4 * Kernel scheduler and related syscalls
6 * Copyright (C) 1991-2002 Linus Torvalds
8 * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
9 * make semaphores SMP safe
10 * 1998-11-19 Implemented schedule_timeout() and related stuff
12 * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
13 * hybrid priority-list and round-robin design with
14 * an array-switch method of distributing timeslices
15 * and per-CPU runqueues. Cleanups and useful suggestions
16 * by Davide Libenzi, preemptible kernel bits by Robert Love.
17 * 2003-09-03 Interactivity tuning by Con Kolivas.
18 * 2004-04-02 Scheduler domains code by Nick Piggin
19 * 2007-04-15 Work begun on replacing all interactivity tuning with a
20 * fair scheduling design by Con Kolivas.
21 * 2007-05-05 Load balancing (smp-nice) and other improvements
23 * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
24 * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
25 * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
26 * Thomas Gleixner, Mike Kravetz
29 #include <linux/kasan.h>
31 #include <linux/module.h>
32 #include <linux/nmi.h>
33 #include <linux/init.h>
34 #include <linux/uaccess.h>
35 #include <linux/highmem.h>
36 #include <asm/mmu_context.h>
37 #include <linux/interrupt.h>
38 #include <linux/capability.h>
39 #include <linux/completion.h>
40 #include <linux/kernel_stat.h>
41 #include <linux/debug_locks.h>
42 #include <linux/perf_event.h>
43 #include <linux/security.h>
44 #include <linux/notifier.h>
45 #include <linux/profile.h>
46 #include <linux/freezer.h>
47 #include <linux/vmalloc.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/pid_namespace.h>
51 #include <linux/smp.h>
52 #include <linux/threads.h>
53 #include <linux/timer.h>
54 #include <linux/rcupdate.h>
55 #include <linux/cpu.h>
56 #include <linux/cpuset.h>
57 #include <linux/percpu.h>
58 #include <linux/proc_fs.h>
59 #include <linux/seq_file.h>
60 #include <linux/sysctl.h>
61 #include <linux/syscalls.h>
62 #include <linux/times.h>
63 #include <linux/tsacct_kern.h>
64 #include <linux/kprobes.h>
65 #include <linux/delayacct.h>
66 #include <linux/unistd.h>
67 #include <linux/pagemap.h>
68 #include <linux/hrtimer.h>
69 #include <linux/tick.h>
70 #include <linux/ctype.h>
71 #include <linux/ftrace.h>
72 #include <linux/slab.h>
73 #include <linux/init_task.h>
74 #include <linux/context_tracking.h>
75 #include <linux/compiler.h>
76 #include <linux/frame.h>
78 #include <asm/switch_to.h>
80 #include <asm/irq_regs.h>
81 #include <asm/mutex.h>
82 #ifdef CONFIG_PARAVIRT
83 #include <asm/paravirt.h>
87 #include "../workqueue_internal.h"
88 #include "../smpboot.h"
90 #define CREATE_TRACE_POINTS
91 #include <trace/events/sched.h>
93 DEFINE_MUTEX(sched_domains_mutex
);
94 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq
, runqueues
);
96 static void update_rq_clock_task(struct rq
*rq
, s64 delta
);
98 void update_rq_clock(struct rq
*rq
)
102 lockdep_assert_held(&rq
->lock
);
104 if (rq
->clock_skip_update
& RQCF_ACT_SKIP
)
107 delta
= sched_clock_cpu(cpu_of(rq
)) - rq
->clock
;
111 update_rq_clock_task(rq
, delta
);
115 * Debugging: various feature bits
118 #define SCHED_FEAT(name, enabled) \
119 (1UL << __SCHED_FEAT_##name) * enabled |
121 const_debug
unsigned int sysctl_sched_features
=
122 #include "features.h"
128 * Number of tasks to iterate in a single balance run.
129 * Limited because this is done with IRQs disabled.
131 const_debug
unsigned int sysctl_sched_nr_migrate
= 32;
134 * period over which we average the RT time consumption, measured
139 const_debug
unsigned int sysctl_sched_time_avg
= MSEC_PER_SEC
;
142 * period over which we measure -rt task cpu usage in us.
145 unsigned int sysctl_sched_rt_period
= 1000000;
147 __read_mostly
int scheduler_running
;
150 * part of the period that we allow rt tasks to run in us.
153 int sysctl_sched_rt_runtime
= 950000;
155 /* cpus with isolated domains */
156 cpumask_var_t cpu_isolated_map
;
159 * this_rq_lock - lock this runqueue and disable interrupts.
161 static struct rq
*this_rq_lock(void)
168 raw_spin_lock(&rq
->lock
);
173 #ifdef CONFIG_SCHED_HRTICK
175 * Use HR-timers to deliver accurate preemption points.
178 static void hrtick_clear(struct rq
*rq
)
180 if (hrtimer_active(&rq
->hrtick_timer
))
181 hrtimer_cancel(&rq
->hrtick_timer
);
185 * High-resolution timer tick.
186 * Runs from hardirq context with interrupts disabled.
188 static enum hrtimer_restart
hrtick(struct hrtimer
*timer
)
190 struct rq
*rq
= container_of(timer
, struct rq
, hrtick_timer
);
192 WARN_ON_ONCE(cpu_of(rq
) != smp_processor_id());
194 raw_spin_lock(&rq
->lock
);
196 rq
->curr
->sched_class
->task_tick(rq
, rq
->curr
, 1);
197 raw_spin_unlock(&rq
->lock
);
199 return HRTIMER_NORESTART
;
204 static void __hrtick_restart(struct rq
*rq
)
206 struct hrtimer
*timer
= &rq
->hrtick_timer
;
208 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
212 * called from hardirq (IPI) context
214 static void __hrtick_start(void *arg
)
218 raw_spin_lock(&rq
->lock
);
219 __hrtick_restart(rq
);
220 rq
->hrtick_csd_pending
= 0;
221 raw_spin_unlock(&rq
->lock
);
225 * Called to set the hrtick timer state.
227 * called with rq->lock held and irqs disabled
229 void hrtick_start(struct rq
*rq
, u64 delay
)
231 struct hrtimer
*timer
= &rq
->hrtick_timer
;
236 * Don't schedule slices shorter than 10000ns, that just
237 * doesn't make sense and can cause timer DoS.
239 delta
= max_t(s64
, delay
, 10000LL);
240 time
= ktime_add_ns(timer
->base
->get_time(), delta
);
242 hrtimer_set_expires(timer
, time
);
244 if (rq
== this_rq()) {
245 __hrtick_restart(rq
);
246 } else if (!rq
->hrtick_csd_pending
) {
247 smp_call_function_single_async(cpu_of(rq
), &rq
->hrtick_csd
);
248 rq
->hrtick_csd_pending
= 1;
253 hotplug_hrtick(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
)
255 int cpu
= (int)(long)hcpu
;
258 case CPU_UP_CANCELED
:
259 case CPU_UP_CANCELED_FROZEN
:
260 case CPU_DOWN_PREPARE
:
261 case CPU_DOWN_PREPARE_FROZEN
:
263 case CPU_DEAD_FROZEN
:
264 hrtick_clear(cpu_rq(cpu
));
271 static __init
void init_hrtick(void)
273 hotcpu_notifier(hotplug_hrtick
, 0);
277 * Called to set the hrtick timer state.
279 * called with rq->lock held and irqs disabled
281 void hrtick_start(struct rq
*rq
, u64 delay
)
284 * Don't schedule slices shorter than 10000ns, that just
285 * doesn't make sense. Rely on vruntime for fairness.
287 delay
= max_t(u64
, delay
, 10000LL);
288 hrtimer_start(&rq
->hrtick_timer
, ns_to_ktime(delay
),
289 HRTIMER_MODE_REL_PINNED
);
292 static inline void init_hrtick(void)
295 #endif /* CONFIG_SMP */
297 static void init_rq_hrtick(struct rq
*rq
)
300 rq
->hrtick_csd_pending
= 0;
302 rq
->hrtick_csd
.flags
= 0;
303 rq
->hrtick_csd
.func
= __hrtick_start
;
304 rq
->hrtick_csd
.info
= rq
;
307 hrtimer_init(&rq
->hrtick_timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
308 rq
->hrtick_timer
.function
= hrtick
;
310 #else /* CONFIG_SCHED_HRTICK */
311 static inline void hrtick_clear(struct rq
*rq
)
315 static inline void init_rq_hrtick(struct rq
*rq
)
319 static inline void init_hrtick(void)
322 #endif /* CONFIG_SCHED_HRTICK */
325 * cmpxchg based fetch_or, macro so it works for different integer types
327 #define fetch_or(ptr, mask) \
329 typeof(ptr) _ptr = (ptr); \
330 typeof(mask) _mask = (mask); \
331 typeof(*_ptr) _old, _val = *_ptr; \
334 _old = cmpxchg(_ptr, _val, _val | _mask); \
342 #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
344 * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
345 * this avoids any races wrt polling state changes and thereby avoids
348 static bool set_nr_and_not_polling(struct task_struct
*p
)
350 struct thread_info
*ti
= task_thread_info(p
);
351 return !(fetch_or(&ti
->flags
, _TIF_NEED_RESCHED
) & _TIF_POLLING_NRFLAG
);
355 * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set.
357 * If this returns true, then the idle task promises to call
358 * sched_ttwu_pending() and reschedule soon.
360 static bool set_nr_if_polling(struct task_struct
*p
)
362 struct thread_info
*ti
= task_thread_info(p
);
363 typeof(ti
->flags
) old
, val
= READ_ONCE(ti
->flags
);
366 if (!(val
& _TIF_POLLING_NRFLAG
))
368 if (val
& _TIF_NEED_RESCHED
)
370 old
= cmpxchg(&ti
->flags
, val
, val
| _TIF_NEED_RESCHED
);
379 static bool set_nr_and_not_polling(struct task_struct
*p
)
381 set_tsk_need_resched(p
);
386 static bool set_nr_if_polling(struct task_struct
*p
)
393 void wake_q_add(struct wake_q_head
*head
, struct task_struct
*task
)
395 struct wake_q_node
*node
= &task
->wake_q
;
398 * Atomically grab the task, if ->wake_q is !nil already it means
399 * its already queued (either by us or someone else) and will get the
400 * wakeup due to that.
402 * This cmpxchg() implies a full barrier, which pairs with the write
403 * barrier implied by the wakeup in wake_up_list().
405 if (cmpxchg(&node
->next
, NULL
, WAKE_Q_TAIL
))
408 get_task_struct(task
);
411 * The head is context local, there can be no concurrency.
414 head
->lastp
= &node
->next
;
417 void wake_up_q(struct wake_q_head
*head
)
419 struct wake_q_node
*node
= head
->first
;
421 while (node
!= WAKE_Q_TAIL
) {
422 struct task_struct
*task
;
424 task
= container_of(node
, struct task_struct
, wake_q
);
426 /* task can safely be re-inserted now */
428 task
->wake_q
.next
= NULL
;
431 * wake_up_process() implies a wmb() to pair with the queueing
432 * in wake_q_add() so as not to miss wakeups.
434 wake_up_process(task
);
435 put_task_struct(task
);
440 * resched_curr - mark rq's current task 'to be rescheduled now'.
442 * On UP this means the setting of the need_resched flag, on SMP it
443 * might also involve a cross-CPU call to trigger the scheduler on
446 void resched_curr(struct rq
*rq
)
448 struct task_struct
*curr
= rq
->curr
;
451 lockdep_assert_held(&rq
->lock
);
453 if (test_tsk_need_resched(curr
))
458 if (cpu
== smp_processor_id()) {
459 set_tsk_need_resched(curr
);
460 set_preempt_need_resched();
464 if (set_nr_and_not_polling(curr
))
465 smp_send_reschedule(cpu
);
467 trace_sched_wake_idle_without_ipi(cpu
);
470 void resched_cpu(int cpu
)
472 struct rq
*rq
= cpu_rq(cpu
);
475 if (!raw_spin_trylock_irqsave(&rq
->lock
, flags
))
478 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
482 #ifdef CONFIG_NO_HZ_COMMON
484 * In the semi idle case, use the nearest busy cpu for migrating timers
485 * from an idle cpu. This is good for power-savings.
487 * We don't do similar optimization for completely idle system, as
488 * selecting an idle cpu will add more delays to the timers than intended
489 * (as that cpu's timer base may not be uptodate wrt jiffies etc).
491 int get_nohz_timer_target(void)
493 int i
, cpu
= smp_processor_id();
494 struct sched_domain
*sd
;
496 if (!idle_cpu(cpu
) && is_housekeeping_cpu(cpu
))
500 for_each_domain(cpu
, sd
) {
501 for_each_cpu(i
, sched_domain_span(sd
)) {
502 if (!idle_cpu(i
) && is_housekeeping_cpu(cpu
)) {
509 if (!is_housekeeping_cpu(cpu
))
510 cpu
= housekeeping_any_cpu();
516 * When add_timer_on() enqueues a timer into the timer wheel of an
517 * idle CPU then this timer might expire before the next timer event
518 * which is scheduled to wake up that CPU. In case of a completely
519 * idle system the next event might even be infinite time into the
520 * future. wake_up_idle_cpu() ensures that the CPU is woken up and
521 * leaves the inner idle loop so the newly added timer is taken into
522 * account when the CPU goes back to idle and evaluates the timer
523 * wheel for the next timer event.
525 static void wake_up_idle_cpu(int cpu
)
527 struct rq
*rq
= cpu_rq(cpu
);
529 if (cpu
== smp_processor_id())
532 if (set_nr_and_not_polling(rq
->idle
))
533 smp_send_reschedule(cpu
);
535 trace_sched_wake_idle_without_ipi(cpu
);
538 static bool wake_up_full_nohz_cpu(int cpu
)
541 * We just need the target to call irq_exit() and re-evaluate
542 * the next tick. The nohz full kick at least implies that.
543 * If needed we can still optimize that later with an
546 if (tick_nohz_full_cpu(cpu
)) {
547 if (cpu
!= smp_processor_id() ||
548 tick_nohz_tick_stopped())
549 tick_nohz_full_kick_cpu(cpu
);
556 void wake_up_nohz_cpu(int cpu
)
558 if (!wake_up_full_nohz_cpu(cpu
))
559 wake_up_idle_cpu(cpu
);
562 static inline bool got_nohz_idle_kick(void)
564 int cpu
= smp_processor_id();
566 if (!test_bit(NOHZ_BALANCE_KICK
, nohz_flags(cpu
)))
569 if (idle_cpu(cpu
) && !need_resched())
573 * We can't run Idle Load Balance on this CPU for this time so we
574 * cancel it and clear NOHZ_BALANCE_KICK
576 clear_bit(NOHZ_BALANCE_KICK
, nohz_flags(cpu
));
580 #else /* CONFIG_NO_HZ_COMMON */
582 static inline bool got_nohz_idle_kick(void)
587 #endif /* CONFIG_NO_HZ_COMMON */
589 #ifdef CONFIG_NO_HZ_FULL
590 bool sched_can_stop_tick(struct rq
*rq
)
594 /* Deadline tasks, even if single, need the tick */
595 if (rq
->dl
.dl_nr_running
)
599 * If there are more than one RR tasks, we need the tick to effect the
600 * actual RR behaviour.
602 if (rq
->rt
.rr_nr_running
) {
603 if (rq
->rt
.rr_nr_running
== 1)
610 * If there's no RR tasks, but FIFO tasks, we can skip the tick, no
611 * forced preemption between FIFO tasks.
613 fifo_nr_running
= rq
->rt
.rt_nr_running
- rq
->rt
.rr_nr_running
;
618 * If there are no DL,RR/FIFO tasks, there must only be CFS tasks left;
619 * if there's more than one we need the tick for involuntary
622 if (rq
->nr_running
> 1)
627 #endif /* CONFIG_NO_HZ_FULL */
629 void sched_avg_update(struct rq
*rq
)
631 s64 period
= sched_avg_period();
633 while ((s64
)(rq_clock(rq
) - rq
->age_stamp
) > period
) {
635 * Inline assembly required to prevent the compiler
636 * optimising this loop into a divmod call.
637 * See __iter_div_u64_rem() for another example of this.
639 asm("" : "+rm" (rq
->age_stamp
));
640 rq
->age_stamp
+= period
;
645 #endif /* CONFIG_SMP */
647 #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
648 (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
650 * Iterate task_group tree rooted at *from, calling @down when first entering a
651 * node and @up when leaving it for the final time.
653 * Caller must hold rcu_lock or sufficient equivalent.
655 int walk_tg_tree_from(struct task_group
*from
,
656 tg_visitor down
, tg_visitor up
, void *data
)
658 struct task_group
*parent
, *child
;
664 ret
= (*down
)(parent
, data
);
667 list_for_each_entry_rcu(child
, &parent
->children
, siblings
) {
674 ret
= (*up
)(parent
, data
);
675 if (ret
|| parent
== from
)
679 parent
= parent
->parent
;
686 int tg_nop(struct task_group
*tg
, void *data
)
692 static void set_load_weight(struct task_struct
*p
)
694 int prio
= p
->static_prio
- MAX_RT_PRIO
;
695 struct load_weight
*load
= &p
->se
.load
;
698 * SCHED_IDLE tasks get minimal weight:
700 if (idle_policy(p
->policy
)) {
701 load
->weight
= scale_load(WEIGHT_IDLEPRIO
);
702 load
->inv_weight
= WMULT_IDLEPRIO
;
706 load
->weight
= scale_load(sched_prio_to_weight
[prio
]);
707 load
->inv_weight
= sched_prio_to_wmult
[prio
];
710 static inline void enqueue_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
713 if (!(flags
& ENQUEUE_RESTORE
))
714 sched_info_queued(rq
, p
);
715 p
->sched_class
->enqueue_task(rq
, p
, flags
);
718 static inline void dequeue_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
721 if (!(flags
& DEQUEUE_SAVE
))
722 sched_info_dequeued(rq
, p
);
723 p
->sched_class
->dequeue_task(rq
, p
, flags
);
726 void activate_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
728 if (task_contributes_to_load(p
))
729 rq
->nr_uninterruptible
--;
731 enqueue_task(rq
, p
, flags
);
734 void deactivate_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
736 if (task_contributes_to_load(p
))
737 rq
->nr_uninterruptible
++;
739 dequeue_task(rq
, p
, flags
);
742 static void update_rq_clock_task(struct rq
*rq
, s64 delta
)
745 * In theory, the compile should just see 0 here, and optimize out the call
746 * to sched_rt_avg_update. But I don't trust it...
748 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
749 s64 steal
= 0, irq_delta
= 0;
751 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
752 irq_delta
= irq_time_read(cpu_of(rq
)) - rq
->prev_irq_time
;
755 * Since irq_time is only updated on {soft,}irq_exit, we might run into
756 * this case when a previous update_rq_clock() happened inside a
759 * When this happens, we stop ->clock_task and only update the
760 * prev_irq_time stamp to account for the part that fit, so that a next
761 * update will consume the rest. This ensures ->clock_task is
764 * It does however cause some slight miss-attribution of {soft,}irq
765 * time, a more accurate solution would be to update the irq_time using
766 * the current rq->clock timestamp, except that would require using
769 if (irq_delta
> delta
)
772 rq
->prev_irq_time
+= irq_delta
;
775 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
776 if (static_key_false((¶virt_steal_rq_enabled
))) {
777 steal
= paravirt_steal_clock(cpu_of(rq
));
778 steal
-= rq
->prev_steal_time_rq
;
780 if (unlikely(steal
> delta
))
783 rq
->prev_steal_time_rq
+= steal
;
788 rq
->clock_task
+= delta
;
790 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
791 if ((irq_delta
+ steal
) && sched_feat(NONTASK_CAPACITY
))
792 sched_rt_avg_update(rq
, irq_delta
+ steal
);
796 void sched_set_stop_task(int cpu
, struct task_struct
*stop
)
798 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
799 struct task_struct
*old_stop
= cpu_rq(cpu
)->stop
;
803 * Make it appear like a SCHED_FIFO task, its something
804 * userspace knows about and won't get confused about.
806 * Also, it will make PI more or less work without too
807 * much confusion -- but then, stop work should not
808 * rely on PI working anyway.
810 sched_setscheduler_nocheck(stop
, SCHED_FIFO
, ¶m
);
812 stop
->sched_class
= &stop_sched_class
;
815 cpu_rq(cpu
)->stop
= stop
;
819 * Reset it back to a normal scheduling class so that
820 * it can die in pieces.
822 old_stop
->sched_class
= &rt_sched_class
;
827 * __normal_prio - return the priority that is based on the static prio
829 static inline int __normal_prio(struct task_struct
*p
)
831 return p
->static_prio
;
835 * Calculate the expected normal priority: i.e. priority
836 * without taking RT-inheritance into account. Might be
837 * boosted by interactivity modifiers. Changes upon fork,
838 * setprio syscalls, and whenever the interactivity
839 * estimator recalculates.
841 static inline int normal_prio(struct task_struct
*p
)
845 if (task_has_dl_policy(p
))
846 prio
= MAX_DL_PRIO
-1;
847 else if (task_has_rt_policy(p
))
848 prio
= MAX_RT_PRIO
-1 - p
->rt_priority
;
850 prio
= __normal_prio(p
);
855 * Calculate the current priority, i.e. the priority
856 * taken into account by the scheduler. This value might
857 * be boosted by RT tasks, or might be boosted by
858 * interactivity modifiers. Will be RT if the task got
859 * RT-boosted. If not then it returns p->normal_prio.
861 static int effective_prio(struct task_struct
*p
)
863 p
->normal_prio
= normal_prio(p
);
865 * If we are RT tasks or we were boosted to RT priority,
866 * keep the priority unchanged. Otherwise, update priority
867 * to the normal priority:
869 if (!rt_prio(p
->prio
))
870 return p
->normal_prio
;
875 * task_curr - is this task currently executing on a CPU?
876 * @p: the task in question.
878 * Return: 1 if the task is currently executing. 0 otherwise.
880 inline int task_curr(const struct task_struct
*p
)
882 return cpu_curr(task_cpu(p
)) == p
;
886 * switched_from, switched_to and prio_changed must _NOT_ drop rq->lock,
887 * use the balance_callback list if you want balancing.
889 * this means any call to check_class_changed() must be followed by a call to
890 * balance_callback().
892 static inline void check_class_changed(struct rq
*rq
, struct task_struct
*p
,
893 const struct sched_class
*prev_class
,
896 if (prev_class
!= p
->sched_class
) {
897 if (prev_class
->switched_from
)
898 prev_class
->switched_from(rq
, p
);
900 p
->sched_class
->switched_to(rq
, p
);
901 } else if (oldprio
!= p
->prio
|| dl_task(p
))
902 p
->sched_class
->prio_changed(rq
, p
, oldprio
);
905 void check_preempt_curr(struct rq
*rq
, struct task_struct
*p
, int flags
)
907 const struct sched_class
*class;
909 if (p
->sched_class
== rq
->curr
->sched_class
) {
910 rq
->curr
->sched_class
->check_preempt_curr(rq
, p
, flags
);
912 for_each_class(class) {
913 if (class == rq
->curr
->sched_class
)
915 if (class == p
->sched_class
) {
923 * A queue event has occurred, and we're going to schedule. In
924 * this case, we can save a useless back to back clock update.
926 if (task_on_rq_queued(rq
->curr
) && test_tsk_need_resched(rq
->curr
))
927 rq_clock_skip_update(rq
, true);
932 * This is how migration works:
934 * 1) we invoke migration_cpu_stop() on the target CPU using
936 * 2) stopper starts to run (implicitly forcing the migrated thread
938 * 3) it checks whether the migrated task is still in the wrong runqueue.
939 * 4) if it's in the wrong runqueue then the migration thread removes
940 * it and puts it into the right queue.
941 * 5) stopper completes and stop_one_cpu() returns and the migration
946 * move_queued_task - move a queued task to new rq.
948 * Returns (locked) new rq. Old rq's lock is released.
950 static struct rq
*move_queued_task(struct rq
*rq
, struct task_struct
*p
, int new_cpu
)
952 lockdep_assert_held(&rq
->lock
);
954 p
->on_rq
= TASK_ON_RQ_MIGRATING
;
955 dequeue_task(rq
, p
, 0);
956 set_task_cpu(p
, new_cpu
);
957 raw_spin_unlock(&rq
->lock
);
959 rq
= cpu_rq(new_cpu
);
961 raw_spin_lock(&rq
->lock
);
962 BUG_ON(task_cpu(p
) != new_cpu
);
963 enqueue_task(rq
, p
, 0);
964 p
->on_rq
= TASK_ON_RQ_QUEUED
;
965 check_preempt_curr(rq
, p
, 0);
970 struct migration_arg
{
971 struct task_struct
*task
;
976 * Move (not current) task off this cpu, onto dest cpu. We're doing
977 * this because either it can't run here any more (set_cpus_allowed()
978 * away from this CPU, or CPU going down), or because we're
979 * attempting to rebalance this task on exec (sched_exec).
981 * So we race with normal scheduler movements, but that's OK, as long
982 * as the task is no longer on this CPU.
984 static struct rq
*__migrate_task(struct rq
*rq
, struct task_struct
*p
, int dest_cpu
)
986 if (unlikely(!cpu_active(dest_cpu
)))
989 /* Affinity changed (again). */
990 if (!cpumask_test_cpu(dest_cpu
, tsk_cpus_allowed(p
)))
993 rq
= move_queued_task(rq
, p
, dest_cpu
);
999 * migration_cpu_stop - this will be executed by a highprio stopper thread
1000 * and performs thread migration by bumping thread off CPU then
1001 * 'pushing' onto another runqueue.
1003 static int migration_cpu_stop(void *data
)
1005 struct migration_arg
*arg
= data
;
1006 struct task_struct
*p
= arg
->task
;
1007 struct rq
*rq
= this_rq();
1010 * The original target cpu might have gone down and we might
1011 * be on another cpu but it doesn't matter.
1013 local_irq_disable();
1015 * We need to explicitly wake pending tasks before running
1016 * __migrate_task() such that we will not miss enforcing cpus_allowed
1017 * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
1019 sched_ttwu_pending();
1021 raw_spin_lock(&p
->pi_lock
);
1022 raw_spin_lock(&rq
->lock
);
1024 * If task_rq(p) != rq, it cannot be migrated here, because we're
1025 * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because
1026 * we're holding p->pi_lock.
1028 if (task_rq(p
) == rq
&& task_on_rq_queued(p
))
1029 rq
= __migrate_task(rq
, p
, arg
->dest_cpu
);
1030 raw_spin_unlock(&rq
->lock
);
1031 raw_spin_unlock(&p
->pi_lock
);
1038 * sched_class::set_cpus_allowed must do the below, but is not required to
1039 * actually call this function.
1041 void set_cpus_allowed_common(struct task_struct
*p
, const struct cpumask
*new_mask
)
1043 cpumask_copy(&p
->cpus_allowed
, new_mask
);
1044 p
->nr_cpus_allowed
= cpumask_weight(new_mask
);
1047 void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
)
1049 struct rq
*rq
= task_rq(p
);
1050 bool queued
, running
;
1052 lockdep_assert_held(&p
->pi_lock
);
1054 queued
= task_on_rq_queued(p
);
1055 running
= task_current(rq
, p
);
1059 * Because __kthread_bind() calls this on blocked tasks without
1062 lockdep_assert_held(&rq
->lock
);
1063 dequeue_task(rq
, p
, DEQUEUE_SAVE
);
1066 put_prev_task(rq
, p
);
1068 p
->sched_class
->set_cpus_allowed(p
, new_mask
);
1071 p
->sched_class
->set_curr_task(rq
);
1073 enqueue_task(rq
, p
, ENQUEUE_RESTORE
);
1077 * Change a given task's CPU affinity. Migrate the thread to a
1078 * proper CPU and schedule it away if the CPU it's executing on
1079 * is removed from the allowed bitmask.
1081 * NOTE: the caller must have a valid reference to the task, the
1082 * task must not exit() & deallocate itself prematurely. The
1083 * call is not atomic; no spinlocks may be held.
1085 static int __set_cpus_allowed_ptr(struct task_struct
*p
,
1086 const struct cpumask
*new_mask
, bool check
)
1088 unsigned long flags
;
1090 unsigned int dest_cpu
;
1093 rq
= task_rq_lock(p
, &flags
);
1096 * Must re-check here, to close a race against __kthread_bind(),
1097 * sched_setaffinity() is not guaranteed to observe the flag.
1099 if (check
&& (p
->flags
& PF_NO_SETAFFINITY
)) {
1104 if (cpumask_equal(&p
->cpus_allowed
, new_mask
))
1107 if (!cpumask_intersects(new_mask
, cpu_active_mask
)) {
1112 do_set_cpus_allowed(p
, new_mask
);
1114 /* Can the task run on the task's current CPU? If so, we're done */
1115 if (cpumask_test_cpu(task_cpu(p
), new_mask
))
1118 dest_cpu
= cpumask_any_and(cpu_active_mask
, new_mask
);
1119 if (task_running(rq
, p
) || p
->state
== TASK_WAKING
) {
1120 struct migration_arg arg
= { p
, dest_cpu
};
1121 /* Need help from migration thread: drop lock and wait. */
1122 task_rq_unlock(rq
, p
, &flags
);
1123 stop_one_cpu(cpu_of(rq
), migration_cpu_stop
, &arg
);
1124 tlb_migrate_finish(p
->mm
);
1126 } else if (task_on_rq_queued(p
)) {
1128 * OK, since we're going to drop the lock immediately
1129 * afterwards anyway.
1131 lockdep_unpin_lock(&rq
->lock
);
1132 rq
= move_queued_task(rq
, p
, dest_cpu
);
1133 lockdep_pin_lock(&rq
->lock
);
1136 task_rq_unlock(rq
, p
, &flags
);
1141 int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
)
1143 return __set_cpus_allowed_ptr(p
, new_mask
, false);
1145 EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr
);
1147 void set_task_cpu(struct task_struct
*p
, unsigned int new_cpu
)
1149 #ifdef CONFIG_SCHED_DEBUG
1151 * We should never call set_task_cpu() on a blocked task,
1152 * ttwu() will sort out the placement.
1154 WARN_ON_ONCE(p
->state
!= TASK_RUNNING
&& p
->state
!= TASK_WAKING
&&
1158 * Migrating fair class task must have p->on_rq = TASK_ON_RQ_MIGRATING,
1159 * because schedstat_wait_{start,end} rebase migrating task's wait_start
1160 * time relying on p->on_rq.
1162 WARN_ON_ONCE(p
->state
== TASK_RUNNING
&&
1163 p
->sched_class
== &fair_sched_class
&&
1164 (p
->on_rq
&& !task_on_rq_migrating(p
)));
1166 #ifdef CONFIG_LOCKDEP
1168 * The caller should hold either p->pi_lock or rq->lock, when changing
1169 * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
1171 * sched_move_task() holds both and thus holding either pins the cgroup,
1174 * Furthermore, all task_rq users should acquire both locks, see
1177 WARN_ON_ONCE(debug_locks
&& !(lockdep_is_held(&p
->pi_lock
) ||
1178 lockdep_is_held(&task_rq(p
)->lock
)));
1182 trace_sched_migrate_task(p
, new_cpu
);
1184 if (task_cpu(p
) != new_cpu
) {
1185 if (p
->sched_class
->migrate_task_rq
)
1186 p
->sched_class
->migrate_task_rq(p
);
1187 p
->se
.nr_migrations
++;
1188 perf_event_task_migrate(p
);
1191 __set_task_cpu(p
, new_cpu
);
1194 static void __migrate_swap_task(struct task_struct
*p
, int cpu
)
1196 if (task_on_rq_queued(p
)) {
1197 struct rq
*src_rq
, *dst_rq
;
1199 src_rq
= task_rq(p
);
1200 dst_rq
= cpu_rq(cpu
);
1202 p
->on_rq
= TASK_ON_RQ_MIGRATING
;
1203 deactivate_task(src_rq
, p
, 0);
1204 set_task_cpu(p
, cpu
);
1205 activate_task(dst_rq
, p
, 0);
1206 p
->on_rq
= TASK_ON_RQ_QUEUED
;
1207 check_preempt_curr(dst_rq
, p
, 0);
1210 * Task isn't running anymore; make it appear like we migrated
1211 * it before it went to sleep. This means on wakeup we make the
1212 * previous cpu our targer instead of where it really is.
1218 struct migration_swap_arg
{
1219 struct task_struct
*src_task
, *dst_task
;
1220 int src_cpu
, dst_cpu
;
1223 static int migrate_swap_stop(void *data
)
1225 struct migration_swap_arg
*arg
= data
;
1226 struct rq
*src_rq
, *dst_rq
;
1229 if (!cpu_active(arg
->src_cpu
) || !cpu_active(arg
->dst_cpu
))
1232 src_rq
= cpu_rq(arg
->src_cpu
);
1233 dst_rq
= cpu_rq(arg
->dst_cpu
);
1235 double_raw_lock(&arg
->src_task
->pi_lock
,
1236 &arg
->dst_task
->pi_lock
);
1237 double_rq_lock(src_rq
, dst_rq
);
1239 if (task_cpu(arg
->dst_task
) != arg
->dst_cpu
)
1242 if (task_cpu(arg
->src_task
) != arg
->src_cpu
)
1245 if (!cpumask_test_cpu(arg
->dst_cpu
, tsk_cpus_allowed(arg
->src_task
)))
1248 if (!cpumask_test_cpu(arg
->src_cpu
, tsk_cpus_allowed(arg
->dst_task
)))
1251 __migrate_swap_task(arg
->src_task
, arg
->dst_cpu
);
1252 __migrate_swap_task(arg
->dst_task
, arg
->src_cpu
);
1257 double_rq_unlock(src_rq
, dst_rq
);
1258 raw_spin_unlock(&arg
->dst_task
->pi_lock
);
1259 raw_spin_unlock(&arg
->src_task
->pi_lock
);
1265 * Cross migrate two tasks
1267 int migrate_swap(struct task_struct
*cur
, struct task_struct
*p
)
1269 struct migration_swap_arg arg
;
1272 arg
= (struct migration_swap_arg
){
1274 .src_cpu
= task_cpu(cur
),
1276 .dst_cpu
= task_cpu(p
),
1279 if (arg
.src_cpu
== arg
.dst_cpu
)
1283 * These three tests are all lockless; this is OK since all of them
1284 * will be re-checked with proper locks held further down the line.
1286 if (!cpu_active(arg
.src_cpu
) || !cpu_active(arg
.dst_cpu
))
1289 if (!cpumask_test_cpu(arg
.dst_cpu
, tsk_cpus_allowed(arg
.src_task
)))
1292 if (!cpumask_test_cpu(arg
.src_cpu
, tsk_cpus_allowed(arg
.dst_task
)))
1295 trace_sched_swap_numa(cur
, arg
.src_cpu
, p
, arg
.dst_cpu
);
1296 ret
= stop_two_cpus(arg
.dst_cpu
, arg
.src_cpu
, migrate_swap_stop
, &arg
);
1303 * wait_task_inactive - wait for a thread to unschedule.
1305 * If @match_state is nonzero, it's the @p->state value just checked and
1306 * not expected to change. If it changes, i.e. @p might have woken up,
1307 * then return zero. When we succeed in waiting for @p to be off its CPU,
1308 * we return a positive number (its total switch count). If a second call
1309 * a short while later returns the same number, the caller can be sure that
1310 * @p has remained unscheduled the whole time.
1312 * The caller must ensure that the task *will* unschedule sometime soon,
1313 * else this function might spin for a *long* time. This function can't
1314 * be called with interrupts off, or it may introduce deadlock with
1315 * smp_call_function() if an IPI is sent by the same process we are
1316 * waiting to become inactive.
1318 unsigned long wait_task_inactive(struct task_struct
*p
, long match_state
)
1320 unsigned long flags
;
1321 int running
, queued
;
1327 * We do the initial early heuristics without holding
1328 * any task-queue locks at all. We'll only try to get
1329 * the runqueue lock when things look like they will
1335 * If the task is actively running on another CPU
1336 * still, just relax and busy-wait without holding
1339 * NOTE! Since we don't hold any locks, it's not
1340 * even sure that "rq" stays as the right runqueue!
1341 * But we don't care, since "task_running()" will
1342 * return false if the runqueue has changed and p
1343 * is actually now running somewhere else!
1345 while (task_running(rq
, p
)) {
1346 if (match_state
&& unlikely(p
->state
!= match_state
))
1352 * Ok, time to look more closely! We need the rq
1353 * lock now, to be *sure*. If we're wrong, we'll
1354 * just go back and repeat.
1356 rq
= task_rq_lock(p
, &flags
);
1357 trace_sched_wait_task(p
);
1358 running
= task_running(rq
, p
);
1359 queued
= task_on_rq_queued(p
);
1361 if (!match_state
|| p
->state
== match_state
)
1362 ncsw
= p
->nvcsw
| LONG_MIN
; /* sets MSB */
1363 task_rq_unlock(rq
, p
, &flags
);
1366 * If it changed from the expected state, bail out now.
1368 if (unlikely(!ncsw
))
1372 * Was it really running after all now that we
1373 * checked with the proper locks actually held?
1375 * Oops. Go back and try again..
1377 if (unlikely(running
)) {
1383 * It's not enough that it's not actively running,
1384 * it must be off the runqueue _entirely_, and not
1387 * So if it was still runnable (but just not actively
1388 * running right now), it's preempted, and we should
1389 * yield - it could be a while.
1391 if (unlikely(queued
)) {
1392 ktime_t to
= ktime_set(0, NSEC_PER_SEC
/HZ
);
1394 set_current_state(TASK_UNINTERRUPTIBLE
);
1395 schedule_hrtimeout(&to
, HRTIMER_MODE_REL
);
1400 * Ahh, all good. It wasn't running, and it wasn't
1401 * runnable, which means that it will never become
1402 * running in the future either. We're all done!
1411 * kick_process - kick a running thread to enter/exit the kernel
1412 * @p: the to-be-kicked thread
1414 * Cause a process which is running on another CPU to enter
1415 * kernel-mode, without any delay. (to get signals handled.)
1417 * NOTE: this function doesn't have to take the runqueue lock,
1418 * because all it wants to ensure is that the remote task enters
1419 * the kernel. If the IPI races and the task has been migrated
1420 * to another CPU then no harm is done and the purpose has been
1423 void kick_process(struct task_struct
*p
)
1429 if ((cpu
!= smp_processor_id()) && task_curr(p
))
1430 smp_send_reschedule(cpu
);
1433 EXPORT_SYMBOL_GPL(kick_process
);
1436 * ->cpus_allowed is protected by both rq->lock and p->pi_lock
1438 static int select_fallback_rq(int cpu
, struct task_struct
*p
)
1440 int nid
= cpu_to_node(cpu
);
1441 const struct cpumask
*nodemask
= NULL
;
1442 enum { cpuset
, possible
, fail
} state
= cpuset
;
1446 * If the node that the cpu is on has been offlined, cpu_to_node()
1447 * will return -1. There is no cpu on the node, and we should
1448 * select the cpu on the other node.
1451 nodemask
= cpumask_of_node(nid
);
1453 /* Look for allowed, online CPU in same node. */
1454 for_each_cpu(dest_cpu
, nodemask
) {
1455 if (!cpu_online(dest_cpu
))
1457 if (!cpu_active(dest_cpu
))
1459 if (cpumask_test_cpu(dest_cpu
, tsk_cpus_allowed(p
)))
1465 /* Any allowed, online CPU? */
1466 for_each_cpu(dest_cpu
, tsk_cpus_allowed(p
)) {
1467 if (!cpu_online(dest_cpu
))
1469 if (!cpu_active(dest_cpu
))
1474 /* No more Mr. Nice Guy. */
1477 if (IS_ENABLED(CONFIG_CPUSETS
)) {
1478 cpuset_cpus_allowed_fallback(p
);
1484 do_set_cpus_allowed(p
, cpu_possible_mask
);
1495 if (state
!= cpuset
) {
1497 * Don't tell them about moving exiting tasks or
1498 * kernel threads (both mm NULL), since they never
1501 if (p
->mm
&& printk_ratelimit()) {
1502 printk_deferred("process %d (%s) no longer affine to cpu%d\n",
1503 task_pid_nr(p
), p
->comm
, cpu
);
1511 * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
1514 int select_task_rq(struct task_struct
*p
, int cpu
, int sd_flags
, int wake_flags
)
1516 lockdep_assert_held(&p
->pi_lock
);
1518 if (p
->nr_cpus_allowed
> 1)
1519 cpu
= p
->sched_class
->select_task_rq(p
, cpu
, sd_flags
, wake_flags
);
1522 * In order not to call set_task_cpu() on a blocking task we need
1523 * to rely on ttwu() to place the task on a valid ->cpus_allowed
1526 * Since this is common to all placement strategies, this lives here.
1528 * [ this allows ->select_task() to simply return task_cpu(p) and
1529 * not worry about this generic constraint ]
1531 if (unlikely(!cpumask_test_cpu(cpu
, tsk_cpus_allowed(p
)) ||
1533 cpu
= select_fallback_rq(task_cpu(p
), p
);
1538 static void update_avg(u64
*avg
, u64 sample
)
1540 s64 diff
= sample
- *avg
;
1546 static inline int __set_cpus_allowed_ptr(struct task_struct
*p
,
1547 const struct cpumask
*new_mask
, bool check
)
1549 return set_cpus_allowed_ptr(p
, new_mask
);
1552 #endif /* CONFIG_SMP */
1555 ttwu_stat(struct task_struct
*p
, int cpu
, int wake_flags
)
1557 #ifdef CONFIG_SCHEDSTATS
1558 struct rq
*rq
= this_rq();
1561 int this_cpu
= smp_processor_id();
1563 if (cpu
== this_cpu
) {
1564 schedstat_inc(rq
, ttwu_local
);
1565 schedstat_inc(p
, se
.statistics
.nr_wakeups_local
);
1567 struct sched_domain
*sd
;
1569 schedstat_inc(p
, se
.statistics
.nr_wakeups_remote
);
1571 for_each_domain(this_cpu
, sd
) {
1572 if (cpumask_test_cpu(cpu
, sched_domain_span(sd
))) {
1573 schedstat_inc(sd
, ttwu_wake_remote
);
1580 if (wake_flags
& WF_MIGRATED
)
1581 schedstat_inc(p
, se
.statistics
.nr_wakeups_migrate
);
1583 #endif /* CONFIG_SMP */
1585 schedstat_inc(rq
, ttwu_count
);
1586 schedstat_inc(p
, se
.statistics
.nr_wakeups
);
1588 if (wake_flags
& WF_SYNC
)
1589 schedstat_inc(p
, se
.statistics
.nr_wakeups_sync
);
1591 #endif /* CONFIG_SCHEDSTATS */
1594 static inline void ttwu_activate(struct rq
*rq
, struct task_struct
*p
, int en_flags
)
1596 activate_task(rq
, p
, en_flags
);
1597 p
->on_rq
= TASK_ON_RQ_QUEUED
;
1599 /* if a worker is waking up, notify workqueue */
1600 if (p
->flags
& PF_WQ_WORKER
)
1601 wq_worker_waking_up(p
, cpu_of(rq
));
1605 * Mark the task runnable and perform wakeup-preemption.
1608 ttwu_do_wakeup(struct rq
*rq
, struct task_struct
*p
, int wake_flags
)
1610 check_preempt_curr(rq
, p
, wake_flags
);
1611 p
->state
= TASK_RUNNING
;
1612 trace_sched_wakeup(p
);
1615 if (p
->sched_class
->task_woken
) {
1617 * Our task @p is fully woken up and running; so its safe to
1618 * drop the rq->lock, hereafter rq is only used for statistics.
1620 lockdep_unpin_lock(&rq
->lock
);
1621 p
->sched_class
->task_woken(rq
, p
);
1622 lockdep_pin_lock(&rq
->lock
);
1625 if (rq
->idle_stamp
) {
1626 u64 delta
= rq_clock(rq
) - rq
->idle_stamp
;
1627 u64 max
= 2*rq
->max_idle_balance_cost
;
1629 update_avg(&rq
->avg_idle
, delta
);
1631 if (rq
->avg_idle
> max
)
1640 ttwu_do_activate(struct rq
*rq
, struct task_struct
*p
, int wake_flags
)
1642 lockdep_assert_held(&rq
->lock
);
1645 if (p
->sched_contributes_to_load
)
1646 rq
->nr_uninterruptible
--;
1649 ttwu_activate(rq
, p
, ENQUEUE_WAKEUP
| ENQUEUE_WAKING
);
1650 ttwu_do_wakeup(rq
, p
, wake_flags
);
1654 * Called in case the task @p isn't fully descheduled from its runqueue,
1655 * in this case we must do a remote wakeup. Its a 'light' wakeup though,
1656 * since all we need to do is flip p->state to TASK_RUNNING, since
1657 * the task is still ->on_rq.
1659 static int ttwu_remote(struct task_struct
*p
, int wake_flags
)
1664 rq
= __task_rq_lock(p
);
1665 if (task_on_rq_queued(p
)) {
1666 /* check_preempt_curr() may use rq clock */
1667 update_rq_clock(rq
);
1668 ttwu_do_wakeup(rq
, p
, wake_flags
);
1671 __task_rq_unlock(rq
);
1677 void sched_ttwu_pending(void)
1679 struct rq
*rq
= this_rq();
1680 struct llist_node
*llist
= llist_del_all(&rq
->wake_list
);
1681 struct task_struct
*p
;
1682 unsigned long flags
;
1687 raw_spin_lock_irqsave(&rq
->lock
, flags
);
1688 lockdep_pin_lock(&rq
->lock
);
1691 p
= llist_entry(llist
, struct task_struct
, wake_entry
);
1692 llist
= llist_next(llist
);
1693 ttwu_do_activate(rq
, p
, 0);
1696 lockdep_unpin_lock(&rq
->lock
);
1697 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
1700 void scheduler_ipi(void)
1703 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1704 * TIF_NEED_RESCHED remotely (for the first time) will also send
1707 preempt_fold_need_resched();
1709 if (llist_empty(&this_rq()->wake_list
) && !got_nohz_idle_kick())
1713 * Not all reschedule IPI handlers call irq_enter/irq_exit, since
1714 * traditionally all their work was done from the interrupt return
1715 * path. Now that we actually do some work, we need to make sure
1718 * Some archs already do call them, luckily irq_enter/exit nest
1721 * Arguably we should visit all archs and update all handlers,
1722 * however a fair share of IPIs are still resched only so this would
1723 * somewhat pessimize the simple resched case.
1726 sched_ttwu_pending();
1729 * Check if someone kicked us for doing the nohz idle load balance.
1731 if (unlikely(got_nohz_idle_kick())) {
1732 this_rq()->idle_balance
= 1;
1733 raise_softirq_irqoff(SCHED_SOFTIRQ
);
1738 static void ttwu_queue_remote(struct task_struct
*p
, int cpu
)
1740 struct rq
*rq
= cpu_rq(cpu
);
1742 if (llist_add(&p
->wake_entry
, &cpu_rq(cpu
)->wake_list
)) {
1743 if (!set_nr_if_polling(rq
->idle
))
1744 smp_send_reschedule(cpu
);
1746 trace_sched_wake_idle_without_ipi(cpu
);
1750 void wake_up_if_idle(int cpu
)
1752 struct rq
*rq
= cpu_rq(cpu
);
1753 unsigned long flags
;
1757 if (!is_idle_task(rcu_dereference(rq
->curr
)))
1760 if (set_nr_if_polling(rq
->idle
)) {
1761 trace_sched_wake_idle_without_ipi(cpu
);
1763 raw_spin_lock_irqsave(&rq
->lock
, flags
);
1764 if (is_idle_task(rq
->curr
))
1765 smp_send_reschedule(cpu
);
1766 /* Else cpu is not in idle, do nothing here */
1767 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
1774 bool cpus_share_cache(int this_cpu
, int that_cpu
)
1776 return per_cpu(sd_llc_id
, this_cpu
) == per_cpu(sd_llc_id
, that_cpu
);
1778 #endif /* CONFIG_SMP */
1780 static void ttwu_queue(struct task_struct
*p
, int cpu
)
1782 struct rq
*rq
= cpu_rq(cpu
);
1784 #if defined(CONFIG_SMP)
1785 if (sched_feat(TTWU_QUEUE
) && !cpus_share_cache(smp_processor_id(), cpu
)) {
1786 sched_clock_cpu(cpu
); /* sync clocks x-cpu */
1787 ttwu_queue_remote(p
, cpu
);
1792 raw_spin_lock(&rq
->lock
);
1793 lockdep_pin_lock(&rq
->lock
);
1794 ttwu_do_activate(rq
, p
, 0);
1795 lockdep_unpin_lock(&rq
->lock
);
1796 raw_spin_unlock(&rq
->lock
);
1800 * Notes on Program-Order guarantees on SMP systems.
1804 * The basic program-order guarantee on SMP systems is that when a task [t]
1805 * migrates, all its activity on its old cpu [c0] happens-before any subsequent
1806 * execution on its new cpu [c1].
1808 * For migration (of runnable tasks) this is provided by the following means:
1810 * A) UNLOCK of the rq(c0)->lock scheduling out task t
1811 * B) migration for t is required to synchronize *both* rq(c0)->lock and
1812 * rq(c1)->lock (if not at the same time, then in that order).
1813 * C) LOCK of the rq(c1)->lock scheduling in task
1815 * Transitivity guarantees that B happens after A and C after B.
1816 * Note: we only require RCpc transitivity.
1817 * Note: the cpu doing B need not be c0 or c1
1826 * UNLOCK rq(0)->lock
1828 * LOCK rq(0)->lock // orders against CPU0
1830 * UNLOCK rq(0)->lock
1834 * UNLOCK rq(1)->lock
1836 * LOCK rq(1)->lock // orders against CPU2
1839 * UNLOCK rq(1)->lock
1842 * BLOCKING -- aka. SLEEP + WAKEUP
1844 * For blocking we (obviously) need to provide the same guarantee as for
1845 * migration. However the means are completely different as there is no lock
1846 * chain to provide order. Instead we do:
1848 * 1) smp_store_release(X->on_cpu, 0)
1849 * 2) smp_cond_acquire(!X->on_cpu)
1853 * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule)
1855 * LOCK rq(0)->lock LOCK X->pi_lock
1858 * smp_store_release(X->on_cpu, 0);
1860 * smp_cond_acquire(!X->on_cpu);
1866 * X->state = RUNNING
1867 * UNLOCK rq(2)->lock
1869 * LOCK rq(2)->lock // orders against CPU1
1872 * UNLOCK rq(2)->lock
1875 * UNLOCK rq(0)->lock
1878 * However; for wakeups there is a second guarantee we must provide, namely we
1879 * must observe the state that lead to our wakeup. That is, not only must our
1880 * task observe its own prior state, it must also observe the stores prior to
1883 * This means that any means of doing remote wakeups must order the CPU doing
1884 * the wakeup against the CPU the task is going to end up running on. This,
1885 * however, is already required for the regular Program-Order guarantee above,
1886 * since the waking CPU is the one issueing the ACQUIRE (smp_cond_acquire).
1891 * try_to_wake_up - wake up a thread
1892 * @p: the thread to be awakened
1893 * @state: the mask of task states that can be woken
1894 * @wake_flags: wake modifier flags (WF_*)
1896 * Put it on the run-queue if it's not already there. The "current"
1897 * thread is always on the run-queue (except when the actual
1898 * re-schedule is in progress), and as such you're allowed to do
1899 * the simpler "current->state = TASK_RUNNING" to mark yourself
1900 * runnable without the overhead of this.
1902 * Return: %true if @p was woken up, %false if it was already running.
1903 * or @state didn't match @p's state.
1906 try_to_wake_up(struct task_struct
*p
, unsigned int state
, int wake_flags
)
1908 unsigned long flags
;
1909 int cpu
, success
= 0;
1912 * If we are going to wake up a thread waiting for CONDITION we
1913 * need to ensure that CONDITION=1 done by the caller can not be
1914 * reordered with p->state check below. This pairs with mb() in
1915 * set_current_state() the waiting thread does.
1917 smp_mb__before_spinlock();
1918 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
1919 if (!(p
->state
& state
))
1922 trace_sched_waking(p
);
1924 success
= 1; /* we're going to change ->state */
1927 if (p
->on_rq
&& ttwu_remote(p
, wake_flags
))
1932 * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be
1933 * possible to, falsely, observe p->on_cpu == 0.
1935 * One must be running (->on_cpu == 1) in order to remove oneself
1936 * from the runqueue.
1938 * [S] ->on_cpu = 1; [L] ->on_rq
1942 * [S] ->on_rq = 0; [L] ->on_cpu
1944 * Pairs with the full barrier implied in the UNLOCK+LOCK on rq->lock
1945 * from the consecutive calls to schedule(); the first switching to our
1946 * task, the second putting it to sleep.
1951 * If the owning (remote) cpu is still in the middle of schedule() with
1952 * this task as prev, wait until its done referencing the task.
1954 * Pairs with the smp_store_release() in finish_lock_switch().
1956 * This ensures that tasks getting woken will be fully ordered against
1957 * their previous state and preserve Program Order.
1959 smp_cond_acquire(!p
->on_cpu
);
1961 p
->sched_contributes_to_load
= !!task_contributes_to_load(p
);
1962 p
->state
= TASK_WAKING
;
1964 if (p
->sched_class
->task_waking
)
1965 p
->sched_class
->task_waking(p
);
1967 cpu
= select_task_rq(p
, p
->wake_cpu
, SD_BALANCE_WAKE
, wake_flags
);
1968 if (task_cpu(p
) != cpu
) {
1969 wake_flags
|= WF_MIGRATED
;
1970 set_task_cpu(p
, cpu
);
1972 #endif /* CONFIG_SMP */
1976 if (schedstat_enabled())
1977 ttwu_stat(p
, cpu
, wake_flags
);
1979 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
1985 * try_to_wake_up_local - try to wake up a local task with rq lock held
1986 * @p: the thread to be awakened
1988 * Put @p on the run-queue if it's not already there. The caller must
1989 * ensure that this_rq() is locked, @p is bound to this_rq() and not
1992 static void try_to_wake_up_local(struct task_struct
*p
)
1994 struct rq
*rq
= task_rq(p
);
1996 if (WARN_ON_ONCE(rq
!= this_rq()) ||
1997 WARN_ON_ONCE(p
== current
))
2000 lockdep_assert_held(&rq
->lock
);
2002 if (!raw_spin_trylock(&p
->pi_lock
)) {
2004 * This is OK, because current is on_cpu, which avoids it being
2005 * picked for load-balance and preemption/IRQs are still
2006 * disabled avoiding further scheduler activity on it and we've
2007 * not yet picked a replacement task.
2009 lockdep_unpin_lock(&rq
->lock
);
2010 raw_spin_unlock(&rq
->lock
);
2011 raw_spin_lock(&p
->pi_lock
);
2012 raw_spin_lock(&rq
->lock
);
2013 lockdep_pin_lock(&rq
->lock
);
2016 if (!(p
->state
& TASK_NORMAL
))
2019 trace_sched_waking(p
);
2021 if (!task_on_rq_queued(p
))
2022 ttwu_activate(rq
, p
, ENQUEUE_WAKEUP
);
2024 ttwu_do_wakeup(rq
, p
, 0);
2025 if (schedstat_enabled())
2026 ttwu_stat(p
, smp_processor_id(), 0);
2028 raw_spin_unlock(&p
->pi_lock
);
2032 * wake_up_process - Wake up a specific process
2033 * @p: The process to be woken up.
2035 * Attempt to wake up the nominated process and move it to the set of runnable
2038 * Return: 1 if the process was woken up, 0 if it was already running.
2040 * It may be assumed that this function implies a write memory barrier before
2041 * changing the task state if and only if any tasks are woken up.
2043 int wake_up_process(struct task_struct
*p
)
2045 return try_to_wake_up(p
, TASK_NORMAL
, 0);
2047 EXPORT_SYMBOL(wake_up_process
);
2049 int wake_up_state(struct task_struct
*p
, unsigned int state
)
2051 return try_to_wake_up(p
, state
, 0);
2055 * This function clears the sched_dl_entity static params.
2057 void __dl_clear_params(struct task_struct
*p
)
2059 struct sched_dl_entity
*dl_se
= &p
->dl
;
2061 dl_se
->dl_runtime
= 0;
2062 dl_se
->dl_deadline
= 0;
2063 dl_se
->dl_period
= 0;
2067 dl_se
->dl_throttled
= 0;
2068 dl_se
->dl_yielded
= 0;
2072 * Perform scheduler related setup for a newly forked process p.
2073 * p is forked by current.
2075 * __sched_fork() is basic setup used by init_idle() too:
2077 static void __sched_fork(unsigned long clone_flags
, struct task_struct
*p
)
2082 p
->se
.exec_start
= 0;
2083 p
->se
.sum_exec_runtime
= 0;
2084 p
->se
.prev_sum_exec_runtime
= 0;
2085 p
->se
.nr_migrations
= 0;
2087 INIT_LIST_HEAD(&p
->se
.group_node
);
2089 #ifdef CONFIG_FAIR_GROUP_SCHED
2090 p
->se
.cfs_rq
= NULL
;
2093 #ifdef CONFIG_SCHEDSTATS
2094 /* Even if schedstat is disabled, there should not be garbage */
2095 memset(&p
->se
.statistics
, 0, sizeof(p
->se
.statistics
));
2098 RB_CLEAR_NODE(&p
->dl
.rb_node
);
2099 init_dl_task_timer(&p
->dl
);
2100 __dl_clear_params(p
);
2102 INIT_LIST_HEAD(&p
->rt
.run_list
);
2104 p
->rt
.time_slice
= sched_rr_timeslice
;
2108 #ifdef CONFIG_PREEMPT_NOTIFIERS
2109 INIT_HLIST_HEAD(&p
->preempt_notifiers
);
2112 #ifdef CONFIG_NUMA_BALANCING
2113 if (p
->mm
&& atomic_read(&p
->mm
->mm_users
) == 1) {
2114 p
->mm
->numa_next_scan
= jiffies
+ msecs_to_jiffies(sysctl_numa_balancing_scan_delay
);
2115 p
->mm
->numa_scan_seq
= 0;
2118 if (clone_flags
& CLONE_VM
)
2119 p
->numa_preferred_nid
= current
->numa_preferred_nid
;
2121 p
->numa_preferred_nid
= -1;
2123 p
->node_stamp
= 0ULL;
2124 p
->numa_scan_seq
= p
->mm
? p
->mm
->numa_scan_seq
: 0;
2125 p
->numa_scan_period
= sysctl_numa_balancing_scan_delay
;
2126 p
->numa_work
.next
= &p
->numa_work
;
2127 p
->numa_faults
= NULL
;
2128 p
->last_task_numa_placement
= 0;
2129 p
->last_sum_exec_runtime
= 0;
2131 p
->numa_group
= NULL
;
2132 #endif /* CONFIG_NUMA_BALANCING */
2135 DEFINE_STATIC_KEY_FALSE(sched_numa_balancing
);
2137 #ifdef CONFIG_NUMA_BALANCING
2139 void set_numabalancing_state(bool enabled
)
2142 static_branch_enable(&sched_numa_balancing
);
2144 static_branch_disable(&sched_numa_balancing
);
2147 #ifdef CONFIG_PROC_SYSCTL
2148 int sysctl_numa_balancing(struct ctl_table
*table
, int write
,
2149 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2153 int state
= static_branch_likely(&sched_numa_balancing
);
2155 if (write
&& !capable(CAP_SYS_ADMIN
))
2160 err
= proc_dointvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2164 set_numabalancing_state(state
);
2170 DEFINE_STATIC_KEY_FALSE(sched_schedstats
);
2172 #ifdef CONFIG_SCHEDSTATS
2173 static void set_schedstats(bool enabled
)
2176 static_branch_enable(&sched_schedstats
);
2178 static_branch_disable(&sched_schedstats
);
2181 void force_schedstat_enabled(void)
2183 if (!schedstat_enabled()) {
2184 pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n");
2185 static_branch_enable(&sched_schedstats
);
2189 static int __init
setup_schedstats(char *str
)
2195 if (!strcmp(str
, "enable")) {
2196 set_schedstats(true);
2198 } else if (!strcmp(str
, "disable")) {
2199 set_schedstats(false);
2204 pr_warn("Unable to parse schedstats=\n");
2208 __setup("schedstats=", setup_schedstats
);
2210 #ifdef CONFIG_PROC_SYSCTL
2211 int sysctl_schedstats(struct ctl_table
*table
, int write
,
2212 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2216 int state
= static_branch_likely(&sched_schedstats
);
2218 if (write
&& !capable(CAP_SYS_ADMIN
))
2223 err
= proc_dointvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2227 set_schedstats(state
);
2234 * fork()/clone()-time setup:
2236 int sched_fork(unsigned long clone_flags
, struct task_struct
*p
)
2238 unsigned long flags
;
2239 int cpu
= get_cpu();
2241 __sched_fork(clone_flags
, p
);
2243 * We mark the process as running here. This guarantees that
2244 * nobody will actually run it, and a signal or other external
2245 * event cannot wake it up and insert it on the runqueue either.
2247 p
->state
= TASK_RUNNING
;
2250 * Make sure we do not leak PI boosting priority to the child.
2252 p
->prio
= current
->normal_prio
;
2255 * Revert to default priority/policy on fork if requested.
2257 if (unlikely(p
->sched_reset_on_fork
)) {
2258 if (task_has_dl_policy(p
) || task_has_rt_policy(p
)) {
2259 p
->policy
= SCHED_NORMAL
;
2260 p
->static_prio
= NICE_TO_PRIO(0);
2262 } else if (PRIO_TO_NICE(p
->static_prio
) < 0)
2263 p
->static_prio
= NICE_TO_PRIO(0);
2265 p
->prio
= p
->normal_prio
= __normal_prio(p
);
2269 * We don't need the reset flag anymore after the fork. It has
2270 * fulfilled its duty:
2272 p
->sched_reset_on_fork
= 0;
2275 if (dl_prio(p
->prio
)) {
2278 } else if (rt_prio(p
->prio
)) {
2279 p
->sched_class
= &rt_sched_class
;
2281 p
->sched_class
= &fair_sched_class
;
2284 if (p
->sched_class
->task_fork
)
2285 p
->sched_class
->task_fork(p
);
2288 * The child is not yet in the pid-hash so no cgroup attach races,
2289 * and the cgroup is pinned to this child due to cgroup_fork()
2290 * is ran before sched_fork().
2292 * Silence PROVE_RCU.
2294 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
2295 set_task_cpu(p
, cpu
);
2296 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
2298 #ifdef CONFIG_SCHED_INFO
2299 if (likely(sched_info_on()))
2300 memset(&p
->sched_info
, 0, sizeof(p
->sched_info
));
2302 #if defined(CONFIG_SMP)
2305 init_task_preempt_count(p
);
2307 plist_node_init(&p
->pushable_tasks
, MAX_PRIO
);
2308 RB_CLEAR_NODE(&p
->pushable_dl_tasks
);
2315 unsigned long to_ratio(u64 period
, u64 runtime
)
2317 if (runtime
== RUNTIME_INF
)
2321 * Doing this here saves a lot of checks in all
2322 * the calling paths, and returning zero seems
2323 * safe for them anyway.
2328 return div64_u64(runtime
<< 20, period
);
2332 inline struct dl_bw
*dl_bw_of(int i
)
2334 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
2335 "sched RCU must be held");
2336 return &cpu_rq(i
)->rd
->dl_bw
;
2339 static inline int dl_bw_cpus(int i
)
2341 struct root_domain
*rd
= cpu_rq(i
)->rd
;
2344 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
2345 "sched RCU must be held");
2346 for_each_cpu_and(i
, rd
->span
, cpu_active_mask
)
2352 inline struct dl_bw
*dl_bw_of(int i
)
2354 return &cpu_rq(i
)->dl
.dl_bw
;
2357 static inline int dl_bw_cpus(int i
)
2364 * We must be sure that accepting a new task (or allowing changing the
2365 * parameters of an existing one) is consistent with the bandwidth
2366 * constraints. If yes, this function also accordingly updates the currently
2367 * allocated bandwidth to reflect the new situation.
2369 * This function is called while holding p's rq->lock.
2371 * XXX we should delay bw change until the task's 0-lag point, see
2374 static int dl_overflow(struct task_struct
*p
, int policy
,
2375 const struct sched_attr
*attr
)
2378 struct dl_bw
*dl_b
= dl_bw_of(task_cpu(p
));
2379 u64 period
= attr
->sched_period
?: attr
->sched_deadline
;
2380 u64 runtime
= attr
->sched_runtime
;
2381 u64 new_bw
= dl_policy(policy
) ? to_ratio(period
, runtime
) : 0;
2384 if (new_bw
== p
->dl
.dl_bw
)
2388 * Either if a task, enters, leave, or stays -deadline but changes
2389 * its parameters, we may need to update accordingly the total
2390 * allocated bandwidth of the container.
2392 raw_spin_lock(&dl_b
->lock
);
2393 cpus
= dl_bw_cpus(task_cpu(p
));
2394 if (dl_policy(policy
) && !task_has_dl_policy(p
) &&
2395 !__dl_overflow(dl_b
, cpus
, 0, new_bw
)) {
2396 __dl_add(dl_b
, new_bw
);
2398 } else if (dl_policy(policy
) && task_has_dl_policy(p
) &&
2399 !__dl_overflow(dl_b
, cpus
, p
->dl
.dl_bw
, new_bw
)) {
2400 __dl_clear(dl_b
, p
->dl
.dl_bw
);
2401 __dl_add(dl_b
, new_bw
);
2403 } else if (!dl_policy(policy
) && task_has_dl_policy(p
)) {
2404 __dl_clear(dl_b
, p
->dl
.dl_bw
);
2407 raw_spin_unlock(&dl_b
->lock
);
2412 extern void init_dl_bw(struct dl_bw
*dl_b
);
2415 * wake_up_new_task - wake up a newly created task for the first time.
2417 * This function will do some initial scheduler statistics housekeeping
2418 * that must be done for every newly created context, then puts the task
2419 * on the runqueue and wakes it.
2421 void wake_up_new_task(struct task_struct
*p
)
2423 unsigned long flags
;
2426 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
2427 /* Initialize new task's runnable average */
2428 init_entity_runnable_average(&p
->se
);
2431 * Fork balancing, do it here and not earlier because:
2432 * - cpus_allowed can change in the fork path
2433 * - any previously selected cpu might disappear through hotplug
2435 set_task_cpu(p
, select_task_rq(p
, task_cpu(p
), SD_BALANCE_FORK
, 0));
2438 rq
= __task_rq_lock(p
);
2439 activate_task(rq
, p
, 0);
2440 p
->on_rq
= TASK_ON_RQ_QUEUED
;
2441 trace_sched_wakeup_new(p
);
2442 check_preempt_curr(rq
, p
, WF_FORK
);
2444 if (p
->sched_class
->task_woken
) {
2446 * Nothing relies on rq->lock after this, so its fine to
2449 lockdep_unpin_lock(&rq
->lock
);
2450 p
->sched_class
->task_woken(rq
, p
);
2451 lockdep_pin_lock(&rq
->lock
);
2454 task_rq_unlock(rq
, p
, &flags
);
2457 #ifdef CONFIG_PREEMPT_NOTIFIERS
2459 static struct static_key preempt_notifier_key
= STATIC_KEY_INIT_FALSE
;
2461 void preempt_notifier_inc(void)
2463 static_key_slow_inc(&preempt_notifier_key
);
2465 EXPORT_SYMBOL_GPL(preempt_notifier_inc
);
2467 void preempt_notifier_dec(void)
2469 static_key_slow_dec(&preempt_notifier_key
);
2471 EXPORT_SYMBOL_GPL(preempt_notifier_dec
);
2474 * preempt_notifier_register - tell me when current is being preempted & rescheduled
2475 * @notifier: notifier struct to register
2477 void preempt_notifier_register(struct preempt_notifier
*notifier
)
2479 if (!static_key_false(&preempt_notifier_key
))
2480 WARN(1, "registering preempt_notifier while notifiers disabled\n");
2482 hlist_add_head(¬ifier
->link
, ¤t
->preempt_notifiers
);
2484 EXPORT_SYMBOL_GPL(preempt_notifier_register
);
2487 * preempt_notifier_unregister - no longer interested in preemption notifications
2488 * @notifier: notifier struct to unregister
2490 * This is *not* safe to call from within a preemption notifier.
2492 void preempt_notifier_unregister(struct preempt_notifier
*notifier
)
2494 hlist_del(¬ifier
->link
);
2496 EXPORT_SYMBOL_GPL(preempt_notifier_unregister
);
2498 static void __fire_sched_in_preempt_notifiers(struct task_struct
*curr
)
2500 struct preempt_notifier
*notifier
;
2502 hlist_for_each_entry(notifier
, &curr
->preempt_notifiers
, link
)
2503 notifier
->ops
->sched_in(notifier
, raw_smp_processor_id());
2506 static __always_inline
void fire_sched_in_preempt_notifiers(struct task_struct
*curr
)
2508 if (static_key_false(&preempt_notifier_key
))
2509 __fire_sched_in_preempt_notifiers(curr
);
2513 __fire_sched_out_preempt_notifiers(struct task_struct
*curr
,
2514 struct task_struct
*next
)
2516 struct preempt_notifier
*notifier
;
2518 hlist_for_each_entry(notifier
, &curr
->preempt_notifiers
, link
)
2519 notifier
->ops
->sched_out(notifier
, next
);
2522 static __always_inline
void
2523 fire_sched_out_preempt_notifiers(struct task_struct
*curr
,
2524 struct task_struct
*next
)
2526 if (static_key_false(&preempt_notifier_key
))
2527 __fire_sched_out_preempt_notifiers(curr
, next
);
2530 #else /* !CONFIG_PREEMPT_NOTIFIERS */
2532 static inline void fire_sched_in_preempt_notifiers(struct task_struct
*curr
)
2537 fire_sched_out_preempt_notifiers(struct task_struct
*curr
,
2538 struct task_struct
*next
)
2542 #endif /* CONFIG_PREEMPT_NOTIFIERS */
2545 * prepare_task_switch - prepare to switch tasks
2546 * @rq: the runqueue preparing to switch
2547 * @prev: the current task that is being switched out
2548 * @next: the task we are going to switch to.
2550 * This is called with the rq lock held and interrupts off. It must
2551 * be paired with a subsequent finish_task_switch after the context
2554 * prepare_task_switch sets up locking and calls architecture specific
2558 prepare_task_switch(struct rq
*rq
, struct task_struct
*prev
,
2559 struct task_struct
*next
)
2561 sched_info_switch(rq
, prev
, next
);
2562 perf_event_task_sched_out(prev
, next
);
2563 fire_sched_out_preempt_notifiers(prev
, next
);
2564 prepare_lock_switch(rq
, next
);
2565 prepare_arch_switch(next
);
2569 * finish_task_switch - clean up after a task-switch
2570 * @prev: the thread we just switched away from.
2572 * finish_task_switch must be called after the context switch, paired
2573 * with a prepare_task_switch call before the context switch.
2574 * finish_task_switch will reconcile locking set up by prepare_task_switch,
2575 * and do any other architecture-specific cleanup actions.
2577 * Note that we may have delayed dropping an mm in context_switch(). If
2578 * so, we finish that here outside of the runqueue lock. (Doing it
2579 * with the lock held can cause deadlocks; see schedule() for
2582 * The context switch have flipped the stack from under us and restored the
2583 * local variables which were saved when this task called schedule() in the
2584 * past. prev == current is still correct but we need to recalculate this_rq
2585 * because prev may have moved to another CPU.
2587 static struct rq
*finish_task_switch(struct task_struct
*prev
)
2588 __releases(rq
->lock
)
2590 struct rq
*rq
= this_rq();
2591 struct mm_struct
*mm
= rq
->prev_mm
;
2595 * The previous task will have left us with a preempt_count of 2
2596 * because it left us after:
2599 * preempt_disable(); // 1
2601 * raw_spin_lock_irq(&rq->lock) // 2
2603 * Also, see FORK_PREEMPT_COUNT.
2605 if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET
,
2606 "corrupted preempt_count: %s/%d/0x%x\n",
2607 current
->comm
, current
->pid
, preempt_count()))
2608 preempt_count_set(FORK_PREEMPT_COUNT
);
2613 * A task struct has one reference for the use as "current".
2614 * If a task dies, then it sets TASK_DEAD in tsk->state and calls
2615 * schedule one last time. The schedule call will never return, and
2616 * the scheduled task must drop that reference.
2618 * We must observe prev->state before clearing prev->on_cpu (in
2619 * finish_lock_switch), otherwise a concurrent wakeup can get prev
2620 * running on another CPU and we could rave with its RUNNING -> DEAD
2621 * transition, resulting in a double drop.
2623 prev_state
= prev
->state
;
2624 vtime_task_switch(prev
);
2625 perf_event_task_sched_in(prev
, current
);
2626 finish_lock_switch(rq
, prev
);
2627 finish_arch_post_lock_switch();
2629 fire_sched_in_preempt_notifiers(current
);
2632 if (unlikely(prev_state
== TASK_DEAD
)) {
2633 if (prev
->sched_class
->task_dead
)
2634 prev
->sched_class
->task_dead(prev
);
2637 * Remove function-return probe instances associated with this
2638 * task and put them back on the free list.
2640 kprobe_flush_task(prev
);
2641 put_task_struct(prev
);
2644 tick_nohz_task_switch();
2650 /* rq->lock is NOT held, but preemption is disabled */
2651 static void __balance_callback(struct rq
*rq
)
2653 struct callback_head
*head
, *next
;
2654 void (*func
)(struct rq
*rq
);
2655 unsigned long flags
;
2657 raw_spin_lock_irqsave(&rq
->lock
, flags
);
2658 head
= rq
->balance_callback
;
2659 rq
->balance_callback
= NULL
;
2661 func
= (void (*)(struct rq
*))head
->func
;
2668 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
2671 static inline void balance_callback(struct rq
*rq
)
2673 if (unlikely(rq
->balance_callback
))
2674 __balance_callback(rq
);
2679 static inline void balance_callback(struct rq
*rq
)
2686 * schedule_tail - first thing a freshly forked thread must call.
2687 * @prev: the thread we just switched away from.
2689 asmlinkage __visible
void schedule_tail(struct task_struct
*prev
)
2690 __releases(rq
->lock
)
2695 * New tasks start with FORK_PREEMPT_COUNT, see there and
2696 * finish_task_switch() for details.
2698 * finish_task_switch() will drop rq->lock() and lower preempt_count
2699 * and the preempt_enable() will end up enabling preemption (on
2700 * PREEMPT_COUNT kernels).
2703 rq
= finish_task_switch(prev
);
2704 balance_callback(rq
);
2707 if (current
->set_child_tid
)
2708 put_user(task_pid_vnr(current
), current
->set_child_tid
);
2712 * context_switch - switch to the new MM and the new thread's register state.
2714 static __always_inline
struct rq
*
2715 context_switch(struct rq
*rq
, struct task_struct
*prev
,
2716 struct task_struct
*next
)
2718 struct mm_struct
*mm
, *oldmm
;
2720 prepare_task_switch(rq
, prev
, next
);
2723 oldmm
= prev
->active_mm
;
2725 * For paravirt, this is coupled with an exit in switch_to to
2726 * combine the page table reload and the switch backend into
2729 arch_start_context_switch(prev
);
2732 next
->active_mm
= oldmm
;
2733 atomic_inc(&oldmm
->mm_count
);
2734 enter_lazy_tlb(oldmm
, next
);
2736 switch_mm(oldmm
, mm
, next
);
2739 prev
->active_mm
= NULL
;
2740 rq
->prev_mm
= oldmm
;
2743 * Since the runqueue lock will be released by the next
2744 * task (which is an invalid locking op but in the case
2745 * of the scheduler it's an obvious special-case), so we
2746 * do an early lockdep release here:
2748 lockdep_unpin_lock(&rq
->lock
);
2749 spin_release(&rq
->lock
.dep_map
, 1, _THIS_IP_
);
2751 /* Here we just switch the register state and the stack. */
2752 switch_to(prev
, next
, prev
);
2755 return finish_task_switch(prev
);
2759 * nr_running and nr_context_switches:
2761 * externally visible scheduler statistics: current number of runnable
2762 * threads, total number of context switches performed since bootup.
2764 unsigned long nr_running(void)
2766 unsigned long i
, sum
= 0;
2768 for_each_online_cpu(i
)
2769 sum
+= cpu_rq(i
)->nr_running
;
2775 * Check if only the current task is running on the cpu.
2777 * Caution: this function does not check that the caller has disabled
2778 * preemption, thus the result might have a time-of-check-to-time-of-use
2779 * race. The caller is responsible to use it correctly, for example:
2781 * - from a non-preemptable section (of course)
2783 * - from a thread that is bound to a single CPU
2785 * - in a loop with very short iterations (e.g. a polling loop)
2787 bool single_task_running(void)
2789 return raw_rq()->nr_running
== 1;
2791 EXPORT_SYMBOL(single_task_running
);
2793 unsigned long long nr_context_switches(void)
2796 unsigned long long sum
= 0;
2798 for_each_possible_cpu(i
)
2799 sum
+= cpu_rq(i
)->nr_switches
;
2804 unsigned long nr_iowait(void)
2806 unsigned long i
, sum
= 0;
2808 for_each_possible_cpu(i
)
2809 sum
+= atomic_read(&cpu_rq(i
)->nr_iowait
);
2814 unsigned long nr_iowait_cpu(int cpu
)
2816 struct rq
*this = cpu_rq(cpu
);
2817 return atomic_read(&this->nr_iowait
);
2820 void get_iowait_load(unsigned long *nr_waiters
, unsigned long *load
)
2822 struct rq
*rq
= this_rq();
2823 *nr_waiters
= atomic_read(&rq
->nr_iowait
);
2824 *load
= rq
->load
.weight
;
2830 * sched_exec - execve() is a valuable balancing opportunity, because at
2831 * this point the task has the smallest effective memory and cache footprint.
2833 void sched_exec(void)
2835 struct task_struct
*p
= current
;
2836 unsigned long flags
;
2839 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
2840 dest_cpu
= p
->sched_class
->select_task_rq(p
, task_cpu(p
), SD_BALANCE_EXEC
, 0);
2841 if (dest_cpu
== smp_processor_id())
2844 if (likely(cpu_active(dest_cpu
))) {
2845 struct migration_arg arg
= { p
, dest_cpu
};
2847 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
2848 stop_one_cpu(task_cpu(p
), migration_cpu_stop
, &arg
);
2852 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
2857 DEFINE_PER_CPU(struct kernel_stat
, kstat
);
2858 DEFINE_PER_CPU(struct kernel_cpustat
, kernel_cpustat
);
2860 EXPORT_PER_CPU_SYMBOL(kstat
);
2861 EXPORT_PER_CPU_SYMBOL(kernel_cpustat
);
2864 * Return accounted runtime for the task.
2865 * In case the task is currently running, return the runtime plus current's
2866 * pending runtime that have not been accounted yet.
2868 unsigned long long task_sched_runtime(struct task_struct
*p
)
2870 unsigned long flags
;
2874 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
2876 * 64-bit doesn't need locks to atomically read a 64bit value.
2877 * So we have a optimization chance when the task's delta_exec is 0.
2878 * Reading ->on_cpu is racy, but this is ok.
2880 * If we race with it leaving cpu, we'll take a lock. So we're correct.
2881 * If we race with it entering cpu, unaccounted time is 0. This is
2882 * indistinguishable from the read occurring a few cycles earlier.
2883 * If we see ->on_cpu without ->on_rq, the task is leaving, and has
2884 * been accounted, so we're correct here as well.
2886 if (!p
->on_cpu
|| !task_on_rq_queued(p
))
2887 return p
->se
.sum_exec_runtime
;
2890 rq
= task_rq_lock(p
, &flags
);
2892 * Must be ->curr _and_ ->on_rq. If dequeued, we would
2893 * project cycles that may never be accounted to this
2894 * thread, breaking clock_gettime().
2896 if (task_current(rq
, p
) && task_on_rq_queued(p
)) {
2897 update_rq_clock(rq
);
2898 p
->sched_class
->update_curr(rq
);
2900 ns
= p
->se
.sum_exec_runtime
;
2901 task_rq_unlock(rq
, p
, &flags
);
2907 * This function gets called by the timer code, with HZ frequency.
2908 * We call it with interrupts disabled.
2910 void scheduler_tick(void)
2912 int cpu
= smp_processor_id();
2913 struct rq
*rq
= cpu_rq(cpu
);
2914 struct task_struct
*curr
= rq
->curr
;
2918 raw_spin_lock(&rq
->lock
);
2919 update_rq_clock(rq
);
2920 curr
->sched_class
->task_tick(rq
, curr
, 0);
2921 update_cpu_load_active(rq
);
2922 calc_global_load_tick(rq
);
2923 raw_spin_unlock(&rq
->lock
);
2925 perf_event_task_tick();
2928 rq
->idle_balance
= idle_cpu(cpu
);
2929 trigger_load_balance(rq
);
2931 rq_last_tick_reset(rq
);
2934 #ifdef CONFIG_NO_HZ_FULL
2936 * scheduler_tick_max_deferment
2938 * Keep at least one tick per second when a single
2939 * active task is running because the scheduler doesn't
2940 * yet completely support full dynticks environment.
2942 * This makes sure that uptime, CFS vruntime, load
2943 * balancing, etc... continue to move forward, even
2944 * with a very low granularity.
2946 * Return: Maximum deferment in nanoseconds.
2948 u64
scheduler_tick_max_deferment(void)
2950 struct rq
*rq
= this_rq();
2951 unsigned long next
, now
= READ_ONCE(jiffies
);
2953 next
= rq
->last_sched_tick
+ HZ
;
2955 if (time_before_eq(next
, now
))
2958 return jiffies_to_nsecs(next
- now
);
2962 #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
2963 defined(CONFIG_PREEMPT_TRACER))
2965 void preempt_count_add(int val
)
2967 #ifdef CONFIG_DEBUG_PREEMPT
2971 if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
2974 __preempt_count_add(val
);
2975 #ifdef CONFIG_DEBUG_PREEMPT
2977 * Spinlock count overflowing soon?
2979 DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK
) >=
2982 if (preempt_count() == val
) {
2983 unsigned long ip
= get_lock_parent_ip();
2984 #ifdef CONFIG_DEBUG_PREEMPT
2985 current
->preempt_disable_ip
= ip
;
2987 trace_preempt_off(CALLER_ADDR0
, ip
);
2990 EXPORT_SYMBOL(preempt_count_add
);
2991 NOKPROBE_SYMBOL(preempt_count_add
);
2993 void preempt_count_sub(int val
)
2995 #ifdef CONFIG_DEBUG_PREEMPT
2999 if (DEBUG_LOCKS_WARN_ON(val
> preempt_count()))
3002 * Is the spinlock portion underflowing?
3004 if (DEBUG_LOCKS_WARN_ON((val
< PREEMPT_MASK
) &&
3005 !(preempt_count() & PREEMPT_MASK
)))
3009 if (preempt_count() == val
)
3010 trace_preempt_on(CALLER_ADDR0
, get_lock_parent_ip());
3011 __preempt_count_sub(val
);
3013 EXPORT_SYMBOL(preempt_count_sub
);
3014 NOKPROBE_SYMBOL(preempt_count_sub
);
3019 * Print scheduling while atomic bug:
3021 static noinline
void __schedule_bug(struct task_struct
*prev
)
3023 if (oops_in_progress
)
3026 printk(KERN_ERR
"BUG: scheduling while atomic: %s/%d/0x%08x\n",
3027 prev
->comm
, prev
->pid
, preempt_count());
3029 debug_show_held_locks(prev
);
3031 if (irqs_disabled())
3032 print_irqtrace_events(prev
);
3033 #ifdef CONFIG_DEBUG_PREEMPT
3034 if (in_atomic_preempt_off()) {
3035 pr_err("Preemption disabled at:");
3036 print_ip_sym(current
->preempt_disable_ip
);
3041 add_taint(TAINT_WARN
, LOCKDEP_STILL_OK
);
3045 * Various schedule()-time debugging checks and statistics:
3047 static inline void schedule_debug(struct task_struct
*prev
)
3049 #ifdef CONFIG_SCHED_STACK_END_CHECK
3050 BUG_ON(task_stack_end_corrupted(prev
));
3053 if (unlikely(in_atomic_preempt_off())) {
3054 __schedule_bug(prev
);
3055 preempt_count_set(PREEMPT_DISABLED
);
3059 profile_hit(SCHED_PROFILING
, __builtin_return_address(0));
3061 schedstat_inc(this_rq(), sched_count
);
3065 * Pick up the highest-prio task:
3067 static inline struct task_struct
*
3068 pick_next_task(struct rq
*rq
, struct task_struct
*prev
)
3070 const struct sched_class
*class = &fair_sched_class
;
3071 struct task_struct
*p
;
3074 * Optimization: we know that if all tasks are in
3075 * the fair class we can call that function directly:
3077 if (likely(prev
->sched_class
== class &&
3078 rq
->nr_running
== rq
->cfs
.h_nr_running
)) {
3079 p
= fair_sched_class
.pick_next_task(rq
, prev
);
3080 if (unlikely(p
== RETRY_TASK
))
3083 /* assumes fair_sched_class->next == idle_sched_class */
3085 p
= idle_sched_class
.pick_next_task(rq
, prev
);
3091 for_each_class(class) {
3092 p
= class->pick_next_task(rq
, prev
);
3094 if (unlikely(p
== RETRY_TASK
))
3100 BUG(); /* the idle class will always have a runnable task */
3104 * __schedule() is the main scheduler function.
3106 * The main means of driving the scheduler and thus entering this function are:
3108 * 1. Explicit blocking: mutex, semaphore, waitqueue, etc.
3110 * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
3111 * paths. For example, see arch/x86/entry_64.S.
3113 * To drive preemption between tasks, the scheduler sets the flag in timer
3114 * interrupt handler scheduler_tick().
3116 * 3. Wakeups don't really cause entry into schedule(). They add a
3117 * task to the run-queue and that's it.
3119 * Now, if the new task added to the run-queue preempts the current
3120 * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
3121 * called on the nearest possible occasion:
3123 * - If the kernel is preemptible (CONFIG_PREEMPT=y):
3125 * - in syscall or exception context, at the next outmost
3126 * preempt_enable(). (this might be as soon as the wake_up()'s
3129 * - in IRQ context, return from interrupt-handler to
3130 * preemptible context
3132 * - If the kernel is not preemptible (CONFIG_PREEMPT is not set)
3135 * - cond_resched() call
3136 * - explicit schedule() call
3137 * - return from syscall or exception to user-space
3138 * - return from interrupt-handler to user-space
3140 * WARNING: must be called with preemption disabled!
3142 static void __sched notrace
__schedule(bool preempt
)
3144 struct task_struct
*prev
, *next
;
3145 unsigned long *switch_count
;
3149 cpu
= smp_processor_id();
3154 * do_exit() calls schedule() with preemption disabled as an exception;
3155 * however we must fix that up, otherwise the next task will see an
3156 * inconsistent (higher) preempt count.
3158 * It also avoids the below schedule_debug() test from complaining
3161 if (unlikely(prev
->state
== TASK_DEAD
))
3162 preempt_enable_no_resched_notrace();
3164 schedule_debug(prev
);
3166 if (sched_feat(HRTICK
))
3169 local_irq_disable();
3170 rcu_note_context_switch();
3173 * Make sure that signal_pending_state()->signal_pending() below
3174 * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
3175 * done by the caller to avoid the race with signal_wake_up().
3177 smp_mb__before_spinlock();
3178 raw_spin_lock(&rq
->lock
);
3179 lockdep_pin_lock(&rq
->lock
);
3181 rq
->clock_skip_update
<<= 1; /* promote REQ to ACT */
3183 switch_count
= &prev
->nivcsw
;
3184 if (!preempt
&& prev
->state
) {
3185 if (unlikely(signal_pending_state(prev
->state
, prev
))) {
3186 prev
->state
= TASK_RUNNING
;
3188 deactivate_task(rq
, prev
, DEQUEUE_SLEEP
);
3192 * If a worker went to sleep, notify and ask workqueue
3193 * whether it wants to wake up a task to maintain
3196 if (prev
->flags
& PF_WQ_WORKER
) {
3197 struct task_struct
*to_wakeup
;
3199 to_wakeup
= wq_worker_sleeping(prev
);
3201 try_to_wake_up_local(to_wakeup
);
3204 switch_count
= &prev
->nvcsw
;
3207 if (task_on_rq_queued(prev
))
3208 update_rq_clock(rq
);
3210 next
= pick_next_task(rq
, prev
);
3211 clear_tsk_need_resched(prev
);
3212 clear_preempt_need_resched();
3213 rq
->clock_skip_update
= 0;
3215 if (likely(prev
!= next
)) {
3220 trace_sched_switch(preempt
, prev
, next
);
3221 rq
= context_switch(rq
, prev
, next
); /* unlocks the rq */
3223 lockdep_unpin_lock(&rq
->lock
);
3224 raw_spin_unlock_irq(&rq
->lock
);
3227 balance_callback(rq
);
3229 STACK_FRAME_NON_STANDARD(__schedule
); /* switch_to() */
3231 static inline void sched_submit_work(struct task_struct
*tsk
)
3233 if (!tsk
->state
|| tsk_is_pi_blocked(tsk
))
3236 * If we are going to sleep and we have plugged IO queued,
3237 * make sure to submit it to avoid deadlocks.
3239 if (blk_needs_flush_plug(tsk
))
3240 blk_schedule_flush_plug(tsk
);
3243 asmlinkage __visible
void __sched
schedule(void)
3245 struct task_struct
*tsk
= current
;
3247 sched_submit_work(tsk
);
3251 sched_preempt_enable_no_resched();
3252 } while (need_resched());
3254 EXPORT_SYMBOL(schedule
);
3256 #ifdef CONFIG_CONTEXT_TRACKING
3257 asmlinkage __visible
void __sched
schedule_user(void)
3260 * If we come here after a random call to set_need_resched(),
3261 * or we have been woken up remotely but the IPI has not yet arrived,
3262 * we haven't yet exited the RCU idle mode. Do it here manually until
3263 * we find a better solution.
3265 * NB: There are buggy callers of this function. Ideally we
3266 * should warn if prev_state != CONTEXT_USER, but that will trigger
3267 * too frequently to make sense yet.
3269 enum ctx_state prev_state
= exception_enter();
3271 exception_exit(prev_state
);
3276 * schedule_preempt_disabled - called with preemption disabled
3278 * Returns with preemption disabled. Note: preempt_count must be 1
3280 void __sched
schedule_preempt_disabled(void)
3282 sched_preempt_enable_no_resched();
3287 static void __sched notrace
preempt_schedule_common(void)
3290 preempt_disable_notrace();
3292 preempt_enable_no_resched_notrace();
3295 * Check again in case we missed a preemption opportunity
3296 * between schedule and now.
3298 } while (need_resched());
3301 #ifdef CONFIG_PREEMPT
3303 * this is the entry point to schedule() from in-kernel preemption
3304 * off of preempt_enable. Kernel preemptions off return from interrupt
3305 * occur there and call schedule directly.
3307 asmlinkage __visible
void __sched notrace
preempt_schedule(void)
3310 * If there is a non-zero preempt_count or interrupts are disabled,
3311 * we do not want to preempt the current task. Just return..
3313 if (likely(!preemptible()))
3316 preempt_schedule_common();
3318 NOKPROBE_SYMBOL(preempt_schedule
);
3319 EXPORT_SYMBOL(preempt_schedule
);
3322 * preempt_schedule_notrace - preempt_schedule called by tracing
3324 * The tracing infrastructure uses preempt_enable_notrace to prevent
3325 * recursion and tracing preempt enabling caused by the tracing
3326 * infrastructure itself. But as tracing can happen in areas coming
3327 * from userspace or just about to enter userspace, a preempt enable
3328 * can occur before user_exit() is called. This will cause the scheduler
3329 * to be called when the system is still in usermode.
3331 * To prevent this, the preempt_enable_notrace will use this function
3332 * instead of preempt_schedule() to exit user context if needed before
3333 * calling the scheduler.
3335 asmlinkage __visible
void __sched notrace
preempt_schedule_notrace(void)
3337 enum ctx_state prev_ctx
;
3339 if (likely(!preemptible()))
3343 preempt_disable_notrace();
3345 * Needs preempt disabled in case user_exit() is traced
3346 * and the tracer calls preempt_enable_notrace() causing
3347 * an infinite recursion.
3349 prev_ctx
= exception_enter();
3351 exception_exit(prev_ctx
);
3353 preempt_enable_no_resched_notrace();
3354 } while (need_resched());
3356 EXPORT_SYMBOL_GPL(preempt_schedule_notrace
);
3358 #endif /* CONFIG_PREEMPT */
3361 * this is the entry point to schedule() from kernel preemption
3362 * off of irq context.
3363 * Note, that this is called and return with irqs disabled. This will
3364 * protect us against recursive calling from irq.
3366 asmlinkage __visible
void __sched
preempt_schedule_irq(void)
3368 enum ctx_state prev_state
;
3370 /* Catch callers which need to be fixed */
3371 BUG_ON(preempt_count() || !irqs_disabled());
3373 prev_state
= exception_enter();
3379 local_irq_disable();
3380 sched_preempt_enable_no_resched();
3381 } while (need_resched());
3383 exception_exit(prev_state
);
3386 int default_wake_function(wait_queue_t
*curr
, unsigned mode
, int wake_flags
,
3389 return try_to_wake_up(curr
->private, mode
, wake_flags
);
3391 EXPORT_SYMBOL(default_wake_function
);
3393 #ifdef CONFIG_RT_MUTEXES
3396 * rt_mutex_setprio - set the current priority of a task
3398 * @prio: prio value (kernel-internal form)
3400 * This function changes the 'effective' priority of a task. It does
3401 * not touch ->normal_prio like __setscheduler().
3403 * Used by the rt_mutex code to implement priority inheritance
3404 * logic. Call site only calls if the priority of the task changed.
3406 void rt_mutex_setprio(struct task_struct
*p
, int prio
)
3408 int oldprio
, queued
, running
, queue_flag
= DEQUEUE_SAVE
| DEQUEUE_MOVE
;
3410 const struct sched_class
*prev_class
;
3412 BUG_ON(prio
> MAX_PRIO
);
3414 rq
= __task_rq_lock(p
);
3417 * Idle task boosting is a nono in general. There is one
3418 * exception, when PREEMPT_RT and NOHZ is active:
3420 * The idle task calls get_next_timer_interrupt() and holds
3421 * the timer wheel base->lock on the CPU and another CPU wants
3422 * to access the timer (probably to cancel it). We can safely
3423 * ignore the boosting request, as the idle CPU runs this code
3424 * with interrupts disabled and will complete the lock
3425 * protected section without being interrupted. So there is no
3426 * real need to boost.
3428 if (unlikely(p
== rq
->idle
)) {
3429 WARN_ON(p
!= rq
->curr
);
3430 WARN_ON(p
->pi_blocked_on
);
3434 trace_sched_pi_setprio(p
, prio
);
3437 if (oldprio
== prio
)
3438 queue_flag
&= ~DEQUEUE_MOVE
;
3440 prev_class
= p
->sched_class
;
3441 queued
= task_on_rq_queued(p
);
3442 running
= task_current(rq
, p
);
3444 dequeue_task(rq
, p
, queue_flag
);
3446 put_prev_task(rq
, p
);
3449 * Boosting condition are:
3450 * 1. -rt task is running and holds mutex A
3451 * --> -dl task blocks on mutex A
3453 * 2. -dl task is running and holds mutex A
3454 * --> -dl task blocks on mutex A and could preempt the
3457 if (dl_prio(prio
)) {
3458 struct task_struct
*pi_task
= rt_mutex_get_top_task(p
);
3459 if (!dl_prio(p
->normal_prio
) ||
3460 (pi_task
&& dl_entity_preempt(&pi_task
->dl
, &p
->dl
))) {
3461 p
->dl
.dl_boosted
= 1;
3462 queue_flag
|= ENQUEUE_REPLENISH
;
3464 p
->dl
.dl_boosted
= 0;
3465 p
->sched_class
= &dl_sched_class
;
3466 } else if (rt_prio(prio
)) {
3467 if (dl_prio(oldprio
))
3468 p
->dl
.dl_boosted
= 0;
3470 queue_flag
|= ENQUEUE_HEAD
;
3471 p
->sched_class
= &rt_sched_class
;
3473 if (dl_prio(oldprio
))
3474 p
->dl
.dl_boosted
= 0;
3475 if (rt_prio(oldprio
))
3477 p
->sched_class
= &fair_sched_class
;
3483 p
->sched_class
->set_curr_task(rq
);
3485 enqueue_task(rq
, p
, queue_flag
);
3487 check_class_changed(rq
, p
, prev_class
, oldprio
);
3489 preempt_disable(); /* avoid rq from going away on us */
3490 __task_rq_unlock(rq
);
3492 balance_callback(rq
);
3497 void set_user_nice(struct task_struct
*p
, long nice
)
3499 int old_prio
, delta
, queued
;
3500 unsigned long flags
;
3503 if (task_nice(p
) == nice
|| nice
< MIN_NICE
|| nice
> MAX_NICE
)
3506 * We have to be careful, if called from sys_setpriority(),
3507 * the task might be in the middle of scheduling on another CPU.
3509 rq
= task_rq_lock(p
, &flags
);
3511 * The RT priorities are set via sched_setscheduler(), but we still
3512 * allow the 'normal' nice value to be set - but as expected
3513 * it wont have any effect on scheduling until the task is
3514 * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR:
3516 if (task_has_dl_policy(p
) || task_has_rt_policy(p
)) {
3517 p
->static_prio
= NICE_TO_PRIO(nice
);
3520 queued
= task_on_rq_queued(p
);
3522 dequeue_task(rq
, p
, DEQUEUE_SAVE
);
3524 p
->static_prio
= NICE_TO_PRIO(nice
);
3527 p
->prio
= effective_prio(p
);
3528 delta
= p
->prio
- old_prio
;
3531 enqueue_task(rq
, p
, ENQUEUE_RESTORE
);
3533 * If the task increased its priority or is running and
3534 * lowered its priority, then reschedule its CPU:
3536 if (delta
< 0 || (delta
> 0 && task_running(rq
, p
)))
3540 task_rq_unlock(rq
, p
, &flags
);
3542 EXPORT_SYMBOL(set_user_nice
);
3545 * can_nice - check if a task can reduce its nice value
3549 int can_nice(const struct task_struct
*p
, const int nice
)
3551 /* convert nice value [19,-20] to rlimit style value [1,40] */
3552 int nice_rlim
= nice_to_rlimit(nice
);
3554 return (nice_rlim
<= task_rlimit(p
, RLIMIT_NICE
) ||
3555 capable(CAP_SYS_NICE
));
3558 #ifdef __ARCH_WANT_SYS_NICE
3561 * sys_nice - change the priority of the current process.
3562 * @increment: priority increment
3564 * sys_setpriority is a more generic, but much slower function that
3565 * does similar things.
3567 SYSCALL_DEFINE1(nice
, int, increment
)
3572 * Setpriority might change our priority at the same moment.
3573 * We don't have to worry. Conceptually one call occurs first
3574 * and we have a single winner.
3576 increment
= clamp(increment
, -NICE_WIDTH
, NICE_WIDTH
);
3577 nice
= task_nice(current
) + increment
;
3579 nice
= clamp_val(nice
, MIN_NICE
, MAX_NICE
);
3580 if (increment
< 0 && !can_nice(current
, nice
))
3583 retval
= security_task_setnice(current
, nice
);
3587 set_user_nice(current
, nice
);
3594 * task_prio - return the priority value of a given task.
3595 * @p: the task in question.
3597 * Return: The priority value as seen by users in /proc.
3598 * RT tasks are offset by -200. Normal tasks are centered
3599 * around 0, value goes from -16 to +15.
3601 int task_prio(const struct task_struct
*p
)
3603 return p
->prio
- MAX_RT_PRIO
;
3607 * idle_cpu - is a given cpu idle currently?
3608 * @cpu: the processor in question.
3610 * Return: 1 if the CPU is currently idle. 0 otherwise.
3612 int idle_cpu(int cpu
)
3614 struct rq
*rq
= cpu_rq(cpu
);
3616 if (rq
->curr
!= rq
->idle
)
3623 if (!llist_empty(&rq
->wake_list
))
3631 * idle_task - return the idle task for a given cpu.
3632 * @cpu: the processor in question.
3634 * Return: The idle task for the cpu @cpu.
3636 struct task_struct
*idle_task(int cpu
)
3638 return cpu_rq(cpu
)->idle
;
3642 * find_process_by_pid - find a process with a matching PID value.
3643 * @pid: the pid in question.
3645 * The task of @pid, if found. %NULL otherwise.
3647 static struct task_struct
*find_process_by_pid(pid_t pid
)
3649 return pid
? find_task_by_vpid(pid
) : current
;
3653 * This function initializes the sched_dl_entity of a newly becoming
3654 * SCHED_DEADLINE task.
3656 * Only the static values are considered here, the actual runtime and the
3657 * absolute deadline will be properly calculated when the task is enqueued
3658 * for the first time with its new policy.
3661 __setparam_dl(struct task_struct
*p
, const struct sched_attr
*attr
)
3663 struct sched_dl_entity
*dl_se
= &p
->dl
;
3665 dl_se
->dl_runtime
= attr
->sched_runtime
;
3666 dl_se
->dl_deadline
= attr
->sched_deadline
;
3667 dl_se
->dl_period
= attr
->sched_period
?: dl_se
->dl_deadline
;
3668 dl_se
->flags
= attr
->sched_flags
;
3669 dl_se
->dl_bw
= to_ratio(dl_se
->dl_period
, dl_se
->dl_runtime
);
3672 * Changing the parameters of a task is 'tricky' and we're not doing
3673 * the correct thing -- also see task_dead_dl() and switched_from_dl().
3675 * What we SHOULD do is delay the bandwidth release until the 0-lag
3676 * point. This would include retaining the task_struct until that time
3677 * and change dl_overflow() to not immediately decrement the current
3680 * Instead we retain the current runtime/deadline and let the new
3681 * parameters take effect after the current reservation period lapses.
3682 * This is safe (albeit pessimistic) because the 0-lag point is always
3683 * before the current scheduling deadline.
3685 * We can still have temporary overloads because we do not delay the
3686 * change in bandwidth until that time; so admission control is
3687 * not on the safe side. It does however guarantee tasks will never
3688 * consume more than promised.
3693 * sched_setparam() passes in -1 for its policy, to let the functions
3694 * it calls know not to change it.
3696 #define SETPARAM_POLICY -1
3698 static void __setscheduler_params(struct task_struct
*p
,
3699 const struct sched_attr
*attr
)
3701 int policy
= attr
->sched_policy
;
3703 if (policy
== SETPARAM_POLICY
)
3708 if (dl_policy(policy
))
3709 __setparam_dl(p
, attr
);
3710 else if (fair_policy(policy
))
3711 p
->static_prio
= NICE_TO_PRIO(attr
->sched_nice
);
3714 * __sched_setscheduler() ensures attr->sched_priority == 0 when
3715 * !rt_policy. Always setting this ensures that things like
3716 * getparam()/getattr() don't report silly values for !rt tasks.
3718 p
->rt_priority
= attr
->sched_priority
;
3719 p
->normal_prio
= normal_prio(p
);
3723 /* Actually do priority change: must hold pi & rq lock. */
3724 static void __setscheduler(struct rq
*rq
, struct task_struct
*p
,
3725 const struct sched_attr
*attr
, bool keep_boost
)
3727 __setscheduler_params(p
, attr
);
3730 * Keep a potential priority boosting if called from
3731 * sched_setscheduler().
3734 p
->prio
= rt_mutex_get_effective_prio(p
, normal_prio(p
));
3736 p
->prio
= normal_prio(p
);
3738 if (dl_prio(p
->prio
))
3739 p
->sched_class
= &dl_sched_class
;
3740 else if (rt_prio(p
->prio
))
3741 p
->sched_class
= &rt_sched_class
;
3743 p
->sched_class
= &fair_sched_class
;
3747 __getparam_dl(struct task_struct
*p
, struct sched_attr
*attr
)
3749 struct sched_dl_entity
*dl_se
= &p
->dl
;
3751 attr
->sched_priority
= p
->rt_priority
;
3752 attr
->sched_runtime
= dl_se
->dl_runtime
;
3753 attr
->sched_deadline
= dl_se
->dl_deadline
;
3754 attr
->sched_period
= dl_se
->dl_period
;
3755 attr
->sched_flags
= dl_se
->flags
;
3759 * This function validates the new parameters of a -deadline task.
3760 * We ask for the deadline not being zero, and greater or equal
3761 * than the runtime, as well as the period of being zero or
3762 * greater than deadline. Furthermore, we have to be sure that
3763 * user parameters are above the internal resolution of 1us (we
3764 * check sched_runtime only since it is always the smaller one) and
3765 * below 2^63 ns (we have to check both sched_deadline and
3766 * sched_period, as the latter can be zero).
3769 __checkparam_dl(const struct sched_attr
*attr
)
3772 if (attr
->sched_deadline
== 0)
3776 * Since we truncate DL_SCALE bits, make sure we're at least
3779 if (attr
->sched_runtime
< (1ULL << DL_SCALE
))
3783 * Since we use the MSB for wrap-around and sign issues, make
3784 * sure it's not set (mind that period can be equal to zero).
3786 if (attr
->sched_deadline
& (1ULL << 63) ||
3787 attr
->sched_period
& (1ULL << 63))
3790 /* runtime <= deadline <= period (if period != 0) */
3791 if ((attr
->sched_period
!= 0 &&
3792 attr
->sched_period
< attr
->sched_deadline
) ||
3793 attr
->sched_deadline
< attr
->sched_runtime
)
3800 * check the target process has a UID that matches the current process's
3802 static bool check_same_owner(struct task_struct
*p
)
3804 const struct cred
*cred
= current_cred(), *pcred
;
3808 pcred
= __task_cred(p
);
3809 match
= (uid_eq(cred
->euid
, pcred
->euid
) ||
3810 uid_eq(cred
->euid
, pcred
->uid
));
3815 static bool dl_param_changed(struct task_struct
*p
,
3816 const struct sched_attr
*attr
)
3818 struct sched_dl_entity
*dl_se
= &p
->dl
;
3820 if (dl_se
->dl_runtime
!= attr
->sched_runtime
||
3821 dl_se
->dl_deadline
!= attr
->sched_deadline
||
3822 dl_se
->dl_period
!= attr
->sched_period
||
3823 dl_se
->flags
!= attr
->sched_flags
)
3829 static int __sched_setscheduler(struct task_struct
*p
,
3830 const struct sched_attr
*attr
,
3833 int newprio
= dl_policy(attr
->sched_policy
) ? MAX_DL_PRIO
- 1 :
3834 MAX_RT_PRIO
- 1 - attr
->sched_priority
;
3835 int retval
, oldprio
, oldpolicy
= -1, queued
, running
;
3836 int new_effective_prio
, policy
= attr
->sched_policy
;
3837 unsigned long flags
;
3838 const struct sched_class
*prev_class
;
3841 int queue_flags
= DEQUEUE_SAVE
| DEQUEUE_MOVE
;
3843 /* may grab non-irq protected spin_locks */
3844 BUG_ON(in_interrupt());
3846 /* double check policy once rq lock held */
3848 reset_on_fork
= p
->sched_reset_on_fork
;
3849 policy
= oldpolicy
= p
->policy
;
3851 reset_on_fork
= !!(attr
->sched_flags
& SCHED_FLAG_RESET_ON_FORK
);
3853 if (!valid_policy(policy
))
3857 if (attr
->sched_flags
& ~(SCHED_FLAG_RESET_ON_FORK
))
3861 * Valid priorities for SCHED_FIFO and SCHED_RR are
3862 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
3863 * SCHED_BATCH and SCHED_IDLE is 0.
3865 if ((p
->mm
&& attr
->sched_priority
> MAX_USER_RT_PRIO
-1) ||
3866 (!p
->mm
&& attr
->sched_priority
> MAX_RT_PRIO
-1))
3868 if ((dl_policy(policy
) && !__checkparam_dl(attr
)) ||
3869 (rt_policy(policy
) != (attr
->sched_priority
!= 0)))
3873 * Allow unprivileged RT tasks to decrease priority:
3875 if (user
&& !capable(CAP_SYS_NICE
)) {
3876 if (fair_policy(policy
)) {
3877 if (attr
->sched_nice
< task_nice(p
) &&
3878 !can_nice(p
, attr
->sched_nice
))
3882 if (rt_policy(policy
)) {
3883 unsigned long rlim_rtprio
=
3884 task_rlimit(p
, RLIMIT_RTPRIO
);
3886 /* can't set/change the rt policy */
3887 if (policy
!= p
->policy
&& !rlim_rtprio
)
3890 /* can't increase priority */
3891 if (attr
->sched_priority
> p
->rt_priority
&&
3892 attr
->sched_priority
> rlim_rtprio
)
3897 * Can't set/change SCHED_DEADLINE policy at all for now
3898 * (safest behavior); in the future we would like to allow
3899 * unprivileged DL tasks to increase their relative deadline
3900 * or reduce their runtime (both ways reducing utilization)
3902 if (dl_policy(policy
))
3906 * Treat SCHED_IDLE as nice 20. Only allow a switch to
3907 * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
3909 if (idle_policy(p
->policy
) && !idle_policy(policy
)) {
3910 if (!can_nice(p
, task_nice(p
)))
3914 /* can't change other user's priorities */
3915 if (!check_same_owner(p
))
3918 /* Normal users shall not reset the sched_reset_on_fork flag */
3919 if (p
->sched_reset_on_fork
&& !reset_on_fork
)
3924 retval
= security_task_setscheduler(p
);
3930 * make sure no PI-waiters arrive (or leave) while we are
3931 * changing the priority of the task:
3933 * To be able to change p->policy safely, the appropriate
3934 * runqueue lock must be held.
3936 rq
= task_rq_lock(p
, &flags
);
3939 * Changing the policy of the stop threads its a very bad idea
3941 if (p
== rq
->stop
) {
3942 task_rq_unlock(rq
, p
, &flags
);
3947 * If not changing anything there's no need to proceed further,
3948 * but store a possible modification of reset_on_fork.
3950 if (unlikely(policy
== p
->policy
)) {
3951 if (fair_policy(policy
) && attr
->sched_nice
!= task_nice(p
))
3953 if (rt_policy(policy
) && attr
->sched_priority
!= p
->rt_priority
)
3955 if (dl_policy(policy
) && dl_param_changed(p
, attr
))
3958 p
->sched_reset_on_fork
= reset_on_fork
;
3959 task_rq_unlock(rq
, p
, &flags
);
3965 #ifdef CONFIG_RT_GROUP_SCHED
3967 * Do not allow realtime tasks into groups that have no runtime
3970 if (rt_bandwidth_enabled() && rt_policy(policy
) &&
3971 task_group(p
)->rt_bandwidth
.rt_runtime
== 0 &&
3972 !task_group_is_autogroup(task_group(p
))) {
3973 task_rq_unlock(rq
, p
, &flags
);
3978 if (dl_bandwidth_enabled() && dl_policy(policy
)) {
3979 cpumask_t
*span
= rq
->rd
->span
;
3982 * Don't allow tasks with an affinity mask smaller than
3983 * the entire root_domain to become SCHED_DEADLINE. We
3984 * will also fail if there's no bandwidth available.
3986 if (!cpumask_subset(span
, &p
->cpus_allowed
) ||
3987 rq
->rd
->dl_bw
.bw
== 0) {
3988 task_rq_unlock(rq
, p
, &flags
);
3995 /* recheck policy now with rq lock held */
3996 if (unlikely(oldpolicy
!= -1 && oldpolicy
!= p
->policy
)) {
3997 policy
= oldpolicy
= -1;
3998 task_rq_unlock(rq
, p
, &flags
);
4003 * If setscheduling to SCHED_DEADLINE (or changing the parameters
4004 * of a SCHED_DEADLINE task) we need to check if enough bandwidth
4007 if ((dl_policy(policy
) || dl_task(p
)) && dl_overflow(p
, policy
, attr
)) {
4008 task_rq_unlock(rq
, p
, &flags
);
4012 p
->sched_reset_on_fork
= reset_on_fork
;
4017 * Take priority boosted tasks into account. If the new
4018 * effective priority is unchanged, we just store the new
4019 * normal parameters and do not touch the scheduler class and
4020 * the runqueue. This will be done when the task deboost
4023 new_effective_prio
= rt_mutex_get_effective_prio(p
, newprio
);
4024 if (new_effective_prio
== oldprio
)
4025 queue_flags
&= ~DEQUEUE_MOVE
;
4028 queued
= task_on_rq_queued(p
);
4029 running
= task_current(rq
, p
);
4031 dequeue_task(rq
, p
, queue_flags
);
4033 put_prev_task(rq
, p
);
4035 prev_class
= p
->sched_class
;
4036 __setscheduler(rq
, p
, attr
, pi
);
4039 p
->sched_class
->set_curr_task(rq
);
4042 * We enqueue to tail when the priority of a task is
4043 * increased (user space view).
4045 if (oldprio
< p
->prio
)
4046 queue_flags
|= ENQUEUE_HEAD
;
4048 enqueue_task(rq
, p
, queue_flags
);
4051 check_class_changed(rq
, p
, prev_class
, oldprio
);
4052 preempt_disable(); /* avoid rq from going away on us */
4053 task_rq_unlock(rq
, p
, &flags
);
4056 rt_mutex_adjust_pi(p
);
4059 * Run balance callbacks after we've adjusted the PI chain.
4061 balance_callback(rq
);
4067 static int _sched_setscheduler(struct task_struct
*p
, int policy
,
4068 const struct sched_param
*param
, bool check
)
4070 struct sched_attr attr
= {
4071 .sched_policy
= policy
,
4072 .sched_priority
= param
->sched_priority
,
4073 .sched_nice
= PRIO_TO_NICE(p
->static_prio
),
4076 /* Fixup the legacy SCHED_RESET_ON_FORK hack. */
4077 if ((policy
!= SETPARAM_POLICY
) && (policy
& SCHED_RESET_ON_FORK
)) {
4078 attr
.sched_flags
|= SCHED_FLAG_RESET_ON_FORK
;
4079 policy
&= ~SCHED_RESET_ON_FORK
;
4080 attr
.sched_policy
= policy
;
4083 return __sched_setscheduler(p
, &attr
, check
, true);
4086 * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
4087 * @p: the task in question.
4088 * @policy: new policy.
4089 * @param: structure containing the new RT priority.
4091 * Return: 0 on success. An error code otherwise.
4093 * NOTE that the task may be already dead.
4095 int sched_setscheduler(struct task_struct
*p
, int policy
,
4096 const struct sched_param
*param
)
4098 return _sched_setscheduler(p
, policy
, param
, true);
4100 EXPORT_SYMBOL_GPL(sched_setscheduler
);
4102 int sched_setattr(struct task_struct
*p
, const struct sched_attr
*attr
)
4104 return __sched_setscheduler(p
, attr
, true, true);
4106 EXPORT_SYMBOL_GPL(sched_setattr
);
4109 * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
4110 * @p: the task in question.
4111 * @policy: new policy.
4112 * @param: structure containing the new RT priority.
4114 * Just like sched_setscheduler, only don't bother checking if the
4115 * current context has permission. For example, this is needed in
4116 * stop_machine(): we create temporary high priority worker threads,
4117 * but our caller might not have that capability.
4119 * Return: 0 on success. An error code otherwise.
4121 int sched_setscheduler_nocheck(struct task_struct
*p
, int policy
,
4122 const struct sched_param
*param
)
4124 return _sched_setscheduler(p
, policy
, param
, false);
4126 EXPORT_SYMBOL_GPL(sched_setscheduler_nocheck
);
4129 do_sched_setscheduler(pid_t pid
, int policy
, struct sched_param __user
*param
)
4131 struct sched_param lparam
;
4132 struct task_struct
*p
;
4135 if (!param
|| pid
< 0)
4137 if (copy_from_user(&lparam
, param
, sizeof(struct sched_param
)))
4142 p
= find_process_by_pid(pid
);
4144 retval
= sched_setscheduler(p
, policy
, &lparam
);
4151 * Mimics kernel/events/core.c perf_copy_attr().
4153 static int sched_copy_attr(struct sched_attr __user
*uattr
,
4154 struct sched_attr
*attr
)
4159 if (!access_ok(VERIFY_WRITE
, uattr
, SCHED_ATTR_SIZE_VER0
))
4163 * zero the full structure, so that a short copy will be nice.
4165 memset(attr
, 0, sizeof(*attr
));
4167 ret
= get_user(size
, &uattr
->size
);
4171 if (size
> PAGE_SIZE
) /* silly large */
4174 if (!size
) /* abi compat */
4175 size
= SCHED_ATTR_SIZE_VER0
;
4177 if (size
< SCHED_ATTR_SIZE_VER0
)
4181 * If we're handed a bigger struct than we know of,
4182 * ensure all the unknown bits are 0 - i.e. new
4183 * user-space does not rely on any kernel feature
4184 * extensions we dont know about yet.
4186 if (size
> sizeof(*attr
)) {
4187 unsigned char __user
*addr
;
4188 unsigned char __user
*end
;
4191 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4192 end
= (void __user
*)uattr
+ size
;
4194 for (; addr
< end
; addr
++) {
4195 ret
= get_user(val
, addr
);
4201 size
= sizeof(*attr
);
4204 ret
= copy_from_user(attr
, uattr
, size
);
4209 * XXX: do we want to be lenient like existing syscalls; or do we want
4210 * to be strict and return an error on out-of-bounds values?
4212 attr
->sched_nice
= clamp(attr
->sched_nice
, MIN_NICE
, MAX_NICE
);
4217 put_user(sizeof(*attr
), &uattr
->size
);
4222 * sys_sched_setscheduler - set/change the scheduler policy and RT priority
4223 * @pid: the pid in question.
4224 * @policy: new policy.
4225 * @param: structure containing the new RT priority.
4227 * Return: 0 on success. An error code otherwise.
4229 SYSCALL_DEFINE3(sched_setscheduler
, pid_t
, pid
, int, policy
,
4230 struct sched_param __user
*, param
)
4232 /* negative values for policy are not valid */
4236 return do_sched_setscheduler(pid
, policy
, param
);
4240 * sys_sched_setparam - set/change the RT priority of a thread
4241 * @pid: the pid in question.
4242 * @param: structure containing the new RT priority.
4244 * Return: 0 on success. An error code otherwise.
4246 SYSCALL_DEFINE2(sched_setparam
, pid_t
, pid
, struct sched_param __user
*, param
)
4248 return do_sched_setscheduler(pid
, SETPARAM_POLICY
, param
);
4252 * sys_sched_setattr - same as above, but with extended sched_attr
4253 * @pid: the pid in question.
4254 * @uattr: structure containing the extended parameters.
4255 * @flags: for future extension.
4257 SYSCALL_DEFINE3(sched_setattr
, pid_t
, pid
, struct sched_attr __user
*, uattr
,
4258 unsigned int, flags
)
4260 struct sched_attr attr
;
4261 struct task_struct
*p
;
4264 if (!uattr
|| pid
< 0 || flags
)
4267 retval
= sched_copy_attr(uattr
, &attr
);
4271 if ((int)attr
.sched_policy
< 0)
4276 p
= find_process_by_pid(pid
);
4278 retval
= sched_setattr(p
, &attr
);
4285 * sys_sched_getscheduler - get the policy (scheduling class) of a thread
4286 * @pid: the pid in question.
4288 * Return: On success, the policy of the thread. Otherwise, a negative error
4291 SYSCALL_DEFINE1(sched_getscheduler
, pid_t
, pid
)
4293 struct task_struct
*p
;
4301 p
= find_process_by_pid(pid
);
4303 retval
= security_task_getscheduler(p
);
4306 | (p
->sched_reset_on_fork
? SCHED_RESET_ON_FORK
: 0);
4313 * sys_sched_getparam - get the RT priority of a thread
4314 * @pid: the pid in question.
4315 * @param: structure containing the RT priority.
4317 * Return: On success, 0 and the RT priority is in @param. Otherwise, an error
4320 SYSCALL_DEFINE2(sched_getparam
, pid_t
, pid
, struct sched_param __user
*, param
)
4322 struct sched_param lp
= { .sched_priority
= 0 };
4323 struct task_struct
*p
;
4326 if (!param
|| pid
< 0)
4330 p
= find_process_by_pid(pid
);
4335 retval
= security_task_getscheduler(p
);
4339 if (task_has_rt_policy(p
))
4340 lp
.sched_priority
= p
->rt_priority
;
4344 * This one might sleep, we cannot do it with a spinlock held ...
4346 retval
= copy_to_user(param
, &lp
, sizeof(*param
)) ? -EFAULT
: 0;
4355 static int sched_read_attr(struct sched_attr __user
*uattr
,
4356 struct sched_attr
*attr
,
4361 if (!access_ok(VERIFY_WRITE
, uattr
, usize
))
4365 * If we're handed a smaller struct than we know of,
4366 * ensure all the unknown bits are 0 - i.e. old
4367 * user-space does not get uncomplete information.
4369 if (usize
< sizeof(*attr
)) {
4370 unsigned char *addr
;
4373 addr
= (void *)attr
+ usize
;
4374 end
= (void *)attr
+ sizeof(*attr
);
4376 for (; addr
< end
; addr
++) {
4384 ret
= copy_to_user(uattr
, attr
, attr
->size
);
4392 * sys_sched_getattr - similar to sched_getparam, but with sched_attr
4393 * @pid: the pid in question.
4394 * @uattr: structure containing the extended parameters.
4395 * @size: sizeof(attr) for fwd/bwd comp.
4396 * @flags: for future extension.
4398 SYSCALL_DEFINE4(sched_getattr
, pid_t
, pid
, struct sched_attr __user
*, uattr
,
4399 unsigned int, size
, unsigned int, flags
)
4401 struct sched_attr attr
= {
4402 .size
= sizeof(struct sched_attr
),
4404 struct task_struct
*p
;
4407 if (!uattr
|| pid
< 0 || size
> PAGE_SIZE
||
4408 size
< SCHED_ATTR_SIZE_VER0
|| flags
)
4412 p
= find_process_by_pid(pid
);
4417 retval
= security_task_getscheduler(p
);
4421 attr
.sched_policy
= p
->policy
;
4422 if (p
->sched_reset_on_fork
)
4423 attr
.sched_flags
|= SCHED_FLAG_RESET_ON_FORK
;
4424 if (task_has_dl_policy(p
))
4425 __getparam_dl(p
, &attr
);
4426 else if (task_has_rt_policy(p
))
4427 attr
.sched_priority
= p
->rt_priority
;
4429 attr
.sched_nice
= task_nice(p
);
4433 retval
= sched_read_attr(uattr
, &attr
, size
);
4441 long sched_setaffinity(pid_t pid
, const struct cpumask
*in_mask
)
4443 cpumask_var_t cpus_allowed
, new_mask
;
4444 struct task_struct
*p
;
4449 p
= find_process_by_pid(pid
);
4455 /* Prevent p going away */
4459 if (p
->flags
& PF_NO_SETAFFINITY
) {
4463 if (!alloc_cpumask_var(&cpus_allowed
, GFP_KERNEL
)) {
4467 if (!alloc_cpumask_var(&new_mask
, GFP_KERNEL
)) {
4469 goto out_free_cpus_allowed
;
4472 if (!check_same_owner(p
)) {
4474 if (!ns_capable(__task_cred(p
)->user_ns
, CAP_SYS_NICE
)) {
4476 goto out_free_new_mask
;
4481 retval
= security_task_setscheduler(p
);
4483 goto out_free_new_mask
;
4486 cpuset_cpus_allowed(p
, cpus_allowed
);
4487 cpumask_and(new_mask
, in_mask
, cpus_allowed
);
4490 * Since bandwidth control happens on root_domain basis,
4491 * if admission test is enabled, we only admit -deadline
4492 * tasks allowed to run on all the CPUs in the task's
4496 if (task_has_dl_policy(p
) && dl_bandwidth_enabled()) {
4498 if (!cpumask_subset(task_rq(p
)->rd
->span
, new_mask
)) {
4501 goto out_free_new_mask
;
4507 retval
= __set_cpus_allowed_ptr(p
, new_mask
, true);
4510 cpuset_cpus_allowed(p
, cpus_allowed
);
4511 if (!cpumask_subset(new_mask
, cpus_allowed
)) {
4513 * We must have raced with a concurrent cpuset
4514 * update. Just reset the cpus_allowed to the
4515 * cpuset's cpus_allowed
4517 cpumask_copy(new_mask
, cpus_allowed
);
4522 free_cpumask_var(new_mask
);
4523 out_free_cpus_allowed
:
4524 free_cpumask_var(cpus_allowed
);
4530 static int get_user_cpu_mask(unsigned long __user
*user_mask_ptr
, unsigned len
,
4531 struct cpumask
*new_mask
)
4533 if (len
< cpumask_size())
4534 cpumask_clear(new_mask
);
4535 else if (len
> cpumask_size())
4536 len
= cpumask_size();
4538 return copy_from_user(new_mask
, user_mask_ptr
, len
) ? -EFAULT
: 0;
4542 * sys_sched_setaffinity - set the cpu affinity of a process
4543 * @pid: pid of the process
4544 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
4545 * @user_mask_ptr: user-space pointer to the new cpu mask
4547 * Return: 0 on success. An error code otherwise.
4549 SYSCALL_DEFINE3(sched_setaffinity
, pid_t
, pid
, unsigned int, len
,
4550 unsigned long __user
*, user_mask_ptr
)
4552 cpumask_var_t new_mask
;
4555 if (!alloc_cpumask_var(&new_mask
, GFP_KERNEL
))
4558 retval
= get_user_cpu_mask(user_mask_ptr
, len
, new_mask
);
4560 retval
= sched_setaffinity(pid
, new_mask
);
4561 free_cpumask_var(new_mask
);
4565 long sched_getaffinity(pid_t pid
, struct cpumask
*mask
)
4567 struct task_struct
*p
;
4568 unsigned long flags
;
4574 p
= find_process_by_pid(pid
);
4578 retval
= security_task_getscheduler(p
);
4582 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
4583 cpumask_and(mask
, &p
->cpus_allowed
, cpu_active_mask
);
4584 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
4593 * sys_sched_getaffinity - get the cpu affinity of a process
4594 * @pid: pid of the process
4595 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
4596 * @user_mask_ptr: user-space pointer to hold the current cpu mask
4598 * Return: 0 on success. An error code otherwise.
4600 SYSCALL_DEFINE3(sched_getaffinity
, pid_t
, pid
, unsigned int, len
,
4601 unsigned long __user
*, user_mask_ptr
)
4606 if ((len
* BITS_PER_BYTE
) < nr_cpu_ids
)
4608 if (len
& (sizeof(unsigned long)-1))
4611 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
))
4614 ret
= sched_getaffinity(pid
, mask
);
4616 size_t retlen
= min_t(size_t, len
, cpumask_size());
4618 if (copy_to_user(user_mask_ptr
, mask
, retlen
))
4623 free_cpumask_var(mask
);
4629 * sys_sched_yield - yield the current processor to other threads.
4631 * This function yields the current CPU to other tasks. If there are no
4632 * other threads running on this CPU then this function will return.
4636 SYSCALL_DEFINE0(sched_yield
)
4638 struct rq
*rq
= this_rq_lock();
4640 schedstat_inc(rq
, yld_count
);
4641 current
->sched_class
->yield_task(rq
);
4644 * Since we are going to call schedule() anyway, there's
4645 * no need to preempt or enable interrupts:
4647 __release(rq
->lock
);
4648 spin_release(&rq
->lock
.dep_map
, 1, _THIS_IP_
);
4649 do_raw_spin_unlock(&rq
->lock
);
4650 sched_preempt_enable_no_resched();
4657 int __sched
_cond_resched(void)
4659 if (should_resched(0)) {
4660 preempt_schedule_common();
4665 EXPORT_SYMBOL(_cond_resched
);
4668 * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
4669 * call schedule, and on return reacquire the lock.
4671 * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
4672 * operations here to prevent schedule() from being called twice (once via
4673 * spin_unlock(), once by hand).
4675 int __cond_resched_lock(spinlock_t
*lock
)
4677 int resched
= should_resched(PREEMPT_LOCK_OFFSET
);
4680 lockdep_assert_held(lock
);
4682 if (spin_needbreak(lock
) || resched
) {
4685 preempt_schedule_common();
4693 EXPORT_SYMBOL(__cond_resched_lock
);
4695 int __sched
__cond_resched_softirq(void)
4697 BUG_ON(!in_softirq());
4699 if (should_resched(SOFTIRQ_DISABLE_OFFSET
)) {
4701 preempt_schedule_common();
4707 EXPORT_SYMBOL(__cond_resched_softirq
);
4710 * yield - yield the current processor to other threads.
4712 * Do not ever use this function, there's a 99% chance you're doing it wrong.
4714 * The scheduler is at all times free to pick the calling task as the most
4715 * eligible task to run, if removing the yield() call from your code breaks
4716 * it, its already broken.
4718 * Typical broken usage is:
4723 * where one assumes that yield() will let 'the other' process run that will
4724 * make event true. If the current task is a SCHED_FIFO task that will never
4725 * happen. Never use yield() as a progress guarantee!!
4727 * If you want to use yield() to wait for something, use wait_event().
4728 * If you want to use yield() to be 'nice' for others, use cond_resched().
4729 * If you still want to use yield(), do not!
4731 void __sched
yield(void)
4733 set_current_state(TASK_RUNNING
);
4736 EXPORT_SYMBOL(yield
);
4739 * yield_to - yield the current processor to another thread in
4740 * your thread group, or accelerate that thread toward the
4741 * processor it's on.
4743 * @preempt: whether task preemption is allowed or not
4745 * It's the caller's job to ensure that the target task struct
4746 * can't go away on us before we can do any checks.
4749 * true (>0) if we indeed boosted the target task.
4750 * false (0) if we failed to boost the target.
4751 * -ESRCH if there's no task to yield to.
4753 int __sched
yield_to(struct task_struct
*p
, bool preempt
)
4755 struct task_struct
*curr
= current
;
4756 struct rq
*rq
, *p_rq
;
4757 unsigned long flags
;
4760 local_irq_save(flags
);
4766 * If we're the only runnable task on the rq and target rq also
4767 * has only one task, there's absolutely no point in yielding.
4769 if (rq
->nr_running
== 1 && p_rq
->nr_running
== 1) {
4774 double_rq_lock(rq
, p_rq
);
4775 if (task_rq(p
) != p_rq
) {
4776 double_rq_unlock(rq
, p_rq
);
4780 if (!curr
->sched_class
->yield_to_task
)
4783 if (curr
->sched_class
!= p
->sched_class
)
4786 if (task_running(p_rq
, p
) || p
->state
)
4789 yielded
= curr
->sched_class
->yield_to_task(rq
, p
, preempt
);
4791 schedstat_inc(rq
, yld_count
);
4793 * Make p's CPU reschedule; pick_next_entity takes care of
4796 if (preempt
&& rq
!= p_rq
)
4801 double_rq_unlock(rq
, p_rq
);
4803 local_irq_restore(flags
);
4810 EXPORT_SYMBOL_GPL(yield_to
);
4813 * This task is about to go to sleep on IO. Increment rq->nr_iowait so
4814 * that process accounting knows that this is a task in IO wait state.
4816 long __sched
io_schedule_timeout(long timeout
)
4818 int old_iowait
= current
->in_iowait
;
4822 current
->in_iowait
= 1;
4823 blk_schedule_flush_plug(current
);
4825 delayacct_blkio_start();
4827 atomic_inc(&rq
->nr_iowait
);
4828 ret
= schedule_timeout(timeout
);
4829 current
->in_iowait
= old_iowait
;
4830 atomic_dec(&rq
->nr_iowait
);
4831 delayacct_blkio_end();
4835 EXPORT_SYMBOL(io_schedule_timeout
);
4838 * sys_sched_get_priority_max - return maximum RT priority.
4839 * @policy: scheduling class.
4841 * Return: On success, this syscall returns the maximum
4842 * rt_priority that can be used by a given scheduling class.
4843 * On failure, a negative error code is returned.
4845 SYSCALL_DEFINE1(sched_get_priority_max
, int, policy
)
4852 ret
= MAX_USER_RT_PRIO
-1;
4854 case SCHED_DEADLINE
:
4865 * sys_sched_get_priority_min - return minimum RT priority.
4866 * @policy: scheduling class.
4868 * Return: On success, this syscall returns the minimum
4869 * rt_priority that can be used by a given scheduling class.
4870 * On failure, a negative error code is returned.
4872 SYSCALL_DEFINE1(sched_get_priority_min
, int, policy
)
4881 case SCHED_DEADLINE
:
4891 * sys_sched_rr_get_interval - return the default timeslice of a process.
4892 * @pid: pid of the process.
4893 * @interval: userspace pointer to the timeslice value.
4895 * this syscall writes the default timeslice value of a given process
4896 * into the user-space timespec buffer. A value of '0' means infinity.
4898 * Return: On success, 0 and the timeslice is in @interval. Otherwise,
4901 SYSCALL_DEFINE2(sched_rr_get_interval
, pid_t
, pid
,
4902 struct timespec __user
*, interval
)
4904 struct task_struct
*p
;
4905 unsigned int time_slice
;
4906 unsigned long flags
;
4916 p
= find_process_by_pid(pid
);
4920 retval
= security_task_getscheduler(p
);
4924 rq
= task_rq_lock(p
, &flags
);
4926 if (p
->sched_class
->get_rr_interval
)
4927 time_slice
= p
->sched_class
->get_rr_interval(rq
, p
);
4928 task_rq_unlock(rq
, p
, &flags
);
4931 jiffies_to_timespec(time_slice
, &t
);
4932 retval
= copy_to_user(interval
, &t
, sizeof(t
)) ? -EFAULT
: 0;
4940 static const char stat_nam
[] = TASK_STATE_TO_CHAR_STR
;
4942 void sched_show_task(struct task_struct
*p
)
4944 unsigned long free
= 0;
4946 unsigned long state
= p
->state
;
4949 state
= __ffs(state
) + 1;
4950 printk(KERN_INFO
"%-15.15s %c", p
->comm
,
4951 state
< sizeof(stat_nam
) - 1 ? stat_nam
[state
] : '?');
4952 #if BITS_PER_LONG == 32
4953 if (state
== TASK_RUNNING
)
4954 printk(KERN_CONT
" running ");
4956 printk(KERN_CONT
" %08lx ", thread_saved_pc(p
));
4958 if (state
== TASK_RUNNING
)
4959 printk(KERN_CONT
" running task ");
4961 printk(KERN_CONT
" %016lx ", thread_saved_pc(p
));
4963 #ifdef CONFIG_DEBUG_STACK_USAGE
4964 free
= stack_not_used(p
);
4969 ppid
= task_pid_nr(rcu_dereference(p
->real_parent
));
4971 printk(KERN_CONT
"%5lu %5d %6d 0x%08lx\n", free
,
4972 task_pid_nr(p
), ppid
,
4973 (unsigned long)task_thread_info(p
)->flags
);
4975 print_worker_info(KERN_INFO
, p
);
4976 show_stack(p
, NULL
);
4979 void show_state_filter(unsigned long state_filter
)
4981 struct task_struct
*g
, *p
;
4983 #if BITS_PER_LONG == 32
4985 " task PC stack pid father\n");
4988 " task PC stack pid father\n");
4991 for_each_process_thread(g
, p
) {
4993 * reset the NMI-timeout, listing all files on a slow
4994 * console might take a lot of time:
4996 touch_nmi_watchdog();
4997 if (!state_filter
|| (p
->state
& state_filter
))
5001 touch_all_softlockup_watchdogs();
5003 #ifdef CONFIG_SCHED_DEBUG
5004 sysrq_sched_debug_show();
5008 * Only show locks if all tasks are dumped:
5011 debug_show_all_locks();
5014 void init_idle_bootup_task(struct task_struct
*idle
)
5016 idle
->sched_class
= &idle_sched_class
;
5020 * init_idle - set up an idle thread for a given CPU
5021 * @idle: task in question
5022 * @cpu: cpu the idle task belongs to
5024 * NOTE: this function does not set the idle thread's NEED_RESCHED
5025 * flag, to make booting more robust.
5027 void init_idle(struct task_struct
*idle
, int cpu
)
5029 struct rq
*rq
= cpu_rq(cpu
);
5030 unsigned long flags
;
5032 raw_spin_lock_irqsave(&idle
->pi_lock
, flags
);
5033 raw_spin_lock(&rq
->lock
);
5035 __sched_fork(0, idle
);
5036 idle
->state
= TASK_RUNNING
;
5037 idle
->se
.exec_start
= sched_clock();
5039 kasan_unpoison_task_stack(idle
);
5043 * Its possible that init_idle() gets called multiple times on a task,
5044 * in that case do_set_cpus_allowed() will not do the right thing.
5046 * And since this is boot we can forgo the serialization.
5048 set_cpus_allowed_common(idle
, cpumask_of(cpu
));
5051 * We're having a chicken and egg problem, even though we are
5052 * holding rq->lock, the cpu isn't yet set to this cpu so the
5053 * lockdep check in task_group() will fail.
5055 * Similar case to sched_fork(). / Alternatively we could
5056 * use task_rq_lock() here and obtain the other rq->lock.
5061 __set_task_cpu(idle
, cpu
);
5064 rq
->curr
= rq
->idle
= idle
;
5065 idle
->on_rq
= TASK_ON_RQ_QUEUED
;
5069 raw_spin_unlock(&rq
->lock
);
5070 raw_spin_unlock_irqrestore(&idle
->pi_lock
, flags
);
5072 /* Set the preempt count _outside_ the spinlocks! */
5073 init_idle_preempt_count(idle
, cpu
);
5076 * The idle tasks have their own, simple scheduling class:
5078 idle
->sched_class
= &idle_sched_class
;
5079 ftrace_graph_init_idle_task(idle
, cpu
);
5080 vtime_init_idle(idle
, cpu
);
5082 sprintf(idle
->comm
, "%s/%d", INIT_TASK_COMM
, cpu
);
5086 int cpuset_cpumask_can_shrink(const struct cpumask
*cur
,
5087 const struct cpumask
*trial
)
5089 int ret
= 1, trial_cpus
;
5090 struct dl_bw
*cur_dl_b
;
5091 unsigned long flags
;
5093 if (!cpumask_weight(cur
))
5096 rcu_read_lock_sched();
5097 cur_dl_b
= dl_bw_of(cpumask_any(cur
));
5098 trial_cpus
= cpumask_weight(trial
);
5100 raw_spin_lock_irqsave(&cur_dl_b
->lock
, flags
);
5101 if (cur_dl_b
->bw
!= -1 &&
5102 cur_dl_b
->bw
* trial_cpus
< cur_dl_b
->total_bw
)
5104 raw_spin_unlock_irqrestore(&cur_dl_b
->lock
, flags
);
5105 rcu_read_unlock_sched();
5110 int task_can_attach(struct task_struct
*p
,
5111 const struct cpumask
*cs_cpus_allowed
)
5116 * Kthreads which disallow setaffinity shouldn't be moved
5117 * to a new cpuset; we don't want to change their cpu
5118 * affinity and isolating such threads by their set of
5119 * allowed nodes is unnecessary. Thus, cpusets are not
5120 * applicable for such threads. This prevents checking for
5121 * success of set_cpus_allowed_ptr() on all attached tasks
5122 * before cpus_allowed may be changed.
5124 if (p
->flags
& PF_NO_SETAFFINITY
) {
5130 if (dl_task(p
) && !cpumask_intersects(task_rq(p
)->rd
->span
,
5132 unsigned int dest_cpu
= cpumask_any_and(cpu_active_mask
,
5137 unsigned long flags
;
5139 rcu_read_lock_sched();
5140 dl_b
= dl_bw_of(dest_cpu
);
5141 raw_spin_lock_irqsave(&dl_b
->lock
, flags
);
5142 cpus
= dl_bw_cpus(dest_cpu
);
5143 overflow
= __dl_overflow(dl_b
, cpus
, 0, p
->dl
.dl_bw
);
5148 * We reserve space for this task in the destination
5149 * root_domain, as we can't fail after this point.
5150 * We will free resources in the source root_domain
5151 * later on (see set_cpus_allowed_dl()).
5153 __dl_add(dl_b
, p
->dl
.dl_bw
);
5155 raw_spin_unlock_irqrestore(&dl_b
->lock
, flags
);
5156 rcu_read_unlock_sched();
5166 #ifdef CONFIG_NUMA_BALANCING
5167 /* Migrate current task p to target_cpu */
5168 int migrate_task_to(struct task_struct
*p
, int target_cpu
)
5170 struct migration_arg arg
= { p
, target_cpu
};
5171 int curr_cpu
= task_cpu(p
);
5173 if (curr_cpu
== target_cpu
)
5176 if (!cpumask_test_cpu(target_cpu
, tsk_cpus_allowed(p
)))
5179 /* TODO: This is not properly updating schedstats */
5181 trace_sched_move_numa(p
, curr_cpu
, target_cpu
);
5182 return stop_one_cpu(curr_cpu
, migration_cpu_stop
, &arg
);
5186 * Requeue a task on a given node and accurately track the number of NUMA
5187 * tasks on the runqueues
5189 void sched_setnuma(struct task_struct
*p
, int nid
)
5192 unsigned long flags
;
5193 bool queued
, running
;
5195 rq
= task_rq_lock(p
, &flags
);
5196 queued
= task_on_rq_queued(p
);
5197 running
= task_current(rq
, p
);
5200 dequeue_task(rq
, p
, DEQUEUE_SAVE
);
5202 put_prev_task(rq
, p
);
5204 p
->numa_preferred_nid
= nid
;
5207 p
->sched_class
->set_curr_task(rq
);
5209 enqueue_task(rq
, p
, ENQUEUE_RESTORE
);
5210 task_rq_unlock(rq
, p
, &flags
);
5212 #endif /* CONFIG_NUMA_BALANCING */
5214 #ifdef CONFIG_HOTPLUG_CPU
5216 * Ensures that the idle task is using init_mm right before its cpu goes
5219 void idle_task_exit(void)
5221 struct mm_struct
*mm
= current
->active_mm
;
5223 BUG_ON(cpu_online(smp_processor_id()));
5225 if (mm
!= &init_mm
) {
5226 switch_mm(mm
, &init_mm
, current
);
5227 finish_arch_post_lock_switch();
5233 * Since this CPU is going 'away' for a while, fold any nr_active delta
5234 * we might have. Assumes we're called after migrate_tasks() so that the
5235 * nr_active count is stable.
5237 * Also see the comment "Global load-average calculations".
5239 static void calc_load_migrate(struct rq
*rq
)
5241 long delta
= calc_load_fold_active(rq
);
5243 atomic_long_add(delta
, &calc_load_tasks
);
5246 static void put_prev_task_fake(struct rq
*rq
, struct task_struct
*prev
)
5250 static const struct sched_class fake_sched_class
= {
5251 .put_prev_task
= put_prev_task_fake
,
5254 static struct task_struct fake_task
= {
5256 * Avoid pull_{rt,dl}_task()
5258 .prio
= MAX_PRIO
+ 1,
5259 .sched_class
= &fake_sched_class
,
5263 * Migrate all tasks from the rq, sleeping tasks will be migrated by
5264 * try_to_wake_up()->select_task_rq().
5266 * Called with rq->lock held even though we'er in stop_machine() and
5267 * there's no concurrency possible, we hold the required locks anyway
5268 * because of lock validation efforts.
5270 static void migrate_tasks(struct rq
*dead_rq
)
5272 struct rq
*rq
= dead_rq
;
5273 struct task_struct
*next
, *stop
= rq
->stop
;
5277 * Fudge the rq selection such that the below task selection loop
5278 * doesn't get stuck on the currently eligible stop task.
5280 * We're currently inside stop_machine() and the rq is either stuck
5281 * in the stop_machine_cpu_stop() loop, or we're executing this code,
5282 * either way we should never end up calling schedule() until we're
5288 * put_prev_task() and pick_next_task() sched
5289 * class method both need to have an up-to-date
5290 * value of rq->clock[_task]
5292 update_rq_clock(rq
);
5296 * There's this thread running, bail when that's the only
5299 if (rq
->nr_running
== 1)
5303 * pick_next_task assumes pinned rq->lock.
5305 lockdep_pin_lock(&rq
->lock
);
5306 next
= pick_next_task(rq
, &fake_task
);
5308 next
->sched_class
->put_prev_task(rq
, next
);
5311 * Rules for changing task_struct::cpus_allowed are holding
5312 * both pi_lock and rq->lock, such that holding either
5313 * stabilizes the mask.
5315 * Drop rq->lock is not quite as disastrous as it usually is
5316 * because !cpu_active at this point, which means load-balance
5317 * will not interfere. Also, stop-machine.
5319 lockdep_unpin_lock(&rq
->lock
);
5320 raw_spin_unlock(&rq
->lock
);
5321 raw_spin_lock(&next
->pi_lock
);
5322 raw_spin_lock(&rq
->lock
);
5325 * Since we're inside stop-machine, _nothing_ should have
5326 * changed the task, WARN if weird stuff happened, because in
5327 * that case the above rq->lock drop is a fail too.
5329 if (WARN_ON(task_rq(next
) != rq
|| !task_on_rq_queued(next
))) {
5330 raw_spin_unlock(&next
->pi_lock
);
5334 /* Find suitable destination for @next, with force if needed. */
5335 dest_cpu
= select_fallback_rq(dead_rq
->cpu
, next
);
5337 rq
= __migrate_task(rq
, next
, dest_cpu
);
5338 if (rq
!= dead_rq
) {
5339 raw_spin_unlock(&rq
->lock
);
5341 raw_spin_lock(&rq
->lock
);
5343 raw_spin_unlock(&next
->pi_lock
);
5348 #endif /* CONFIG_HOTPLUG_CPU */
5350 static void set_rq_online(struct rq
*rq
)
5353 const struct sched_class
*class;
5355 cpumask_set_cpu(rq
->cpu
, rq
->rd
->online
);
5358 for_each_class(class) {
5359 if (class->rq_online
)
5360 class->rq_online(rq
);
5365 static void set_rq_offline(struct rq
*rq
)
5368 const struct sched_class
*class;
5370 for_each_class(class) {
5371 if (class->rq_offline
)
5372 class->rq_offline(rq
);
5375 cpumask_clear_cpu(rq
->cpu
, rq
->rd
->online
);
5381 * migration_call - callback that gets triggered when a CPU is added.
5382 * Here we can start up the necessary migration thread for the new CPU.
5385 migration_call(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
)
5387 int cpu
= (long)hcpu
;
5388 unsigned long flags
;
5389 struct rq
*rq
= cpu_rq(cpu
);
5391 switch (action
& ~CPU_TASKS_FROZEN
) {
5393 case CPU_UP_PREPARE
:
5394 rq
->calc_load_update
= calc_load_update
;
5395 account_reset_rq(rq
);
5399 /* Update our root-domain */
5400 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5402 BUG_ON(!cpumask_test_cpu(cpu
, rq
->rd
->span
));
5406 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5409 #ifdef CONFIG_HOTPLUG_CPU
5411 sched_ttwu_pending();
5412 /* Update our root-domain */
5413 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5415 BUG_ON(!cpumask_test_cpu(cpu
, rq
->rd
->span
));
5419 BUG_ON(rq
->nr_running
!= 1); /* the migration thread */
5420 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5424 calc_load_migrate(rq
);
5429 update_max_interval();
5435 * Register at high priority so that task migration (migrate_all_tasks)
5436 * happens before everything else. This has to be lower priority than
5437 * the notifier in the perf_event subsystem, though.
5439 static struct notifier_block migration_notifier
= {
5440 .notifier_call
= migration_call
,
5441 .priority
= CPU_PRI_MIGRATION
,
5444 static void set_cpu_rq_start_time(void)
5446 int cpu
= smp_processor_id();
5447 struct rq
*rq
= cpu_rq(cpu
);
5448 rq
->age_stamp
= sched_clock_cpu(cpu
);
5451 static int sched_cpu_active(struct notifier_block
*nfb
,
5452 unsigned long action
, void *hcpu
)
5454 int cpu
= (long)hcpu
;
5456 switch (action
& ~CPU_TASKS_FROZEN
) {
5458 set_cpu_rq_start_time();
5461 case CPU_DOWN_FAILED
:
5462 set_cpu_active(cpu
, true);
5470 static int sched_cpu_inactive(struct notifier_block
*nfb
,
5471 unsigned long action
, void *hcpu
)
5473 switch (action
& ~CPU_TASKS_FROZEN
) {
5474 case CPU_DOWN_PREPARE
:
5475 set_cpu_active((long)hcpu
, false);
5482 static int __init
migration_init(void)
5484 void *cpu
= (void *)(long)smp_processor_id();
5487 /* Initialize migration for the boot CPU */
5488 err
= migration_call(&migration_notifier
, CPU_UP_PREPARE
, cpu
);
5489 BUG_ON(err
== NOTIFY_BAD
);
5490 migration_call(&migration_notifier
, CPU_ONLINE
, cpu
);
5491 register_cpu_notifier(&migration_notifier
);
5493 /* Register cpu active notifiers */
5494 cpu_notifier(sched_cpu_active
, CPU_PRI_SCHED_ACTIVE
);
5495 cpu_notifier(sched_cpu_inactive
, CPU_PRI_SCHED_INACTIVE
);
5499 early_initcall(migration_init
);
5501 static cpumask_var_t sched_domains_tmpmask
; /* sched_domains_mutex */
5503 #ifdef CONFIG_SCHED_DEBUG
5505 static __read_mostly
int sched_debug_enabled
;
5507 static int __init
sched_debug_setup(char *str
)
5509 sched_debug_enabled
= 1;
5513 early_param("sched_debug", sched_debug_setup
);
5515 static inline bool sched_debug(void)
5517 return sched_debug_enabled
;
5520 static int sched_domain_debug_one(struct sched_domain
*sd
, int cpu
, int level
,
5521 struct cpumask
*groupmask
)
5523 struct sched_group
*group
= sd
->groups
;
5525 cpumask_clear(groupmask
);
5527 printk(KERN_DEBUG
"%*s domain %d: ", level
, "", level
);
5529 if (!(sd
->flags
& SD_LOAD_BALANCE
)) {
5530 printk("does not load-balance\n");
5532 printk(KERN_ERR
"ERROR: !SD_LOAD_BALANCE domain"
5537 printk(KERN_CONT
"span %*pbl level %s\n",
5538 cpumask_pr_args(sched_domain_span(sd
)), sd
->name
);
5540 if (!cpumask_test_cpu(cpu
, sched_domain_span(sd
))) {
5541 printk(KERN_ERR
"ERROR: domain->span does not contain "
5544 if (!cpumask_test_cpu(cpu
, sched_group_cpus(group
))) {
5545 printk(KERN_ERR
"ERROR: domain->groups does not contain"
5549 printk(KERN_DEBUG
"%*s groups:", level
+ 1, "");
5553 printk(KERN_ERR
"ERROR: group is NULL\n");
5557 if (!cpumask_weight(sched_group_cpus(group
))) {
5558 printk(KERN_CONT
"\n");
5559 printk(KERN_ERR
"ERROR: empty group\n");
5563 if (!(sd
->flags
& SD_OVERLAP
) &&
5564 cpumask_intersects(groupmask
, sched_group_cpus(group
))) {
5565 printk(KERN_CONT
"\n");
5566 printk(KERN_ERR
"ERROR: repeated CPUs\n");
5570 cpumask_or(groupmask
, groupmask
, sched_group_cpus(group
));
5572 printk(KERN_CONT
" %*pbl",
5573 cpumask_pr_args(sched_group_cpus(group
)));
5574 if (group
->sgc
->capacity
!= SCHED_CAPACITY_SCALE
) {
5575 printk(KERN_CONT
" (cpu_capacity = %d)",
5576 group
->sgc
->capacity
);
5579 group
= group
->next
;
5580 } while (group
!= sd
->groups
);
5581 printk(KERN_CONT
"\n");
5583 if (!cpumask_equal(sched_domain_span(sd
), groupmask
))
5584 printk(KERN_ERR
"ERROR: groups don't span domain->span\n");
5587 !cpumask_subset(groupmask
, sched_domain_span(sd
->parent
)))
5588 printk(KERN_ERR
"ERROR: parent span is not a superset "
5589 "of domain->span\n");
5593 static void sched_domain_debug(struct sched_domain
*sd
, int cpu
)
5597 if (!sched_debug_enabled
)
5601 printk(KERN_DEBUG
"CPU%d attaching NULL sched-domain.\n", cpu
);
5605 printk(KERN_DEBUG
"CPU%d attaching sched-domain:\n", cpu
);
5608 if (sched_domain_debug_one(sd
, cpu
, level
, sched_domains_tmpmask
))
5616 #else /* !CONFIG_SCHED_DEBUG */
5617 # define sched_domain_debug(sd, cpu) do { } while (0)
5618 static inline bool sched_debug(void)
5622 #endif /* CONFIG_SCHED_DEBUG */
5624 static int sd_degenerate(struct sched_domain
*sd
)
5626 if (cpumask_weight(sched_domain_span(sd
)) == 1)
5629 /* Following flags need at least 2 groups */
5630 if (sd
->flags
& (SD_LOAD_BALANCE
|
5631 SD_BALANCE_NEWIDLE
|
5634 SD_SHARE_CPUCAPACITY
|
5635 SD_SHARE_PKG_RESOURCES
|
5636 SD_SHARE_POWERDOMAIN
)) {
5637 if (sd
->groups
!= sd
->groups
->next
)
5641 /* Following flags don't use groups */
5642 if (sd
->flags
& (SD_WAKE_AFFINE
))
5649 sd_parent_degenerate(struct sched_domain
*sd
, struct sched_domain
*parent
)
5651 unsigned long cflags
= sd
->flags
, pflags
= parent
->flags
;
5653 if (sd_degenerate(parent
))
5656 if (!cpumask_equal(sched_domain_span(sd
), sched_domain_span(parent
)))
5659 /* Flags needing groups don't count if only 1 group in parent */
5660 if (parent
->groups
== parent
->groups
->next
) {
5661 pflags
&= ~(SD_LOAD_BALANCE
|
5662 SD_BALANCE_NEWIDLE
|
5665 SD_SHARE_CPUCAPACITY
|
5666 SD_SHARE_PKG_RESOURCES
|
5668 SD_SHARE_POWERDOMAIN
);
5669 if (nr_node_ids
== 1)
5670 pflags
&= ~SD_SERIALIZE
;
5672 if (~cflags
& pflags
)
5678 static void free_rootdomain(struct rcu_head
*rcu
)
5680 struct root_domain
*rd
= container_of(rcu
, struct root_domain
, rcu
);
5682 cpupri_cleanup(&rd
->cpupri
);
5683 cpudl_cleanup(&rd
->cpudl
);
5684 free_cpumask_var(rd
->dlo_mask
);
5685 free_cpumask_var(rd
->rto_mask
);
5686 free_cpumask_var(rd
->online
);
5687 free_cpumask_var(rd
->span
);
5691 static void rq_attach_root(struct rq
*rq
, struct root_domain
*rd
)
5693 struct root_domain
*old_rd
= NULL
;
5694 unsigned long flags
;
5696 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5701 if (cpumask_test_cpu(rq
->cpu
, old_rd
->online
))
5704 cpumask_clear_cpu(rq
->cpu
, old_rd
->span
);
5707 * If we dont want to free the old_rd yet then
5708 * set old_rd to NULL to skip the freeing later
5711 if (!atomic_dec_and_test(&old_rd
->refcount
))
5715 atomic_inc(&rd
->refcount
);
5718 cpumask_set_cpu(rq
->cpu
, rd
->span
);
5719 if (cpumask_test_cpu(rq
->cpu
, cpu_active_mask
))
5722 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5725 call_rcu_sched(&old_rd
->rcu
, free_rootdomain
);
5728 static int init_rootdomain(struct root_domain
*rd
)
5730 memset(rd
, 0, sizeof(*rd
));
5732 if (!zalloc_cpumask_var(&rd
->span
, GFP_KERNEL
))
5734 if (!zalloc_cpumask_var(&rd
->online
, GFP_KERNEL
))
5736 if (!zalloc_cpumask_var(&rd
->dlo_mask
, GFP_KERNEL
))
5738 if (!zalloc_cpumask_var(&rd
->rto_mask
, GFP_KERNEL
))
5741 init_dl_bw(&rd
->dl_bw
);
5742 if (cpudl_init(&rd
->cpudl
) != 0)
5745 if (cpupri_init(&rd
->cpupri
) != 0)
5750 free_cpumask_var(rd
->rto_mask
);
5752 free_cpumask_var(rd
->dlo_mask
);
5754 free_cpumask_var(rd
->online
);
5756 free_cpumask_var(rd
->span
);
5762 * By default the system creates a single root-domain with all cpus as
5763 * members (mimicking the global state we have today).
5765 struct root_domain def_root_domain
;
5767 static void init_defrootdomain(void)
5769 init_rootdomain(&def_root_domain
);
5771 atomic_set(&def_root_domain
.refcount
, 1);
5774 static struct root_domain
*alloc_rootdomain(void)
5776 struct root_domain
*rd
;
5778 rd
= kmalloc(sizeof(*rd
), GFP_KERNEL
);
5782 if (init_rootdomain(rd
) != 0) {
5790 static void free_sched_groups(struct sched_group
*sg
, int free_sgc
)
5792 struct sched_group
*tmp
, *first
;
5801 if (free_sgc
&& atomic_dec_and_test(&sg
->sgc
->ref
))
5806 } while (sg
!= first
);
5809 static void free_sched_domain(struct rcu_head
*rcu
)
5811 struct sched_domain
*sd
= container_of(rcu
, struct sched_domain
, rcu
);
5814 * If its an overlapping domain it has private groups, iterate and
5817 if (sd
->flags
& SD_OVERLAP
) {
5818 free_sched_groups(sd
->groups
, 1);
5819 } else if (atomic_dec_and_test(&sd
->groups
->ref
)) {
5820 kfree(sd
->groups
->sgc
);
5826 static void destroy_sched_domain(struct sched_domain
*sd
, int cpu
)
5828 call_rcu(&sd
->rcu
, free_sched_domain
);
5831 static void destroy_sched_domains(struct sched_domain
*sd
, int cpu
)
5833 for (; sd
; sd
= sd
->parent
)
5834 destroy_sched_domain(sd
, cpu
);
5838 * Keep a special pointer to the highest sched_domain that has
5839 * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
5840 * allows us to avoid some pointer chasing select_idle_sibling().
5842 * Also keep a unique ID per domain (we use the first cpu number in
5843 * the cpumask of the domain), this allows us to quickly tell if
5844 * two cpus are in the same cache domain, see cpus_share_cache().
5846 DEFINE_PER_CPU(struct sched_domain
*, sd_llc
);
5847 DEFINE_PER_CPU(int, sd_llc_size
);
5848 DEFINE_PER_CPU(int, sd_llc_id
);
5849 DEFINE_PER_CPU(struct sched_domain
*, sd_numa
);
5850 DEFINE_PER_CPU(struct sched_domain
*, sd_busy
);
5851 DEFINE_PER_CPU(struct sched_domain
*, sd_asym
);
5853 static void update_top_cache_domain(int cpu
)
5855 struct sched_domain
*sd
;
5856 struct sched_domain
*busy_sd
= NULL
;
5860 sd
= highest_flag_domain(cpu
, SD_SHARE_PKG_RESOURCES
);
5862 id
= cpumask_first(sched_domain_span(sd
));
5863 size
= cpumask_weight(sched_domain_span(sd
));
5864 busy_sd
= sd
->parent
; /* sd_busy */
5866 rcu_assign_pointer(per_cpu(sd_busy
, cpu
), busy_sd
);
5868 rcu_assign_pointer(per_cpu(sd_llc
, cpu
), sd
);
5869 per_cpu(sd_llc_size
, cpu
) = size
;
5870 per_cpu(sd_llc_id
, cpu
) = id
;
5872 sd
= lowest_flag_domain(cpu
, SD_NUMA
);
5873 rcu_assign_pointer(per_cpu(sd_numa
, cpu
), sd
);
5875 sd
= highest_flag_domain(cpu
, SD_ASYM_PACKING
);
5876 rcu_assign_pointer(per_cpu(sd_asym
, cpu
), sd
);
5880 * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
5881 * hold the hotplug lock.
5884 cpu_attach_domain(struct sched_domain
*sd
, struct root_domain
*rd
, int cpu
)
5886 struct rq
*rq
= cpu_rq(cpu
);
5887 struct sched_domain
*tmp
;
5889 /* Remove the sched domains which do not contribute to scheduling. */
5890 for (tmp
= sd
; tmp
; ) {
5891 struct sched_domain
*parent
= tmp
->parent
;
5895 if (sd_parent_degenerate(tmp
, parent
)) {
5896 tmp
->parent
= parent
->parent
;
5898 parent
->parent
->child
= tmp
;
5900 * Transfer SD_PREFER_SIBLING down in case of a
5901 * degenerate parent; the spans match for this
5902 * so the property transfers.
5904 if (parent
->flags
& SD_PREFER_SIBLING
)
5905 tmp
->flags
|= SD_PREFER_SIBLING
;
5906 destroy_sched_domain(parent
, cpu
);
5911 if (sd
&& sd_degenerate(sd
)) {
5914 destroy_sched_domain(tmp
, cpu
);
5919 sched_domain_debug(sd
, cpu
);
5921 rq_attach_root(rq
, rd
);
5923 rcu_assign_pointer(rq
->sd
, sd
);
5924 destroy_sched_domains(tmp
, cpu
);
5926 update_top_cache_domain(cpu
);
5929 /* Setup the mask of cpus configured for isolated domains */
5930 static int __init
isolated_cpu_setup(char *str
)
5934 alloc_bootmem_cpumask_var(&cpu_isolated_map
);
5935 ret
= cpulist_parse(str
, cpu_isolated_map
);
5937 pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids
);
5942 __setup("isolcpus=", isolated_cpu_setup
);
5945 struct sched_domain
** __percpu sd
;
5946 struct root_domain
*rd
;
5957 * Build an iteration mask that can exclude certain CPUs from the upwards
5960 * Asymmetric node setups can result in situations where the domain tree is of
5961 * unequal depth, make sure to skip domains that already cover the entire
5964 * In that case build_sched_domains() will have terminated the iteration early
5965 * and our sibling sd spans will be empty. Domains should always include the
5966 * cpu they're built on, so check that.
5969 static void build_group_mask(struct sched_domain
*sd
, struct sched_group
*sg
)
5971 const struct cpumask
*span
= sched_domain_span(sd
);
5972 struct sd_data
*sdd
= sd
->private;
5973 struct sched_domain
*sibling
;
5976 for_each_cpu(i
, span
) {
5977 sibling
= *per_cpu_ptr(sdd
->sd
, i
);
5978 if (!cpumask_test_cpu(i
, sched_domain_span(sibling
)))
5981 cpumask_set_cpu(i
, sched_group_mask(sg
));
5986 * Return the canonical balance cpu for this group, this is the first cpu
5987 * of this group that's also in the iteration mask.
5989 int group_balance_cpu(struct sched_group
*sg
)
5991 return cpumask_first_and(sched_group_cpus(sg
), sched_group_mask(sg
));
5995 build_overlap_sched_groups(struct sched_domain
*sd
, int cpu
)
5997 struct sched_group
*first
= NULL
, *last
= NULL
, *groups
= NULL
, *sg
;
5998 const struct cpumask
*span
= sched_domain_span(sd
);
5999 struct cpumask
*covered
= sched_domains_tmpmask
;
6000 struct sd_data
*sdd
= sd
->private;
6001 struct sched_domain
*sibling
;
6004 cpumask_clear(covered
);
6006 for_each_cpu(i
, span
) {
6007 struct cpumask
*sg_span
;
6009 if (cpumask_test_cpu(i
, covered
))
6012 sibling
= *per_cpu_ptr(sdd
->sd
, i
);
6014 /* See the comment near build_group_mask(). */
6015 if (!cpumask_test_cpu(i
, sched_domain_span(sibling
)))
6018 sg
= kzalloc_node(sizeof(struct sched_group
) + cpumask_size(),
6019 GFP_KERNEL
, cpu_to_node(cpu
));
6024 sg_span
= sched_group_cpus(sg
);
6026 cpumask_copy(sg_span
, sched_domain_span(sibling
->child
));
6028 cpumask_set_cpu(i
, sg_span
);
6030 cpumask_or(covered
, covered
, sg_span
);
6032 sg
->sgc
= *per_cpu_ptr(sdd
->sgc
, i
);
6033 if (atomic_inc_return(&sg
->sgc
->ref
) == 1)
6034 build_group_mask(sd
, sg
);
6037 * Initialize sgc->capacity such that even if we mess up the
6038 * domains and no possible iteration will get us here, we won't
6041 sg
->sgc
->capacity
= SCHED_CAPACITY_SCALE
* cpumask_weight(sg_span
);
6044 * Make sure the first group of this domain contains the
6045 * canonical balance cpu. Otherwise the sched_domain iteration
6046 * breaks. See update_sg_lb_stats().
6048 if ((!groups
&& cpumask_test_cpu(cpu
, sg_span
)) ||
6049 group_balance_cpu(sg
) == cpu
)
6059 sd
->groups
= groups
;
6064 free_sched_groups(first
, 0);
6069 static int get_group(int cpu
, struct sd_data
*sdd
, struct sched_group
**sg
)
6071 struct sched_domain
*sd
= *per_cpu_ptr(sdd
->sd
, cpu
);
6072 struct sched_domain
*child
= sd
->child
;
6075 cpu
= cpumask_first(sched_domain_span(child
));
6078 *sg
= *per_cpu_ptr(sdd
->sg
, cpu
);
6079 (*sg
)->sgc
= *per_cpu_ptr(sdd
->sgc
, cpu
);
6080 atomic_set(&(*sg
)->sgc
->ref
, 1); /* for claim_allocations */
6087 * build_sched_groups will build a circular linked list of the groups
6088 * covered by the given span, and will set each group's ->cpumask correctly,
6089 * and ->cpu_capacity to 0.
6091 * Assumes the sched_domain tree is fully constructed
6094 build_sched_groups(struct sched_domain
*sd
, int cpu
)
6096 struct sched_group
*first
= NULL
, *last
= NULL
;
6097 struct sd_data
*sdd
= sd
->private;
6098 const struct cpumask
*span
= sched_domain_span(sd
);
6099 struct cpumask
*covered
;
6102 get_group(cpu
, sdd
, &sd
->groups
);
6103 atomic_inc(&sd
->groups
->ref
);
6105 if (cpu
!= cpumask_first(span
))
6108 lockdep_assert_held(&sched_domains_mutex
);
6109 covered
= sched_domains_tmpmask
;
6111 cpumask_clear(covered
);
6113 for_each_cpu(i
, span
) {
6114 struct sched_group
*sg
;
6117 if (cpumask_test_cpu(i
, covered
))
6120 group
= get_group(i
, sdd
, &sg
);
6121 cpumask_setall(sched_group_mask(sg
));
6123 for_each_cpu(j
, span
) {
6124 if (get_group(j
, sdd
, NULL
) != group
)
6127 cpumask_set_cpu(j
, covered
);
6128 cpumask_set_cpu(j
, sched_group_cpus(sg
));
6143 * Initialize sched groups cpu_capacity.
6145 * cpu_capacity indicates the capacity of sched group, which is used while
6146 * distributing the load between different sched groups in a sched domain.
6147 * Typically cpu_capacity for all the groups in a sched domain will be same
6148 * unless there are asymmetries in the topology. If there are asymmetries,
6149 * group having more cpu_capacity will pickup more load compared to the
6150 * group having less cpu_capacity.
6152 static void init_sched_groups_capacity(int cpu
, struct sched_domain
*sd
)
6154 struct sched_group
*sg
= sd
->groups
;
6159 sg
->group_weight
= cpumask_weight(sched_group_cpus(sg
));
6161 } while (sg
!= sd
->groups
);
6163 if (cpu
!= group_balance_cpu(sg
))
6166 update_group_capacity(sd
, cpu
);
6167 atomic_set(&sg
->sgc
->nr_busy_cpus
, sg
->group_weight
);
6171 * Initializers for schedule domains
6172 * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
6175 static int default_relax_domain_level
= -1;
6176 int sched_domain_level_max
;
6178 static int __init
setup_relax_domain_level(char *str
)
6180 if (kstrtoint(str
, 0, &default_relax_domain_level
))
6181 pr_warn("Unable to set relax_domain_level\n");
6185 __setup("relax_domain_level=", setup_relax_domain_level
);
6187 static void set_domain_attribute(struct sched_domain
*sd
,
6188 struct sched_domain_attr
*attr
)
6192 if (!attr
|| attr
->relax_domain_level
< 0) {
6193 if (default_relax_domain_level
< 0)
6196 request
= default_relax_domain_level
;
6198 request
= attr
->relax_domain_level
;
6199 if (request
< sd
->level
) {
6200 /* turn off idle balance on this domain */
6201 sd
->flags
&= ~(SD_BALANCE_WAKE
|SD_BALANCE_NEWIDLE
);
6203 /* turn on idle balance on this domain */
6204 sd
->flags
|= (SD_BALANCE_WAKE
|SD_BALANCE_NEWIDLE
);
6208 static void __sdt_free(const struct cpumask
*cpu_map
);
6209 static int __sdt_alloc(const struct cpumask
*cpu_map
);
6211 static void __free_domain_allocs(struct s_data
*d
, enum s_alloc what
,
6212 const struct cpumask
*cpu_map
)
6216 if (!atomic_read(&d
->rd
->refcount
))
6217 free_rootdomain(&d
->rd
->rcu
); /* fall through */
6219 free_percpu(d
->sd
); /* fall through */
6221 __sdt_free(cpu_map
); /* fall through */
6227 static enum s_alloc
__visit_domain_allocation_hell(struct s_data
*d
,
6228 const struct cpumask
*cpu_map
)
6230 memset(d
, 0, sizeof(*d
));
6232 if (__sdt_alloc(cpu_map
))
6233 return sa_sd_storage
;
6234 d
->sd
= alloc_percpu(struct sched_domain
*);
6236 return sa_sd_storage
;
6237 d
->rd
= alloc_rootdomain();
6240 return sa_rootdomain
;
6244 * NULL the sd_data elements we've used to build the sched_domain and
6245 * sched_group structure so that the subsequent __free_domain_allocs()
6246 * will not free the data we're using.
6248 static void claim_allocations(int cpu
, struct sched_domain
*sd
)
6250 struct sd_data
*sdd
= sd
->private;
6252 WARN_ON_ONCE(*per_cpu_ptr(sdd
->sd
, cpu
) != sd
);
6253 *per_cpu_ptr(sdd
->sd
, cpu
) = NULL
;
6255 if (atomic_read(&(*per_cpu_ptr(sdd
->sg
, cpu
))->ref
))
6256 *per_cpu_ptr(sdd
->sg
, cpu
) = NULL
;
6258 if (atomic_read(&(*per_cpu_ptr(sdd
->sgc
, cpu
))->ref
))
6259 *per_cpu_ptr(sdd
->sgc
, cpu
) = NULL
;
6263 static int sched_domains_numa_levels
;
6264 enum numa_topology_type sched_numa_topology_type
;
6265 static int *sched_domains_numa_distance
;
6266 int sched_max_numa_distance
;
6267 static struct cpumask
***sched_domains_numa_masks
;
6268 static int sched_domains_curr_level
;
6272 * SD_flags allowed in topology descriptions.
6274 * SD_SHARE_CPUCAPACITY - describes SMT topologies
6275 * SD_SHARE_PKG_RESOURCES - describes shared caches
6276 * SD_NUMA - describes NUMA topologies
6277 * SD_SHARE_POWERDOMAIN - describes shared power domain
6280 * SD_ASYM_PACKING - describes SMT quirks
6282 #define TOPOLOGY_SD_FLAGS \
6283 (SD_SHARE_CPUCAPACITY | \
6284 SD_SHARE_PKG_RESOURCES | \
6287 SD_SHARE_POWERDOMAIN)
6289 static struct sched_domain
*
6290 sd_init(struct sched_domain_topology_level
*tl
, int cpu
)
6292 struct sched_domain
*sd
= *per_cpu_ptr(tl
->data
.sd
, cpu
);
6293 int sd_weight
, sd_flags
= 0;
6297 * Ugly hack to pass state to sd_numa_mask()...
6299 sched_domains_curr_level
= tl
->numa_level
;
6302 sd_weight
= cpumask_weight(tl
->mask(cpu
));
6305 sd_flags
= (*tl
->sd_flags
)();
6306 if (WARN_ONCE(sd_flags
& ~TOPOLOGY_SD_FLAGS
,
6307 "wrong sd_flags in topology description\n"))
6308 sd_flags
&= ~TOPOLOGY_SD_FLAGS
;
6310 *sd
= (struct sched_domain
){
6311 .min_interval
= sd_weight
,
6312 .max_interval
= 2*sd_weight
,
6314 .imbalance_pct
= 125,
6316 .cache_nice_tries
= 0,
6323 .flags
= 1*SD_LOAD_BALANCE
6324 | 1*SD_BALANCE_NEWIDLE
6329 | 0*SD_SHARE_CPUCAPACITY
6330 | 0*SD_SHARE_PKG_RESOURCES
6332 | 0*SD_PREFER_SIBLING
6337 .last_balance
= jiffies
,
6338 .balance_interval
= sd_weight
,
6340 .max_newidle_lb_cost
= 0,
6341 .next_decay_max_lb_cost
= jiffies
,
6342 #ifdef CONFIG_SCHED_DEBUG
6348 * Convert topological properties into behaviour.
6351 if (sd
->flags
& SD_SHARE_CPUCAPACITY
) {
6352 sd
->flags
|= SD_PREFER_SIBLING
;
6353 sd
->imbalance_pct
= 110;
6354 sd
->smt_gain
= 1178; /* ~15% */
6356 } else if (sd
->flags
& SD_SHARE_PKG_RESOURCES
) {
6357 sd
->imbalance_pct
= 117;
6358 sd
->cache_nice_tries
= 1;
6362 } else if (sd
->flags
& SD_NUMA
) {
6363 sd
->cache_nice_tries
= 2;
6367 sd
->flags
|= SD_SERIALIZE
;
6368 if (sched_domains_numa_distance
[tl
->numa_level
] > RECLAIM_DISTANCE
) {
6369 sd
->flags
&= ~(SD_BALANCE_EXEC
|
6376 sd
->flags
|= SD_PREFER_SIBLING
;
6377 sd
->cache_nice_tries
= 1;
6382 sd
->private = &tl
->data
;
6388 * Topology list, bottom-up.
6390 static struct sched_domain_topology_level default_topology
[] = {
6391 #ifdef CONFIG_SCHED_SMT
6392 { cpu_smt_mask
, cpu_smt_flags
, SD_INIT_NAME(SMT
) },
6394 #ifdef CONFIG_SCHED_MC
6395 { cpu_coregroup_mask
, cpu_core_flags
, SD_INIT_NAME(MC
) },
6397 { cpu_cpu_mask
, SD_INIT_NAME(DIE
) },
6401 static struct sched_domain_topology_level
*sched_domain_topology
=
6404 #define for_each_sd_topology(tl) \
6405 for (tl = sched_domain_topology; tl->mask; tl++)
6407 void set_sched_topology(struct sched_domain_topology_level
*tl
)
6409 sched_domain_topology
= tl
;
6414 static const struct cpumask
*sd_numa_mask(int cpu
)
6416 return sched_domains_numa_masks
[sched_domains_curr_level
][cpu_to_node(cpu
)];
6419 static void sched_numa_warn(const char *str
)
6421 static int done
= false;
6429 printk(KERN_WARNING
"ERROR: %s\n\n", str
);
6431 for (i
= 0; i
< nr_node_ids
; i
++) {
6432 printk(KERN_WARNING
" ");
6433 for (j
= 0; j
< nr_node_ids
; j
++)
6434 printk(KERN_CONT
"%02d ", node_distance(i
,j
));
6435 printk(KERN_CONT
"\n");
6437 printk(KERN_WARNING
"\n");
6440 bool find_numa_distance(int distance
)
6444 if (distance
== node_distance(0, 0))
6447 for (i
= 0; i
< sched_domains_numa_levels
; i
++) {
6448 if (sched_domains_numa_distance
[i
] == distance
)
6456 * A system can have three types of NUMA topology:
6457 * NUMA_DIRECT: all nodes are directly connected, or not a NUMA system
6458 * NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes
6459 * NUMA_BACKPLANE: nodes can reach other nodes through a backplane
6461 * The difference between a glueless mesh topology and a backplane
6462 * topology lies in whether communication between not directly
6463 * connected nodes goes through intermediary nodes (where programs
6464 * could run), or through backplane controllers. This affects
6465 * placement of programs.
6467 * The type of topology can be discerned with the following tests:
6468 * - If the maximum distance between any nodes is 1 hop, the system
6469 * is directly connected.
6470 * - If for two nodes A and B, located N > 1 hops away from each other,
6471 * there is an intermediary node C, which is < N hops away from both
6472 * nodes A and B, the system is a glueless mesh.
6474 static void init_numa_topology_type(void)
6478 n
= sched_max_numa_distance
;
6480 if (sched_domains_numa_levels
<= 1) {
6481 sched_numa_topology_type
= NUMA_DIRECT
;
6485 for_each_online_node(a
) {
6486 for_each_online_node(b
) {
6487 /* Find two nodes furthest removed from each other. */
6488 if (node_distance(a
, b
) < n
)
6491 /* Is there an intermediary node between a and b? */
6492 for_each_online_node(c
) {
6493 if (node_distance(a
, c
) < n
&&
6494 node_distance(b
, c
) < n
) {
6495 sched_numa_topology_type
=
6501 sched_numa_topology_type
= NUMA_BACKPLANE
;
6507 static void sched_init_numa(void)
6509 int next_distance
, curr_distance
= node_distance(0, 0);
6510 struct sched_domain_topology_level
*tl
;
6514 sched_domains_numa_distance
= kzalloc(sizeof(int) * nr_node_ids
, GFP_KERNEL
);
6515 if (!sched_domains_numa_distance
)
6519 * O(nr_nodes^2) deduplicating selection sort -- in order to find the
6520 * unique distances in the node_distance() table.
6522 * Assumes node_distance(0,j) includes all distances in
6523 * node_distance(i,j) in order to avoid cubic time.
6525 next_distance
= curr_distance
;
6526 for (i
= 0; i
< nr_node_ids
; i
++) {
6527 for (j
= 0; j
< nr_node_ids
; j
++) {
6528 for (k
= 0; k
< nr_node_ids
; k
++) {
6529 int distance
= node_distance(i
, k
);
6531 if (distance
> curr_distance
&&
6532 (distance
< next_distance
||
6533 next_distance
== curr_distance
))
6534 next_distance
= distance
;
6537 * While not a strong assumption it would be nice to know
6538 * about cases where if node A is connected to B, B is not
6539 * equally connected to A.
6541 if (sched_debug() && node_distance(k
, i
) != distance
)
6542 sched_numa_warn("Node-distance not symmetric");
6544 if (sched_debug() && i
&& !find_numa_distance(distance
))
6545 sched_numa_warn("Node-0 not representative");
6547 if (next_distance
!= curr_distance
) {
6548 sched_domains_numa_distance
[level
++] = next_distance
;
6549 sched_domains_numa_levels
= level
;
6550 curr_distance
= next_distance
;
6555 * In case of sched_debug() we verify the above assumption.
6565 * 'level' contains the number of unique distances, excluding the
6566 * identity distance node_distance(i,i).
6568 * The sched_domains_numa_distance[] array includes the actual distance
6573 * Here, we should temporarily reset sched_domains_numa_levels to 0.
6574 * If it fails to allocate memory for array sched_domains_numa_masks[][],
6575 * the array will contain less then 'level' members. This could be
6576 * dangerous when we use it to iterate array sched_domains_numa_masks[][]
6577 * in other functions.
6579 * We reset it to 'level' at the end of this function.
6581 sched_domains_numa_levels
= 0;
6583 sched_domains_numa_masks
= kzalloc(sizeof(void *) * level
, GFP_KERNEL
);
6584 if (!sched_domains_numa_masks
)
6588 * Now for each level, construct a mask per node which contains all
6589 * cpus of nodes that are that many hops away from us.
6591 for (i
= 0; i
< level
; i
++) {
6592 sched_domains_numa_masks
[i
] =
6593 kzalloc(nr_node_ids
* sizeof(void *), GFP_KERNEL
);
6594 if (!sched_domains_numa_masks
[i
])
6597 for (j
= 0; j
< nr_node_ids
; j
++) {
6598 struct cpumask
*mask
= kzalloc(cpumask_size(), GFP_KERNEL
);
6602 sched_domains_numa_masks
[i
][j
] = mask
;
6605 if (node_distance(j
, k
) > sched_domains_numa_distance
[i
])
6608 cpumask_or(mask
, mask
, cpumask_of_node(k
));
6613 /* Compute default topology size */
6614 for (i
= 0; sched_domain_topology
[i
].mask
; i
++);
6616 tl
= kzalloc((i
+ level
+ 1) *
6617 sizeof(struct sched_domain_topology_level
), GFP_KERNEL
);
6622 * Copy the default topology bits..
6624 for (i
= 0; sched_domain_topology
[i
].mask
; i
++)
6625 tl
[i
] = sched_domain_topology
[i
];
6628 * .. and append 'j' levels of NUMA goodness.
6630 for (j
= 0; j
< level
; i
++, j
++) {
6631 tl
[i
] = (struct sched_domain_topology_level
){
6632 .mask
= sd_numa_mask
,
6633 .sd_flags
= cpu_numa_flags
,
6634 .flags
= SDTL_OVERLAP
,
6640 sched_domain_topology
= tl
;
6642 sched_domains_numa_levels
= level
;
6643 sched_max_numa_distance
= sched_domains_numa_distance
[level
- 1];
6645 init_numa_topology_type();
6648 static void sched_domains_numa_masks_set(int cpu
)
6651 int node
= cpu_to_node(cpu
);
6653 for (i
= 0; i
< sched_domains_numa_levels
; i
++) {
6654 for (j
= 0; j
< nr_node_ids
; j
++) {
6655 if (node_distance(j
, node
) <= sched_domains_numa_distance
[i
])
6656 cpumask_set_cpu(cpu
, sched_domains_numa_masks
[i
][j
]);
6661 static void sched_domains_numa_masks_clear(int cpu
)
6664 for (i
= 0; i
< sched_domains_numa_levels
; i
++) {
6665 for (j
= 0; j
< nr_node_ids
; j
++)
6666 cpumask_clear_cpu(cpu
, sched_domains_numa_masks
[i
][j
]);
6671 * Update sched_domains_numa_masks[level][node] array when new cpus
6674 static int sched_domains_numa_masks_update(struct notifier_block
*nfb
,
6675 unsigned long action
,
6678 int cpu
= (long)hcpu
;
6680 switch (action
& ~CPU_TASKS_FROZEN
) {
6682 sched_domains_numa_masks_set(cpu
);
6686 sched_domains_numa_masks_clear(cpu
);
6696 static inline void sched_init_numa(void)
6700 static int sched_domains_numa_masks_update(struct notifier_block
*nfb
,
6701 unsigned long action
,
6706 #endif /* CONFIG_NUMA */
6708 static int __sdt_alloc(const struct cpumask
*cpu_map
)
6710 struct sched_domain_topology_level
*tl
;
6713 for_each_sd_topology(tl
) {
6714 struct sd_data
*sdd
= &tl
->data
;
6716 sdd
->sd
= alloc_percpu(struct sched_domain
*);
6720 sdd
->sg
= alloc_percpu(struct sched_group
*);
6724 sdd
->sgc
= alloc_percpu(struct sched_group_capacity
*);
6728 for_each_cpu(j
, cpu_map
) {
6729 struct sched_domain
*sd
;
6730 struct sched_group
*sg
;
6731 struct sched_group_capacity
*sgc
;
6733 sd
= kzalloc_node(sizeof(struct sched_domain
) + cpumask_size(),
6734 GFP_KERNEL
, cpu_to_node(j
));
6738 *per_cpu_ptr(sdd
->sd
, j
) = sd
;
6740 sg
= kzalloc_node(sizeof(struct sched_group
) + cpumask_size(),
6741 GFP_KERNEL
, cpu_to_node(j
));
6747 *per_cpu_ptr(sdd
->sg
, j
) = sg
;
6749 sgc
= kzalloc_node(sizeof(struct sched_group_capacity
) + cpumask_size(),
6750 GFP_KERNEL
, cpu_to_node(j
));
6754 *per_cpu_ptr(sdd
->sgc
, j
) = sgc
;
6761 static void __sdt_free(const struct cpumask
*cpu_map
)
6763 struct sched_domain_topology_level
*tl
;
6766 for_each_sd_topology(tl
) {
6767 struct sd_data
*sdd
= &tl
->data
;
6769 for_each_cpu(j
, cpu_map
) {
6770 struct sched_domain
*sd
;
6773 sd
= *per_cpu_ptr(sdd
->sd
, j
);
6774 if (sd
&& (sd
->flags
& SD_OVERLAP
))
6775 free_sched_groups(sd
->groups
, 0);
6776 kfree(*per_cpu_ptr(sdd
->sd
, j
));
6780 kfree(*per_cpu_ptr(sdd
->sg
, j
));
6782 kfree(*per_cpu_ptr(sdd
->sgc
, j
));
6784 free_percpu(sdd
->sd
);
6786 free_percpu(sdd
->sg
);
6788 free_percpu(sdd
->sgc
);
6793 struct sched_domain
*build_sched_domain(struct sched_domain_topology_level
*tl
,
6794 const struct cpumask
*cpu_map
, struct sched_domain_attr
*attr
,
6795 struct sched_domain
*child
, int cpu
)
6797 struct sched_domain
*sd
= sd_init(tl
, cpu
);
6801 cpumask_and(sched_domain_span(sd
), cpu_map
, tl
->mask(cpu
));
6803 sd
->level
= child
->level
+ 1;
6804 sched_domain_level_max
= max(sched_domain_level_max
, sd
->level
);
6808 if (!cpumask_subset(sched_domain_span(child
),
6809 sched_domain_span(sd
))) {
6810 pr_err("BUG: arch topology borken\n");
6811 #ifdef CONFIG_SCHED_DEBUG
6812 pr_err(" the %s domain not a subset of the %s domain\n",
6813 child
->name
, sd
->name
);
6815 /* Fixup, ensure @sd has at least @child cpus. */
6816 cpumask_or(sched_domain_span(sd
),
6817 sched_domain_span(sd
),
6818 sched_domain_span(child
));
6822 set_domain_attribute(sd
, attr
);
6828 * Build sched domains for a given set of cpus and attach the sched domains
6829 * to the individual cpus
6831 static int build_sched_domains(const struct cpumask
*cpu_map
,
6832 struct sched_domain_attr
*attr
)
6834 enum s_alloc alloc_state
;
6835 struct sched_domain
*sd
;
6837 int i
, ret
= -ENOMEM
;
6839 alloc_state
= __visit_domain_allocation_hell(&d
, cpu_map
);
6840 if (alloc_state
!= sa_rootdomain
)
6843 /* Set up domains for cpus specified by the cpu_map. */
6844 for_each_cpu(i
, cpu_map
) {
6845 struct sched_domain_topology_level
*tl
;
6848 for_each_sd_topology(tl
) {
6849 sd
= build_sched_domain(tl
, cpu_map
, attr
, sd
, i
);
6850 if (tl
== sched_domain_topology
)
6851 *per_cpu_ptr(d
.sd
, i
) = sd
;
6852 if (tl
->flags
& SDTL_OVERLAP
|| sched_feat(FORCE_SD_OVERLAP
))
6853 sd
->flags
|= SD_OVERLAP
;
6854 if (cpumask_equal(cpu_map
, sched_domain_span(sd
)))
6859 /* Build the groups for the domains */
6860 for_each_cpu(i
, cpu_map
) {
6861 for (sd
= *per_cpu_ptr(d
.sd
, i
); sd
; sd
= sd
->parent
) {
6862 sd
->span_weight
= cpumask_weight(sched_domain_span(sd
));
6863 if (sd
->flags
& SD_OVERLAP
) {
6864 if (build_overlap_sched_groups(sd
, i
))
6867 if (build_sched_groups(sd
, i
))
6873 /* Calculate CPU capacity for physical packages and nodes */
6874 for (i
= nr_cpumask_bits
-1; i
>= 0; i
--) {
6875 if (!cpumask_test_cpu(i
, cpu_map
))
6878 for (sd
= *per_cpu_ptr(d
.sd
, i
); sd
; sd
= sd
->parent
) {
6879 claim_allocations(i
, sd
);
6880 init_sched_groups_capacity(i
, sd
);
6884 /* Attach the domains */
6886 for_each_cpu(i
, cpu_map
) {
6887 sd
= *per_cpu_ptr(d
.sd
, i
);
6888 cpu_attach_domain(sd
, d
.rd
, i
);
6894 __free_domain_allocs(&d
, alloc_state
, cpu_map
);
6898 static cpumask_var_t
*doms_cur
; /* current sched domains */
6899 static int ndoms_cur
; /* number of sched domains in 'doms_cur' */
6900 static struct sched_domain_attr
*dattr_cur
;
6901 /* attribues of custom domains in 'doms_cur' */
6904 * Special case: If a kmalloc of a doms_cur partition (array of
6905 * cpumask) fails, then fallback to a single sched domain,
6906 * as determined by the single cpumask fallback_doms.
6908 static cpumask_var_t fallback_doms
;
6911 * arch_update_cpu_topology lets virtualized architectures update the
6912 * cpu core maps. It is supposed to return 1 if the topology changed
6913 * or 0 if it stayed the same.
6915 int __weak
arch_update_cpu_topology(void)
6920 cpumask_var_t
*alloc_sched_domains(unsigned int ndoms
)
6923 cpumask_var_t
*doms
;
6925 doms
= kmalloc(sizeof(*doms
) * ndoms
, GFP_KERNEL
);
6928 for (i
= 0; i
< ndoms
; i
++) {
6929 if (!alloc_cpumask_var(&doms
[i
], GFP_KERNEL
)) {
6930 free_sched_domains(doms
, i
);
6937 void free_sched_domains(cpumask_var_t doms
[], unsigned int ndoms
)
6940 for (i
= 0; i
< ndoms
; i
++)
6941 free_cpumask_var(doms
[i
]);
6946 * Set up scheduler domains and groups. Callers must hold the hotplug lock.
6947 * For now this just excludes isolated cpus, but could be used to
6948 * exclude other special cases in the future.
6950 static int init_sched_domains(const struct cpumask
*cpu_map
)
6954 arch_update_cpu_topology();
6956 doms_cur
= alloc_sched_domains(ndoms_cur
);
6958 doms_cur
= &fallback_doms
;
6959 cpumask_andnot(doms_cur
[0], cpu_map
, cpu_isolated_map
);
6960 err
= build_sched_domains(doms_cur
[0], NULL
);
6961 register_sched_domain_sysctl();
6967 * Detach sched domains from a group of cpus specified in cpu_map
6968 * These cpus will now be attached to the NULL domain
6970 static void detach_destroy_domains(const struct cpumask
*cpu_map
)
6975 for_each_cpu(i
, cpu_map
)
6976 cpu_attach_domain(NULL
, &def_root_domain
, i
);
6980 /* handle null as "default" */
6981 static int dattrs_equal(struct sched_domain_attr
*cur
, int idx_cur
,
6982 struct sched_domain_attr
*new, int idx_new
)
6984 struct sched_domain_attr tmp
;
6991 return !memcmp(cur
? (cur
+ idx_cur
) : &tmp
,
6992 new ? (new + idx_new
) : &tmp
,
6993 sizeof(struct sched_domain_attr
));
6997 * Partition sched domains as specified by the 'ndoms_new'
6998 * cpumasks in the array doms_new[] of cpumasks. This compares
6999 * doms_new[] to the current sched domain partitioning, doms_cur[].
7000 * It destroys each deleted domain and builds each new domain.
7002 * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
7003 * The masks don't intersect (don't overlap.) We should setup one
7004 * sched domain for each mask. CPUs not in any of the cpumasks will
7005 * not be load balanced. If the same cpumask appears both in the
7006 * current 'doms_cur' domains and in the new 'doms_new', we can leave
7009 * The passed in 'doms_new' should be allocated using
7010 * alloc_sched_domains. This routine takes ownership of it and will
7011 * free_sched_domains it when done with it. If the caller failed the
7012 * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
7013 * and partition_sched_domains() will fallback to the single partition
7014 * 'fallback_doms', it also forces the domains to be rebuilt.
7016 * If doms_new == NULL it will be replaced with cpu_online_mask.
7017 * ndoms_new == 0 is a special case for destroying existing domains,
7018 * and it will not create the default domain.
7020 * Call with hotplug lock held
7022 void partition_sched_domains(int ndoms_new
, cpumask_var_t doms_new
[],
7023 struct sched_domain_attr
*dattr_new
)
7028 mutex_lock(&sched_domains_mutex
);
7030 /* always unregister in case we don't destroy any domains */
7031 unregister_sched_domain_sysctl();
7033 /* Let architecture update cpu core mappings. */
7034 new_topology
= arch_update_cpu_topology();
7036 n
= doms_new
? ndoms_new
: 0;
7038 /* Destroy deleted domains */
7039 for (i
= 0; i
< ndoms_cur
; i
++) {
7040 for (j
= 0; j
< n
&& !new_topology
; j
++) {
7041 if (cpumask_equal(doms_cur
[i
], doms_new
[j
])
7042 && dattrs_equal(dattr_cur
, i
, dattr_new
, j
))
7045 /* no match - a current sched domain not in new doms_new[] */
7046 detach_destroy_domains(doms_cur
[i
]);
7052 if (doms_new
== NULL
) {
7054 doms_new
= &fallback_doms
;
7055 cpumask_andnot(doms_new
[0], cpu_active_mask
, cpu_isolated_map
);
7056 WARN_ON_ONCE(dattr_new
);
7059 /* Build new domains */
7060 for (i
= 0; i
< ndoms_new
; i
++) {
7061 for (j
= 0; j
< n
&& !new_topology
; j
++) {
7062 if (cpumask_equal(doms_new
[i
], doms_cur
[j
])
7063 && dattrs_equal(dattr_new
, i
, dattr_cur
, j
))
7066 /* no match - add a new doms_new */
7067 build_sched_domains(doms_new
[i
], dattr_new
? dattr_new
+ i
: NULL
);
7072 /* Remember the new sched domains */
7073 if (doms_cur
!= &fallback_doms
)
7074 free_sched_domains(doms_cur
, ndoms_cur
);
7075 kfree(dattr_cur
); /* kfree(NULL) is safe */
7076 doms_cur
= doms_new
;
7077 dattr_cur
= dattr_new
;
7078 ndoms_cur
= ndoms_new
;
7080 register_sched_domain_sysctl();
7082 mutex_unlock(&sched_domains_mutex
);
7085 static int num_cpus_frozen
; /* used to mark begin/end of suspend/resume */
7088 * Update cpusets according to cpu_active mask. If cpusets are
7089 * disabled, cpuset_update_active_cpus() becomes a simple wrapper
7090 * around partition_sched_domains().
7092 * If we come here as part of a suspend/resume, don't touch cpusets because we
7093 * want to restore it back to its original state upon resume anyway.
7095 static int cpuset_cpu_active(struct notifier_block
*nfb
, unsigned long action
,
7099 case CPU_ONLINE_FROZEN
:
7100 case CPU_DOWN_FAILED_FROZEN
:
7103 * num_cpus_frozen tracks how many CPUs are involved in suspend
7104 * resume sequence. As long as this is not the last online
7105 * operation in the resume sequence, just build a single sched
7106 * domain, ignoring cpusets.
7109 if (likely(num_cpus_frozen
)) {
7110 partition_sched_domains(1, NULL
, NULL
);
7115 * This is the last CPU online operation. So fall through and
7116 * restore the original sched domains by considering the
7117 * cpuset configurations.
7121 cpuset_update_active_cpus(true);
7129 static int cpuset_cpu_inactive(struct notifier_block
*nfb
, unsigned long action
,
7132 unsigned long flags
;
7133 long cpu
= (long)hcpu
;
7139 case CPU_DOWN_PREPARE
:
7140 rcu_read_lock_sched();
7141 dl_b
= dl_bw_of(cpu
);
7143 raw_spin_lock_irqsave(&dl_b
->lock
, flags
);
7144 cpus
= dl_bw_cpus(cpu
);
7145 overflow
= __dl_overflow(dl_b
, cpus
, 0, 0);
7146 raw_spin_unlock_irqrestore(&dl_b
->lock
, flags
);
7148 rcu_read_unlock_sched();
7151 return notifier_from_errno(-EBUSY
);
7152 cpuset_update_active_cpus(false);
7154 case CPU_DOWN_PREPARE_FROZEN
:
7156 partition_sched_domains(1, NULL
, NULL
);
7164 void __init
sched_init_smp(void)
7166 cpumask_var_t non_isolated_cpus
;
7168 alloc_cpumask_var(&non_isolated_cpus
, GFP_KERNEL
);
7169 alloc_cpumask_var(&fallback_doms
, GFP_KERNEL
);
7174 * There's no userspace yet to cause hotplug operations; hence all the
7175 * cpu masks are stable and all blatant races in the below code cannot
7178 mutex_lock(&sched_domains_mutex
);
7179 init_sched_domains(cpu_active_mask
);
7180 cpumask_andnot(non_isolated_cpus
, cpu_possible_mask
, cpu_isolated_map
);
7181 if (cpumask_empty(non_isolated_cpus
))
7182 cpumask_set_cpu(smp_processor_id(), non_isolated_cpus
);
7183 mutex_unlock(&sched_domains_mutex
);
7185 hotcpu_notifier(sched_domains_numa_masks_update
, CPU_PRI_SCHED_ACTIVE
);
7186 hotcpu_notifier(cpuset_cpu_active
, CPU_PRI_CPUSET_ACTIVE
);
7187 hotcpu_notifier(cpuset_cpu_inactive
, CPU_PRI_CPUSET_INACTIVE
);
7191 /* Move init over to a non-isolated CPU */
7192 if (set_cpus_allowed_ptr(current
, non_isolated_cpus
) < 0)
7194 sched_init_granularity();
7195 free_cpumask_var(non_isolated_cpus
);
7197 init_sched_rt_class();
7198 init_sched_dl_class();
7201 void __init
sched_init_smp(void)
7203 sched_init_granularity();
7205 #endif /* CONFIG_SMP */
7207 int in_sched_functions(unsigned long addr
)
7209 return in_lock_functions(addr
) ||
7210 (addr
>= (unsigned long)__sched_text_start
7211 && addr
< (unsigned long)__sched_text_end
);
7214 #ifdef CONFIG_CGROUP_SCHED
7216 * Default task group.
7217 * Every task in system belongs to this group at bootup.
7219 struct task_group root_task_group
;
7220 LIST_HEAD(task_groups
);
7222 /* Cacheline aligned slab cache for task_group */
7223 static struct kmem_cache
*task_group_cache __read_mostly
;
7226 DECLARE_PER_CPU(cpumask_var_t
, load_balance_mask
);
7228 void __init
sched_init(void)
7231 unsigned long alloc_size
= 0, ptr
;
7233 #ifdef CONFIG_FAIR_GROUP_SCHED
7234 alloc_size
+= 2 * nr_cpu_ids
* sizeof(void **);
7236 #ifdef CONFIG_RT_GROUP_SCHED
7237 alloc_size
+= 2 * nr_cpu_ids
* sizeof(void **);
7240 ptr
= (unsigned long)kzalloc(alloc_size
, GFP_NOWAIT
);
7242 #ifdef CONFIG_FAIR_GROUP_SCHED
7243 root_task_group
.se
= (struct sched_entity
**)ptr
;
7244 ptr
+= nr_cpu_ids
* sizeof(void **);
7246 root_task_group
.cfs_rq
= (struct cfs_rq
**)ptr
;
7247 ptr
+= nr_cpu_ids
* sizeof(void **);
7249 #endif /* CONFIG_FAIR_GROUP_SCHED */
7250 #ifdef CONFIG_RT_GROUP_SCHED
7251 root_task_group
.rt_se
= (struct sched_rt_entity
**)ptr
;
7252 ptr
+= nr_cpu_ids
* sizeof(void **);
7254 root_task_group
.rt_rq
= (struct rt_rq
**)ptr
;
7255 ptr
+= nr_cpu_ids
* sizeof(void **);
7257 #endif /* CONFIG_RT_GROUP_SCHED */
7259 #ifdef CONFIG_CPUMASK_OFFSTACK
7260 for_each_possible_cpu(i
) {
7261 per_cpu(load_balance_mask
, i
) = (cpumask_var_t
)kzalloc_node(
7262 cpumask_size(), GFP_KERNEL
, cpu_to_node(i
));
7264 #endif /* CONFIG_CPUMASK_OFFSTACK */
7266 init_rt_bandwidth(&def_rt_bandwidth
,
7267 global_rt_period(), global_rt_runtime());
7268 init_dl_bandwidth(&def_dl_bandwidth
,
7269 global_rt_period(), global_rt_runtime());
7272 init_defrootdomain();
7275 #ifdef CONFIG_RT_GROUP_SCHED
7276 init_rt_bandwidth(&root_task_group
.rt_bandwidth
,
7277 global_rt_period(), global_rt_runtime());
7278 #endif /* CONFIG_RT_GROUP_SCHED */
7280 #ifdef CONFIG_CGROUP_SCHED
7281 task_group_cache
= KMEM_CACHE(task_group
, 0);
7283 list_add(&root_task_group
.list
, &task_groups
);
7284 INIT_LIST_HEAD(&root_task_group
.children
);
7285 INIT_LIST_HEAD(&root_task_group
.siblings
);
7286 autogroup_init(&init_task
);
7287 #endif /* CONFIG_CGROUP_SCHED */
7289 for_each_possible_cpu(i
) {
7293 raw_spin_lock_init(&rq
->lock
);
7295 rq
->calc_load_active
= 0;
7296 rq
->calc_load_update
= jiffies
+ LOAD_FREQ
;
7297 init_cfs_rq(&rq
->cfs
);
7298 init_rt_rq(&rq
->rt
);
7299 init_dl_rq(&rq
->dl
);
7300 #ifdef CONFIG_FAIR_GROUP_SCHED
7301 root_task_group
.shares
= ROOT_TASK_GROUP_LOAD
;
7302 INIT_LIST_HEAD(&rq
->leaf_cfs_rq_list
);
7304 * How much cpu bandwidth does root_task_group get?
7306 * In case of task-groups formed thr' the cgroup filesystem, it
7307 * gets 100% of the cpu resources in the system. This overall
7308 * system cpu resource is divided among the tasks of
7309 * root_task_group and its child task-groups in a fair manner,
7310 * based on each entity's (task or task-group's) weight
7311 * (se->load.weight).
7313 * In other words, if root_task_group has 10 tasks of weight
7314 * 1024) and two child groups A0 and A1 (of weight 1024 each),
7315 * then A0's share of the cpu resource is:
7317 * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
7319 * We achieve this by letting root_task_group's tasks sit
7320 * directly in rq->cfs (i.e root_task_group->se[] = NULL).
7322 init_cfs_bandwidth(&root_task_group
.cfs_bandwidth
);
7323 init_tg_cfs_entry(&root_task_group
, &rq
->cfs
, NULL
, i
, NULL
);
7324 #endif /* CONFIG_FAIR_GROUP_SCHED */
7326 rq
->rt
.rt_runtime
= def_rt_bandwidth
.rt_runtime
;
7327 #ifdef CONFIG_RT_GROUP_SCHED
7328 init_tg_rt_entry(&root_task_group
, &rq
->rt
, NULL
, i
, NULL
);
7331 for (j
= 0; j
< CPU_LOAD_IDX_MAX
; j
++)
7332 rq
->cpu_load
[j
] = 0;
7334 rq
->last_load_update_tick
= jiffies
;
7339 rq
->cpu_capacity
= rq
->cpu_capacity_orig
= SCHED_CAPACITY_SCALE
;
7340 rq
->balance_callback
= NULL
;
7341 rq
->active_balance
= 0;
7342 rq
->next_balance
= jiffies
;
7347 rq
->avg_idle
= 2*sysctl_sched_migration_cost
;
7348 rq
->max_idle_balance_cost
= sysctl_sched_migration_cost
;
7350 INIT_LIST_HEAD(&rq
->cfs_tasks
);
7352 rq_attach_root(rq
, &def_root_domain
);
7353 #ifdef CONFIG_NO_HZ_COMMON
7356 #ifdef CONFIG_NO_HZ_FULL
7357 rq
->last_sched_tick
= 0;
7361 atomic_set(&rq
->nr_iowait
, 0);
7364 set_load_weight(&init_task
);
7366 #ifdef CONFIG_PREEMPT_NOTIFIERS
7367 INIT_HLIST_HEAD(&init_task
.preempt_notifiers
);
7371 * The boot idle thread does lazy MMU switching as well:
7373 atomic_inc(&init_mm
.mm_count
);
7374 enter_lazy_tlb(&init_mm
, current
);
7377 * During early bootup we pretend to be a normal task:
7379 current
->sched_class
= &fair_sched_class
;
7382 * Make us the idle thread. Technically, schedule() should not be
7383 * called from this thread, however somewhere below it might be,
7384 * but because we are the idle thread, we just pick up running again
7385 * when this runqueue becomes "idle".
7387 init_idle(current
, smp_processor_id());
7389 calc_load_update
= jiffies
+ LOAD_FREQ
;
7392 zalloc_cpumask_var(&sched_domains_tmpmask
, GFP_NOWAIT
);
7393 /* May be allocated at isolcpus cmdline parse time */
7394 if (cpu_isolated_map
== NULL
)
7395 zalloc_cpumask_var(&cpu_isolated_map
, GFP_NOWAIT
);
7396 idle_thread_set_boot_cpu();
7397 set_cpu_rq_start_time();
7399 init_sched_fair_class();
7401 scheduler_running
= 1;
7404 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
7405 static inline int preempt_count_equals(int preempt_offset
)
7407 int nested
= preempt_count() + rcu_preempt_depth();
7409 return (nested
== preempt_offset
);
7412 void __might_sleep(const char *file
, int line
, int preempt_offset
)
7415 * Blocking primitives will set (and therefore destroy) current->state,
7416 * since we will exit with TASK_RUNNING make sure we enter with it,
7417 * otherwise we will destroy state.
7419 WARN_ONCE(current
->state
!= TASK_RUNNING
&& current
->task_state_change
,
7420 "do not call blocking ops when !TASK_RUNNING; "
7421 "state=%lx set at [<%p>] %pS\n",
7423 (void *)current
->task_state_change
,
7424 (void *)current
->task_state_change
);
7426 ___might_sleep(file
, line
, preempt_offset
);
7428 EXPORT_SYMBOL(__might_sleep
);
7430 void ___might_sleep(const char *file
, int line
, int preempt_offset
)
7432 static unsigned long prev_jiffy
; /* ratelimiting */
7434 rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
7435 if ((preempt_count_equals(preempt_offset
) && !irqs_disabled() &&
7436 !is_idle_task(current
)) ||
7437 system_state
!= SYSTEM_RUNNING
|| oops_in_progress
)
7439 if (time_before(jiffies
, prev_jiffy
+ HZ
) && prev_jiffy
)
7441 prev_jiffy
= jiffies
;
7444 "BUG: sleeping function called from invalid context at %s:%d\n",
7447 "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
7448 in_atomic(), irqs_disabled(),
7449 current
->pid
, current
->comm
);
7451 if (task_stack_end_corrupted(current
))
7452 printk(KERN_EMERG
"Thread overran stack, or stack corrupted\n");
7454 debug_show_held_locks(current
);
7455 if (irqs_disabled())
7456 print_irqtrace_events(current
);
7457 #ifdef CONFIG_DEBUG_PREEMPT
7458 if (!preempt_count_equals(preempt_offset
)) {
7459 pr_err("Preemption disabled at:");
7460 print_ip_sym(current
->preempt_disable_ip
);
7466 EXPORT_SYMBOL(___might_sleep
);
7469 #ifdef CONFIG_MAGIC_SYSRQ
7470 void normalize_rt_tasks(void)
7472 struct task_struct
*g
, *p
;
7473 struct sched_attr attr
= {
7474 .sched_policy
= SCHED_NORMAL
,
7477 read_lock(&tasklist_lock
);
7478 for_each_process_thread(g
, p
) {
7480 * Only normalize user tasks:
7482 if (p
->flags
& PF_KTHREAD
)
7485 p
->se
.exec_start
= 0;
7486 #ifdef CONFIG_SCHEDSTATS
7487 p
->se
.statistics
.wait_start
= 0;
7488 p
->se
.statistics
.sleep_start
= 0;
7489 p
->se
.statistics
.block_start
= 0;
7492 if (!dl_task(p
) && !rt_task(p
)) {
7494 * Renice negative nice level userspace
7497 if (task_nice(p
) < 0)
7498 set_user_nice(p
, 0);
7502 __sched_setscheduler(p
, &attr
, false, false);
7504 read_unlock(&tasklist_lock
);
7507 #endif /* CONFIG_MAGIC_SYSRQ */
7509 #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
7511 * These functions are only useful for the IA64 MCA handling, or kdb.
7513 * They can only be called when the whole system has been
7514 * stopped - every CPU needs to be quiescent, and no scheduling
7515 * activity can take place. Using them for anything else would
7516 * be a serious bug, and as a result, they aren't even visible
7517 * under any other configuration.
7521 * curr_task - return the current task for a given cpu.
7522 * @cpu: the processor in question.
7524 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
7526 * Return: The current task for @cpu.
7528 struct task_struct
*curr_task(int cpu
)
7530 return cpu_curr(cpu
);
7533 #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
7537 * set_curr_task - set the current task for a given cpu.
7538 * @cpu: the processor in question.
7539 * @p: the task pointer to set.
7541 * Description: This function must only be used when non-maskable interrupts
7542 * are serviced on a separate stack. It allows the architecture to switch the
7543 * notion of the current task on a cpu in a non-blocking manner. This function
7544 * must be called with all CPU's synchronized, and interrupts disabled, the
7545 * and caller must save the original value of the current task (see
7546 * curr_task() above) and restore that value before reenabling interrupts and
7547 * re-starting the system.
7549 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
7551 void set_curr_task(int cpu
, struct task_struct
*p
)
7558 #ifdef CONFIG_CGROUP_SCHED
7559 /* task_group_lock serializes the addition/removal of task groups */
7560 static DEFINE_SPINLOCK(task_group_lock
);
7562 static void sched_free_group(struct task_group
*tg
)
7564 free_fair_sched_group(tg
);
7565 free_rt_sched_group(tg
);
7567 kmem_cache_free(task_group_cache
, tg
);
7570 /* allocate runqueue etc for a new task group */
7571 struct task_group
*sched_create_group(struct task_group
*parent
)
7573 struct task_group
*tg
;
7575 tg
= kmem_cache_alloc(task_group_cache
, GFP_KERNEL
| __GFP_ZERO
);
7577 return ERR_PTR(-ENOMEM
);
7579 if (!alloc_fair_sched_group(tg
, parent
))
7582 if (!alloc_rt_sched_group(tg
, parent
))
7588 sched_free_group(tg
);
7589 return ERR_PTR(-ENOMEM
);
7592 void sched_online_group(struct task_group
*tg
, struct task_group
*parent
)
7594 unsigned long flags
;
7596 spin_lock_irqsave(&task_group_lock
, flags
);
7597 list_add_rcu(&tg
->list
, &task_groups
);
7599 WARN_ON(!parent
); /* root should already exist */
7601 tg
->parent
= parent
;
7602 INIT_LIST_HEAD(&tg
->children
);
7603 list_add_rcu(&tg
->siblings
, &parent
->children
);
7604 spin_unlock_irqrestore(&task_group_lock
, flags
);
7607 /* rcu callback to free various structures associated with a task group */
7608 static void sched_free_group_rcu(struct rcu_head
*rhp
)
7610 /* now it should be safe to free those cfs_rqs */
7611 sched_free_group(container_of(rhp
, struct task_group
, rcu
));
7614 void sched_destroy_group(struct task_group
*tg
)
7616 /* wait for possible concurrent references to cfs_rqs complete */
7617 call_rcu(&tg
->rcu
, sched_free_group_rcu
);
7620 void sched_offline_group(struct task_group
*tg
)
7622 unsigned long flags
;
7624 /* end participation in shares distribution */
7625 unregister_fair_sched_group(tg
);
7627 spin_lock_irqsave(&task_group_lock
, flags
);
7628 list_del_rcu(&tg
->list
);
7629 list_del_rcu(&tg
->siblings
);
7630 spin_unlock_irqrestore(&task_group_lock
, flags
);
7633 /* change task's runqueue when it moves between groups.
7634 * The caller of this function should have put the task in its new group
7635 * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
7636 * reflect its new group.
7638 void sched_move_task(struct task_struct
*tsk
)
7640 struct task_group
*tg
;
7641 int queued
, running
;
7642 unsigned long flags
;
7645 rq
= task_rq_lock(tsk
, &flags
);
7647 running
= task_current(rq
, tsk
);
7648 queued
= task_on_rq_queued(tsk
);
7651 dequeue_task(rq
, tsk
, DEQUEUE_SAVE
| DEQUEUE_MOVE
);
7652 if (unlikely(running
))
7653 put_prev_task(rq
, tsk
);
7656 * All callers are synchronized by task_rq_lock(); we do not use RCU
7657 * which is pointless here. Thus, we pass "true" to task_css_check()
7658 * to prevent lockdep warnings.
7660 tg
= container_of(task_css_check(tsk
, cpu_cgrp_id
, true),
7661 struct task_group
, css
);
7662 tg
= autogroup_task_group(tsk
, tg
);
7663 tsk
->sched_task_group
= tg
;
7665 #ifdef CONFIG_FAIR_GROUP_SCHED
7666 if (tsk
->sched_class
->task_move_group
)
7667 tsk
->sched_class
->task_move_group(tsk
);
7670 set_task_rq(tsk
, task_cpu(tsk
));
7672 if (unlikely(running
))
7673 tsk
->sched_class
->set_curr_task(rq
);
7675 enqueue_task(rq
, tsk
, ENQUEUE_RESTORE
| ENQUEUE_MOVE
);
7677 task_rq_unlock(rq
, tsk
, &flags
);
7679 #endif /* CONFIG_CGROUP_SCHED */
7681 #ifdef CONFIG_RT_GROUP_SCHED
7683 * Ensure that the real time constraints are schedulable.
7685 static DEFINE_MUTEX(rt_constraints_mutex
);
7687 /* Must be called with tasklist_lock held */
7688 static inline int tg_has_rt_tasks(struct task_group
*tg
)
7690 struct task_struct
*g
, *p
;
7693 * Autogroups do not have RT tasks; see autogroup_create().
7695 if (task_group_is_autogroup(tg
))
7698 for_each_process_thread(g
, p
) {
7699 if (rt_task(p
) && task_group(p
) == tg
)
7706 struct rt_schedulable_data
{
7707 struct task_group
*tg
;
7712 static int tg_rt_schedulable(struct task_group
*tg
, void *data
)
7714 struct rt_schedulable_data
*d
= data
;
7715 struct task_group
*child
;
7716 unsigned long total
, sum
= 0;
7717 u64 period
, runtime
;
7719 period
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7720 runtime
= tg
->rt_bandwidth
.rt_runtime
;
7723 period
= d
->rt_period
;
7724 runtime
= d
->rt_runtime
;
7728 * Cannot have more runtime than the period.
7730 if (runtime
> period
&& runtime
!= RUNTIME_INF
)
7734 * Ensure we don't starve existing RT tasks.
7736 if (rt_bandwidth_enabled() && !runtime
&& tg_has_rt_tasks(tg
))
7739 total
= to_ratio(period
, runtime
);
7742 * Nobody can have more than the global setting allows.
7744 if (total
> to_ratio(global_rt_period(), global_rt_runtime()))
7748 * The sum of our children's runtime should not exceed our own.
7750 list_for_each_entry_rcu(child
, &tg
->children
, siblings
) {
7751 period
= ktime_to_ns(child
->rt_bandwidth
.rt_period
);
7752 runtime
= child
->rt_bandwidth
.rt_runtime
;
7754 if (child
== d
->tg
) {
7755 period
= d
->rt_period
;
7756 runtime
= d
->rt_runtime
;
7759 sum
+= to_ratio(period
, runtime
);
7768 static int __rt_schedulable(struct task_group
*tg
, u64 period
, u64 runtime
)
7772 struct rt_schedulable_data data
= {
7774 .rt_period
= period
,
7775 .rt_runtime
= runtime
,
7779 ret
= walk_tg_tree(tg_rt_schedulable
, tg_nop
, &data
);
7785 static int tg_set_rt_bandwidth(struct task_group
*tg
,
7786 u64 rt_period
, u64 rt_runtime
)
7791 * Disallowing the root group RT runtime is BAD, it would disallow the
7792 * kernel creating (and or operating) RT threads.
7794 if (tg
== &root_task_group
&& rt_runtime
== 0)
7797 /* No period doesn't make any sense. */
7801 mutex_lock(&rt_constraints_mutex
);
7802 read_lock(&tasklist_lock
);
7803 err
= __rt_schedulable(tg
, rt_period
, rt_runtime
);
7807 raw_spin_lock_irq(&tg
->rt_bandwidth
.rt_runtime_lock
);
7808 tg
->rt_bandwidth
.rt_period
= ns_to_ktime(rt_period
);
7809 tg
->rt_bandwidth
.rt_runtime
= rt_runtime
;
7811 for_each_possible_cpu(i
) {
7812 struct rt_rq
*rt_rq
= tg
->rt_rq
[i
];
7814 raw_spin_lock(&rt_rq
->rt_runtime_lock
);
7815 rt_rq
->rt_runtime
= rt_runtime
;
7816 raw_spin_unlock(&rt_rq
->rt_runtime_lock
);
7818 raw_spin_unlock_irq(&tg
->rt_bandwidth
.rt_runtime_lock
);
7820 read_unlock(&tasklist_lock
);
7821 mutex_unlock(&rt_constraints_mutex
);
7826 static int sched_group_set_rt_runtime(struct task_group
*tg
, long rt_runtime_us
)
7828 u64 rt_runtime
, rt_period
;
7830 rt_period
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7831 rt_runtime
= (u64
)rt_runtime_us
* NSEC_PER_USEC
;
7832 if (rt_runtime_us
< 0)
7833 rt_runtime
= RUNTIME_INF
;
7835 return tg_set_rt_bandwidth(tg
, rt_period
, rt_runtime
);
7838 static long sched_group_rt_runtime(struct task_group
*tg
)
7842 if (tg
->rt_bandwidth
.rt_runtime
== RUNTIME_INF
)
7845 rt_runtime_us
= tg
->rt_bandwidth
.rt_runtime
;
7846 do_div(rt_runtime_us
, NSEC_PER_USEC
);
7847 return rt_runtime_us
;
7850 static int sched_group_set_rt_period(struct task_group
*tg
, u64 rt_period_us
)
7852 u64 rt_runtime
, rt_period
;
7854 rt_period
= rt_period_us
* NSEC_PER_USEC
;
7855 rt_runtime
= tg
->rt_bandwidth
.rt_runtime
;
7857 return tg_set_rt_bandwidth(tg
, rt_period
, rt_runtime
);
7860 static long sched_group_rt_period(struct task_group
*tg
)
7864 rt_period_us
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7865 do_div(rt_period_us
, NSEC_PER_USEC
);
7866 return rt_period_us
;
7868 #endif /* CONFIG_RT_GROUP_SCHED */
7870 #ifdef CONFIG_RT_GROUP_SCHED
7871 static int sched_rt_global_constraints(void)
7875 mutex_lock(&rt_constraints_mutex
);
7876 read_lock(&tasklist_lock
);
7877 ret
= __rt_schedulable(NULL
, 0, 0);
7878 read_unlock(&tasklist_lock
);
7879 mutex_unlock(&rt_constraints_mutex
);
7884 static int sched_rt_can_attach(struct task_group
*tg
, struct task_struct
*tsk
)
7886 /* Don't accept realtime tasks when there is no way for them to run */
7887 if (rt_task(tsk
) && tg
->rt_bandwidth
.rt_runtime
== 0)
7893 #else /* !CONFIG_RT_GROUP_SCHED */
7894 static int sched_rt_global_constraints(void)
7896 unsigned long flags
;
7899 raw_spin_lock_irqsave(&def_rt_bandwidth
.rt_runtime_lock
, flags
);
7900 for_each_possible_cpu(i
) {
7901 struct rt_rq
*rt_rq
= &cpu_rq(i
)->rt
;
7903 raw_spin_lock(&rt_rq
->rt_runtime_lock
);
7904 rt_rq
->rt_runtime
= global_rt_runtime();
7905 raw_spin_unlock(&rt_rq
->rt_runtime_lock
);
7907 raw_spin_unlock_irqrestore(&def_rt_bandwidth
.rt_runtime_lock
, flags
);
7911 #endif /* CONFIG_RT_GROUP_SCHED */
7913 static int sched_dl_global_validate(void)
7915 u64 runtime
= global_rt_runtime();
7916 u64 period
= global_rt_period();
7917 u64 new_bw
= to_ratio(period
, runtime
);
7920 unsigned long flags
;
7923 * Here we want to check the bandwidth not being set to some
7924 * value smaller than the currently allocated bandwidth in
7925 * any of the root_domains.
7927 * FIXME: Cycling on all the CPUs is overdoing, but simpler than
7928 * cycling on root_domains... Discussion on different/better
7929 * solutions is welcome!
7931 for_each_possible_cpu(cpu
) {
7932 rcu_read_lock_sched();
7933 dl_b
= dl_bw_of(cpu
);
7935 raw_spin_lock_irqsave(&dl_b
->lock
, flags
);
7936 if (new_bw
< dl_b
->total_bw
)
7938 raw_spin_unlock_irqrestore(&dl_b
->lock
, flags
);
7940 rcu_read_unlock_sched();
7949 static void sched_dl_do_global(void)
7954 unsigned long flags
;
7956 def_dl_bandwidth
.dl_period
= global_rt_period();
7957 def_dl_bandwidth
.dl_runtime
= global_rt_runtime();
7959 if (global_rt_runtime() != RUNTIME_INF
)
7960 new_bw
= to_ratio(global_rt_period(), global_rt_runtime());
7963 * FIXME: As above...
7965 for_each_possible_cpu(cpu
) {
7966 rcu_read_lock_sched();
7967 dl_b
= dl_bw_of(cpu
);
7969 raw_spin_lock_irqsave(&dl_b
->lock
, flags
);
7971 raw_spin_unlock_irqrestore(&dl_b
->lock
, flags
);
7973 rcu_read_unlock_sched();
7977 static int sched_rt_global_validate(void)
7979 if (sysctl_sched_rt_period
<= 0)
7982 if ((sysctl_sched_rt_runtime
!= RUNTIME_INF
) &&
7983 (sysctl_sched_rt_runtime
> sysctl_sched_rt_period
))
7989 static void sched_rt_do_global(void)
7991 def_rt_bandwidth
.rt_runtime
= global_rt_runtime();
7992 def_rt_bandwidth
.rt_period
= ns_to_ktime(global_rt_period());
7995 int sched_rt_handler(struct ctl_table
*table
, int write
,
7996 void __user
*buffer
, size_t *lenp
,
7999 int old_period
, old_runtime
;
8000 static DEFINE_MUTEX(mutex
);
8004 old_period
= sysctl_sched_rt_period
;
8005 old_runtime
= sysctl_sched_rt_runtime
;
8007 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
8009 if (!ret
&& write
) {
8010 ret
= sched_rt_global_validate();
8014 ret
= sched_dl_global_validate();
8018 ret
= sched_rt_global_constraints();
8022 sched_rt_do_global();
8023 sched_dl_do_global();
8027 sysctl_sched_rt_period
= old_period
;
8028 sysctl_sched_rt_runtime
= old_runtime
;
8030 mutex_unlock(&mutex
);
8035 int sched_rr_handler(struct ctl_table
*table
, int write
,
8036 void __user
*buffer
, size_t *lenp
,
8040 static DEFINE_MUTEX(mutex
);
8043 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
8044 /* make sure that internally we keep jiffies */
8045 /* also, writing zero resets timeslice to default */
8046 if (!ret
&& write
) {
8047 sched_rr_timeslice
= sched_rr_timeslice
<= 0 ?
8048 RR_TIMESLICE
: msecs_to_jiffies(sched_rr_timeslice
);
8050 mutex_unlock(&mutex
);
8054 #ifdef CONFIG_CGROUP_SCHED
8056 static inline struct task_group
*css_tg(struct cgroup_subsys_state
*css
)
8058 return css
? container_of(css
, struct task_group
, css
) : NULL
;
8061 static struct cgroup_subsys_state
*
8062 cpu_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
8064 struct task_group
*parent
= css_tg(parent_css
);
8065 struct task_group
*tg
;
8068 /* This is early initialization for the top cgroup */
8069 return &root_task_group
.css
;
8072 tg
= sched_create_group(parent
);
8074 return ERR_PTR(-ENOMEM
);
8076 sched_online_group(tg
, parent
);
8081 static void cpu_cgroup_css_released(struct cgroup_subsys_state
*css
)
8083 struct task_group
*tg
= css_tg(css
);
8085 sched_offline_group(tg
);
8088 static void cpu_cgroup_css_free(struct cgroup_subsys_state
*css
)
8090 struct task_group
*tg
= css_tg(css
);
8093 * Relies on the RCU grace period between css_released() and this.
8095 sched_free_group(tg
);
8098 static void cpu_cgroup_fork(struct task_struct
*task
)
8100 sched_move_task(task
);
8103 static int cpu_cgroup_can_attach(struct cgroup_taskset
*tset
)
8105 struct task_struct
*task
;
8106 struct cgroup_subsys_state
*css
;
8108 cgroup_taskset_for_each(task
, css
, tset
) {
8109 #ifdef CONFIG_RT_GROUP_SCHED
8110 if (!sched_rt_can_attach(css_tg(css
), task
))
8113 /* We don't support RT-tasks being in separate groups */
8114 if (task
->sched_class
!= &fair_sched_class
)
8121 static void cpu_cgroup_attach(struct cgroup_taskset
*tset
)
8123 struct task_struct
*task
;
8124 struct cgroup_subsys_state
*css
;
8126 cgroup_taskset_for_each(task
, css
, tset
)
8127 sched_move_task(task
);
8130 #ifdef CONFIG_FAIR_GROUP_SCHED
8131 static int cpu_shares_write_u64(struct cgroup_subsys_state
*css
,
8132 struct cftype
*cftype
, u64 shareval
)
8134 return sched_group_set_shares(css_tg(css
), scale_load(shareval
));
8137 static u64
cpu_shares_read_u64(struct cgroup_subsys_state
*css
,
8140 struct task_group
*tg
= css_tg(css
);
8142 return (u64
) scale_load_down(tg
->shares
);
8145 #ifdef CONFIG_CFS_BANDWIDTH
8146 static DEFINE_MUTEX(cfs_constraints_mutex
);
8148 const u64 max_cfs_quota_period
= 1 * NSEC_PER_SEC
; /* 1s */
8149 const u64 min_cfs_quota_period
= 1 * NSEC_PER_MSEC
; /* 1ms */
8151 static int __cfs_schedulable(struct task_group
*tg
, u64 period
, u64 runtime
);
8153 static int tg_set_cfs_bandwidth(struct task_group
*tg
, u64 period
, u64 quota
)
8155 int i
, ret
= 0, runtime_enabled
, runtime_was_enabled
;
8156 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8158 if (tg
== &root_task_group
)
8162 * Ensure we have at some amount of bandwidth every period. This is
8163 * to prevent reaching a state of large arrears when throttled via
8164 * entity_tick() resulting in prolonged exit starvation.
8166 if (quota
< min_cfs_quota_period
|| period
< min_cfs_quota_period
)
8170 * Likewise, bound things on the otherside by preventing insane quota
8171 * periods. This also allows us to normalize in computing quota
8174 if (period
> max_cfs_quota_period
)
8178 * Prevent race between setting of cfs_rq->runtime_enabled and
8179 * unthrottle_offline_cfs_rqs().
8182 mutex_lock(&cfs_constraints_mutex
);
8183 ret
= __cfs_schedulable(tg
, period
, quota
);
8187 runtime_enabled
= quota
!= RUNTIME_INF
;
8188 runtime_was_enabled
= cfs_b
->quota
!= RUNTIME_INF
;
8190 * If we need to toggle cfs_bandwidth_used, off->on must occur
8191 * before making related changes, and on->off must occur afterwards
8193 if (runtime_enabled
&& !runtime_was_enabled
)
8194 cfs_bandwidth_usage_inc();
8195 raw_spin_lock_irq(&cfs_b
->lock
);
8196 cfs_b
->period
= ns_to_ktime(period
);
8197 cfs_b
->quota
= quota
;
8199 __refill_cfs_bandwidth_runtime(cfs_b
);
8200 /* restart the period timer (if active) to handle new period expiry */
8201 if (runtime_enabled
)
8202 start_cfs_bandwidth(cfs_b
);
8203 raw_spin_unlock_irq(&cfs_b
->lock
);
8205 for_each_online_cpu(i
) {
8206 struct cfs_rq
*cfs_rq
= tg
->cfs_rq
[i
];
8207 struct rq
*rq
= cfs_rq
->rq
;
8209 raw_spin_lock_irq(&rq
->lock
);
8210 cfs_rq
->runtime_enabled
= runtime_enabled
;
8211 cfs_rq
->runtime_remaining
= 0;
8213 if (cfs_rq
->throttled
)
8214 unthrottle_cfs_rq(cfs_rq
);
8215 raw_spin_unlock_irq(&rq
->lock
);
8217 if (runtime_was_enabled
&& !runtime_enabled
)
8218 cfs_bandwidth_usage_dec();
8220 mutex_unlock(&cfs_constraints_mutex
);
8226 int tg_set_cfs_quota(struct task_group
*tg
, long cfs_quota_us
)
8230 period
= ktime_to_ns(tg
->cfs_bandwidth
.period
);
8231 if (cfs_quota_us
< 0)
8232 quota
= RUNTIME_INF
;
8234 quota
= (u64
)cfs_quota_us
* NSEC_PER_USEC
;
8236 return tg_set_cfs_bandwidth(tg
, period
, quota
);
8239 long tg_get_cfs_quota(struct task_group
*tg
)
8243 if (tg
->cfs_bandwidth
.quota
== RUNTIME_INF
)
8246 quota_us
= tg
->cfs_bandwidth
.quota
;
8247 do_div(quota_us
, NSEC_PER_USEC
);
8252 int tg_set_cfs_period(struct task_group
*tg
, long cfs_period_us
)
8256 period
= (u64
)cfs_period_us
* NSEC_PER_USEC
;
8257 quota
= tg
->cfs_bandwidth
.quota
;
8259 return tg_set_cfs_bandwidth(tg
, period
, quota
);
8262 long tg_get_cfs_period(struct task_group
*tg
)
8266 cfs_period_us
= ktime_to_ns(tg
->cfs_bandwidth
.period
);
8267 do_div(cfs_period_us
, NSEC_PER_USEC
);
8269 return cfs_period_us
;
8272 static s64
cpu_cfs_quota_read_s64(struct cgroup_subsys_state
*css
,
8275 return tg_get_cfs_quota(css_tg(css
));
8278 static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state
*css
,
8279 struct cftype
*cftype
, s64 cfs_quota_us
)
8281 return tg_set_cfs_quota(css_tg(css
), cfs_quota_us
);
8284 static u64
cpu_cfs_period_read_u64(struct cgroup_subsys_state
*css
,
8287 return tg_get_cfs_period(css_tg(css
));
8290 static int cpu_cfs_period_write_u64(struct cgroup_subsys_state
*css
,
8291 struct cftype
*cftype
, u64 cfs_period_us
)
8293 return tg_set_cfs_period(css_tg(css
), cfs_period_us
);
8296 struct cfs_schedulable_data
{
8297 struct task_group
*tg
;
8302 * normalize group quota/period to be quota/max_period
8303 * note: units are usecs
8305 static u64
normalize_cfs_quota(struct task_group
*tg
,
8306 struct cfs_schedulable_data
*d
)
8314 period
= tg_get_cfs_period(tg
);
8315 quota
= tg_get_cfs_quota(tg
);
8318 /* note: these should typically be equivalent */
8319 if (quota
== RUNTIME_INF
|| quota
== -1)
8322 return to_ratio(period
, quota
);
8325 static int tg_cfs_schedulable_down(struct task_group
*tg
, void *data
)
8327 struct cfs_schedulable_data
*d
= data
;
8328 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8329 s64 quota
= 0, parent_quota
= -1;
8332 quota
= RUNTIME_INF
;
8334 struct cfs_bandwidth
*parent_b
= &tg
->parent
->cfs_bandwidth
;
8336 quota
= normalize_cfs_quota(tg
, d
);
8337 parent_quota
= parent_b
->hierarchical_quota
;
8340 * ensure max(child_quota) <= parent_quota, inherit when no
8343 if (quota
== RUNTIME_INF
)
8344 quota
= parent_quota
;
8345 else if (parent_quota
!= RUNTIME_INF
&& quota
> parent_quota
)
8348 cfs_b
->hierarchical_quota
= quota
;
8353 static int __cfs_schedulable(struct task_group
*tg
, u64 period
, u64 quota
)
8356 struct cfs_schedulable_data data
= {
8362 if (quota
!= RUNTIME_INF
) {
8363 do_div(data
.period
, NSEC_PER_USEC
);
8364 do_div(data
.quota
, NSEC_PER_USEC
);
8368 ret
= walk_tg_tree(tg_cfs_schedulable_down
, tg_nop
, &data
);
8374 static int cpu_stats_show(struct seq_file
*sf
, void *v
)
8376 struct task_group
*tg
= css_tg(seq_css(sf
));
8377 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8379 seq_printf(sf
, "nr_periods %d\n", cfs_b
->nr_periods
);
8380 seq_printf(sf
, "nr_throttled %d\n", cfs_b
->nr_throttled
);
8381 seq_printf(sf
, "throttled_time %llu\n", cfs_b
->throttled_time
);
8385 #endif /* CONFIG_CFS_BANDWIDTH */
8386 #endif /* CONFIG_FAIR_GROUP_SCHED */
8388 #ifdef CONFIG_RT_GROUP_SCHED
8389 static int cpu_rt_runtime_write(struct cgroup_subsys_state
*css
,
8390 struct cftype
*cft
, s64 val
)
8392 return sched_group_set_rt_runtime(css_tg(css
), val
);
8395 static s64
cpu_rt_runtime_read(struct cgroup_subsys_state
*css
,
8398 return sched_group_rt_runtime(css_tg(css
));
8401 static int cpu_rt_period_write_uint(struct cgroup_subsys_state
*css
,
8402 struct cftype
*cftype
, u64 rt_period_us
)
8404 return sched_group_set_rt_period(css_tg(css
), rt_period_us
);
8407 static u64
cpu_rt_period_read_uint(struct cgroup_subsys_state
*css
,
8410 return sched_group_rt_period(css_tg(css
));
8412 #endif /* CONFIG_RT_GROUP_SCHED */
8414 static struct cftype cpu_files
[] = {
8415 #ifdef CONFIG_FAIR_GROUP_SCHED
8418 .read_u64
= cpu_shares_read_u64
,
8419 .write_u64
= cpu_shares_write_u64
,
8422 #ifdef CONFIG_CFS_BANDWIDTH
8424 .name
= "cfs_quota_us",
8425 .read_s64
= cpu_cfs_quota_read_s64
,
8426 .write_s64
= cpu_cfs_quota_write_s64
,
8429 .name
= "cfs_period_us",
8430 .read_u64
= cpu_cfs_period_read_u64
,
8431 .write_u64
= cpu_cfs_period_write_u64
,
8435 .seq_show
= cpu_stats_show
,
8438 #ifdef CONFIG_RT_GROUP_SCHED
8440 .name
= "rt_runtime_us",
8441 .read_s64
= cpu_rt_runtime_read
,
8442 .write_s64
= cpu_rt_runtime_write
,
8445 .name
= "rt_period_us",
8446 .read_u64
= cpu_rt_period_read_uint
,
8447 .write_u64
= cpu_rt_period_write_uint
,
8453 struct cgroup_subsys cpu_cgrp_subsys
= {
8454 .css_alloc
= cpu_cgroup_css_alloc
,
8455 .css_released
= cpu_cgroup_css_released
,
8456 .css_free
= cpu_cgroup_css_free
,
8457 .fork
= cpu_cgroup_fork
,
8458 .can_attach
= cpu_cgroup_can_attach
,
8459 .attach
= cpu_cgroup_attach
,
8460 .legacy_cftypes
= cpu_files
,
8464 #endif /* CONFIG_CGROUP_SCHED */
8466 void dump_cpu_task(int cpu
)
8468 pr_info("Task dump for CPU %d:\n", cpu
);
8469 sched_show_task(cpu_curr(cpu
));
8473 * Nice levels are multiplicative, with a gentle 10% change for every
8474 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
8475 * nice 1, it will get ~10% less CPU time than another CPU-bound task
8476 * that remained on nice 0.
8478 * The "10% effect" is relative and cumulative: from _any_ nice level,
8479 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
8480 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
8481 * If a task goes up by ~10% and another task goes down by ~10% then
8482 * the relative distance between them is ~25%.)
8484 const int sched_prio_to_weight
[40] = {
8485 /* -20 */ 88761, 71755, 56483, 46273, 36291,
8486 /* -15 */ 29154, 23254, 18705, 14949, 11916,
8487 /* -10 */ 9548, 7620, 6100, 4904, 3906,
8488 /* -5 */ 3121, 2501, 1991, 1586, 1277,
8489 /* 0 */ 1024, 820, 655, 526, 423,
8490 /* 5 */ 335, 272, 215, 172, 137,
8491 /* 10 */ 110, 87, 70, 56, 45,
8492 /* 15 */ 36, 29, 23, 18, 15,
8496 * Inverse (2^32/x) values of the sched_prio_to_weight[] array, precalculated.
8498 * In cases where the weight does not change often, we can use the
8499 * precalculated inverse to speed up arithmetics by turning divisions
8500 * into multiplications:
8502 const u32 sched_prio_to_wmult
[40] = {
8503 /* -20 */ 48388, 59856, 76040, 92818, 118348,
8504 /* -15 */ 147320, 184698, 229616, 287308, 360437,
8505 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
8506 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
8507 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
8508 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
8509 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
8510 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,