group *tg = NULL
438 if (cfs_rq)
439 tg = cfs_rq->tg;
441 if (tg && tg->shares < NICE_0_LOAD) {
443 * scale shares to what it would have been had
444 * tg->weight been NICE_0_LOAD:
446 * weight = 1024 * shares / tg->weight
448 lw.weight *= se->load.weight;
449 lw.weight /= tg->shares;
451 lw.inv_weight = 0;
453 se_lw = &lw;
454 rw += lw.weight - se->load.weight;
455 } else
456 #endif
458 if (se->load.weight < NICE_0_LOAD) {
459 se_lw = &lw;
460 rw += NICE_0_LOAD - se->load.weight;
463 delta = calc_delta_mine(delta, rw, se_lw);
466 return delta;
470 * Update the current task's runtime statistics. Skip current tasks that
471 * are not in our scheduling class.
473 static inline void
474 __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
475 unsigned long delta_exec)
477 unsigned long delta_exec_weighted;
479 schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
481 curr->sum_exec_runtime += delta_exec;
482 schedstat_add(cfs_rq, exec_clock, delta_exec);
483 delta_exec_weighted = calc_delta_fair(delta_exec, curr);
484 curr->vruntime += delta_exec_weighted;
487 static void update_curr(struct cfs_rq *cfs_rq)
489 struct sched_entity *curr = cfs_rq->curr;
490 u64 now = rq_of(cfs_rq)->clock;
491 unsigned long delta_exec;
493 if (unlikely(!curr))
494 return;
497 * Get the amount of time the current task was running
498 * since the last time we changed load (this cannot
499 * overflow on 32 bits):
501 delta_exec = (unsigned long)(now - curr->exec_start);
503 __update_curr(cfs_rq, curr, delta_exec);
504 curr->exec_start = now;
506 if (entity_is_task(curr)) {
507 struct task_struct *curtask = task_of(curr);
509 cpuacct_charge(curtask, delta_exec);
513 static inline void
514 update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
516 schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
520 * Task is being enqueued - update stats:
522 static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
525 * Are we enqueueing a waiting task? (for current tasks
526 * a dequeue/enqueue event is a NOP)
528 if (se != cfs_rq->curr)
529 update_stats_wait_start(cfs_rq, se);
532 static void
533 update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
535 schedstat_set(se->wait_max, max(se->wait_max,
536 rq_of(cfs_rq)->clock - se->wait_start));
537 schedstat_set(se->wait_count, se->wait_count + 1);
538 schedstat_set(se->wait_sum, se->wait_sum +
539 rq_of(cfs_rq)->clock - se->wait_start);
540 schedstat_set(se->wait_start, 0);
543 static inline void
544 update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
547 * Mark the end of the wait period if dequeueing a
548 * waiting task:
550 if (se != cfs_rq->curr)
551 update_stats_wait_end(cfs_rq, se);
555 * We are picking a new current task - update its stats:
557 static inline void
558 update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
561 * We are starting a new run period:
563 se->exec_start = rq_of(cfs_rq)->clock;
566 /**************************************************
567 * Scheduling class queueing methods:
570 #if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
571 static void
572 add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
574 cfs_rq->task_weight += weight;
576 #else
577 static inline void
578 add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
581 #endif
583 static void
584 account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
586 update_load_add(&cfs_rq->load, se->load.weight);
587 if (!parent_entity(se))
588 inc_cpu_load(rq_of(cfs_rq), se->load.weight);
589 if (entity_is_task(se))
590 add_cfs_task_weight(cfs_rq, se->load.weight);
591 cfs_rq->nr_running++;
592 se->on_rq = 1;
593 list_add(&se->group_node, &cfs_rq->tasks);
596 static void
597 account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
599 update_load_sub(&cfs_rq->load, se->load.weight);
600 if (!parent_entity(se))
601 dec_cpu_load(rq_of(cfs_rq), se->load.weight);
602 if (entity_is_task(se))
603 add_cfs_task_weight(cfs_rq, -se->load.weight);
604 cfs_rq->nr_running--;
605 se->on_rq = 0;
606 list_del_init(&se->group_node);
609 static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
611 #ifdef CONFIG_SCHEDSTATS
612 if (se->sleep_start) {
613 u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
614 struct task_struct *tsk = task_of(se);
616 if ((s64)delta < 0)
617 delta = 0;
619 if (unlikely(delta > se->sleep_max))
620 se->sleep_max = delta;
622 se->sleep_start = 0;
623 se->sum_sleep_runtime += delta;
625 account_scheduler_latency(tsk, delta >> 10, 1);
627 if (se->block_start) {
628 u64 delta = rq_of(cfs_rq)->clock - se->block_start;
629 struct task_struct *tsk = task_of(se);
631 if ((s64)delta < 0)
632 delta = 0;
634 if (unlikely(delta > se->block_max))
635 se->block_max = delta;
637 se->block_start = 0;
638 se->sum_sleep_runtime += delta;
641 * Blocking time is in units of nanosecs, so shift by 20 to
642 * get a milliseconds-range estimation of the amount of
643 * time that the task spent sleeping:
645 if (unlikely(prof_on == SLEEP_PROFILING)) {
647 profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk),
648 delta >> 20);
650 account_scheduler_latency(tsk, delta >> 10, 0);
652 #endif
655 static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
657 #ifdef CONFIG_SCHED_DEBUG
658 s64 d = se->vruntime - cfs_rq->min_vruntime;
660 if (d < 0)
661 d = -d;
663 if (d > 3*sysctl_sched_latency)
664 schedstat_inc(cfs_rq, nr_spread_over);
665 #endif
668 static void
669 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
671 u64 vruntime;
673 if (first_fair(cfs_rq)) {
674 vruntime = min_vruntime(cfs_rq->min_vruntime,
675 __pick_next_entity(cfs_rq)->vruntime);
676 } else
677 vruntime = cfs_rq->min_vruntime;
680 * The 'current' period is already promised to the current tasks,
681 * however the extra weight of the new task will slow them down a
682 * little, place the new task so that it fits in the slot that
683 * stays open at the end.
685 if (initial && sched_feat(START_DEBIT))
686 vruntime += sched_vslice_add(cfs_rq, se);
688 if (!initial) {
689 /* sleeps upto a single latency don't count. */
690 if (sched_feat(NEW_FAIR_SLEEPERS)) {
691 unsigned long thresh = sysctl_sched_latency;
694 * convert the sleeper threshold into virtual time
696 if (sched_feat(NORMALIZED_SLEEPER))
697 thresh = calc_delta_fair(thresh, se);
699 vruntime -= thresh;
702 /* ensure we never gain time by being placed backwards. */
703 vruntime = max_vruntime(se->vruntime, vruntime);
706 se->vruntime = vruntime;
709 static void
710 enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
713 * Update run-time statistics of the 'current'.
715 update_curr(cfs_rq);
716 account_entity_enqueue(cfs_rq, se);
718 if (wakeup) {
719 place_entity(cfs_rq, se, 0);
720 enqueue_sleeper(cfs_rq, se);
723 update_stats_enqueue(cfs_rq, se);
724 check_spread(cfs_rq, se);
725 if (se != cfs_rq->curr)
726 __enqueue_entity(cfs_rq, se);
729 static void
730 dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
733 * Update run-time statistics of the 'current'.
735 update_curr(cfs_rq);
737 update_stats_dequeue(cfs_rq, se);
738 if (sleep) {
739 #ifdef CONFIG_SCHEDSTATS
740 if (entity_is_task(se)) {
741 struct task_struct *tsk = task_of(se);
743 if (tsk->state & TASK_INTERRUPTIBLE)
744 se->sleep_start = rq_of(cfs_rq)->clock;
745 if (tsk->state & TASK_UNINTERRUPTIBLE)
746 se->block_start = rq_of(cfs_rq)->clock;
748 #endif
751 if (se != cfs_rq->curr)
752 __dequeue_entity(cfs_rq, se);
753 account_entity_dequeue(cfs_rq, se);
757 * Preempt the current task with a newly woken task if needed:
759 static void
760 check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
762 unsigned long ideal_runtime, delta_exec;
764 ideal_runtime = sched_slice(cfs_rq, curr);
765 delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
766 if (delta_exec > ideal_runtime)
767 resched_task(rq_of(cfs_rq)->curr);
770 static void
771 set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
773 /* 'current' is not kept within the tree. */
774 if (se->on_rq) {
776 * Any task has to be enqueued before it get to execute on
777 * a CPU. So account for the time it spent waiting on the
778 * runqueue.
780 update_stats_wait_end(cfs_rq, se);
781 __dequeue_entity(cfs_rq, se);
784 update_stats_curr_start(cfs_rq, se);
785 cfs_rq->curr = se;
786 #ifdef CONFIG_SCHEDSTATS
788 * Track our maximum slice length, if the CPU's load is at
789 * least twice that of our own weight (i.e. dont track it
790 * when there are only lesser-weight tasks around):
792 if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
793 se->slice_max = max(se->slice_max,
794 se->sum_exec_runtime - se->prev_sum_exec_runtime);
796 #endif
797 se->prev_sum_exec_runtime = se->sum_exec_runtime;
800 static struct sched_entity *
801 pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
803 struct rq *rq = rq_of(cfs_rq);
804 u64 pair_slice = rq->clock - cfs_rq->pair_start;
806 if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) {
807 cfs_rq->pair_start = rq->clock;
808 return se;
811 return cfs_rq->next;
814 static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
816 struct sched_entity *se = NULL;
818 if (first_fair(cfs_rq)) {
819 se = __pick_next_entity(cfs_rq);
820 se = pick_next(cfs_rq, se);
821 set_next_entity(cfs_rq, se);
824 return se;
827 static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
830 * If still on the runqueue then deactivate_task()
831 * was not called and update_curr() has to be done:
833 if (prev->on_rq)
834 update_curr(cfs_rq);
836 check_spread(cfs_rq, prev);
837 if (prev->on_rq) {
838 update_stats_wait_start(cfs_rq, prev);
839 /* Put 'current' back into the tree. */
840 __enqueue_entity(cfs_rq, prev);
842 cfs_rq->curr = NULL;
845 static void
846 entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
849 * Update run-time statistics of the 'current'.
851 update_curr(cfs_rq);
853 #ifdef CONFIG_SCHED_HRTICK
855 * queued ticks are scheduled to match the slice, so don't bother
856 * validating it and just reschedule.
858 if (queued) {
859 resched_task(rq_of(cfs_rq)->curr);
860 return;
863 * don't let the period tick interfere with the hrtick preemption
865 if (!sched_feat(DOUBLE_TICK) &&
866 hrtimer_active(&rq_of(cfs_rq)->hrtick_timer))
867 return;
868 #endif
870 if (cfs_rq->nr_running > 1 || !sched_feat(WAKEUP_PREEMPT))
871 check_preempt_tick(cfs_rq, curr);
874 /**************************************************
875 * CFS operations on tasks:
878 #ifdef CONFIG_SCHED_HRTICK
879 static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
881 struct sched_entity *se = &p->se;
882 struct cfs_rq *cfs_rq = cfs_rq_of(se);
884 WARN_ON(task_rq(p) != rq);
886 if (hrtick_enabled(rq) && cfs_rq->nr_running > 1) {
887 u64 slice = sched_slice(cfs_rq, se);
888 u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime;
889 s64 delta = slice - ran;
891 if (delta < 0) {
892 if (rq->curr == p)
893 resched_task(p);
894 return;
898 * Don't schedule slices shorter than 10000ns, that just
899 * doesn't make sense. Rely on vruntime for fairness.
901 if (rq->curr != p)
902 delta = max_t(s64, 10000LL, delta);
904 hrtick_start(rq, delta);
907 #else /* !CONFIG_SCHED_HRTICK */
908 static inline void
909 hrtick_start_fair(struct rq *rq, struct task_struct *p)
912 #endif
915 * The enqueue_task method is called before nr_running is
916 * increased. Here we update the fair scheduling stats and
917 * then put the task into the rbtree:
919 static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup)
921 struct cfs_rq *cfs_rq;
922 struct sched_entity *se = &p->se;
924 for_each_sched_entity(se) {
925 if (se->on_rq)
926 break;
927 cfs_rq = cfs_rq_of(se);
928 enqueue_entity(cfs_rq, se, wakeup);
929 wakeup = 1;
932 hrtick_start_fair(rq, rq->curr);
936 * The dequeue_task method is called before nr_running is
937 * decreased. We remove the task from the rbtree and
938 * update the fair scheduling stats:
940 static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
942 struct cfs_rq *cfs_rq;
943 struct sched_entity *se = &p->se;
945 for_each_sched_entity(se) {
946 cfs_rq = cfs_rq_of(se);
947 dequeue_entity(cfs_rq, se, sleep);
948 /* Don't dequeue parent if it has other entities besides us */
949 if (cfs_rq->load.weight)
950 break;
951 sleep = 1;
954 hrtick_start_fair(rq, rq->curr);
958 * sched_yield() support is very simple - we dequeue and enqueue.
960 * If compat_yield is turned on then we requeue to the end of the tree.
962 static void yield_task_fair(struct rq *rq)
964 struct task_struct *curr = rq->curr;
965 struct cfs_rq *cfs_rq = task_cfs_rq(curr);
966 struct sched_entity *rightmost, *se = &curr->se;
969 * Are we the only task in the tree?
971 if (unlikely(cfs_rq->nr_running == 1))
972 return;
974 if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
975 update_rq_clock(rq);
977 * Update run-time statistics of the 'current'.
979 update_curr(cfs_rq);
981 return;
984 * Find the rightmost entry in the rbtree:
986 rightmost = __pick_last_entity(cfs_rq);
988 * Already in the rightmost position?
990 if (unlikely(!rightmost || rightmost->vruntime < se->vruntime))
991 return;
994 * Minimally necessary key value to be last in the tree:
995 * Upon rescheduling, sched_class::put_prev_task() will place
996 * 'current' within the tree based on its new key value.
998 se->vruntime = rightmost->vruntime + 1;
1002 * wake_idle() will wake a task on an idle cpu if task->cpu is
1003 * not idle and an idle cpu is available. The span of cpus to
1004 * search starts with cpus closest then further out as needed,
1005 * so we always favor a closer, idle cpu.
1006 * Domains may include CPUs that are not usable for migration,
1007 * hence we need to mask them out (cpu_active_map)
1009 * Returns the CPU we should wake onto.
1011 #if defined(ARCH_HAS_SCHED_WAKE_IDLE)
1012 static int wake_idle(int cpu, struct task_struct *p)
1014 cpumask_t tmp;
1015 struct sched_domain *sd;
1016 int i;
1019 * If it is idle, then it is the best cpu to run this task.
1021 * This cpu is also the best, if it has more than one task already.
1022 * Siblings must be also busy(in most cases) as they didn't already
1023 * pickup the extra load from this cpu and hence we need not check
1024 * sibling runqueue info. This will avoid the checks and cache miss
1025 * penalities associated with that.
1027 if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1)
1028 return cpu;
1030 for_each_domain(cpu, sd) {
1031 if ((sd->flags & SD_WAKE_IDLE)
1032 || ((sd->flags & SD_WAKE_IDLE_FAR)
1033 && !task_hot(p, task_rq(p)->clock, sd))) {
1034 cpus_and(tmp, sd->span, p->cpus_allowed);
1035 cpus_and(tmp, tmp, cpu_active_map);
1036 for_each_cpu_mask_nr(i, tmp) {
1037 if (idle_cpu(i)) {
1038 if (i != task_cpu(p)) {
1039 schedstat_inc(p,
1040 se.nr_wakeups_idle);
1042 return i;
1045 } else {
1046 break;
1049 return cpu;
1051 #else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
1052 static inline int wake_idle(int cpu, struct task_struct *p)
1054 return cpu;
1056 #endif
1058 #ifdef CONFIG_SMP
1060 static const struct sched_class fair_sched_class;
1062 #ifdef CONFIG_FAIR_GROUP_SCHED
1064 * effective_load() calculates the load change as seen from the root_task_group
1066 * Adding load to a group doesn't make a group heavier, but can cause movement
1067 * of group shares between cpus. Assuming the shares were perfectly aligned one
1068 * can calculate the shift in shares.
1070 * The problem is that perfectly aligning the shares is rather expensive, hence
1071 * we try to avoid doing that too often - see update_shares(), which ratelimits
1072 * this change.
1074 * We compensate this by not only taking the current delta into account, but
1075 * also considering the delta between when the shares were last adjusted and
1076 * now.
1078 * We still saw a performance dip, some tracing learned us that between
1079 * cgroup:/ and cgroup:/foo balancing the number of affine wakeups increased
1080 * significantly. Therefore try to bias the error in direction of failing
1081 * the affine wakeup.
1084 static long effective_load(struct task_group *tg, int cpu,
1085 long wl, long wg)
1087 struct sched_entity *se = tg->se[cpu];
1088 long more_w;
1090 if (!tg->parent)
1091 return wl;
1094 * By not taking the decrease of shares on the other cpu into
1095 * account our error leans towards reducing the affine wakeups.
1097 if (!wl && sched_feat(ASYM_EFF_LOAD))
1098 return wl;
1101 * Instead of using this increment, also add the difference
1102 * between when the shares were last updated and now.
1104 more_w = se->my_q->load.weight - se->my_q->rq_weight;
1105 wl += more_w;
1106 wg += more_w;
1108 for_each_sched_entity(se) {
1109 #define D(n) (likely(n) ? (n) : 1)
1111 long S, rw, s, a, b;
1113 S = se->my_q->tg->shares;
1114 s = se->my_q->shares;
1115 rw = se->my_q->rq_weight;
1117 a = S*(rw + wl);
1118 b = S*rw + s*wg;
1120 wl = s*(a-b)/D(b);
1122 * Assume the group is already running and will
1123 * thus already be accounted for in the weight.
1125 * That is, moving shares between CPUs, does not
1126 * alter the group weight.
1128 wg = 0;
1129 #undef D
1132 return wl;
1135 #else
1137 static inline unsigned long effective_load(struct task_group *tg, int cpu,
1138 unsigned long wl, unsigned long wg)
1140 return wl;
1143 #endif
1145 static int
1146 wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
1147 struct task_struct *p, int prev_cpu, int this_cpu, int sync,
1148 int idx, unsigned long load, unsigned long this_load,
1149 unsigned int imbalance)
1151 struct task_struct *curr = this_rq->curr;
1152 struct task_group *tg;
1153 unsigned long tl = this_load;
1154 unsigned long tl_per_task;
1155 unsigned long weight;
1156 int balanced;
1158 if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
1159 return 0;
1162 * If sync wakeup then subtract the (maximum possible)
1163 * effect of the currently running task from the load
1164 * of the current CPU:
1166 if (sync) {
1167 tg = task_group(current);
1168 weight = current->se.load.weight;
1170 tl += effective_load(tg, this_cpu, -weight, -weight);
1171 load += effective_load(tg, prev_cpu, 0, -weight);
1174 tg = task_group(p);
1175 weight = p->se.load.weight;
1177 balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
1178 imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
1181 * If the currently running task will sleep within
1182 * a reasonable amount of time then attract this newly
1183 * woken task:
1185 if (sync && balanced) {
1186 if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
1187 p->se.avg_overlap < sysctl_sched_migration_cost)
1188 return 1;
1191 schedstat_inc(p, se.nr_wakeups_affine_attempts);
1192 tl_per_task = cpu_avg_load_per_task(this_cpu);
1194 if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
1195 balanced) {
1197 * This domain has SD_WAKE_AFFINE and
1198 * p is cache cold in this domain, and
1199 * there is no bad imbalance.
1201 schedstat_inc(this_sd, ttwu_move_affine);
1202 schedstat_inc(p, se.nr_wakeups_affine);
1204 return 1;
1206 return 0;
1209 static int select_task_rq_fair(struct task_struct *p, int sync)
1211 struct sched_domain *sd, *this_sd = NULL;
1212 int prev_cpu, this_cpu, new_cpu;
1213 unsigned long load, this_load;
1214 struct rq *rq, *this_rq;
1215 unsigned int imbalance;
1216 int idx;
1218 prev_cpu = task_cpu(p);
1219 rq = task_rq(p);
1220 this_cpu = smp_processor_id();
1221 this_rq = cpu_rq(this_cpu);
1222 new_cpu = prev_cpu;
1225 * 'this_sd' is the first domain that both
1226 * this_cpu and prev_cpu are present in:
1228 for_each_domain(this_cpu, sd) {
1229 if (cpu_isset(prev_cpu, sd->span)) {
1230 this_sd = sd;
1231 break;
1235 if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
1236 goto out;
1239 * Check for affine wakeup and passive balancing possibilities.
1241 if (!this_sd)
1242 goto out;
1244 idx = this_sd->wake_idx;
1246 imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
1248 load = source_load(prev_cpu, idx);
1249 this_load = target_load(this_cpu, idx);
1251 if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
1252 load, this_load, imbalance))
1253 return this_cpu;
1255 if (prev_cpu == this_cpu)
1256 goto out;
1259 * Start passive balancing when half the imbalance_pct
1260 * limit is reached.
1262 if (this_sd->flags & SD_WAKE_BALANCE) {
1263 if (imbalance*this_load <= 100*load) {
1264 schedstat_inc(this_sd, ttwu_move_balance);
1265 schedstat_inc(p, se.nr_wakeups_passive);
1266 return this_cpu;
1270 out:
1271 return wake_idle(new_cpu, p);
1273 #endif /* CONFIG_SMP */
1275 static unsigned long wakeup_gran(struct sched_entity *se)
1277 unsigned long gran = sysctl_sched_wakeup_granularity;
1280 * More easily preempt - nice tasks, while not making it harder for
1281 * + nice tasks.
1283 if (sched_feat(ASYM_GRAN))
1284 gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
1285 else
1286 gran = calc_delta_fair(sysctl_sched_wakeup_granularity, se);
1288 return gran;
1292 * Should 'se' preempt 'curr'.
1294 * |s1
1295 * |s2
1296 * |s3
1298 * |<--->|c
1300 * w(c, s1) = -1
1301 * w(c, s2) = 0
1302 * w(c, s3) = 1
1305 static int
1306 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
1308 s64 gran, vdiff = curr->vruntime - se->vruntime;
1310 if (vdiff < 0)
1311 return -1;
1313 gran = wakeup_gran(curr);
1314 if (vdiff > gran)
1315 return 1;
1317 return 0;
1320 /* return depth at which a sched entity is present in the hierarchy */
1321 static inline int depth_se(struct sched_entity *se)
1323 int depth = 0;
1325 for_each_sched_entity(se)
1326 depth++;
1328 return depth;
1332 * Preempt the current task with a newly woken task if needed:
1334 static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
1336 struct task_struct *curr = rq->curr;
1337 struct cfs_rq *cfs_rq = task_cfs_rq(curr);
1338 struct sched_entity *se = &curr->se, *pse = &p->se;
1339 int se_depth, pse_depth;
1341 if (unlikely(rt_prio(p->prio))) {
1342 update_rq_clock(rq);
1343 update_curr(cfs_rq);
1344 resched_task(curr);
1345 return;
1348 if (unlikely(se == pse))
1349 return;
1351 cfs_rq_of(pse)->next = pse;
1354 * Batch tasks do not preempt (their preemption is driven by
1355 * the tick):
1357 if (unlikely(p->policy == SCHED_BATCH))
1358 return;
1360 if (!sched_feat(WAKEUP_PREEMPT))
1361 return;
1364 * preemption test can be made between sibling entities who are in the
1365 * same cfs_rq i.e who have a common parent. Walk up the hierarchy of
1366 * both tasks until we find their ancestors who are siblings of common
1367 * parent.
1370 /* First walk up until both entities are at same depth */
1371 se_depth = depth_se(se);
1372 pse_depth = depth_se(pse);
1374 while (se_depth > pse_depth) {
1375 se_depth--;
1376 se = parent_entity(se);
1379 while (pse_depth > se_depth) {
1380 pse_depth--;
1381 pse = parent_entity(pse);
1384 while (!is_same_group(se, pse)) {
1385 se = parent_entity(se);
1386 pse = parent_entity(pse);
1389 if (wakeup_preempt_entity(se, pse) == 1)
1390 resched_task(curr);
1393 static struct task_struct *pick_next_task_fair(struct rq *rq)
1395 struct task_struct *p;
1396 struct cfs_rq *cfs_rq = &rq->cfs;
1397 struct sched_entity *se;
1399 if (unlikely(!cfs_rq->nr_running))
1400 return NULL;
1402 do {
1403 se = pick_next_entity(cfs_rq);
1404 cfs_rq = group_cfs_rq(se);
1405 } while (cfs_rq);
1407 p = task_of(se);
1408 hrtick_start_fair(rq, p);
1410 return p;
1414 * Account for a descheduled task:
1416 static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
1418 struct sched_entity *se = &prev->se;
1419 struct cfs_rq *cfs_rq;
1421 for_each_sched_entity(se) {
1422 cfs_rq = cfs_rq_of(se);
1423 put_prev_entity(cfs_rq, se);
1427 #ifdef CONFIG_SMP
1428 /**************************************************
1429 * Fair scheduling class load-balancing methods:
1433 * Load-balancing iterator. Note: while the runqueue stays locked
1434 * during the whole iteration, the current task might be
1435 * dequeued so the iterator has to be dequeue-safe. Here we
1436 * achieve that by always pre-iterating before returning
1437 * the current task:
1439 static struct task_struct *
1440 __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
1442 struct task_struct *p = NULL;
1443 struct sched_entity *se;
1445 if (next == &cfs_rq->tasks)
1446 return NULL;
1448 /* Skip over entities that are not tasks */
1449 do {
1450 se = list_entry(next, struct sched_entity, group_node);
1451 next = next->next;
1452 } while (next != &cfs_rq->tasks && !entity_is_task(se));
1454 if (next == &cfs_rq->tasks)
1455 return NULL;
1457 cfs_rq->balance_iterator = next;
1459 if (entity_is_task(se))
1460 p = task_of(se);
1462 return p;
1465 static struct task_struct *load_balance_start_fair(void *arg)
1467 struct cfs_rq *cfs_rq = arg;
1469 return __load_balance_iterator(cfs_rq, cfs_rq->tasks.next);
1472 static struct task_struct *load_balance_next_fair(void *arg)
1474 struct cfs_rq *cfs_rq = arg;
1476 return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
1479 static unsigned long
1480 __load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
1481 unsigned long max_load_move, struct sched_domain *sd,
1482 enum cpu_idle_type idle, int *all_pinned, int *this_best_prio,
1483 struct cfs_rq *cfs_rq)
1485 struct rq_iterator cfs_rq_iterator;
1487 cfs_rq_iterator.start = load_balance_start_fair;
1488 cfs_rq_iterator.next = load_balance_next_fair;
1489 cfs_rq_iterator.arg = cfs_rq;
1491 return balance_tasks(this_rq, this_cpu, busiest,
1492 max_load_move, sd, idle, all_pinned,
1493 this_best_prio, &cfs_rq_iterator);
1496 #ifdef CONFIG_FAIR_GROUP_SCHED
1497 static unsigned long
1498 load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
1499 unsigned long max_load_move,
1500 struct sched_domain *sd, enum cpu_idle_type idle,
1501 int *all_pinned, int *this_best_prio)
1503 long rem_load_move = max_load_move;
1504 int busiest_cpu = cpu_of(busiest);
1505 struct task_group *tg;
1507 rcu_read_lock();
1508 update_h_load(busiest_cpu);
1510 list_for_each_entry(tg, &task_groups, list) {
1511 struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu];
1512 unsigned long busiest_h_load = busiest_cfs_rq->h_load;
1513 unsigned long busiest_weight = busiest_cfs_rq->load.weight;
1514 u64 rem_load, moved_load;
1517 * empty group
1519 if (!busiest_cfs_rq->task_weight)
1520 continue;
1522 rem_load = (u64)rem_load_move * busiest_weight;
1523 rem_load = div_u64(rem_load, busiest_h_load + 1);
1525 moved_load = __load_balance_fair(this_rq, this_cpu, busiest,
1526 rem_load, sd, idle, all_pinned, this_best_prio,
1527 tg->cfs_rq[busiest_cpu]);
1529 if (!moved_load)
1530 continue;
1532 moved_load *= busiest_h_load;
1533 moved_load = div_u64(moved_load, busiest_weight + 1);
1535 rem_load_move -= moved_load;
1536 if (rem_load_move < 0)
1537 break;
1539 rcu_read_unlock();
1541 return max_load_move - rem_load_move;
1543 #else
1544 static unsigned long
1545 load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
1546 unsigned long max_load_move,
1547 struct sched_domain *sd, enum cpu_idle_type idle,
1548 int *all_pinned, int *this_best_prio)
1550 return __load_balance_fair(this_rq, this_cpu, busiest,
1551 max_load_move, sd, idle, all_pinned,
1552 this_best_prio, &busiest->cfs);
1554 #endif
1556 static int
1557 move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
1558 struct sched_domain *sd, enum cpu_idle_type idle)
1560 struct cfs_rq *busy_cfs_rq;
1561 struct rq_iterator cfs_rq_iterator;
1563 cfs_rq_iterator.start = load_balance_start_fair;
1564 cfs_rq_iterator.next = load_balance_next_fair;
1566 for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
1568 * pass busy_cfs_rq argument into
1569 * load_balance_[start|next]_fair iterators
1571 cfs_rq_iterator.arg = busy_cfs_rq;
1572 if (iter_move_one_task(this_rq, this_cpu, busiest, sd, idle,
1573 &cfs_rq_iterator))
1574 return 1;
1577 return 0;
1579 #endif /* CONFIG_SMP */
1582 * scheduler tick hitting a task of our scheduling class:
1584 static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
1586 struct cfs_rq *cfs_rq;
1587 struct sched_entity *se = &curr->se;
1589 for_each_sched_entity(se) {
1590 cfs_rq = cfs_rq_of(se);
1591 entity_tick(cfs_rq, se, queued);
1595 #define swap(a, b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
1598 * Share the fairness runtime between parent and child, thus the
1599 * total amount of pressure for CPU stays equal - new tasks
1600 * get a chance to run but frequent forkers are not allowed to
1601 * monopolize the CPU. Note: the parent runqueue is locked,
1602 * the child is not running yet.
1604 static void task_new_fair(struct rq *rq, struct task_struct *p)
1606 struct cfs_rq *cfs_rq = task_cfs_rq(p);
1607 struct sched_entity *se = &p->se, *curr = cfs_rq->curr;
1608 int this_cpu = smp_processor_id();
1610 sched_info_queued(p);
1612 update_curr(cfs_rq);
1613 place_entity(cfs_rq, se, 1);
1615 /* 'curr' will be NULL if the child belongs to a different group */
1616 if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) &&
1617 curr && curr->vruntime < se->vruntime) {
1619 * Upon rescheduling, sched_class::put_prev_task() will place
1620 * 'current' within the tree based on its new key value.
1622 swap(curr->vruntime, se->vruntime);
1625 enqueue_task_fair(rq, p, 0);
1626 resched_task(rq->curr);
1630 * Priority of the task has changed. Check to see if we preempt
1631 * the current task.
1633 static void prio_changed_fair(struct rq *rq, struct task_struct *p,
1634 int oldprio, int running)
1637 * Reschedule if we are currently running on this runqueue and
1638 * our priority decreased, or if we are not currently running on
1639 * this runqueue and our priority is higher than the current's
1641 if (running) {
1642 if (p->prio > oldprio)
1643 resched_task(rq->curr);
1644 } else
1645 check_preempt_curr(rq, p);
1649 * We switched to the sched_fair class.
1651 static void switched_to_fair(struct rq *rq, struct task_struct *p,
1652 int running)
1655 * We were most likely switched from sched_rt, so
1656 * kick off the schedule if running, otherwise just see
1657 * if we can still preempt the current task.
1659 if (running)
1660 resched_task(rq->curr);
1661 else
1662 check_preempt_curr(rq, p);
1665 /* Account for a task changing its policy or group.
1667 * This routine is mostly called to set cfs_rq->curr field when a task
1668 * migrates between groups/classes.
1670 static void set_curr_task_fair(struct rq *rq)
1672 struct sched_entity *se = &rq->curr->se;
1674 for_each_sched_entity(se)
1675 set_next_entity(cfs_rq_of(se), se);
1678 #ifdef CONFIG_FAIR_GROUP_SCHED
1679 static void moved_group_fair(struct task_struct *p)
1681 struct cfs_rq *cfs_rq = task_cfs_rq(p);
1683 update_curr(cfs_rq);
1684 place_entity(cfs_rq, &p->se, 1);
1686 #endif
1689 * All the scheduling class methods:
1691 static const struct sched_class fair_sched_class = {
1692 .next = &idle_sched_class,
1693 .enqueue_task = enqueue_task_fair,
1694 .dequeue_task = dequeue_task_fair,
1695 .yield_task = yield_task_fair,
1696 #ifdef CONFIG_SMP
1697 .select_task_rq = select_task_rq_fair,
1698 #endif /* CONFIG_SMP */
1700 .check_preempt_curr = check_preempt_wakeup,
1702 .pick_next_task = pick_next_task_fair,
1703 .put_prev_task = put_prev_task_fair,
1705 #ifdef CONFIG_SMP
1706 .load_balance = load_balance_fair,
1707 .move_one_task = move_one_task_fair,
1708 #endif
1710 .set_curr_task = set_curr_task_fair,
1711 .task_tick = task_tick_fair,
1712 .task_new = task_new_fair,
1714 .prio_changed = prio_changed_fair,
1715 .switched_to = switched_to_fair,
1717 #ifdef CONFIG_FAIR_GROUP_SCHED
1718 .moved_group = moved_group_fair,
1719 #endif
1722 #ifdef CONFIG_SCHED_DEBUG
1723 static void print_cfs_stats(struct seq_file *m, int cpu)
1725 struct cfs_rq *cfs_rq;
1727 rcu_read_lock();
1728 for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
1729 print_cfs_rq(m, cpu, cfs_rq);
1730 rcu_read_unlock();
1732 #endif