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
30 #include <linux/module.h>
31 #include <linux/nmi.h>
32 #include <linux/init.h>
33 #include <linux/uaccess.h>
34 #include <linux/highmem.h>
35 #include <asm/mmu_context.h>
36 #include <linux/interrupt.h>
37 #include <linux/capability.h>
38 #include <linux/completion.h>
39 #include <linux/kernel_stat.h>
40 #include <linux/debug_locks.h>
41 #include <linux/perf_event.h>
42 #include <linux/security.h>
43 #include <linux/notifier.h>
44 #include <linux/profile.h>
45 #include <linux/freezer.h>
46 #include <linux/vmalloc.h>
47 #include <linux/blkdev.h>
48 #include <linux/delay.h>
49 #include <linux/pid_namespace.h>
50 #include <linux/smp.h>
51 #include <linux/threads.h>
52 #include <linux/timer.h>
53 #include <linux/rcupdate.h>
54 #include <linux/cpu.h>
55 #include <linux/cpuset.h>
56 #include <linux/percpu.h>
57 #include <linux/proc_fs.h>
58 #include <linux/seq_file.h>
59 #include <linux/sysctl.h>
60 #include <linux/syscalls.h>
61 #include <linux/times.h>
62 #include <linux/tsacct_kern.h>
63 #include <linux/kprobes.h>
64 #include <linux/delayacct.h>
65 #include <linux/unistd.h>
66 #include <linux/pagemap.h>
67 #include <linux/hrtimer.h>
68 #include <linux/tick.h>
69 #include <linux/debugfs.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/binfmts.h>
76 #include <asm/switch_to.h>
78 #include <asm/irq_regs.h>
79 #include <asm/mutex.h>
80 #ifdef CONFIG_PARAVIRT
81 #include <asm/paravirt.h>
85 #include "../workqueue_sched.h"
86 #include "../smpboot.h"
88 #define CREATE_TRACE_POINTS
89 #include <trace/events/sched.h>
91 void start_bandwidth_timer(struct hrtimer
*period_timer
, ktime_t period
)
94 ktime_t soft
, hard
, now
;
97 if (hrtimer_active(period_timer
))
100 now
= hrtimer_cb_get_time(period_timer
);
101 hrtimer_forward(period_timer
, now
, period
);
103 soft
= hrtimer_get_softexpires(period_timer
);
104 hard
= hrtimer_get_expires(period_timer
);
105 delta
= ktime_to_ns(ktime_sub(hard
, soft
));
106 __hrtimer_start_range_ns(period_timer
, soft
, delta
,
107 HRTIMER_MODE_ABS_PINNED
, 0);
111 DEFINE_MUTEX(sched_domains_mutex
);
112 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq
, runqueues
);
114 static void update_rq_clock_task(struct rq
*rq
, s64 delta
);
116 void update_rq_clock(struct rq
*rq
)
120 if (rq
->skip_clock_update
> 0)
123 delta
= sched_clock_cpu(cpu_of(rq
)) - rq
->clock
;
125 update_rq_clock_task(rq
, delta
);
129 * Debugging: various feature bits
132 #define SCHED_FEAT(name, enabled) \
133 (1UL << __SCHED_FEAT_##name) * enabled |
135 const_debug
unsigned int sysctl_sched_features
=
136 #include "features.h"
141 #ifdef CONFIG_SCHED_DEBUG
142 #define SCHED_FEAT(name, enabled) \
145 static const char * const sched_feat_names
[] = {
146 #include "features.h"
151 static int sched_feat_show(struct seq_file
*m
, void *v
)
155 for (i
= 0; i
< __SCHED_FEAT_NR
; i
++) {
156 if (!(sysctl_sched_features
& (1UL << i
)))
158 seq_printf(m
, "%s ", sched_feat_names
[i
]);
165 #ifdef HAVE_JUMP_LABEL
167 #define jump_label_key__true STATIC_KEY_INIT_TRUE
168 #define jump_label_key__false STATIC_KEY_INIT_FALSE
170 #define SCHED_FEAT(name, enabled) \
171 jump_label_key__##enabled ,
173 struct static_key sched_feat_keys
[__SCHED_FEAT_NR
] = {
174 #include "features.h"
179 static void sched_feat_disable(int i
)
181 if (static_key_enabled(&sched_feat_keys
[i
]))
182 static_key_slow_dec(&sched_feat_keys
[i
]);
185 static void sched_feat_enable(int i
)
187 if (!static_key_enabled(&sched_feat_keys
[i
]))
188 static_key_slow_inc(&sched_feat_keys
[i
]);
191 static void sched_feat_disable(int i
) { };
192 static void sched_feat_enable(int i
) { };
193 #endif /* HAVE_JUMP_LABEL */
196 sched_feat_write(struct file
*filp
, const char __user
*ubuf
,
197 size_t cnt
, loff_t
*ppos
)
207 if (copy_from_user(&buf
, ubuf
, cnt
))
213 if (strncmp(cmp
, "NO_", 3) == 0) {
218 for (i
= 0; i
< __SCHED_FEAT_NR
; i
++) {
219 if (strcmp(cmp
, sched_feat_names
[i
]) == 0) {
221 sysctl_sched_features
&= ~(1UL << i
);
222 sched_feat_disable(i
);
224 sysctl_sched_features
|= (1UL << i
);
225 sched_feat_enable(i
);
231 if (i
== __SCHED_FEAT_NR
)
239 static int sched_feat_open(struct inode
*inode
, struct file
*filp
)
241 return single_open(filp
, sched_feat_show
, NULL
);
244 static const struct file_operations sched_feat_fops
= {
245 .open
= sched_feat_open
,
246 .write
= sched_feat_write
,
249 .release
= single_release
,
252 static __init
int sched_init_debug(void)
254 debugfs_create_file("sched_features", 0644, NULL
, NULL
,
259 late_initcall(sched_init_debug
);
260 #endif /* CONFIG_SCHED_DEBUG */
263 * Number of tasks to iterate in a single balance run.
264 * Limited because this is done with IRQs disabled.
266 const_debug
unsigned int sysctl_sched_nr_migrate
= 32;
269 * period over which we average the RT time consumption, measured
274 const_debug
unsigned int sysctl_sched_time_avg
= MSEC_PER_SEC
;
277 * period over which we measure -rt task cpu usage in us.
280 unsigned int sysctl_sched_rt_period
= 1000000;
282 __read_mostly
int scheduler_running
;
285 * part of the period that we allow rt tasks to run in us.
288 int sysctl_sched_rt_runtime
= 950000;
293 * __task_rq_lock - lock the rq @p resides on.
295 static inline struct rq
*__task_rq_lock(struct task_struct
*p
)
300 lockdep_assert_held(&p
->pi_lock
);
304 raw_spin_lock(&rq
->lock
);
305 if (likely(rq
== task_rq(p
)))
307 raw_spin_unlock(&rq
->lock
);
312 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
314 static struct rq
*task_rq_lock(struct task_struct
*p
, unsigned long *flags
)
315 __acquires(p
->pi_lock
)
321 raw_spin_lock_irqsave(&p
->pi_lock
, *flags
);
323 raw_spin_lock(&rq
->lock
);
324 if (likely(rq
== task_rq(p
)))
326 raw_spin_unlock(&rq
->lock
);
327 raw_spin_unlock_irqrestore(&p
->pi_lock
, *flags
);
331 static void __task_rq_unlock(struct rq
*rq
)
334 raw_spin_unlock(&rq
->lock
);
338 task_rq_unlock(struct rq
*rq
, struct task_struct
*p
, unsigned long *flags
)
340 __releases(p
->pi_lock
)
342 raw_spin_unlock(&rq
->lock
);
343 raw_spin_unlock_irqrestore(&p
->pi_lock
, *flags
);
347 * this_rq_lock - lock this runqueue and disable interrupts.
349 static struct rq
*this_rq_lock(void)
356 raw_spin_lock(&rq
->lock
);
361 #ifdef CONFIG_SCHED_HRTICK
363 * Use HR-timers to deliver accurate preemption points.
365 * Its all a bit involved since we cannot program an hrt while holding the
366 * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
369 * When we get rescheduled we reprogram the hrtick_timer outside of the
373 static void hrtick_clear(struct rq
*rq
)
375 if (hrtimer_active(&rq
->hrtick_timer
))
376 hrtimer_cancel(&rq
->hrtick_timer
);
380 * High-resolution timer tick.
381 * Runs from hardirq context with interrupts disabled.
383 static enum hrtimer_restart
hrtick(struct hrtimer
*timer
)
385 struct rq
*rq
= container_of(timer
, struct rq
, hrtick_timer
);
387 WARN_ON_ONCE(cpu_of(rq
) != smp_processor_id());
389 raw_spin_lock(&rq
->lock
);
391 rq
->curr
->sched_class
->task_tick(rq
, rq
->curr
, 1);
392 raw_spin_unlock(&rq
->lock
);
394 return HRTIMER_NORESTART
;
399 * called from hardirq (IPI) context
401 static void __hrtick_start(void *arg
)
405 raw_spin_lock(&rq
->lock
);
406 hrtimer_restart(&rq
->hrtick_timer
);
407 rq
->hrtick_csd_pending
= 0;
408 raw_spin_unlock(&rq
->lock
);
412 * Called to set the hrtick timer state.
414 * called with rq->lock held and irqs disabled
416 void hrtick_start(struct rq
*rq
, u64 delay
)
418 struct hrtimer
*timer
= &rq
->hrtick_timer
;
419 ktime_t time
= ktime_add_ns(timer
->base
->get_time(), delay
);
421 hrtimer_set_expires(timer
, time
);
423 if (rq
== this_rq()) {
424 hrtimer_restart(timer
);
425 } else if (!rq
->hrtick_csd_pending
) {
426 __smp_call_function_single(cpu_of(rq
), &rq
->hrtick_csd
, 0);
427 rq
->hrtick_csd_pending
= 1;
432 hotplug_hrtick(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
)
434 int cpu
= (int)(long)hcpu
;
437 case CPU_UP_CANCELED
:
438 case CPU_UP_CANCELED_FROZEN
:
439 case CPU_DOWN_PREPARE
:
440 case CPU_DOWN_PREPARE_FROZEN
:
442 case CPU_DEAD_FROZEN
:
443 hrtick_clear(cpu_rq(cpu
));
450 static __init
void init_hrtick(void)
452 hotcpu_notifier(hotplug_hrtick
, 0);
456 * Called to set the hrtick timer state.
458 * called with rq->lock held and irqs disabled
460 void hrtick_start(struct rq
*rq
, u64 delay
)
462 __hrtimer_start_range_ns(&rq
->hrtick_timer
, ns_to_ktime(delay
), 0,
463 HRTIMER_MODE_REL_PINNED
, 0);
466 static inline void init_hrtick(void)
469 #endif /* CONFIG_SMP */
471 static void init_rq_hrtick(struct rq
*rq
)
474 rq
->hrtick_csd_pending
= 0;
476 rq
->hrtick_csd
.flags
= 0;
477 rq
->hrtick_csd
.func
= __hrtick_start
;
478 rq
->hrtick_csd
.info
= rq
;
481 hrtimer_init(&rq
->hrtick_timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
482 rq
->hrtick_timer
.function
= hrtick
;
484 #else /* CONFIG_SCHED_HRTICK */
485 static inline void hrtick_clear(struct rq
*rq
)
489 static inline void init_rq_hrtick(struct rq
*rq
)
493 static inline void init_hrtick(void)
496 #endif /* CONFIG_SCHED_HRTICK */
499 * resched_task - mark a task 'to be rescheduled now'.
501 * On UP this means the setting of the need_resched flag, on SMP it
502 * might also involve a cross-CPU call to trigger the scheduler on
507 #ifndef tsk_is_polling
508 #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
511 void resched_task(struct task_struct
*p
)
515 assert_raw_spin_locked(&task_rq(p
)->lock
);
517 if (test_tsk_need_resched(p
))
520 set_tsk_need_resched(p
);
523 if (cpu
== smp_processor_id())
526 /* NEED_RESCHED must be visible before we test polling */
528 if (!tsk_is_polling(p
))
529 smp_send_reschedule(cpu
);
532 void resched_cpu(int cpu
)
534 struct rq
*rq
= cpu_rq(cpu
);
537 if (!raw_spin_trylock_irqsave(&rq
->lock
, flags
))
539 resched_task(cpu_curr(cpu
));
540 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
545 * In the semi idle case, use the nearest busy cpu for migrating timers
546 * from an idle cpu. This is good for power-savings.
548 * We don't do similar optimization for completely idle system, as
549 * selecting an idle cpu will add more delays to the timers than intended
550 * (as that cpu's timer base may not be uptodate wrt jiffies etc).
552 int get_nohz_timer_target(void)
554 int cpu
= smp_processor_id();
556 struct sched_domain
*sd
;
559 for_each_domain(cpu
, sd
) {
560 for_each_cpu(i
, sched_domain_span(sd
)) {
572 * When add_timer_on() enqueues a timer into the timer wheel of an
573 * idle CPU then this timer might expire before the next timer event
574 * which is scheduled to wake up that CPU. In case of a completely
575 * idle system the next event might even be infinite time into the
576 * future. wake_up_idle_cpu() ensures that the CPU is woken up and
577 * leaves the inner idle loop so the newly added timer is taken into
578 * account when the CPU goes back to idle and evaluates the timer
579 * wheel for the next timer event.
581 void wake_up_idle_cpu(int cpu
)
583 struct rq
*rq
= cpu_rq(cpu
);
585 if (cpu
== smp_processor_id())
589 * This is safe, as this function is called with the timer
590 * wheel base lock of (cpu) held. When the CPU is on the way
591 * to idle and has not yet set rq->curr to idle then it will
592 * be serialized on the timer wheel base lock and take the new
593 * timer into account automatically.
595 if (rq
->curr
!= rq
->idle
)
599 * We can set TIF_RESCHED on the idle task of the other CPU
600 * lockless. The worst case is that the other CPU runs the
601 * idle task through an additional NOOP schedule()
603 set_tsk_need_resched(rq
->idle
);
605 /* NEED_RESCHED must be visible before we test polling */
607 if (!tsk_is_polling(rq
->idle
))
608 smp_send_reschedule(cpu
);
611 static inline bool got_nohz_idle_kick(void)
613 int cpu
= smp_processor_id();
614 return idle_cpu(cpu
) && test_bit(NOHZ_BALANCE_KICK
, nohz_flags(cpu
));
617 #else /* CONFIG_NO_HZ */
619 static inline bool got_nohz_idle_kick(void)
624 #endif /* CONFIG_NO_HZ */
626 void sched_avg_update(struct rq
*rq
)
628 s64 period
= sched_avg_period();
630 while ((s64
)(rq
->clock
- rq
->age_stamp
) > period
) {
632 * Inline assembly required to prevent the compiler
633 * optimising this loop into a divmod call.
634 * See __iter_div_u64_rem() for another example of this.
636 asm("" : "+rm" (rq
->age_stamp
));
637 rq
->age_stamp
+= period
;
642 #else /* !CONFIG_SMP */
643 void resched_task(struct task_struct
*p
)
645 assert_raw_spin_locked(&task_rq(p
)->lock
);
646 set_tsk_need_resched(p
);
648 #endif /* CONFIG_SMP */
650 #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
651 (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
653 * Iterate task_group tree rooted at *from, calling @down when first entering a
654 * node and @up when leaving it for the final time.
656 * Caller must hold rcu_lock or sufficient equivalent.
658 int walk_tg_tree_from(struct task_group
*from
,
659 tg_visitor down
, tg_visitor up
, void *data
)
661 struct task_group
*parent
, *child
;
667 ret
= (*down
)(parent
, data
);
670 list_for_each_entry_rcu(child
, &parent
->children
, siblings
) {
677 ret
= (*up
)(parent
, data
);
678 if (ret
|| parent
== from
)
682 parent
= parent
->parent
;
689 int tg_nop(struct task_group
*tg
, void *data
)
695 static void set_load_weight(struct task_struct
*p
)
697 int prio
= p
->static_prio
- MAX_RT_PRIO
;
698 struct load_weight
*load
= &p
->se
.load
;
701 * SCHED_IDLE tasks get minimal weight:
703 if (p
->policy
== SCHED_IDLE
) {
704 load
->weight
= scale_load(WEIGHT_IDLEPRIO
);
705 load
->inv_weight
= WMULT_IDLEPRIO
;
709 load
->weight
= scale_load(prio_to_weight
[prio
]);
710 load
->inv_weight
= prio_to_wmult
[prio
];
713 static void enqueue_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
716 sched_info_queued(p
);
717 p
->sched_class
->enqueue_task(rq
, p
, flags
);
720 static void dequeue_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
723 sched_info_dequeued(p
);
724 p
->sched_class
->dequeue_task(rq
, p
, flags
);
727 void activate_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
729 if (task_contributes_to_load(p
))
730 rq
->nr_uninterruptible
--;
732 enqueue_task(rq
, p
, flags
);
735 void deactivate_task(struct rq
*rq
, struct task_struct
*p
, int flags
)
737 if (task_contributes_to_load(p
))
738 rq
->nr_uninterruptible
++;
740 dequeue_task(rq
, p
, flags
);
743 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
746 * There are no locks covering percpu hardirq/softirq time.
747 * They are only modified in account_system_vtime, on corresponding CPU
748 * with interrupts disabled. So, writes are safe.
749 * They are read and saved off onto struct rq in update_rq_clock().
750 * This may result in other CPU reading this CPU's irq time and can
751 * race with irq/account_system_vtime on this CPU. We would either get old
752 * or new value with a side effect of accounting a slice of irq time to wrong
753 * task when irq is in progress while we read rq->clock. That is a worthy
754 * compromise in place of having locks on each irq in account_system_time.
756 static DEFINE_PER_CPU(u64
, cpu_hardirq_time
);
757 static DEFINE_PER_CPU(u64
, cpu_softirq_time
);
759 static DEFINE_PER_CPU(u64
, irq_start_time
);
760 static int sched_clock_irqtime
;
762 void enable_sched_clock_irqtime(void)
764 sched_clock_irqtime
= 1;
767 void disable_sched_clock_irqtime(void)
769 sched_clock_irqtime
= 0;
773 static DEFINE_PER_CPU(seqcount_t
, irq_time_seq
);
775 static inline void irq_time_write_begin(void)
777 __this_cpu_inc(irq_time_seq
.sequence
);
781 static inline void irq_time_write_end(void)
784 __this_cpu_inc(irq_time_seq
.sequence
);
787 static inline u64
irq_time_read(int cpu
)
793 seq
= read_seqcount_begin(&per_cpu(irq_time_seq
, cpu
));
794 irq_time
= per_cpu(cpu_softirq_time
, cpu
) +
795 per_cpu(cpu_hardirq_time
, cpu
);
796 } while (read_seqcount_retry(&per_cpu(irq_time_seq
, cpu
), seq
));
800 #else /* CONFIG_64BIT */
801 static inline void irq_time_write_begin(void)
805 static inline void irq_time_write_end(void)
809 static inline u64
irq_time_read(int cpu
)
811 return per_cpu(cpu_softirq_time
, cpu
) + per_cpu(cpu_hardirq_time
, cpu
);
813 #endif /* CONFIG_64BIT */
816 * Called before incrementing preempt_count on {soft,}irq_enter
817 * and before decrementing preempt_count on {soft,}irq_exit.
819 void account_system_vtime(struct task_struct
*curr
)
825 if (!sched_clock_irqtime
)
828 local_irq_save(flags
);
830 cpu
= smp_processor_id();
831 delta
= sched_clock_cpu(cpu
) - __this_cpu_read(irq_start_time
);
832 __this_cpu_add(irq_start_time
, delta
);
834 irq_time_write_begin();
836 * We do not account for softirq time from ksoftirqd here.
837 * We want to continue accounting softirq time to ksoftirqd thread
838 * in that case, so as not to confuse scheduler with a special task
839 * that do not consume any time, but still wants to run.
842 __this_cpu_add(cpu_hardirq_time
, delta
);
843 else if (in_serving_softirq() && curr
!= this_cpu_ksoftirqd())
844 __this_cpu_add(cpu_softirq_time
, delta
);
846 irq_time_write_end();
847 local_irq_restore(flags
);
849 EXPORT_SYMBOL_GPL(account_system_vtime
);
851 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
853 #ifdef CONFIG_PARAVIRT
854 static inline u64
steal_ticks(u64 steal
)
856 if (unlikely(steal
> NSEC_PER_SEC
))
857 return div_u64(steal
, TICK_NSEC
);
859 return __iter_div_u64_rem(steal
, TICK_NSEC
, &steal
);
863 static void update_rq_clock_task(struct rq
*rq
, s64 delta
)
866 * In theory, the compile should just see 0 here, and optimize out the call
867 * to sched_rt_avg_update. But I don't trust it...
869 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
870 s64 steal
= 0, irq_delta
= 0;
872 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
873 irq_delta
= irq_time_read(cpu_of(rq
)) - rq
->prev_irq_time
;
876 * Since irq_time is only updated on {soft,}irq_exit, we might run into
877 * this case when a previous update_rq_clock() happened inside a
880 * When this happens, we stop ->clock_task and only update the
881 * prev_irq_time stamp to account for the part that fit, so that a next
882 * update will consume the rest. This ensures ->clock_task is
885 * It does however cause some slight miss-attribution of {soft,}irq
886 * time, a more accurate solution would be to update the irq_time using
887 * the current rq->clock timestamp, except that would require using
890 if (irq_delta
> delta
)
893 rq
->prev_irq_time
+= irq_delta
;
896 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
897 if (static_key_false((¶virt_steal_rq_enabled
))) {
900 steal
= paravirt_steal_clock(cpu_of(rq
));
901 steal
-= rq
->prev_steal_time_rq
;
903 if (unlikely(steal
> delta
))
906 st
= steal_ticks(steal
);
907 steal
= st
* TICK_NSEC
;
909 rq
->prev_steal_time_rq
+= steal
;
915 rq
->clock_task
+= delta
;
917 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
918 if ((irq_delta
+ steal
) && sched_feat(NONTASK_POWER
))
919 sched_rt_avg_update(rq
, irq_delta
+ steal
);
923 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
924 static int irqtime_account_hi_update(void)
926 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
931 local_irq_save(flags
);
932 latest_ns
= this_cpu_read(cpu_hardirq_time
);
933 if (nsecs_to_cputime64(latest_ns
) > cpustat
[CPUTIME_IRQ
])
935 local_irq_restore(flags
);
939 static int irqtime_account_si_update(void)
941 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
946 local_irq_save(flags
);
947 latest_ns
= this_cpu_read(cpu_softirq_time
);
948 if (nsecs_to_cputime64(latest_ns
) > cpustat
[CPUTIME_SOFTIRQ
])
950 local_irq_restore(flags
);
954 #else /* CONFIG_IRQ_TIME_ACCOUNTING */
956 #define sched_clock_irqtime (0)
960 void sched_set_stop_task(int cpu
, struct task_struct
*stop
)
962 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
963 struct task_struct
*old_stop
= cpu_rq(cpu
)->stop
;
967 * Make it appear like a SCHED_FIFO task, its something
968 * userspace knows about and won't get confused about.
970 * Also, it will make PI more or less work without too
971 * much confusion -- but then, stop work should not
972 * rely on PI working anyway.
974 sched_setscheduler_nocheck(stop
, SCHED_FIFO
, ¶m
);
976 stop
->sched_class
= &stop_sched_class
;
979 cpu_rq(cpu
)->stop
= stop
;
983 * Reset it back to a normal scheduling class so that
984 * it can die in pieces.
986 old_stop
->sched_class
= &rt_sched_class
;
991 * __normal_prio - return the priority that is based on the static prio
993 static inline int __normal_prio(struct task_struct
*p
)
995 return p
->static_prio
;
999 * Calculate the expected normal priority: i.e. priority
1000 * without taking RT-inheritance into account. Might be
1001 * boosted by interactivity modifiers. Changes upon fork,
1002 * setprio syscalls, and whenever the interactivity
1003 * estimator recalculates.
1005 static inline int normal_prio(struct task_struct
*p
)
1009 if (task_has_rt_policy(p
))
1010 prio
= MAX_RT_PRIO
-1 - p
->rt_priority
;
1012 prio
= __normal_prio(p
);
1017 * Calculate the current priority, i.e. the priority
1018 * taken into account by the scheduler. This value might
1019 * be boosted by RT tasks, or might be boosted by
1020 * interactivity modifiers. Will be RT if the task got
1021 * RT-boosted. If not then it returns p->normal_prio.
1023 static int effective_prio(struct task_struct
*p
)
1025 p
->normal_prio
= normal_prio(p
);
1027 * If we are RT tasks or we were boosted to RT priority,
1028 * keep the priority unchanged. Otherwise, update priority
1029 * to the normal priority:
1031 if (!rt_prio(p
->prio
))
1032 return p
->normal_prio
;
1037 * task_curr - is this task currently executing on a CPU?
1038 * @p: the task in question.
1040 inline int task_curr(const struct task_struct
*p
)
1042 return cpu_curr(task_cpu(p
)) == p
;
1045 static inline void check_class_changed(struct rq
*rq
, struct task_struct
*p
,
1046 const struct sched_class
*prev_class
,
1049 if (prev_class
!= p
->sched_class
) {
1050 if (prev_class
->switched_from
)
1051 prev_class
->switched_from(rq
, p
);
1052 p
->sched_class
->switched_to(rq
, p
);
1053 } else if (oldprio
!= p
->prio
)
1054 p
->sched_class
->prio_changed(rq
, p
, oldprio
);
1057 void check_preempt_curr(struct rq
*rq
, struct task_struct
*p
, int flags
)
1059 const struct sched_class
*class;
1061 if (p
->sched_class
== rq
->curr
->sched_class
) {
1062 rq
->curr
->sched_class
->check_preempt_curr(rq
, p
, flags
);
1064 for_each_class(class) {
1065 if (class == rq
->curr
->sched_class
)
1067 if (class == p
->sched_class
) {
1068 resched_task(rq
->curr
);
1075 * A queue event has occurred, and we're going to schedule. In
1076 * this case, we can save a useless back to back clock update.
1078 if (rq
->curr
->on_rq
&& test_tsk_need_resched(rq
->curr
))
1079 rq
->skip_clock_update
= 1;
1083 void set_task_cpu(struct task_struct
*p
, unsigned int new_cpu
)
1085 #ifdef CONFIG_SCHED_DEBUG
1087 * We should never call set_task_cpu() on a blocked task,
1088 * ttwu() will sort out the placement.
1090 WARN_ON_ONCE(p
->state
!= TASK_RUNNING
&& p
->state
!= TASK_WAKING
&&
1091 !(task_thread_info(p
)->preempt_count
& PREEMPT_ACTIVE
));
1093 #ifdef CONFIG_LOCKDEP
1095 * The caller should hold either p->pi_lock or rq->lock, when changing
1096 * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
1098 * sched_move_task() holds both and thus holding either pins the cgroup,
1099 * see set_task_rq().
1101 * Furthermore, all task_rq users should acquire both locks, see
1104 WARN_ON_ONCE(debug_locks
&& !(lockdep_is_held(&p
->pi_lock
) ||
1105 lockdep_is_held(&task_rq(p
)->lock
)));
1109 trace_sched_migrate_task(p
, new_cpu
);
1111 if (task_cpu(p
) != new_cpu
) {
1112 p
->se
.nr_migrations
++;
1113 perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS
, 1, NULL
, 0);
1116 __set_task_cpu(p
, new_cpu
);
1119 struct migration_arg
{
1120 struct task_struct
*task
;
1124 static int migration_cpu_stop(void *data
);
1127 * wait_task_inactive - wait for a thread to unschedule.
1129 * If @match_state is nonzero, it's the @p->state value just checked and
1130 * not expected to change. If it changes, i.e. @p might have woken up,
1131 * then return zero. When we succeed in waiting for @p to be off its CPU,
1132 * we return a positive number (its total switch count). If a second call
1133 * a short while later returns the same number, the caller can be sure that
1134 * @p has remained unscheduled the whole time.
1136 * The caller must ensure that the task *will* unschedule sometime soon,
1137 * else this function might spin for a *long* time. This function can't
1138 * be called with interrupts off, or it may introduce deadlock with
1139 * smp_call_function() if an IPI is sent by the same process we are
1140 * waiting to become inactive.
1142 unsigned long wait_task_inactive(struct task_struct
*p
, long match_state
)
1144 unsigned long flags
;
1151 * We do the initial early heuristics without holding
1152 * any task-queue locks at all. We'll only try to get
1153 * the runqueue lock when things look like they will
1159 * If the task is actively running on another CPU
1160 * still, just relax and busy-wait without holding
1163 * NOTE! Since we don't hold any locks, it's not
1164 * even sure that "rq" stays as the right runqueue!
1165 * But we don't care, since "task_running()" will
1166 * return false if the runqueue has changed and p
1167 * is actually now running somewhere else!
1169 while (task_running(rq
, p
)) {
1170 if (match_state
&& unlikely(p
->state
!= match_state
))
1176 * Ok, time to look more closely! We need the rq
1177 * lock now, to be *sure*. If we're wrong, we'll
1178 * just go back and repeat.
1180 rq
= task_rq_lock(p
, &flags
);
1181 trace_sched_wait_task(p
);
1182 running
= task_running(rq
, p
);
1185 if (!match_state
|| p
->state
== match_state
)
1186 ncsw
= p
->nvcsw
| LONG_MIN
; /* sets MSB */
1187 task_rq_unlock(rq
, p
, &flags
);
1190 * If it changed from the expected state, bail out now.
1192 if (unlikely(!ncsw
))
1196 * Was it really running after all now that we
1197 * checked with the proper locks actually held?
1199 * Oops. Go back and try again..
1201 if (unlikely(running
)) {
1207 * It's not enough that it's not actively running,
1208 * it must be off the runqueue _entirely_, and not
1211 * So if it was still runnable (but just not actively
1212 * running right now), it's preempted, and we should
1213 * yield - it could be a while.
1215 if (unlikely(on_rq
)) {
1216 ktime_t to
= ktime_set(0, NSEC_PER_SEC
/HZ
);
1218 set_current_state(TASK_UNINTERRUPTIBLE
);
1219 schedule_hrtimeout(&to
, HRTIMER_MODE_REL
);
1224 * Ahh, all good. It wasn't running, and it wasn't
1225 * runnable, which means that it will never become
1226 * running in the future either. We're all done!
1235 * kick_process - kick a running thread to enter/exit the kernel
1236 * @p: the to-be-kicked thread
1238 * Cause a process which is running on another CPU to enter
1239 * kernel-mode, without any delay. (to get signals handled.)
1241 * NOTE: this function doesn't have to take the runqueue lock,
1242 * because all it wants to ensure is that the remote task enters
1243 * the kernel. If the IPI races and the task has been migrated
1244 * to another CPU then no harm is done and the purpose has been
1247 void kick_process(struct task_struct
*p
)
1253 if ((cpu
!= smp_processor_id()) && task_curr(p
))
1254 smp_send_reschedule(cpu
);
1257 EXPORT_SYMBOL_GPL(kick_process
);
1258 #endif /* CONFIG_SMP */
1262 * ->cpus_allowed is protected by both rq->lock and p->pi_lock
1264 static int select_fallback_rq(int cpu
, struct task_struct
*p
)
1266 const struct cpumask
*nodemask
= cpumask_of_node(cpu_to_node(cpu
));
1267 enum { cpuset
, possible
, fail
} state
= cpuset
;
1270 /* Look for allowed, online CPU in same node. */
1271 for_each_cpu(dest_cpu
, nodemask
) {
1272 if (!cpu_online(dest_cpu
))
1274 if (!cpu_active(dest_cpu
))
1276 if (cpumask_test_cpu(dest_cpu
, tsk_cpus_allowed(p
)))
1281 /* Any allowed, online CPU? */
1282 for_each_cpu(dest_cpu
, tsk_cpus_allowed(p
)) {
1283 if (!cpu_online(dest_cpu
))
1285 if (!cpu_active(dest_cpu
))
1292 /* No more Mr. Nice Guy. */
1293 cpuset_cpus_allowed_fallback(p
);
1298 do_set_cpus_allowed(p
, cpu_possible_mask
);
1309 if (state
!= cpuset
) {
1311 * Don't tell them about moving exiting tasks or
1312 * kernel threads (both mm NULL), since they never
1315 if (p
->mm
&& printk_ratelimit()) {
1316 printk_sched("process %d (%s) no longer affine to cpu%d\n",
1317 task_pid_nr(p
), p
->comm
, cpu
);
1325 * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
1328 int select_task_rq(struct task_struct
*p
, int sd_flags
, int wake_flags
)
1330 int cpu
= p
->sched_class
->select_task_rq(p
, sd_flags
, wake_flags
);
1333 * In order not to call set_task_cpu() on a blocking task we need
1334 * to rely on ttwu() to place the task on a valid ->cpus_allowed
1337 * Since this is common to all placement strategies, this lives here.
1339 * [ this allows ->select_task() to simply return task_cpu(p) and
1340 * not worry about this generic constraint ]
1342 if (unlikely(!cpumask_test_cpu(cpu
, tsk_cpus_allowed(p
)) ||
1344 cpu
= select_fallback_rq(task_cpu(p
), p
);
1349 static void update_avg(u64
*avg
, u64 sample
)
1351 s64 diff
= sample
- *avg
;
1357 ttwu_stat(struct task_struct
*p
, int cpu
, int wake_flags
)
1359 #ifdef CONFIG_SCHEDSTATS
1360 struct rq
*rq
= this_rq();
1363 int this_cpu
= smp_processor_id();
1365 if (cpu
== this_cpu
) {
1366 schedstat_inc(rq
, ttwu_local
);
1367 schedstat_inc(p
, se
.statistics
.nr_wakeups_local
);
1369 struct sched_domain
*sd
;
1371 schedstat_inc(p
, se
.statistics
.nr_wakeups_remote
);
1373 for_each_domain(this_cpu
, sd
) {
1374 if (cpumask_test_cpu(cpu
, sched_domain_span(sd
))) {
1375 schedstat_inc(sd
, ttwu_wake_remote
);
1382 if (wake_flags
& WF_MIGRATED
)
1383 schedstat_inc(p
, se
.statistics
.nr_wakeups_migrate
);
1385 #endif /* CONFIG_SMP */
1387 schedstat_inc(rq
, ttwu_count
);
1388 schedstat_inc(p
, se
.statistics
.nr_wakeups
);
1390 if (wake_flags
& WF_SYNC
)
1391 schedstat_inc(p
, se
.statistics
.nr_wakeups_sync
);
1393 #endif /* CONFIG_SCHEDSTATS */
1396 static void ttwu_activate(struct rq
*rq
, struct task_struct
*p
, int en_flags
)
1398 activate_task(rq
, p
, en_flags
);
1401 /* if a worker is waking up, notify workqueue */
1402 if (p
->flags
& PF_WQ_WORKER
)
1403 wq_worker_waking_up(p
, cpu_of(rq
));
1407 * Mark the task runnable and perform wakeup-preemption.
1410 ttwu_do_wakeup(struct rq
*rq
, struct task_struct
*p
, int wake_flags
)
1412 trace_sched_wakeup(p
, true);
1413 check_preempt_curr(rq
, p
, wake_flags
);
1415 p
->state
= TASK_RUNNING
;
1417 if (p
->sched_class
->task_woken
)
1418 p
->sched_class
->task_woken(rq
, p
);
1420 if (rq
->idle_stamp
) {
1421 u64 delta
= rq
->clock
- rq
->idle_stamp
;
1422 u64 max
= 2*sysctl_sched_migration_cost
;
1427 update_avg(&rq
->avg_idle
, delta
);
1434 ttwu_do_activate(struct rq
*rq
, struct task_struct
*p
, int wake_flags
)
1437 if (p
->sched_contributes_to_load
)
1438 rq
->nr_uninterruptible
--;
1441 ttwu_activate(rq
, p
, ENQUEUE_WAKEUP
| ENQUEUE_WAKING
);
1442 ttwu_do_wakeup(rq
, p
, wake_flags
);
1446 * Called in case the task @p isn't fully descheduled from its runqueue,
1447 * in this case we must do a remote wakeup. Its a 'light' wakeup though,
1448 * since all we need to do is flip p->state to TASK_RUNNING, since
1449 * the task is still ->on_rq.
1451 static int ttwu_remote(struct task_struct
*p
, int wake_flags
)
1456 rq
= __task_rq_lock(p
);
1458 ttwu_do_wakeup(rq
, p
, wake_flags
);
1461 __task_rq_unlock(rq
);
1467 static void sched_ttwu_pending(void)
1469 struct rq
*rq
= this_rq();
1470 struct llist_node
*llist
= llist_del_all(&rq
->wake_list
);
1471 struct task_struct
*p
;
1473 raw_spin_lock(&rq
->lock
);
1476 p
= llist_entry(llist
, struct task_struct
, wake_entry
);
1477 llist
= llist_next(llist
);
1478 ttwu_do_activate(rq
, p
, 0);
1481 raw_spin_unlock(&rq
->lock
);
1484 void scheduler_ipi(void)
1486 if (llist_empty(&this_rq()->wake_list
) && !got_nohz_idle_kick())
1490 * Not all reschedule IPI handlers call irq_enter/irq_exit, since
1491 * traditionally all their work was done from the interrupt return
1492 * path. Now that we actually do some work, we need to make sure
1495 * Some archs already do call them, luckily irq_enter/exit nest
1498 * Arguably we should visit all archs and update all handlers,
1499 * however a fair share of IPIs are still resched only so this would
1500 * somewhat pessimize the simple resched case.
1503 sched_ttwu_pending();
1506 * Check if someone kicked us for doing the nohz idle load balance.
1508 if (unlikely(got_nohz_idle_kick() && !need_resched())) {
1509 this_rq()->idle_balance
= 1;
1510 raise_softirq_irqoff(SCHED_SOFTIRQ
);
1515 static void ttwu_queue_remote(struct task_struct
*p
, int cpu
)
1517 if (llist_add(&p
->wake_entry
, &cpu_rq(cpu
)->wake_list
))
1518 smp_send_reschedule(cpu
);
1521 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1522 static int ttwu_activate_remote(struct task_struct
*p
, int wake_flags
)
1527 rq
= __task_rq_lock(p
);
1529 ttwu_activate(rq
, p
, ENQUEUE_WAKEUP
);
1530 ttwu_do_wakeup(rq
, p
, wake_flags
);
1533 __task_rq_unlock(rq
);
1538 #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
1540 bool cpus_share_cache(int this_cpu
, int that_cpu
)
1542 return per_cpu(sd_llc_id
, this_cpu
) == per_cpu(sd_llc_id
, that_cpu
);
1544 #endif /* CONFIG_SMP */
1546 static void ttwu_queue(struct task_struct
*p
, int cpu
)
1548 struct rq
*rq
= cpu_rq(cpu
);
1550 #if defined(CONFIG_SMP)
1551 if (sched_feat(TTWU_QUEUE
) && !cpus_share_cache(smp_processor_id(), cpu
)) {
1552 sched_clock_cpu(cpu
); /* sync clocks x-cpu */
1553 ttwu_queue_remote(p
, cpu
);
1558 raw_spin_lock(&rq
->lock
);
1559 ttwu_do_activate(rq
, p
, 0);
1560 raw_spin_unlock(&rq
->lock
);
1564 * try_to_wake_up - wake up a thread
1565 * @p: the thread to be awakened
1566 * @state: the mask of task states that can be woken
1567 * @wake_flags: wake modifier flags (WF_*)
1569 * Put it on the run-queue if it's not already there. The "current"
1570 * thread is always on the run-queue (except when the actual
1571 * re-schedule is in progress), and as such you're allowed to do
1572 * the simpler "current->state = TASK_RUNNING" to mark yourself
1573 * runnable without the overhead of this.
1575 * Returns %true if @p was woken up, %false if it was already running
1576 * or @state didn't match @p's state.
1579 try_to_wake_up(struct task_struct
*p
, unsigned int state
, int wake_flags
)
1581 unsigned long flags
;
1582 int cpu
, success
= 0;
1585 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
1586 if (!(p
->state
& state
))
1589 success
= 1; /* we're going to change ->state */
1592 if (p
->on_rq
&& ttwu_remote(p
, wake_flags
))
1597 * If the owning (remote) cpu is still in the middle of schedule() with
1598 * this task as prev, wait until its done referencing the task.
1601 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1603 * In case the architecture enables interrupts in
1604 * context_switch(), we cannot busy wait, since that
1605 * would lead to deadlocks when an interrupt hits and
1606 * tries to wake up @prev. So bail and do a complete
1609 if (ttwu_activate_remote(p
, wake_flags
))
1616 * Pairs with the smp_wmb() in finish_lock_switch().
1620 p
->sched_contributes_to_load
= !!task_contributes_to_load(p
);
1621 p
->state
= TASK_WAKING
;
1623 if (p
->sched_class
->task_waking
)
1624 p
->sched_class
->task_waking(p
);
1626 cpu
= select_task_rq(p
, SD_BALANCE_WAKE
, wake_flags
);
1627 if (task_cpu(p
) != cpu
) {
1628 wake_flags
|= WF_MIGRATED
;
1629 set_task_cpu(p
, cpu
);
1631 #endif /* CONFIG_SMP */
1635 ttwu_stat(p
, cpu
, wake_flags
);
1637 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
1643 * try_to_wake_up_local - try to wake up a local task with rq lock held
1644 * @p: the thread to be awakened
1646 * Put @p on the run-queue if it's not already there. The caller must
1647 * ensure that this_rq() is locked, @p is bound to this_rq() and not
1650 static void try_to_wake_up_local(struct task_struct
*p
)
1652 struct rq
*rq
= task_rq(p
);
1654 BUG_ON(rq
!= this_rq());
1655 BUG_ON(p
== current
);
1656 lockdep_assert_held(&rq
->lock
);
1658 if (!raw_spin_trylock(&p
->pi_lock
)) {
1659 raw_spin_unlock(&rq
->lock
);
1660 raw_spin_lock(&p
->pi_lock
);
1661 raw_spin_lock(&rq
->lock
);
1664 if (!(p
->state
& TASK_NORMAL
))
1668 ttwu_activate(rq
, p
, ENQUEUE_WAKEUP
);
1670 ttwu_do_wakeup(rq
, p
, 0);
1671 ttwu_stat(p
, smp_processor_id(), 0);
1673 raw_spin_unlock(&p
->pi_lock
);
1677 * wake_up_process - Wake up a specific process
1678 * @p: The process to be woken up.
1680 * Attempt to wake up the nominated process and move it to the set of runnable
1681 * processes. Returns 1 if the process was woken up, 0 if it was already
1684 * It may be assumed that this function implies a write memory barrier before
1685 * changing the task state if and only if any tasks are woken up.
1687 int wake_up_process(struct task_struct
*p
)
1689 return try_to_wake_up(p
, TASK_ALL
, 0);
1691 EXPORT_SYMBOL(wake_up_process
);
1693 int wake_up_state(struct task_struct
*p
, unsigned int state
)
1695 return try_to_wake_up(p
, state
, 0);
1699 * Perform scheduler related setup for a newly forked process p.
1700 * p is forked by current.
1702 * __sched_fork() is basic setup used by init_idle() too:
1704 static void __sched_fork(struct task_struct
*p
)
1709 p
->se
.exec_start
= 0;
1710 p
->se
.sum_exec_runtime
= 0;
1711 p
->se
.prev_sum_exec_runtime
= 0;
1712 p
->se
.nr_migrations
= 0;
1714 INIT_LIST_HEAD(&p
->se
.group_node
);
1716 #ifdef CONFIG_SCHEDSTATS
1717 memset(&p
->se
.statistics
, 0, sizeof(p
->se
.statistics
));
1720 INIT_LIST_HEAD(&p
->rt
.run_list
);
1722 #ifdef CONFIG_PREEMPT_NOTIFIERS
1723 INIT_HLIST_HEAD(&p
->preempt_notifiers
);
1728 * fork()/clone()-time setup:
1730 void sched_fork(struct task_struct
*p
)
1732 unsigned long flags
;
1733 int cpu
= get_cpu();
1737 * We mark the process as running here. This guarantees that
1738 * nobody will actually run it, and a signal or other external
1739 * event cannot wake it up and insert it on the runqueue either.
1741 p
->state
= TASK_RUNNING
;
1744 * Make sure we do not leak PI boosting priority to the child.
1746 p
->prio
= current
->normal_prio
;
1749 * Revert to default priority/policy on fork if requested.
1751 if (unlikely(p
->sched_reset_on_fork
)) {
1752 if (task_has_rt_policy(p
)) {
1753 p
->policy
= SCHED_NORMAL
;
1754 p
->static_prio
= NICE_TO_PRIO(0);
1756 } else if (PRIO_TO_NICE(p
->static_prio
) < 0)
1757 p
->static_prio
= NICE_TO_PRIO(0);
1759 p
->prio
= p
->normal_prio
= __normal_prio(p
);
1763 * We don't need the reset flag anymore after the fork. It has
1764 * fulfilled its duty:
1766 p
->sched_reset_on_fork
= 0;
1769 if (!rt_prio(p
->prio
))
1770 p
->sched_class
= &fair_sched_class
;
1772 if (p
->sched_class
->task_fork
)
1773 p
->sched_class
->task_fork(p
);
1776 * The child is not yet in the pid-hash so no cgroup attach races,
1777 * and the cgroup is pinned to this child due to cgroup_fork()
1778 * is ran before sched_fork().
1780 * Silence PROVE_RCU.
1782 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
1783 set_task_cpu(p
, cpu
);
1784 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
1786 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1787 if (likely(sched_info_on()))
1788 memset(&p
->sched_info
, 0, sizeof(p
->sched_info
));
1790 #if defined(CONFIG_SMP)
1793 #ifdef CONFIG_PREEMPT_COUNT
1794 /* Want to start with kernel preemption disabled. */
1795 task_thread_info(p
)->preempt_count
= 1;
1798 plist_node_init(&p
->pushable_tasks
, MAX_PRIO
);
1805 * wake_up_new_task - wake up a newly created task for the first time.
1807 * This function will do some initial scheduler statistics housekeeping
1808 * that must be done for every newly created context, then puts the task
1809 * on the runqueue and wakes it.
1811 void wake_up_new_task(struct task_struct
*p
)
1813 unsigned long flags
;
1816 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
1819 * Fork balancing, do it here and not earlier because:
1820 * - cpus_allowed can change in the fork path
1821 * - any previously selected cpu might disappear through hotplug
1823 set_task_cpu(p
, select_task_rq(p
, SD_BALANCE_FORK
, 0));
1826 rq
= __task_rq_lock(p
);
1827 activate_task(rq
, p
, 0);
1829 trace_sched_wakeup_new(p
, true);
1830 check_preempt_curr(rq
, p
, WF_FORK
);
1832 if (p
->sched_class
->task_woken
)
1833 p
->sched_class
->task_woken(rq
, p
);
1835 task_rq_unlock(rq
, p
, &flags
);
1838 #ifdef CONFIG_PREEMPT_NOTIFIERS
1841 * preempt_notifier_register - tell me when current is being preempted & rescheduled
1842 * @notifier: notifier struct to register
1844 void preempt_notifier_register(struct preempt_notifier
*notifier
)
1846 hlist_add_head(¬ifier
->link
, ¤t
->preempt_notifiers
);
1848 EXPORT_SYMBOL_GPL(preempt_notifier_register
);
1851 * preempt_notifier_unregister - no longer interested in preemption notifications
1852 * @notifier: notifier struct to unregister
1854 * This is safe to call from within a preemption notifier.
1856 void preempt_notifier_unregister(struct preempt_notifier
*notifier
)
1858 hlist_del(¬ifier
->link
);
1860 EXPORT_SYMBOL_GPL(preempt_notifier_unregister
);
1862 static void fire_sched_in_preempt_notifiers(struct task_struct
*curr
)
1864 struct preempt_notifier
*notifier
;
1865 struct hlist_node
*node
;
1867 hlist_for_each_entry(notifier
, node
, &curr
->preempt_notifiers
, link
)
1868 notifier
->ops
->sched_in(notifier
, raw_smp_processor_id());
1872 fire_sched_out_preempt_notifiers(struct task_struct
*curr
,
1873 struct task_struct
*next
)
1875 struct preempt_notifier
*notifier
;
1876 struct hlist_node
*node
;
1878 hlist_for_each_entry(notifier
, node
, &curr
->preempt_notifiers
, link
)
1879 notifier
->ops
->sched_out(notifier
, next
);
1882 #else /* !CONFIG_PREEMPT_NOTIFIERS */
1884 static void fire_sched_in_preempt_notifiers(struct task_struct
*curr
)
1889 fire_sched_out_preempt_notifiers(struct task_struct
*curr
,
1890 struct task_struct
*next
)
1894 #endif /* CONFIG_PREEMPT_NOTIFIERS */
1897 * prepare_task_switch - prepare to switch tasks
1898 * @rq: the runqueue preparing to switch
1899 * @prev: the current task that is being switched out
1900 * @next: the task we are going to switch to.
1902 * This is called with the rq lock held and interrupts off. It must
1903 * be paired with a subsequent finish_task_switch after the context
1906 * prepare_task_switch sets up locking and calls architecture specific
1910 prepare_task_switch(struct rq
*rq
, struct task_struct
*prev
,
1911 struct task_struct
*next
)
1913 sched_info_switch(prev
, next
);
1914 perf_event_task_sched_out(prev
, next
);
1915 fire_sched_out_preempt_notifiers(prev
, next
);
1916 prepare_lock_switch(rq
, next
);
1917 prepare_arch_switch(next
);
1918 trace_sched_switch(prev
, next
);
1922 * finish_task_switch - clean up after a task-switch
1923 * @rq: runqueue associated with task-switch
1924 * @prev: the thread we just switched away from.
1926 * finish_task_switch must be called after the context switch, paired
1927 * with a prepare_task_switch call before the context switch.
1928 * finish_task_switch will reconcile locking set up by prepare_task_switch,
1929 * and do any other architecture-specific cleanup actions.
1931 * Note that we may have delayed dropping an mm in context_switch(). If
1932 * so, we finish that here outside of the runqueue lock. (Doing it
1933 * with the lock held can cause deadlocks; see schedule() for
1936 static void finish_task_switch(struct rq
*rq
, struct task_struct
*prev
)
1937 __releases(rq
->lock
)
1939 struct mm_struct
*mm
= rq
->prev_mm
;
1945 * A task struct has one reference for the use as "current".
1946 * If a task dies, then it sets TASK_DEAD in tsk->state and calls
1947 * schedule one last time. The schedule call will never return, and
1948 * the scheduled task must drop that reference.
1949 * The test for TASK_DEAD must occur while the runqueue locks are
1950 * still held, otherwise prev could be scheduled on another cpu, die
1951 * there before we look at prev->state, and then the reference would
1953 * Manfred Spraul <manfred@colorfullife.com>
1955 prev_state
= prev
->state
;
1956 finish_arch_switch(prev
);
1957 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1958 local_irq_disable();
1959 #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
1960 perf_event_task_sched_in(prev
, current
);
1961 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1963 #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
1964 finish_lock_switch(rq
, prev
);
1965 finish_arch_post_lock_switch();
1967 fire_sched_in_preempt_notifiers(current
);
1970 if (unlikely(prev_state
== TASK_DEAD
)) {
1972 * Remove function-return probe instances associated with this
1973 * task and put them back on the free list.
1975 kprobe_flush_task(prev
);
1976 put_task_struct(prev
);
1982 /* assumes rq->lock is held */
1983 static inline void pre_schedule(struct rq
*rq
, struct task_struct
*prev
)
1985 if (prev
->sched_class
->pre_schedule
)
1986 prev
->sched_class
->pre_schedule(rq
, prev
);
1989 /* rq->lock is NOT held, but preemption is disabled */
1990 static inline void post_schedule(struct rq
*rq
)
1992 if (rq
->post_schedule
) {
1993 unsigned long flags
;
1995 raw_spin_lock_irqsave(&rq
->lock
, flags
);
1996 if (rq
->curr
->sched_class
->post_schedule
)
1997 rq
->curr
->sched_class
->post_schedule(rq
);
1998 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
2000 rq
->post_schedule
= 0;
2006 static inline void pre_schedule(struct rq
*rq
, struct task_struct
*p
)
2010 static inline void post_schedule(struct rq
*rq
)
2017 * schedule_tail - first thing a freshly forked thread must call.
2018 * @prev: the thread we just switched away from.
2020 asmlinkage
void schedule_tail(struct task_struct
*prev
)
2021 __releases(rq
->lock
)
2023 struct rq
*rq
= this_rq();
2025 finish_task_switch(rq
, prev
);
2028 * FIXME: do we need to worry about rq being invalidated by the
2033 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
2034 /* In this case, finish_task_switch does not reenable preemption */
2037 if (current
->set_child_tid
)
2038 put_user(task_pid_vnr(current
), current
->set_child_tid
);
2042 * context_switch - switch to the new MM and the new
2043 * thread's register state.
2046 context_switch(struct rq
*rq
, struct task_struct
*prev
,
2047 struct task_struct
*next
)
2049 struct mm_struct
*mm
, *oldmm
;
2051 prepare_task_switch(rq
, prev
, next
);
2054 oldmm
= prev
->active_mm
;
2056 * For paravirt, this is coupled with an exit in switch_to to
2057 * combine the page table reload and the switch backend into
2060 arch_start_context_switch(prev
);
2063 next
->active_mm
= oldmm
;
2064 atomic_inc(&oldmm
->mm_count
);
2065 enter_lazy_tlb(oldmm
, next
);
2067 switch_mm(oldmm
, mm
, next
);
2070 prev
->active_mm
= NULL
;
2071 rq
->prev_mm
= oldmm
;
2074 * Since the runqueue lock will be released by the next
2075 * task (which is an invalid locking op but in the case
2076 * of the scheduler it's an obvious special-case), so we
2077 * do an early lockdep release here:
2079 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
2080 spin_release(&rq
->lock
.dep_map
, 1, _THIS_IP_
);
2083 /* Here we just switch the register state and the stack. */
2084 switch_to(prev
, next
, prev
);
2088 * this_rq must be evaluated again because prev may have moved
2089 * CPUs since it called schedule(), thus the 'rq' on its stack
2090 * frame will be invalid.
2092 finish_task_switch(this_rq(), prev
);
2096 * nr_running, nr_uninterruptible and nr_context_switches:
2098 * externally visible scheduler statistics: current number of runnable
2099 * threads, current number of uninterruptible-sleeping threads, total
2100 * number of context switches performed since bootup.
2102 unsigned long nr_running(void)
2104 unsigned long i
, sum
= 0;
2106 for_each_online_cpu(i
)
2107 sum
+= cpu_rq(i
)->nr_running
;
2112 unsigned long nr_uninterruptible(void)
2114 unsigned long i
, sum
= 0;
2116 for_each_possible_cpu(i
)
2117 sum
+= cpu_rq(i
)->nr_uninterruptible
;
2120 * Since we read the counters lockless, it might be slightly
2121 * inaccurate. Do not allow it to go below zero though:
2123 if (unlikely((long)sum
< 0))
2129 unsigned long long nr_context_switches(void)
2132 unsigned long long sum
= 0;
2134 for_each_possible_cpu(i
)
2135 sum
+= cpu_rq(i
)->nr_switches
;
2140 unsigned long nr_iowait(void)
2142 unsigned long i
, sum
= 0;
2144 for_each_possible_cpu(i
)
2145 sum
+= atomic_read(&cpu_rq(i
)->nr_iowait
);
2150 unsigned long nr_iowait_cpu(int cpu
)
2152 struct rq
*this = cpu_rq(cpu
);
2153 return atomic_read(&this->nr_iowait
);
2156 unsigned long this_cpu_load(void)
2158 struct rq
*this = this_rq();
2159 return this->cpu_load
[0];
2164 * Global load-average calculations
2166 * We take a distributed and async approach to calculating the global load-avg
2167 * in order to minimize overhead.
2169 * The global load average is an exponentially decaying average of nr_running +
2170 * nr_uninterruptible.
2172 * Once every LOAD_FREQ:
2175 * for_each_possible_cpu(cpu)
2176 * nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible;
2178 * avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n)
2180 * Due to a number of reasons the above turns in the mess below:
2182 * - for_each_possible_cpu() is prohibitively expensive on machines with
2183 * serious number of cpus, therefore we need to take a distributed approach
2184 * to calculating nr_active.
2186 * \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
2187 * = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
2189 * So assuming nr_active := 0 when we start out -- true per definition, we
2190 * can simply take per-cpu deltas and fold those into a global accumulate
2191 * to obtain the same result. See calc_load_fold_active().
2193 * Furthermore, in order to avoid synchronizing all per-cpu delta folding
2194 * across the machine, we assume 10 ticks is sufficient time for every
2195 * cpu to have completed this task.
2197 * This places an upper-bound on the IRQ-off latency of the machine. Then
2198 * again, being late doesn't loose the delta, just wrecks the sample.
2200 * - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
2201 * this would add another cross-cpu cacheline miss and atomic operation
2202 * to the wakeup path. Instead we increment on whatever cpu the task ran
2203 * when it went into uninterruptible state and decrement on whatever cpu
2204 * did the wakeup. This means that only the sum of nr_uninterruptible over
2205 * all cpus yields the correct result.
2207 * This covers the NO_HZ=n code, for extra head-aches, see the comment below.
2210 /* Variables and functions for calc_load */
2211 static atomic_long_t calc_load_tasks
;
2212 static unsigned long calc_load_update
;
2213 unsigned long avenrun
[3];
2214 EXPORT_SYMBOL(avenrun
); /* should be removed */
2217 * get_avenrun - get the load average array
2218 * @loads: pointer to dest load array
2219 * @offset: offset to add
2220 * @shift: shift count to shift the result left
2222 * These values are estimates at best, so no need for locking.
2224 void get_avenrun(unsigned long *loads
, unsigned long offset
, int shift
)
2226 loads
[0] = (avenrun
[0] + offset
) << shift
;
2227 loads
[1] = (avenrun
[1] + offset
) << shift
;
2228 loads
[2] = (avenrun
[2] + offset
) << shift
;
2231 static long calc_load_fold_active(struct rq
*this_rq
)
2233 long nr_active
, delta
= 0;
2235 nr_active
= this_rq
->nr_running
;
2236 nr_active
+= (long) this_rq
->nr_uninterruptible
;
2238 if (nr_active
!= this_rq
->calc_load_active
) {
2239 delta
= nr_active
- this_rq
->calc_load_active
;
2240 this_rq
->calc_load_active
= nr_active
;
2247 * a1 = a0 * e + a * (1 - e)
2249 static unsigned long
2250 calc_load(unsigned long load
, unsigned long exp
, unsigned long active
)
2253 load
+= active
* (FIXED_1
- exp
);
2254 load
+= 1UL << (FSHIFT
- 1);
2255 return load
>> FSHIFT
;
2260 * Handle NO_HZ for the global load-average.
2262 * Since the above described distributed algorithm to compute the global
2263 * load-average relies on per-cpu sampling from the tick, it is affected by
2266 * The basic idea is to fold the nr_active delta into a global idle-delta upon
2267 * entering NO_HZ state such that we can include this as an 'extra' cpu delta
2268 * when we read the global state.
2270 * Obviously reality has to ruin such a delightfully simple scheme:
2272 * - When we go NO_HZ idle during the window, we can negate our sample
2273 * contribution, causing under-accounting.
2275 * We avoid this by keeping two idle-delta counters and flipping them
2276 * when the window starts, thus separating old and new NO_HZ load.
2278 * The only trick is the slight shift in index flip for read vs write.
2282 * |-|-----------|-|-----------|-|-----------|-|
2283 * r:0 0 1 1 0 0 1 1 0
2284 * w:0 1 1 0 0 1 1 0 0
2286 * This ensures we'll fold the old idle contribution in this window while
2287 * accumlating the new one.
2289 * - When we wake up from NO_HZ idle during the window, we push up our
2290 * contribution, since we effectively move our sample point to a known
2293 * This is solved by pushing the window forward, and thus skipping the
2294 * sample, for this cpu (effectively using the idle-delta for this cpu which
2295 * was in effect at the time the window opened). This also solves the issue
2296 * of having to deal with a cpu having been in NOHZ idle for multiple
2297 * LOAD_FREQ intervals.
2299 * When making the ILB scale, we should try to pull this in as well.
2301 static atomic_long_t calc_load_idle
[2];
2302 static int calc_load_idx
;
2304 static inline int calc_load_write_idx(void)
2306 int idx
= calc_load_idx
;
2309 * See calc_global_nohz(), if we observe the new index, we also
2310 * need to observe the new update time.
2315 * If the folding window started, make sure we start writing in the
2318 if (!time_before(jiffies
, calc_load_update
))
2324 static inline int calc_load_read_idx(void)
2326 return calc_load_idx
& 1;
2329 void calc_load_enter_idle(void)
2331 struct rq
*this_rq
= this_rq();
2335 * We're going into NOHZ mode, if there's any pending delta, fold it
2336 * into the pending idle delta.
2338 delta
= calc_load_fold_active(this_rq
);
2340 int idx
= calc_load_write_idx();
2341 atomic_long_add(delta
, &calc_load_idle
[idx
]);
2345 void calc_load_exit_idle(void)
2347 struct rq
*this_rq
= this_rq();
2350 * If we're still before the sample window, we're done.
2352 if (time_before(jiffies
, this_rq
->calc_load_update
))
2356 * We woke inside or after the sample window, this means we're already
2357 * accounted through the nohz accounting, so skip the entire deal and
2358 * sync up for the next window.
2360 this_rq
->calc_load_update
= calc_load_update
;
2361 if (time_before(jiffies
, this_rq
->calc_load_update
+ 10))
2362 this_rq
->calc_load_update
+= LOAD_FREQ
;
2365 static long calc_load_fold_idle(void)
2367 int idx
= calc_load_read_idx();
2370 if (atomic_long_read(&calc_load_idle
[idx
]))
2371 delta
= atomic_long_xchg(&calc_load_idle
[idx
], 0);
2377 * fixed_power_int - compute: x^n, in O(log n) time
2379 * @x: base of the power
2380 * @frac_bits: fractional bits of @x
2381 * @n: power to raise @x to.
2383 * By exploiting the relation between the definition of the natural power
2384 * function: x^n := x*x*...*x (x multiplied by itself for n times), and
2385 * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
2386 * (where: n_i \elem {0, 1}, the binary vector representing n),
2387 * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
2388 * of course trivially computable in O(log_2 n), the length of our binary
2391 static unsigned long
2392 fixed_power_int(unsigned long x
, unsigned int frac_bits
, unsigned int n
)
2394 unsigned long result
= 1UL << frac_bits
;
2399 result
+= 1UL << (frac_bits
- 1);
2400 result
>>= frac_bits
;
2406 x
+= 1UL << (frac_bits
- 1);
2414 * a1 = a0 * e + a * (1 - e)
2416 * a2 = a1 * e + a * (1 - e)
2417 * = (a0 * e + a * (1 - e)) * e + a * (1 - e)
2418 * = a0 * e^2 + a * (1 - e) * (1 + e)
2420 * a3 = a2 * e + a * (1 - e)
2421 * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
2422 * = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
2426 * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
2427 * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
2428 * = a0 * e^n + a * (1 - e^n)
2430 * [1] application of the geometric series:
2433 * S_n := \Sum x^i = -------------
2436 static unsigned long
2437 calc_load_n(unsigned long load
, unsigned long exp
,
2438 unsigned long active
, unsigned int n
)
2441 return calc_load(load
, fixed_power_int(exp
, FSHIFT
, n
), active
);
2445 * NO_HZ can leave us missing all per-cpu ticks calling
2446 * calc_load_account_active(), but since an idle CPU folds its delta into
2447 * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
2448 * in the pending idle delta if our idle period crossed a load cycle boundary.
2450 * Once we've updated the global active value, we need to apply the exponential
2451 * weights adjusted to the number of cycles missed.
2453 static void calc_global_nohz(void)
2455 long delta
, active
, n
;
2457 if (!time_before(jiffies
, calc_load_update
+ 10)) {
2459 * Catch-up, fold however many we are behind still
2461 delta
= jiffies
- calc_load_update
- 10;
2462 n
= 1 + (delta
/ LOAD_FREQ
);
2464 active
= atomic_long_read(&calc_load_tasks
);
2465 active
= active
> 0 ? active
* FIXED_1
: 0;
2467 avenrun
[0] = calc_load_n(avenrun
[0], EXP_1
, active
, n
);
2468 avenrun
[1] = calc_load_n(avenrun
[1], EXP_5
, active
, n
);
2469 avenrun
[2] = calc_load_n(avenrun
[2], EXP_15
, active
, n
);
2471 calc_load_update
+= n
* LOAD_FREQ
;
2475 * Flip the idle index...
2477 * Make sure we first write the new time then flip the index, so that
2478 * calc_load_write_idx() will see the new time when it reads the new
2479 * index, this avoids a double flip messing things up.
2484 #else /* !CONFIG_NO_HZ */
2486 static inline long calc_load_fold_idle(void) { return 0; }
2487 static inline void calc_global_nohz(void) { }
2489 #endif /* CONFIG_NO_HZ */
2492 * calc_load - update the avenrun load estimates 10 ticks after the
2493 * CPUs have updated calc_load_tasks.
2495 void calc_global_load(unsigned long ticks
)
2499 if (time_before(jiffies
, calc_load_update
+ 10))
2503 * Fold the 'old' idle-delta to include all NO_HZ cpus.
2505 delta
= calc_load_fold_idle();
2507 atomic_long_add(delta
, &calc_load_tasks
);
2509 active
= atomic_long_read(&calc_load_tasks
);
2510 active
= active
> 0 ? active
* FIXED_1
: 0;
2512 avenrun
[0] = calc_load(avenrun
[0], EXP_1
, active
);
2513 avenrun
[1] = calc_load(avenrun
[1], EXP_5
, active
);
2514 avenrun
[2] = calc_load(avenrun
[2], EXP_15
, active
);
2516 calc_load_update
+= LOAD_FREQ
;
2519 * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
2525 * Called from update_cpu_load() to periodically update this CPU's
2528 static void calc_load_account_active(struct rq
*this_rq
)
2532 if (time_before(jiffies
, this_rq
->calc_load_update
))
2535 delta
= calc_load_fold_active(this_rq
);
2537 atomic_long_add(delta
, &calc_load_tasks
);
2539 this_rq
->calc_load_update
+= LOAD_FREQ
;
2543 * End of global load-average stuff
2547 * The exact cpuload at various idx values, calculated at every tick would be
2548 * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
2550 * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
2551 * on nth tick when cpu may be busy, then we have:
2552 * load = ((2^idx - 1) / 2^idx)^(n-1) * load
2553 * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
2555 * decay_load_missed() below does efficient calculation of
2556 * load = ((2^idx - 1) / 2^idx)^(n-1) * load
2557 * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
2559 * The calculation is approximated on a 128 point scale.
2560 * degrade_zero_ticks is the number of ticks after which load at any
2561 * particular idx is approximated to be zero.
2562 * degrade_factor is a precomputed table, a row for each load idx.
2563 * Each column corresponds to degradation factor for a power of two ticks,
2564 * based on 128 point scale.
2566 * row 2, col 3 (=12) says that the degradation at load idx 2 after
2567 * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
2569 * With this power of 2 load factors, we can degrade the load n times
2570 * by looking at 1 bits in n and doing as many mult/shift instead of
2571 * n mult/shifts needed by the exact degradation.
2573 #define DEGRADE_SHIFT 7
2574 static const unsigned char
2575 degrade_zero_ticks
[CPU_LOAD_IDX_MAX
] = {0, 8, 32, 64, 128};
2576 static const unsigned char
2577 degrade_factor
[CPU_LOAD_IDX_MAX
][DEGRADE_SHIFT
+ 1] = {
2578 {0, 0, 0, 0, 0, 0, 0, 0},
2579 {64, 32, 8, 0, 0, 0, 0, 0},
2580 {96, 72, 40, 12, 1, 0, 0},
2581 {112, 98, 75, 43, 15, 1, 0},
2582 {120, 112, 98, 76, 45, 16, 2} };
2585 * Update cpu_load for any missed ticks, due to tickless idle. The backlog
2586 * would be when CPU is idle and so we just decay the old load without
2587 * adding any new load.
2589 static unsigned long
2590 decay_load_missed(unsigned long load
, unsigned long missed_updates
, int idx
)
2594 if (!missed_updates
)
2597 if (missed_updates
>= degrade_zero_ticks
[idx
])
2601 return load
>> missed_updates
;
2603 while (missed_updates
) {
2604 if (missed_updates
% 2)
2605 load
= (load
* degrade_factor
[idx
][j
]) >> DEGRADE_SHIFT
;
2607 missed_updates
>>= 1;
2614 * Update rq->cpu_load[] statistics. This function is usually called every
2615 * scheduler tick (TICK_NSEC). With tickless idle this will not be called
2616 * every tick. We fix it up based on jiffies.
2618 static void __update_cpu_load(struct rq
*this_rq
, unsigned long this_load
,
2619 unsigned long pending_updates
)
2623 this_rq
->nr_load_updates
++;
2625 /* Update our load: */
2626 this_rq
->cpu_load
[0] = this_load
; /* Fasttrack for idx 0 */
2627 for (i
= 1, scale
= 2; i
< CPU_LOAD_IDX_MAX
; i
++, scale
+= scale
) {
2628 unsigned long old_load
, new_load
;
2630 /* scale is effectively 1 << i now, and >> i divides by scale */
2632 old_load
= this_rq
->cpu_load
[i
];
2633 old_load
= decay_load_missed(old_load
, pending_updates
- 1, i
);
2634 new_load
= this_load
;
2636 * Round up the averaging division if load is increasing. This
2637 * prevents us from getting stuck on 9 if the load is 10, for
2640 if (new_load
> old_load
)
2641 new_load
+= scale
- 1;
2643 this_rq
->cpu_load
[i
] = (old_load
* (scale
- 1) + new_load
) >> i
;
2646 sched_avg_update(this_rq
);
2651 * There is no sane way to deal with nohz on smp when using jiffies because the
2652 * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
2653 * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
2655 * Therefore we cannot use the delta approach from the regular tick since that
2656 * would seriously skew the load calculation. However we'll make do for those
2657 * updates happening while idle (nohz_idle_balance) or coming out of idle
2658 * (tick_nohz_idle_exit).
2660 * This means we might still be one tick off for nohz periods.
2664 * Called from nohz_idle_balance() to update the load ratings before doing the
2667 void update_idle_cpu_load(struct rq
*this_rq
)
2669 unsigned long curr_jiffies
= ACCESS_ONCE(jiffies
);
2670 unsigned long load
= this_rq
->load
.weight
;
2671 unsigned long pending_updates
;
2674 * bail if there's load or we're actually up-to-date.
2676 if (load
|| curr_jiffies
== this_rq
->last_load_update_tick
)
2679 pending_updates
= curr_jiffies
- this_rq
->last_load_update_tick
;
2680 this_rq
->last_load_update_tick
= curr_jiffies
;
2682 __update_cpu_load(this_rq
, load
, pending_updates
);
2686 * Called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
2688 void update_cpu_load_nohz(void)
2690 struct rq
*this_rq
= this_rq();
2691 unsigned long curr_jiffies
= ACCESS_ONCE(jiffies
);
2692 unsigned long pending_updates
;
2694 if (curr_jiffies
== this_rq
->last_load_update_tick
)
2697 raw_spin_lock(&this_rq
->lock
);
2698 pending_updates
= curr_jiffies
- this_rq
->last_load_update_tick
;
2699 if (pending_updates
) {
2700 this_rq
->last_load_update_tick
= curr_jiffies
;
2702 * We were idle, this means load 0, the current load might be
2703 * !0 due to remote wakeups and the sort.
2705 __update_cpu_load(this_rq
, 0, pending_updates
);
2707 raw_spin_unlock(&this_rq
->lock
);
2709 #endif /* CONFIG_NO_HZ */
2712 * Called from scheduler_tick()
2714 static void update_cpu_load_active(struct rq
*this_rq
)
2717 * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
2719 this_rq
->last_load_update_tick
= jiffies
;
2720 __update_cpu_load(this_rq
, this_rq
->load
.weight
, 1);
2722 calc_load_account_active(this_rq
);
2728 * sched_exec - execve() is a valuable balancing opportunity, because at
2729 * this point the task has the smallest effective memory and cache footprint.
2731 void sched_exec(void)
2733 struct task_struct
*p
= current
;
2734 unsigned long flags
;
2737 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
2738 dest_cpu
= p
->sched_class
->select_task_rq(p
, SD_BALANCE_EXEC
, 0);
2739 if (dest_cpu
== smp_processor_id())
2742 if (likely(cpu_active(dest_cpu
))) {
2743 struct migration_arg arg
= { p
, dest_cpu
};
2745 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
2746 stop_one_cpu(task_cpu(p
), migration_cpu_stop
, &arg
);
2750 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
2755 DEFINE_PER_CPU(struct kernel_stat
, kstat
);
2756 DEFINE_PER_CPU(struct kernel_cpustat
, kernel_cpustat
);
2758 EXPORT_PER_CPU_SYMBOL(kstat
);
2759 EXPORT_PER_CPU_SYMBOL(kernel_cpustat
);
2762 * Return any ns on the sched_clock that have not yet been accounted in
2763 * @p in case that task is currently running.
2765 * Called with task_rq_lock() held on @rq.
2767 static u64
do_task_delta_exec(struct task_struct
*p
, struct rq
*rq
)
2771 if (task_current(rq
, p
)) {
2772 update_rq_clock(rq
);
2773 ns
= rq
->clock_task
- p
->se
.exec_start
;
2781 unsigned long long task_delta_exec(struct task_struct
*p
)
2783 unsigned long flags
;
2787 rq
= task_rq_lock(p
, &flags
);
2788 ns
= do_task_delta_exec(p
, rq
);
2789 task_rq_unlock(rq
, p
, &flags
);
2795 * Return accounted runtime for the task.
2796 * In case the task is currently running, return the runtime plus current's
2797 * pending runtime that have not been accounted yet.
2799 unsigned long long task_sched_runtime(struct task_struct
*p
)
2801 unsigned long flags
;
2805 rq
= task_rq_lock(p
, &flags
);
2806 ns
= p
->se
.sum_exec_runtime
+ do_task_delta_exec(p
, rq
);
2807 task_rq_unlock(rq
, p
, &flags
);
2812 #ifdef CONFIG_CGROUP_CPUACCT
2813 struct cgroup_subsys cpuacct_subsys
;
2814 struct cpuacct root_cpuacct
;
2817 static inline void task_group_account_field(struct task_struct
*p
, int index
,
2820 #ifdef CONFIG_CGROUP_CPUACCT
2821 struct kernel_cpustat
*kcpustat
;
2825 * Since all updates are sure to touch the root cgroup, we
2826 * get ourselves ahead and touch it first. If the root cgroup
2827 * is the only cgroup, then nothing else should be necessary.
2830 __get_cpu_var(kernel_cpustat
).cpustat
[index
] += tmp
;
2832 #ifdef CONFIG_CGROUP_CPUACCT
2833 if (unlikely(!cpuacct_subsys
.active
))
2838 while (ca
&& (ca
!= &root_cpuacct
)) {
2839 kcpustat
= this_cpu_ptr(ca
->cpustat
);
2840 kcpustat
->cpustat
[index
] += tmp
;
2849 * Account user cpu time to a process.
2850 * @p: the process that the cpu time gets accounted to
2851 * @cputime: the cpu time spent in user space since the last update
2852 * @cputime_scaled: cputime scaled by cpu frequency
2854 void account_user_time(struct task_struct
*p
, cputime_t cputime
,
2855 cputime_t cputime_scaled
)
2859 /* Add user time to process. */
2860 p
->utime
+= cputime
;
2861 p
->utimescaled
+= cputime_scaled
;
2862 account_group_user_time(p
, cputime
);
2864 index
= (TASK_NICE(p
) > 0) ? CPUTIME_NICE
: CPUTIME_USER
;
2866 /* Add user time to cpustat. */
2867 task_group_account_field(p
, index
, (__force u64
) cputime
);
2869 /* Account for user time used */
2870 acct_update_integrals(p
);
2874 * Account guest cpu time to a process.
2875 * @p: the process that the cpu time gets accounted to
2876 * @cputime: the cpu time spent in virtual machine since the last update
2877 * @cputime_scaled: cputime scaled by cpu frequency
2879 static void account_guest_time(struct task_struct
*p
, cputime_t cputime
,
2880 cputime_t cputime_scaled
)
2882 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
2884 /* Add guest time to process. */
2885 p
->utime
+= cputime
;
2886 p
->utimescaled
+= cputime_scaled
;
2887 account_group_user_time(p
, cputime
);
2888 p
->gtime
+= cputime
;
2890 /* Add guest time to cpustat. */
2891 if (TASK_NICE(p
) > 0) {
2892 cpustat
[CPUTIME_NICE
] += (__force u64
) cputime
;
2893 cpustat
[CPUTIME_GUEST_NICE
] += (__force u64
) cputime
;
2895 cpustat
[CPUTIME_USER
] += (__force u64
) cputime
;
2896 cpustat
[CPUTIME_GUEST
] += (__force u64
) cputime
;
2901 * Account system cpu time to a process and desired cpustat field
2902 * @p: the process that the cpu time gets accounted to
2903 * @cputime: the cpu time spent in kernel space since the last update
2904 * @cputime_scaled: cputime scaled by cpu frequency
2905 * @target_cputime64: pointer to cpustat field that has to be updated
2908 void __account_system_time(struct task_struct
*p
, cputime_t cputime
,
2909 cputime_t cputime_scaled
, int index
)
2911 /* Add system time to process. */
2912 p
->stime
+= cputime
;
2913 p
->stimescaled
+= cputime_scaled
;
2914 account_group_system_time(p
, cputime
);
2916 /* Add system time to cpustat. */
2917 task_group_account_field(p
, index
, (__force u64
) cputime
);
2919 /* Account for system time used */
2920 acct_update_integrals(p
);
2924 * Account system cpu time to a process.
2925 * @p: the process that the cpu time gets accounted to
2926 * @hardirq_offset: the offset to subtract from hardirq_count()
2927 * @cputime: the cpu time spent in kernel space since the last update
2928 * @cputime_scaled: cputime scaled by cpu frequency
2930 void account_system_time(struct task_struct
*p
, int hardirq_offset
,
2931 cputime_t cputime
, cputime_t cputime_scaled
)
2935 if ((p
->flags
& PF_VCPU
) && (irq_count() - hardirq_offset
== 0)) {
2936 account_guest_time(p
, cputime
, cputime_scaled
);
2940 if (hardirq_count() - hardirq_offset
)
2941 index
= CPUTIME_IRQ
;
2942 else if (in_serving_softirq())
2943 index
= CPUTIME_SOFTIRQ
;
2945 index
= CPUTIME_SYSTEM
;
2947 __account_system_time(p
, cputime
, cputime_scaled
, index
);
2951 * Account for involuntary wait time.
2952 * @cputime: the cpu time spent in involuntary wait
2954 void account_steal_time(cputime_t cputime
)
2956 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
2958 cpustat
[CPUTIME_STEAL
] += (__force u64
) cputime
;
2962 * Account for idle time.
2963 * @cputime: the cpu time spent in idle wait
2965 void account_idle_time(cputime_t cputime
)
2967 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
2968 struct rq
*rq
= this_rq();
2970 if (atomic_read(&rq
->nr_iowait
) > 0)
2971 cpustat
[CPUTIME_IOWAIT
] += (__force u64
) cputime
;
2973 cpustat
[CPUTIME_IDLE
] += (__force u64
) cputime
;
2976 static __always_inline
bool steal_account_process_tick(void)
2978 #ifdef CONFIG_PARAVIRT
2979 if (static_key_false(¶virt_steal_enabled
)) {
2982 steal
= paravirt_steal_clock(smp_processor_id());
2983 steal
-= this_rq()->prev_steal_time
;
2985 st
= steal_ticks(steal
);
2986 this_rq()->prev_steal_time
+= st
* TICK_NSEC
;
2988 account_steal_time(st
);
2995 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
2997 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2999 * Account a tick to a process and cpustat
3000 * @p: the process that the cpu time gets accounted to
3001 * @user_tick: is the tick from userspace
3002 * @rq: the pointer to rq
3004 * Tick demultiplexing follows the order
3005 * - pending hardirq update
3006 * - pending softirq update
3010 * - check for guest_time
3011 * - else account as system_time
3013 * Check for hardirq is done both for system and user time as there is
3014 * no timer going off while we are on hardirq and hence we may never get an
3015 * opportunity to update it solely in system time.
3016 * p->stime and friends are only updated on system time and not on irq
3017 * softirq as those do not count in task exec_runtime any more.
3019 static void irqtime_account_process_tick(struct task_struct
*p
, int user_tick
,
3022 cputime_t one_jiffy_scaled
= cputime_to_scaled(cputime_one_jiffy
);
3023 u64
*cpustat
= kcpustat_this_cpu
->cpustat
;
3025 if (steal_account_process_tick())
3028 if (irqtime_account_hi_update()) {
3029 cpustat
[CPUTIME_IRQ
] += (__force u64
) cputime_one_jiffy
;
3030 } else if (irqtime_account_si_update()) {
3031 cpustat
[CPUTIME_SOFTIRQ
] += (__force u64
) cputime_one_jiffy
;
3032 } else if (this_cpu_ksoftirqd() == p
) {
3034 * ksoftirqd time do not get accounted in cpu_softirq_time.
3035 * So, we have to handle it separately here.
3036 * Also, p->stime needs to be updated for ksoftirqd.
3038 __account_system_time(p
, cputime_one_jiffy
, one_jiffy_scaled
,
3040 } else if (user_tick
) {
3041 account_user_time(p
, cputime_one_jiffy
, one_jiffy_scaled
);
3042 } else if (p
== rq
->idle
) {
3043 account_idle_time(cputime_one_jiffy
);
3044 } else if (p
->flags
& PF_VCPU
) { /* System time or guest time */
3045 account_guest_time(p
, cputime_one_jiffy
, one_jiffy_scaled
);
3047 __account_system_time(p
, cputime_one_jiffy
, one_jiffy_scaled
,
3052 static void irqtime_account_idle_ticks(int ticks
)
3055 struct rq
*rq
= this_rq();
3057 for (i
= 0; i
< ticks
; i
++)
3058 irqtime_account_process_tick(current
, 0, rq
);
3060 #else /* CONFIG_IRQ_TIME_ACCOUNTING */
3061 static void irqtime_account_idle_ticks(int ticks
) {}
3062 static void irqtime_account_process_tick(struct task_struct
*p
, int user_tick
,
3064 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
3067 * Account a single tick of cpu time.
3068 * @p: the process that the cpu time gets accounted to
3069 * @user_tick: indicates if the tick is a user or a system tick
3071 void account_process_tick(struct task_struct
*p
, int user_tick
)
3073 cputime_t one_jiffy_scaled
= cputime_to_scaled(cputime_one_jiffy
);
3074 struct rq
*rq
= this_rq();
3076 if (sched_clock_irqtime
) {
3077 irqtime_account_process_tick(p
, user_tick
, rq
);
3081 if (steal_account_process_tick())
3085 account_user_time(p
, cputime_one_jiffy
, one_jiffy_scaled
);
3086 else if ((p
!= rq
->idle
) || (irq_count() != HARDIRQ_OFFSET
))
3087 account_system_time(p
, HARDIRQ_OFFSET
, cputime_one_jiffy
,
3090 account_idle_time(cputime_one_jiffy
);
3094 * Account multiple ticks of steal time.
3095 * @p: the process from which the cpu time has been stolen
3096 * @ticks: number of stolen ticks
3098 void account_steal_ticks(unsigned long ticks
)
3100 account_steal_time(jiffies_to_cputime(ticks
));
3104 * Account multiple ticks of idle time.
3105 * @ticks: number of stolen ticks
3107 void account_idle_ticks(unsigned long ticks
)
3110 if (sched_clock_irqtime
) {
3111 irqtime_account_idle_ticks(ticks
);
3115 account_idle_time(jiffies_to_cputime(ticks
));
3121 * Use precise platform statistics if available:
3123 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
3124 void task_times(struct task_struct
*p
, cputime_t
*ut
, cputime_t
*st
)
3130 void thread_group_times(struct task_struct
*p
, cputime_t
*ut
, cputime_t
*st
)
3132 struct task_cputime cputime
;
3134 thread_group_cputime(p
, &cputime
);
3136 *ut
= cputime
.utime
;
3137 *st
= cputime
.stime
;
3141 #ifndef nsecs_to_cputime
3142 # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
3145 void task_times(struct task_struct
*p
, cputime_t
*ut
, cputime_t
*st
)
3147 cputime_t rtime
, utime
= p
->utime
, total
= utime
+ p
->stime
;
3150 * Use CFS's precise accounting:
3152 rtime
= nsecs_to_cputime(p
->se
.sum_exec_runtime
);
3155 u64 temp
= (__force u64
) rtime
;
3157 temp
*= (__force u64
) utime
;
3158 do_div(temp
, (__force u32
) total
);
3159 utime
= (__force cputime_t
) temp
;
3164 * Compare with previous values, to keep monotonicity:
3166 p
->prev_utime
= max(p
->prev_utime
, utime
);
3167 p
->prev_stime
= max(p
->prev_stime
, rtime
- p
->prev_utime
);
3169 *ut
= p
->prev_utime
;
3170 *st
= p
->prev_stime
;
3174 * Must be called with siglock held.
3176 void thread_group_times(struct task_struct
*p
, cputime_t
*ut
, cputime_t
*st
)
3178 struct signal_struct
*sig
= p
->signal
;
3179 struct task_cputime cputime
;
3180 cputime_t rtime
, utime
, total
;
3182 thread_group_cputime(p
, &cputime
);
3184 total
= cputime
.utime
+ cputime
.stime
;
3185 rtime
= nsecs_to_cputime(cputime
.sum_exec_runtime
);
3188 u64 temp
= (__force u64
) rtime
;
3190 temp
*= (__force u64
) cputime
.utime
;
3191 do_div(temp
, (__force u32
) total
);
3192 utime
= (__force cputime_t
) temp
;
3196 sig
->prev_utime
= max(sig
->prev_utime
, utime
);
3197 sig
->prev_stime
= max(sig
->prev_stime
, rtime
- sig
->prev_utime
);
3199 *ut
= sig
->prev_utime
;
3200 *st
= sig
->prev_stime
;
3205 * This function gets called by the timer code, with HZ frequency.
3206 * We call it with interrupts disabled.
3208 void scheduler_tick(void)
3210 int cpu
= smp_processor_id();
3211 struct rq
*rq
= cpu_rq(cpu
);
3212 struct task_struct
*curr
= rq
->curr
;
3216 raw_spin_lock(&rq
->lock
);
3217 update_rq_clock(rq
);
3218 update_cpu_load_active(rq
);
3219 curr
->sched_class
->task_tick(rq
, curr
, 0);
3220 raw_spin_unlock(&rq
->lock
);
3222 perf_event_task_tick();
3225 rq
->idle_balance
= idle_cpu(cpu
);
3226 trigger_load_balance(rq
, cpu
);
3230 notrace
unsigned long get_parent_ip(unsigned long addr
)
3232 if (in_lock_functions(addr
)) {
3233 addr
= CALLER_ADDR2
;
3234 if (in_lock_functions(addr
))
3235 addr
= CALLER_ADDR3
;
3240 #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
3241 defined(CONFIG_PREEMPT_TRACER))
3243 void __kprobes
add_preempt_count(int val
)
3245 #ifdef CONFIG_DEBUG_PREEMPT
3249 if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
3252 preempt_count() += val
;
3253 #ifdef CONFIG_DEBUG_PREEMPT
3255 * Spinlock count overflowing soon?
3257 DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK
) >=
3260 if (preempt_count() == val
)
3261 trace_preempt_off(CALLER_ADDR0
, get_parent_ip(CALLER_ADDR1
));
3263 EXPORT_SYMBOL(add_preempt_count
);
3265 void __kprobes
sub_preempt_count(int val
)
3267 #ifdef CONFIG_DEBUG_PREEMPT
3271 if (DEBUG_LOCKS_WARN_ON(val
> preempt_count()))
3274 * Is the spinlock portion underflowing?
3276 if (DEBUG_LOCKS_WARN_ON((val
< PREEMPT_MASK
) &&
3277 !(preempt_count() & PREEMPT_MASK
)))
3281 if (preempt_count() == val
)
3282 trace_preempt_on(CALLER_ADDR0
, get_parent_ip(CALLER_ADDR1
));
3283 preempt_count() -= val
;
3285 EXPORT_SYMBOL(sub_preempt_count
);
3290 * Print scheduling while atomic bug:
3292 static noinline
void __schedule_bug(struct task_struct
*prev
)
3294 if (oops_in_progress
)
3297 printk(KERN_ERR
"BUG: scheduling while atomic: %s/%d/0x%08x\n",
3298 prev
->comm
, prev
->pid
, preempt_count());
3300 debug_show_held_locks(prev
);
3302 if (irqs_disabled())
3303 print_irqtrace_events(prev
);
3305 add_taint(TAINT_WARN
);
3309 * Various schedule()-time debugging checks and statistics:
3311 static inline void schedule_debug(struct task_struct
*prev
)
3314 * Test if we are atomic. Since do_exit() needs to call into
3315 * schedule() atomically, we ignore that path for now.
3316 * Otherwise, whine if we are scheduling when we should not be.
3318 if (unlikely(in_atomic_preempt_off() && !prev
->exit_state
))
3319 __schedule_bug(prev
);
3322 profile_hit(SCHED_PROFILING
, __builtin_return_address(0));
3324 schedstat_inc(this_rq(), sched_count
);
3327 static void put_prev_task(struct rq
*rq
, struct task_struct
*prev
)
3329 if (prev
->on_rq
|| rq
->skip_clock_update
< 0)
3330 update_rq_clock(rq
);
3331 prev
->sched_class
->put_prev_task(rq
, prev
);
3335 * Pick up the highest-prio task:
3337 static inline struct task_struct
*
3338 pick_next_task(struct rq
*rq
)
3340 const struct sched_class
*class;
3341 struct task_struct
*p
;
3344 * Optimization: we know that if all tasks are in
3345 * the fair class we can call that function directly:
3347 if (likely(rq
->nr_running
== rq
->cfs
.h_nr_running
)) {
3348 p
= fair_sched_class
.pick_next_task(rq
);
3353 for_each_class(class) {
3354 p
= class->pick_next_task(rq
);
3359 BUG(); /* the idle class will always have a runnable task */
3363 * __schedule() is the main scheduler function.
3365 static void __sched
__schedule(void)
3367 struct task_struct
*prev
, *next
;
3368 unsigned long *switch_count
;
3374 cpu
= smp_processor_id();
3376 rcu_note_context_switch(cpu
);
3379 schedule_debug(prev
);
3381 if (sched_feat(HRTICK
))
3384 raw_spin_lock_irq(&rq
->lock
);
3386 switch_count
= &prev
->nivcsw
;
3387 if (prev
->state
&& !(preempt_count() & PREEMPT_ACTIVE
)) {
3388 if (unlikely(signal_pending_state(prev
->state
, prev
))) {
3389 prev
->state
= TASK_RUNNING
;
3391 deactivate_task(rq
, prev
, DEQUEUE_SLEEP
);
3395 * If a worker went to sleep, notify and ask workqueue
3396 * whether it wants to wake up a task to maintain
3399 if (prev
->flags
& PF_WQ_WORKER
) {
3400 struct task_struct
*to_wakeup
;
3402 to_wakeup
= wq_worker_sleeping(prev
, cpu
);
3404 try_to_wake_up_local(to_wakeup
);
3407 switch_count
= &prev
->nvcsw
;
3410 pre_schedule(rq
, prev
);
3412 if (unlikely(!rq
->nr_running
))
3413 idle_balance(cpu
, rq
);
3415 put_prev_task(rq
, prev
);
3416 next
= pick_next_task(rq
);
3417 clear_tsk_need_resched(prev
);
3418 rq
->skip_clock_update
= 0;
3420 if (likely(prev
!= next
)) {
3425 context_switch(rq
, prev
, next
); /* unlocks the rq */
3427 * The context switch have flipped the stack from under us
3428 * and restored the local variables which were saved when
3429 * this task called schedule() in the past. prev == current
3430 * is still correct, but it can be moved to another cpu/rq.
3432 cpu
= smp_processor_id();
3435 raw_spin_unlock_irq(&rq
->lock
);
3439 sched_preempt_enable_no_resched();
3444 static inline void sched_submit_work(struct task_struct
*tsk
)
3446 if (!tsk
->state
|| tsk_is_pi_blocked(tsk
))
3449 * If we are going to sleep and we have plugged IO queued,
3450 * make sure to submit it to avoid deadlocks.
3452 if (blk_needs_flush_plug(tsk
))
3453 blk_schedule_flush_plug(tsk
);
3456 asmlinkage
void __sched
schedule(void)
3458 struct task_struct
*tsk
= current
;
3460 sched_submit_work(tsk
);
3463 EXPORT_SYMBOL(schedule
);
3466 * schedule_preempt_disabled - called with preemption disabled
3468 * Returns with preemption disabled. Note: preempt_count must be 1
3470 void __sched
schedule_preempt_disabled(void)
3472 sched_preempt_enable_no_resched();
3477 #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
3479 static inline bool owner_running(struct mutex
*lock
, struct task_struct
*owner
)
3481 if (lock
->owner
!= owner
)
3485 * Ensure we emit the owner->on_cpu, dereference _after_ checking
3486 * lock->owner still matches owner, if that fails, owner might
3487 * point to free()d memory, if it still matches, the rcu_read_lock()
3488 * ensures the memory stays valid.
3492 return owner
->on_cpu
;
3496 * Look out! "owner" is an entirely speculative pointer
3497 * access and not reliable.
3499 int mutex_spin_on_owner(struct mutex
*lock
, struct task_struct
*owner
)
3501 if (!sched_feat(OWNER_SPIN
))
3505 while (owner_running(lock
, owner
)) {
3509 arch_mutex_cpu_relax();
3514 * We break out the loop above on need_resched() and when the
3515 * owner changed, which is a sign for heavy contention. Return
3516 * success only when lock->owner is NULL.
3518 return lock
->owner
== NULL
;
3522 #ifdef CONFIG_PREEMPT
3524 * this is the entry point to schedule() from in-kernel preemption
3525 * off of preempt_enable. Kernel preemptions off return from interrupt
3526 * occur there and call schedule directly.
3528 asmlinkage
void __sched notrace
preempt_schedule(void)
3530 struct thread_info
*ti
= current_thread_info();
3533 * If there is a non-zero preempt_count or interrupts are disabled,
3534 * we do not want to preempt the current task. Just return..
3536 if (likely(ti
->preempt_count
|| irqs_disabled()))
3540 add_preempt_count_notrace(PREEMPT_ACTIVE
);
3542 sub_preempt_count_notrace(PREEMPT_ACTIVE
);
3545 * Check again in case we missed a preemption opportunity
3546 * between schedule and now.
3549 } while (need_resched());
3551 EXPORT_SYMBOL(preempt_schedule
);
3554 * this is the entry point to schedule() from kernel preemption
3555 * off of irq context.
3556 * Note, that this is called and return with irqs disabled. This will
3557 * protect us against recursive calling from irq.
3559 asmlinkage
void __sched
preempt_schedule_irq(void)
3561 struct thread_info
*ti
= current_thread_info();
3563 /* Catch callers which need to be fixed */
3564 BUG_ON(ti
->preempt_count
|| !irqs_disabled());
3567 add_preempt_count(PREEMPT_ACTIVE
);
3570 local_irq_disable();
3571 sub_preempt_count(PREEMPT_ACTIVE
);
3574 * Check again in case we missed a preemption opportunity
3575 * between schedule and now.
3578 } while (need_resched());
3581 #endif /* CONFIG_PREEMPT */
3583 int default_wake_function(wait_queue_t
*curr
, unsigned mode
, int wake_flags
,
3586 return try_to_wake_up(curr
->private, mode
, wake_flags
);
3588 EXPORT_SYMBOL(default_wake_function
);
3591 * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
3592 * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
3593 * number) then we wake all the non-exclusive tasks and one exclusive task.
3595 * There are circumstances in which we can try to wake a task which has already
3596 * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
3597 * zero in this (rare) case, and we handle it by continuing to scan the queue.
3599 static void __wake_up_common(wait_queue_head_t
*q
, unsigned int mode
,
3600 int nr_exclusive
, int wake_flags
, void *key
)
3602 wait_queue_t
*curr
, *next
;
3604 list_for_each_entry_safe(curr
, next
, &q
->task_list
, task_list
) {
3605 unsigned flags
= curr
->flags
;
3607 if (curr
->func(curr
, mode
, wake_flags
, key
) &&
3608 (flags
& WQ_FLAG_EXCLUSIVE
) && !--nr_exclusive
)
3614 * __wake_up - wake up threads blocked on a waitqueue.
3616 * @mode: which threads
3617 * @nr_exclusive: how many wake-one or wake-many threads to wake up
3618 * @key: is directly passed to the wakeup function
3620 * It may be assumed that this function implies a write memory barrier before
3621 * changing the task state if and only if any tasks are woken up.
3623 void __wake_up(wait_queue_head_t
*q
, unsigned int mode
,
3624 int nr_exclusive
, void *key
)
3626 unsigned long flags
;
3628 spin_lock_irqsave(&q
->lock
, flags
);
3629 __wake_up_common(q
, mode
, nr_exclusive
, 0, key
);
3630 spin_unlock_irqrestore(&q
->lock
, flags
);
3632 EXPORT_SYMBOL(__wake_up
);
3635 * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
3637 void __wake_up_locked(wait_queue_head_t
*q
, unsigned int mode
, int nr
)
3639 __wake_up_common(q
, mode
, nr
, 0, NULL
);
3641 EXPORT_SYMBOL_GPL(__wake_up_locked
);
3643 void __wake_up_locked_key(wait_queue_head_t
*q
, unsigned int mode
, void *key
)
3645 __wake_up_common(q
, mode
, 1, 0, key
);
3647 EXPORT_SYMBOL_GPL(__wake_up_locked_key
);
3650 * __wake_up_sync_key - wake up threads blocked on a waitqueue.
3652 * @mode: which threads
3653 * @nr_exclusive: how many wake-one or wake-many threads to wake up
3654 * @key: opaque value to be passed to wakeup targets
3656 * The sync wakeup differs that the waker knows that it will schedule
3657 * away soon, so while the target thread will be woken up, it will not
3658 * be migrated to another CPU - ie. the two threads are 'synchronized'
3659 * with each other. This can prevent needless bouncing between CPUs.
3661 * On UP it can prevent extra preemption.
3663 * It may be assumed that this function implies a write memory barrier before
3664 * changing the task state if and only if any tasks are woken up.
3666 void __wake_up_sync_key(wait_queue_head_t
*q
, unsigned int mode
,
3667 int nr_exclusive
, void *key
)
3669 unsigned long flags
;
3670 int wake_flags
= WF_SYNC
;
3675 if (unlikely(!nr_exclusive
))
3678 spin_lock_irqsave(&q
->lock
, flags
);
3679 __wake_up_common(q
, mode
, nr_exclusive
, wake_flags
, key
);
3680 spin_unlock_irqrestore(&q
->lock
, flags
);
3682 EXPORT_SYMBOL_GPL(__wake_up_sync_key
);
3685 * __wake_up_sync - see __wake_up_sync_key()
3687 void __wake_up_sync(wait_queue_head_t
*q
, unsigned int mode
, int nr_exclusive
)
3689 __wake_up_sync_key(q
, mode
, nr_exclusive
, NULL
);
3691 EXPORT_SYMBOL_GPL(__wake_up_sync
); /* For internal use only */
3694 * complete: - signals a single thread waiting on this completion
3695 * @x: holds the state of this particular completion
3697 * This will wake up a single thread waiting on this completion. Threads will be
3698 * awakened in the same order in which they were queued.
3700 * See also complete_all(), wait_for_completion() and related routines.
3702 * It may be assumed that this function implies a write memory barrier before
3703 * changing the task state if and only if any tasks are woken up.
3705 void complete(struct completion
*x
)
3707 unsigned long flags
;
3709 spin_lock_irqsave(&x
->wait
.lock
, flags
);
3711 __wake_up_common(&x
->wait
, TASK_NORMAL
, 1, 0, NULL
);
3712 spin_unlock_irqrestore(&x
->wait
.lock
, flags
);
3714 EXPORT_SYMBOL(complete
);
3717 * complete_all: - signals all threads waiting on this completion
3718 * @x: holds the state of this particular completion
3720 * This will wake up all threads waiting on this particular completion event.
3722 * It may be assumed that this function implies a write memory barrier before
3723 * changing the task state if and only if any tasks are woken up.
3725 void complete_all(struct completion
*x
)
3727 unsigned long flags
;
3729 spin_lock_irqsave(&x
->wait
.lock
, flags
);
3730 x
->done
+= UINT_MAX
/2;
3731 __wake_up_common(&x
->wait
, TASK_NORMAL
, 0, 0, NULL
);
3732 spin_unlock_irqrestore(&x
->wait
.lock
, flags
);
3734 EXPORT_SYMBOL(complete_all
);
3736 static inline long __sched
3737 do_wait_for_common(struct completion
*x
, long timeout
, int state
)
3740 DECLARE_WAITQUEUE(wait
, current
);
3742 __add_wait_queue_tail_exclusive(&x
->wait
, &wait
);
3744 if (signal_pending_state(state
, current
)) {
3745 timeout
= -ERESTARTSYS
;
3748 __set_current_state(state
);
3749 spin_unlock_irq(&x
->wait
.lock
);
3750 timeout
= schedule_timeout(timeout
);
3751 spin_lock_irq(&x
->wait
.lock
);
3752 } while (!x
->done
&& timeout
);
3753 __remove_wait_queue(&x
->wait
, &wait
);
3758 return timeout
?: 1;
3762 wait_for_common(struct completion
*x
, long timeout
, int state
)
3766 spin_lock_irq(&x
->wait
.lock
);
3767 timeout
= do_wait_for_common(x
, timeout
, state
);
3768 spin_unlock_irq(&x
->wait
.lock
);
3773 * wait_for_completion: - waits for completion of a task
3774 * @x: holds the state of this particular completion
3776 * This waits to be signaled for completion of a specific task. It is NOT
3777 * interruptible and there is no timeout.
3779 * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
3780 * and interrupt capability. Also see complete().
3782 void __sched
wait_for_completion(struct completion
*x
)
3784 wait_for_common(x
, MAX_SCHEDULE_TIMEOUT
, TASK_UNINTERRUPTIBLE
);
3786 EXPORT_SYMBOL(wait_for_completion
);
3789 * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
3790 * @x: holds the state of this particular completion
3791 * @timeout: timeout value in jiffies
3793 * This waits for either a completion of a specific task to be signaled or for a
3794 * specified timeout to expire. The timeout is in jiffies. It is not
3797 * The return value is 0 if timed out, and positive (at least 1, or number of
3798 * jiffies left till timeout) if completed.
3800 unsigned long __sched
3801 wait_for_completion_timeout(struct completion
*x
, unsigned long timeout
)
3803 return wait_for_common(x
, timeout
, TASK_UNINTERRUPTIBLE
);
3805 EXPORT_SYMBOL(wait_for_completion_timeout
);
3808 * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
3809 * @x: holds the state of this particular completion
3811 * This waits for completion of a specific task to be signaled. It is
3814 * The return value is -ERESTARTSYS if interrupted, 0 if completed.
3816 int __sched
wait_for_completion_interruptible(struct completion
*x
)
3818 long t
= wait_for_common(x
, MAX_SCHEDULE_TIMEOUT
, TASK_INTERRUPTIBLE
);
3819 if (t
== -ERESTARTSYS
)
3823 EXPORT_SYMBOL(wait_for_completion_interruptible
);
3826 * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
3827 * @x: holds the state of this particular completion
3828 * @timeout: timeout value in jiffies
3830 * This waits for either a completion of a specific task to be signaled or for a
3831 * specified timeout to expire. It is interruptible. The timeout is in jiffies.
3833 * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
3834 * positive (at least 1, or number of jiffies left till timeout) if completed.
3837 wait_for_completion_interruptible_timeout(struct completion
*x
,
3838 unsigned long timeout
)
3840 return wait_for_common(x
, timeout
, TASK_INTERRUPTIBLE
);
3842 EXPORT_SYMBOL(wait_for_completion_interruptible_timeout
);
3845 * wait_for_completion_killable: - waits for completion of a task (killable)
3846 * @x: holds the state of this particular completion
3848 * This waits to be signaled for completion of a specific task. It can be
3849 * interrupted by a kill signal.
3851 * The return value is -ERESTARTSYS if interrupted, 0 if completed.
3853 int __sched
wait_for_completion_killable(struct completion
*x
)
3855 long t
= wait_for_common(x
, MAX_SCHEDULE_TIMEOUT
, TASK_KILLABLE
);
3856 if (t
== -ERESTARTSYS
)
3860 EXPORT_SYMBOL(wait_for_completion_killable
);
3863 * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
3864 * @x: holds the state of this particular completion
3865 * @timeout: timeout value in jiffies
3867 * This waits for either a completion of a specific task to be
3868 * signaled or for a specified timeout to expire. It can be
3869 * interrupted by a kill signal. The timeout is in jiffies.
3871 * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
3872 * positive (at least 1, or number of jiffies left till timeout) if completed.
3875 wait_for_completion_killable_timeout(struct completion
*x
,
3876 unsigned long timeout
)
3878 return wait_for_common(x
, timeout
, TASK_KILLABLE
);
3880 EXPORT_SYMBOL(wait_for_completion_killable_timeout
);
3883 * try_wait_for_completion - try to decrement a completion without blocking
3884 * @x: completion structure
3886 * Returns: 0 if a decrement cannot be done without blocking
3887 * 1 if a decrement succeeded.
3889 * If a completion is being used as a counting completion,
3890 * attempt to decrement the counter without blocking. This
3891 * enables us to avoid waiting if the resource the completion
3892 * is protecting is not available.
3894 bool try_wait_for_completion(struct completion
*x
)
3896 unsigned long flags
;
3899 spin_lock_irqsave(&x
->wait
.lock
, flags
);
3904 spin_unlock_irqrestore(&x
->wait
.lock
, flags
);
3907 EXPORT_SYMBOL(try_wait_for_completion
);
3910 * completion_done - Test to see if a completion has any waiters
3911 * @x: completion structure
3913 * Returns: 0 if there are waiters (wait_for_completion() in progress)
3914 * 1 if there are no waiters.
3917 bool completion_done(struct completion
*x
)
3919 unsigned long flags
;
3922 spin_lock_irqsave(&x
->wait
.lock
, flags
);
3925 spin_unlock_irqrestore(&x
->wait
.lock
, flags
);
3928 EXPORT_SYMBOL(completion_done
);
3931 sleep_on_common(wait_queue_head_t
*q
, int state
, long timeout
)
3933 unsigned long flags
;
3936 init_waitqueue_entry(&wait
, current
);
3938 __set_current_state(state
);
3940 spin_lock_irqsave(&q
->lock
, flags
);
3941 __add_wait_queue(q
, &wait
);
3942 spin_unlock(&q
->lock
);
3943 timeout
= schedule_timeout(timeout
);
3944 spin_lock_irq(&q
->lock
);
3945 __remove_wait_queue(q
, &wait
);
3946 spin_unlock_irqrestore(&q
->lock
, flags
);
3951 void __sched
interruptible_sleep_on(wait_queue_head_t
*q
)
3953 sleep_on_common(q
, TASK_INTERRUPTIBLE
, MAX_SCHEDULE_TIMEOUT
);
3955 EXPORT_SYMBOL(interruptible_sleep_on
);
3958 interruptible_sleep_on_timeout(wait_queue_head_t
*q
, long timeout
)
3960 return sleep_on_common(q
, TASK_INTERRUPTIBLE
, timeout
);
3962 EXPORT_SYMBOL(interruptible_sleep_on_timeout
);
3964 void __sched
sleep_on(wait_queue_head_t
*q
)
3966 sleep_on_common(q
, TASK_UNINTERRUPTIBLE
, MAX_SCHEDULE_TIMEOUT
);
3968 EXPORT_SYMBOL(sleep_on
);
3970 long __sched
sleep_on_timeout(wait_queue_head_t
*q
, long timeout
)
3972 return sleep_on_common(q
, TASK_UNINTERRUPTIBLE
, timeout
);
3974 EXPORT_SYMBOL(sleep_on_timeout
);
3976 #ifdef CONFIG_RT_MUTEXES
3979 * rt_mutex_setprio - set the current priority of a task
3981 * @prio: prio value (kernel-internal form)
3983 * This function changes the 'effective' priority of a task. It does
3984 * not touch ->normal_prio like __setscheduler().
3986 * Used by the rt_mutex code to implement priority inheritance logic.
3988 void rt_mutex_setprio(struct task_struct
*p
, int prio
)
3990 int oldprio
, on_rq
, running
;
3992 const struct sched_class
*prev_class
;
3994 BUG_ON(prio
< 0 || prio
> MAX_PRIO
);
3996 rq
= __task_rq_lock(p
);
3999 * Idle task boosting is a nono in general. There is one
4000 * exception, when PREEMPT_RT and NOHZ is active:
4002 * The idle task calls get_next_timer_interrupt() and holds
4003 * the timer wheel base->lock on the CPU and another CPU wants
4004 * to access the timer (probably to cancel it). We can safely
4005 * ignore the boosting request, as the idle CPU runs this code
4006 * with interrupts disabled and will complete the lock
4007 * protected section without being interrupted. So there is no
4008 * real need to boost.
4010 if (unlikely(p
== rq
->idle
)) {
4011 WARN_ON(p
!= rq
->curr
);
4012 WARN_ON(p
->pi_blocked_on
);
4016 trace_sched_pi_setprio(p
, prio
);
4018 prev_class
= p
->sched_class
;
4020 running
= task_current(rq
, p
);
4022 dequeue_task(rq
, p
, 0);
4024 p
->sched_class
->put_prev_task(rq
, p
);
4027 p
->sched_class
= &rt_sched_class
;
4029 p
->sched_class
= &fair_sched_class
;
4034 p
->sched_class
->set_curr_task(rq
);
4036 enqueue_task(rq
, p
, oldprio
< prio
? ENQUEUE_HEAD
: 0);
4038 check_class_changed(rq
, p
, prev_class
, oldprio
);
4040 __task_rq_unlock(rq
);
4043 void set_user_nice(struct task_struct
*p
, long nice
)
4045 int old_prio
, delta
, on_rq
;
4046 unsigned long flags
;
4049 if (TASK_NICE(p
) == nice
|| nice
< -20 || nice
> 19)
4052 * We have to be careful, if called from sys_setpriority(),
4053 * the task might be in the middle of scheduling on another CPU.
4055 rq
= task_rq_lock(p
, &flags
);
4057 * The RT priorities are set via sched_setscheduler(), but we still
4058 * allow the 'normal' nice value to be set - but as expected
4059 * it wont have any effect on scheduling until the task is
4060 * SCHED_FIFO/SCHED_RR:
4062 if (task_has_rt_policy(p
)) {
4063 p
->static_prio
= NICE_TO_PRIO(nice
);
4068 dequeue_task(rq
, p
, 0);
4070 p
->static_prio
= NICE_TO_PRIO(nice
);
4073 p
->prio
= effective_prio(p
);
4074 delta
= p
->prio
- old_prio
;
4077 enqueue_task(rq
, p
, 0);
4079 * If the task increased its priority or is running and
4080 * lowered its priority, then reschedule its CPU:
4082 if (delta
< 0 || (delta
> 0 && task_running(rq
, p
)))
4083 resched_task(rq
->curr
);
4086 task_rq_unlock(rq
, p
, &flags
);
4088 EXPORT_SYMBOL(set_user_nice
);
4091 * can_nice - check if a task can reduce its nice value
4095 int can_nice(const struct task_struct
*p
, const int nice
)
4097 /* convert nice value [19,-20] to rlimit style value [1,40] */
4098 int nice_rlim
= 20 - nice
;
4100 return (nice_rlim
<= task_rlimit(p
, RLIMIT_NICE
) ||
4101 capable(CAP_SYS_NICE
));
4104 #ifdef __ARCH_WANT_SYS_NICE
4107 * sys_nice - change the priority of the current process.
4108 * @increment: priority increment
4110 * sys_setpriority is a more generic, but much slower function that
4111 * does similar things.
4113 SYSCALL_DEFINE1(nice
, int, increment
)
4118 * Setpriority might change our priority at the same moment.
4119 * We don't have to worry. Conceptually one call occurs first
4120 * and we have a single winner.
4122 if (increment
< -40)
4127 nice
= TASK_NICE(current
) + increment
;
4133 if (increment
< 0 && !can_nice(current
, nice
))
4136 retval
= security_task_setnice(current
, nice
);
4140 set_user_nice(current
, nice
);
4147 * task_prio - return the priority value of a given task.
4148 * @p: the task in question.
4150 * This is the priority value as seen by users in /proc.
4151 * RT tasks are offset by -200. Normal tasks are centered
4152 * around 0, value goes from -16 to +15.
4154 int task_prio(const struct task_struct
*p
)
4156 return p
->prio
- MAX_RT_PRIO
;
4160 * task_nice - return the nice value of a given task.
4161 * @p: the task in question.
4163 int task_nice(const struct task_struct
*p
)
4165 return TASK_NICE(p
);
4167 EXPORT_SYMBOL(task_nice
);
4170 * idle_cpu - is a given cpu idle currently?
4171 * @cpu: the processor in question.
4173 int idle_cpu(int cpu
)
4175 struct rq
*rq
= cpu_rq(cpu
);
4177 if (rq
->curr
!= rq
->idle
)
4184 if (!llist_empty(&rq
->wake_list
))
4192 * idle_task - return the idle task for a given cpu.
4193 * @cpu: the processor in question.
4195 struct task_struct
*idle_task(int cpu
)
4197 return cpu_rq(cpu
)->idle
;
4201 * find_process_by_pid - find a process with a matching PID value.
4202 * @pid: the pid in question.
4204 static struct task_struct
*find_process_by_pid(pid_t pid
)
4206 return pid
? find_task_by_vpid(pid
) : current
;
4209 /* Actually do priority change: must hold rq lock. */
4211 __setscheduler(struct rq
*rq
, struct task_struct
*p
, int policy
, int prio
)
4214 p
->rt_priority
= prio
;
4215 p
->normal_prio
= normal_prio(p
);
4216 /* we are holding p->pi_lock already */
4217 p
->prio
= rt_mutex_getprio(p
);
4218 if (rt_prio(p
->prio
))
4219 p
->sched_class
= &rt_sched_class
;
4221 p
->sched_class
= &fair_sched_class
;
4226 * check the target process has a UID that matches the current process's
4228 static bool check_same_owner(struct task_struct
*p
)
4230 const struct cred
*cred
= current_cred(), *pcred
;
4234 pcred
= __task_cred(p
);
4235 match
= (uid_eq(cred
->euid
, pcred
->euid
) ||
4236 uid_eq(cred
->euid
, pcred
->uid
));
4241 static int __sched_setscheduler(struct task_struct
*p
, int policy
,
4242 const struct sched_param
*param
, bool user
)
4244 int retval
, oldprio
, oldpolicy
= -1, on_rq
, running
;
4245 unsigned long flags
;
4246 const struct sched_class
*prev_class
;
4250 /* may grab non-irq protected spin_locks */
4251 BUG_ON(in_interrupt());
4253 /* double check policy once rq lock held */
4255 reset_on_fork
= p
->sched_reset_on_fork
;
4256 policy
= oldpolicy
= p
->policy
;
4258 reset_on_fork
= !!(policy
& SCHED_RESET_ON_FORK
);
4259 policy
&= ~SCHED_RESET_ON_FORK
;
4261 if (policy
!= SCHED_FIFO
&& policy
!= SCHED_RR
&&
4262 policy
!= SCHED_NORMAL
&& policy
!= SCHED_BATCH
&&
4263 policy
!= SCHED_IDLE
)
4268 * Valid priorities for SCHED_FIFO and SCHED_RR are
4269 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
4270 * SCHED_BATCH and SCHED_IDLE is 0.
4272 if (param
->sched_priority
< 0 ||
4273 (p
->mm
&& param
->sched_priority
> MAX_USER_RT_PRIO
-1) ||
4274 (!p
->mm
&& param
->sched_priority
> MAX_RT_PRIO
-1))
4276 if (rt_policy(policy
) != (param
->sched_priority
!= 0))
4280 * Allow unprivileged RT tasks to decrease priority:
4282 if (user
&& !capable(CAP_SYS_NICE
)) {
4283 if (rt_policy(policy
)) {
4284 unsigned long rlim_rtprio
=
4285 task_rlimit(p
, RLIMIT_RTPRIO
);
4287 /* can't set/change the rt policy */
4288 if (policy
!= p
->policy
&& !rlim_rtprio
)
4291 /* can't increase priority */
4292 if (param
->sched_priority
> p
->rt_priority
&&
4293 param
->sched_priority
> rlim_rtprio
)
4298 * Treat SCHED_IDLE as nice 20. Only allow a switch to
4299 * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
4301 if (p
->policy
== SCHED_IDLE
&& policy
!= SCHED_IDLE
) {
4302 if (!can_nice(p
, TASK_NICE(p
)))
4306 /* can't change other user's priorities */
4307 if (!check_same_owner(p
))
4310 /* Normal users shall not reset the sched_reset_on_fork flag */
4311 if (p
->sched_reset_on_fork
&& !reset_on_fork
)
4316 retval
= security_task_setscheduler(p
);
4322 * make sure no PI-waiters arrive (or leave) while we are
4323 * changing the priority of the task:
4325 * To be able to change p->policy safely, the appropriate
4326 * runqueue lock must be held.
4328 rq
= task_rq_lock(p
, &flags
);
4331 * Changing the policy of the stop threads its a very bad idea
4333 if (p
== rq
->stop
) {
4334 task_rq_unlock(rq
, p
, &flags
);
4339 * If not changing anything there's no need to proceed further:
4341 if (unlikely(policy
== p
->policy
&& (!rt_policy(policy
) ||
4342 param
->sched_priority
== p
->rt_priority
))) {
4344 __task_rq_unlock(rq
);
4345 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
4349 #ifdef CONFIG_RT_GROUP_SCHED
4352 * Do not allow realtime tasks into groups that have no runtime
4355 if (rt_bandwidth_enabled() && rt_policy(policy
) &&
4356 task_group(p
)->rt_bandwidth
.rt_runtime
== 0 &&
4357 !task_group_is_autogroup(task_group(p
))) {
4358 task_rq_unlock(rq
, p
, &flags
);
4364 /* recheck policy now with rq lock held */
4365 if (unlikely(oldpolicy
!= -1 && oldpolicy
!= p
->policy
)) {
4366 policy
= oldpolicy
= -1;
4367 task_rq_unlock(rq
, p
, &flags
);
4371 running
= task_current(rq
, p
);
4373 dequeue_task(rq
, p
, 0);
4375 p
->sched_class
->put_prev_task(rq
, p
);
4377 p
->sched_reset_on_fork
= reset_on_fork
;
4380 prev_class
= p
->sched_class
;
4381 __setscheduler(rq
, p
, policy
, param
->sched_priority
);
4384 p
->sched_class
->set_curr_task(rq
);
4386 enqueue_task(rq
, p
, 0);
4388 check_class_changed(rq
, p
, prev_class
, oldprio
);
4389 task_rq_unlock(rq
, p
, &flags
);
4391 rt_mutex_adjust_pi(p
);
4397 * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
4398 * @p: the task in question.
4399 * @policy: new policy.
4400 * @param: structure containing the new RT priority.
4402 * NOTE that the task may be already dead.
4404 int sched_setscheduler(struct task_struct
*p
, int policy
,
4405 const struct sched_param
*param
)
4407 return __sched_setscheduler(p
, policy
, param
, true);
4409 EXPORT_SYMBOL_GPL(sched_setscheduler
);
4412 * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
4413 * @p: the task in question.
4414 * @policy: new policy.
4415 * @param: structure containing the new RT priority.
4417 * Just like sched_setscheduler, only don't bother checking if the
4418 * current context has permission. For example, this is needed in
4419 * stop_machine(): we create temporary high priority worker threads,
4420 * but our caller might not have that capability.
4422 int sched_setscheduler_nocheck(struct task_struct
*p
, int policy
,
4423 const struct sched_param
*param
)
4425 return __sched_setscheduler(p
, policy
, param
, false);
4429 do_sched_setscheduler(pid_t pid
, int policy
, struct sched_param __user
*param
)
4431 struct sched_param lparam
;
4432 struct task_struct
*p
;
4435 if (!param
|| pid
< 0)
4437 if (copy_from_user(&lparam
, param
, sizeof(struct sched_param
)))
4442 p
= find_process_by_pid(pid
);
4444 retval
= sched_setscheduler(p
, policy
, &lparam
);
4451 * sys_sched_setscheduler - set/change the scheduler policy and RT priority
4452 * @pid: the pid in question.
4453 * @policy: new policy.
4454 * @param: structure containing the new RT priority.
4456 SYSCALL_DEFINE3(sched_setscheduler
, pid_t
, pid
, int, policy
,
4457 struct sched_param __user
*, param
)
4459 /* negative values for policy are not valid */
4463 return do_sched_setscheduler(pid
, policy
, param
);
4467 * sys_sched_setparam - set/change the RT priority of a thread
4468 * @pid: the pid in question.
4469 * @param: structure containing the new RT priority.
4471 SYSCALL_DEFINE2(sched_setparam
, pid_t
, pid
, struct sched_param __user
*, param
)
4473 return do_sched_setscheduler(pid
, -1, param
);
4477 * sys_sched_getscheduler - get the policy (scheduling class) of a thread
4478 * @pid: the pid in question.
4480 SYSCALL_DEFINE1(sched_getscheduler
, pid_t
, pid
)
4482 struct task_struct
*p
;
4490 p
= find_process_by_pid(pid
);
4492 retval
= security_task_getscheduler(p
);
4495 | (p
->sched_reset_on_fork
? SCHED_RESET_ON_FORK
: 0);
4502 * sys_sched_getparam - get the RT priority of a thread
4503 * @pid: the pid in question.
4504 * @param: structure containing the RT priority.
4506 SYSCALL_DEFINE2(sched_getparam
, pid_t
, pid
, struct sched_param __user
*, param
)
4508 struct sched_param lp
;
4509 struct task_struct
*p
;
4512 if (!param
|| pid
< 0)
4516 p
= find_process_by_pid(pid
);
4521 retval
= security_task_getscheduler(p
);
4525 lp
.sched_priority
= p
->rt_priority
;
4529 * This one might sleep, we cannot do it with a spinlock held ...
4531 retval
= copy_to_user(param
, &lp
, sizeof(*param
)) ? -EFAULT
: 0;
4540 long sched_setaffinity(pid_t pid
, const struct cpumask
*in_mask
)
4542 cpumask_var_t cpus_allowed
, new_mask
;
4543 struct task_struct
*p
;
4549 p
= find_process_by_pid(pid
);
4556 /* Prevent p going away */
4560 if (!alloc_cpumask_var(&cpus_allowed
, GFP_KERNEL
)) {
4564 if (!alloc_cpumask_var(&new_mask
, GFP_KERNEL
)) {
4566 goto out_free_cpus_allowed
;
4569 if (!check_same_owner(p
) && !ns_capable(task_user_ns(p
), CAP_SYS_NICE
))
4572 retval
= security_task_setscheduler(p
);
4576 cpuset_cpus_allowed(p
, cpus_allowed
);
4577 cpumask_and(new_mask
, in_mask
, cpus_allowed
);
4579 retval
= set_cpus_allowed_ptr(p
, new_mask
);
4582 cpuset_cpus_allowed(p
, cpus_allowed
);
4583 if (!cpumask_subset(new_mask
, cpus_allowed
)) {
4585 * We must have raced with a concurrent cpuset
4586 * update. Just reset the cpus_allowed to the
4587 * cpuset's cpus_allowed
4589 cpumask_copy(new_mask
, cpus_allowed
);
4594 free_cpumask_var(new_mask
);
4595 out_free_cpus_allowed
:
4596 free_cpumask_var(cpus_allowed
);
4603 static int get_user_cpu_mask(unsigned long __user
*user_mask_ptr
, unsigned len
,
4604 struct cpumask
*new_mask
)
4606 if (len
< cpumask_size())
4607 cpumask_clear(new_mask
);
4608 else if (len
> cpumask_size())
4609 len
= cpumask_size();
4611 return copy_from_user(new_mask
, user_mask_ptr
, len
) ? -EFAULT
: 0;
4615 * sys_sched_setaffinity - set the cpu affinity of a process
4616 * @pid: pid of the process
4617 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
4618 * @user_mask_ptr: user-space pointer to the new cpu mask
4620 SYSCALL_DEFINE3(sched_setaffinity
, pid_t
, pid
, unsigned int, len
,
4621 unsigned long __user
*, user_mask_ptr
)
4623 cpumask_var_t new_mask
;
4626 if (!alloc_cpumask_var(&new_mask
, GFP_KERNEL
))
4629 retval
= get_user_cpu_mask(user_mask_ptr
, len
, new_mask
);
4631 retval
= sched_setaffinity(pid
, new_mask
);
4632 free_cpumask_var(new_mask
);
4636 long sched_getaffinity(pid_t pid
, struct cpumask
*mask
)
4638 struct task_struct
*p
;
4639 unsigned long flags
;
4646 p
= find_process_by_pid(pid
);
4650 retval
= security_task_getscheduler(p
);
4654 raw_spin_lock_irqsave(&p
->pi_lock
, flags
);
4655 cpumask_and(mask
, &p
->cpus_allowed
, cpu_online_mask
);
4656 raw_spin_unlock_irqrestore(&p
->pi_lock
, flags
);
4666 * sys_sched_getaffinity - get the cpu affinity of a process
4667 * @pid: pid of the process
4668 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
4669 * @user_mask_ptr: user-space pointer to hold the current cpu mask
4671 SYSCALL_DEFINE3(sched_getaffinity
, pid_t
, pid
, unsigned int, len
,
4672 unsigned long __user
*, user_mask_ptr
)
4677 if ((len
* BITS_PER_BYTE
) < nr_cpu_ids
)
4679 if (len
& (sizeof(unsigned long)-1))
4682 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
))
4685 ret
= sched_getaffinity(pid
, mask
);
4687 size_t retlen
= min_t(size_t, len
, cpumask_size());
4689 if (copy_to_user(user_mask_ptr
, mask
, retlen
))
4694 free_cpumask_var(mask
);
4700 * sys_sched_yield - yield the current processor to other threads.
4702 * This function yields the current CPU to other tasks. If there are no
4703 * other threads running on this CPU then this function will return.
4705 SYSCALL_DEFINE0(sched_yield
)
4707 struct rq
*rq
= this_rq_lock();
4709 schedstat_inc(rq
, yld_count
);
4710 current
->sched_class
->yield_task(rq
);
4713 * Since we are going to call schedule() anyway, there's
4714 * no need to preempt or enable interrupts:
4716 __release(rq
->lock
);
4717 spin_release(&rq
->lock
.dep_map
, 1, _THIS_IP_
);
4718 do_raw_spin_unlock(&rq
->lock
);
4719 sched_preempt_enable_no_resched();
4726 static inline int should_resched(void)
4728 return need_resched() && !(preempt_count() & PREEMPT_ACTIVE
);
4731 static void __cond_resched(void)
4733 add_preempt_count(PREEMPT_ACTIVE
);
4735 sub_preempt_count(PREEMPT_ACTIVE
);
4738 int __sched
_cond_resched(void)
4740 if (should_resched()) {
4746 EXPORT_SYMBOL(_cond_resched
);
4749 * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
4750 * call schedule, and on return reacquire the lock.
4752 * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
4753 * operations here to prevent schedule() from being called twice (once via
4754 * spin_unlock(), once by hand).
4756 int __cond_resched_lock(spinlock_t
*lock
)
4758 int resched
= should_resched();
4761 lockdep_assert_held(lock
);
4763 if (spin_needbreak(lock
) || resched
) {
4774 EXPORT_SYMBOL(__cond_resched_lock
);
4776 int __sched
__cond_resched_softirq(void)
4778 BUG_ON(!in_softirq());
4780 if (should_resched()) {
4788 EXPORT_SYMBOL(__cond_resched_softirq
);
4791 * yield - yield the current processor to other threads.
4793 * Do not ever use this function, there's a 99% chance you're doing it wrong.
4795 * The scheduler is at all times free to pick the calling task as the most
4796 * eligible task to run, if removing the yield() call from your code breaks
4797 * it, its already broken.
4799 * Typical broken usage is:
4804 * where one assumes that yield() will let 'the other' process run that will
4805 * make event true. If the current task is a SCHED_FIFO task that will never
4806 * happen. Never use yield() as a progress guarantee!!
4808 * If you want to use yield() to wait for something, use wait_event().
4809 * If you want to use yield() to be 'nice' for others, use cond_resched().
4810 * If you still want to use yield(), do not!
4812 void __sched
yield(void)
4814 set_current_state(TASK_RUNNING
);
4817 EXPORT_SYMBOL(yield
);
4820 * yield_to - yield the current processor to another thread in
4821 * your thread group, or accelerate that thread toward the
4822 * processor it's on.
4824 * @preempt: whether task preemption is allowed or not
4826 * It's the caller's job to ensure that the target task struct
4827 * can't go away on us before we can do any checks.
4829 * Returns true if we indeed boosted the target task.
4831 bool __sched
yield_to(struct task_struct
*p
, bool preempt
)
4833 struct task_struct
*curr
= current
;
4834 struct rq
*rq
, *p_rq
;
4835 unsigned long flags
;
4838 local_irq_save(flags
);
4843 double_rq_lock(rq
, p_rq
);
4844 while (task_rq(p
) != p_rq
) {
4845 double_rq_unlock(rq
, p_rq
);
4849 if (!curr
->sched_class
->yield_to_task
)
4852 if (curr
->sched_class
!= p
->sched_class
)
4855 if (task_running(p_rq
, p
) || p
->state
)
4858 yielded
= curr
->sched_class
->yield_to_task(rq
, p
, preempt
);
4860 schedstat_inc(rq
, yld_count
);
4862 * Make p's CPU reschedule; pick_next_entity takes care of
4865 if (preempt
&& rq
!= p_rq
)
4866 resched_task(p_rq
->curr
);
4869 * We might have set it in task_yield_fair(), but are
4870 * not going to schedule(), so don't want to skip
4873 rq
->skip_clock_update
= 0;
4877 double_rq_unlock(rq
, p_rq
);
4878 local_irq_restore(flags
);
4885 EXPORT_SYMBOL_GPL(yield_to
);
4888 * This task is about to go to sleep on IO. Increment rq->nr_iowait so
4889 * that process accounting knows that this is a task in IO wait state.
4891 void __sched
io_schedule(void)
4893 struct rq
*rq
= raw_rq();
4895 delayacct_blkio_start();
4896 atomic_inc(&rq
->nr_iowait
);
4897 blk_flush_plug(current
);
4898 current
->in_iowait
= 1;
4900 current
->in_iowait
= 0;
4901 atomic_dec(&rq
->nr_iowait
);
4902 delayacct_blkio_end();
4904 EXPORT_SYMBOL(io_schedule
);
4906 long __sched
io_schedule_timeout(long timeout
)
4908 struct rq
*rq
= raw_rq();
4911 delayacct_blkio_start();
4912 atomic_inc(&rq
->nr_iowait
);
4913 blk_flush_plug(current
);
4914 current
->in_iowait
= 1;
4915 ret
= schedule_timeout(timeout
);
4916 current
->in_iowait
= 0;
4917 atomic_dec(&rq
->nr_iowait
);
4918 delayacct_blkio_end();
4923 * sys_sched_get_priority_max - return maximum RT priority.
4924 * @policy: scheduling class.
4926 * this syscall returns the maximum rt_priority that can be used
4927 * by a given scheduling class.
4929 SYSCALL_DEFINE1(sched_get_priority_max
, int, policy
)
4936 ret
= MAX_USER_RT_PRIO
-1;
4948 * sys_sched_get_priority_min - return minimum RT priority.
4949 * @policy: scheduling class.
4951 * this syscall returns the minimum rt_priority that can be used
4952 * by a given scheduling class.
4954 SYSCALL_DEFINE1(sched_get_priority_min
, int, policy
)
4972 * sys_sched_rr_get_interval - return the default timeslice of a process.
4973 * @pid: pid of the process.
4974 * @interval: userspace pointer to the timeslice value.
4976 * this syscall writes the default timeslice value of a given process
4977 * into the user-space timespec buffer. A value of '0' means infinity.
4979 SYSCALL_DEFINE2(sched_rr_get_interval
, pid_t
, pid
,
4980 struct timespec __user
*, interval
)
4982 struct task_struct
*p
;
4983 unsigned int time_slice
;
4984 unsigned long flags
;
4994 p
= find_process_by_pid(pid
);
4998 retval
= security_task_getscheduler(p
);
5002 rq
= task_rq_lock(p
, &flags
);
5003 time_slice
= p
->sched_class
->get_rr_interval(rq
, p
);
5004 task_rq_unlock(rq
, p
, &flags
);
5007 jiffies_to_timespec(time_slice
, &t
);
5008 retval
= copy_to_user(interval
, &t
, sizeof(t
)) ? -EFAULT
: 0;
5016 static const char stat_nam
[] = TASK_STATE_TO_CHAR_STR
;
5018 void sched_show_task(struct task_struct
*p
)
5020 unsigned long free
= 0;
5023 state
= p
->state
? __ffs(p
->state
) + 1 : 0;
5024 printk(KERN_INFO
"%-15.15s %c", p
->comm
,
5025 state
< sizeof(stat_nam
) - 1 ? stat_nam
[state
] : '?');
5026 #if BITS_PER_LONG == 32
5027 if (state
== TASK_RUNNING
)
5028 printk(KERN_CONT
" running ");
5030 printk(KERN_CONT
" %08lx ", thread_saved_pc(p
));
5032 if (state
== TASK_RUNNING
)
5033 printk(KERN_CONT
" running task ");
5035 printk(KERN_CONT
" %016lx ", thread_saved_pc(p
));
5037 #ifdef CONFIG_DEBUG_STACK_USAGE
5038 free
= stack_not_used(p
);
5040 printk(KERN_CONT
"%5lu %5d %6d 0x%08lx\n", free
,
5041 task_pid_nr(p
), task_pid_nr(rcu_dereference(p
->real_parent
)),
5042 (unsigned long)task_thread_info(p
)->flags
);
5044 show_stack(p
, NULL
);
5047 void show_state_filter(unsigned long state_filter
)
5049 struct task_struct
*g
, *p
;
5051 #if BITS_PER_LONG == 32
5053 " task PC stack pid father\n");
5056 " task PC stack pid father\n");
5059 do_each_thread(g
, p
) {
5061 * reset the NMI-timeout, listing all files on a slow
5062 * console might take a lot of time:
5064 touch_nmi_watchdog();
5065 if (!state_filter
|| (p
->state
& state_filter
))
5067 } while_each_thread(g
, p
);
5069 touch_all_softlockup_watchdogs();
5071 #ifdef CONFIG_SCHED_DEBUG
5072 sysrq_sched_debug_show();
5076 * Only show locks if all tasks are dumped:
5079 debug_show_all_locks();
5082 void __cpuinit
init_idle_bootup_task(struct task_struct
*idle
)
5084 idle
->sched_class
= &idle_sched_class
;
5088 * init_idle - set up an idle thread for a given CPU
5089 * @idle: task in question
5090 * @cpu: cpu the idle task belongs to
5092 * NOTE: this function does not set the idle thread's NEED_RESCHED
5093 * flag, to make booting more robust.
5095 void __cpuinit
init_idle(struct task_struct
*idle
, int cpu
)
5097 struct rq
*rq
= cpu_rq(cpu
);
5098 unsigned long flags
;
5100 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5103 idle
->state
= TASK_RUNNING
;
5104 idle
->se
.exec_start
= sched_clock();
5106 do_set_cpus_allowed(idle
, cpumask_of(cpu
));
5108 * We're having a chicken and egg problem, even though we are
5109 * holding rq->lock, the cpu isn't yet set to this cpu so the
5110 * lockdep check in task_group() will fail.
5112 * Similar case to sched_fork(). / Alternatively we could
5113 * use task_rq_lock() here and obtain the other rq->lock.
5118 __set_task_cpu(idle
, cpu
);
5121 rq
->curr
= rq
->idle
= idle
;
5122 #if defined(CONFIG_SMP)
5125 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5127 /* Set the preempt count _outside_ the spinlocks! */
5128 task_thread_info(idle
)->preempt_count
= 0;
5131 * The idle tasks have their own, simple scheduling class:
5133 idle
->sched_class
= &idle_sched_class
;
5134 ftrace_graph_init_idle_task(idle
, cpu
);
5135 #if defined(CONFIG_SMP)
5136 sprintf(idle
->comm
, "%s/%d", INIT_TASK_COMM
, cpu
);
5141 void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
)
5143 if (p
->sched_class
&& p
->sched_class
->set_cpus_allowed
)
5144 p
->sched_class
->set_cpus_allowed(p
, new_mask
);
5146 cpumask_copy(&p
->cpus_allowed
, new_mask
);
5147 p
->nr_cpus_allowed
= cpumask_weight(new_mask
);
5151 * This is how migration works:
5153 * 1) we invoke migration_cpu_stop() on the target CPU using
5155 * 2) stopper starts to run (implicitly forcing the migrated thread
5157 * 3) it checks whether the migrated task is still in the wrong runqueue.
5158 * 4) if it's in the wrong runqueue then the migration thread removes
5159 * it and puts it into the right queue.
5160 * 5) stopper completes and stop_one_cpu() returns and the migration
5165 * Change a given task's CPU affinity. Migrate the thread to a
5166 * proper CPU and schedule it away if the CPU it's executing on
5167 * is removed from the allowed bitmask.
5169 * NOTE: the caller must have a valid reference to the task, the
5170 * task must not exit() & deallocate itself prematurely. The
5171 * call is not atomic; no spinlocks may be held.
5173 int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
)
5175 unsigned long flags
;
5177 unsigned int dest_cpu
;
5180 rq
= task_rq_lock(p
, &flags
);
5182 if (cpumask_equal(&p
->cpus_allowed
, new_mask
))
5185 if (!cpumask_intersects(new_mask
, cpu_active_mask
)) {
5190 if (unlikely((p
->flags
& PF_THREAD_BOUND
) && p
!= current
)) {
5195 do_set_cpus_allowed(p
, new_mask
);
5197 /* Can the task run on the task's current CPU? If so, we're done */
5198 if (cpumask_test_cpu(task_cpu(p
), new_mask
))
5201 dest_cpu
= cpumask_any_and(cpu_active_mask
, new_mask
);
5203 struct migration_arg arg
= { p
, dest_cpu
};
5204 /* Need help from migration thread: drop lock and wait. */
5205 task_rq_unlock(rq
, p
, &flags
);
5206 stop_one_cpu(cpu_of(rq
), migration_cpu_stop
, &arg
);
5207 tlb_migrate_finish(p
->mm
);
5211 task_rq_unlock(rq
, p
, &flags
);
5215 EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr
);
5218 * Move (not current) task off this cpu, onto dest cpu. We're doing
5219 * this because either it can't run here any more (set_cpus_allowed()
5220 * away from this CPU, or CPU going down), or because we're
5221 * attempting to rebalance this task on exec (sched_exec).
5223 * So we race with normal scheduler movements, but that's OK, as long
5224 * as the task is no longer on this CPU.
5226 * Returns non-zero if task was successfully migrated.
5228 static int __migrate_task(struct task_struct
*p
, int src_cpu
, int dest_cpu
)
5230 struct rq
*rq_dest
, *rq_src
;
5233 if (unlikely(!cpu_active(dest_cpu
)))
5236 rq_src
= cpu_rq(src_cpu
);
5237 rq_dest
= cpu_rq(dest_cpu
);
5239 raw_spin_lock(&p
->pi_lock
);
5240 double_rq_lock(rq_src
, rq_dest
);
5241 /* Already moved. */
5242 if (task_cpu(p
) != src_cpu
)
5244 /* Affinity changed (again). */
5245 if (!cpumask_test_cpu(dest_cpu
, tsk_cpus_allowed(p
)))
5249 * If we're not on a rq, the next wake-up will ensure we're
5253 dequeue_task(rq_src
, p
, 0);
5254 set_task_cpu(p
, dest_cpu
);
5255 enqueue_task(rq_dest
, p
, 0);
5256 check_preempt_curr(rq_dest
, p
, 0);
5261 double_rq_unlock(rq_src
, rq_dest
);
5262 raw_spin_unlock(&p
->pi_lock
);
5267 * migration_cpu_stop - this will be executed by a highprio stopper thread
5268 * and performs thread migration by bumping thread off CPU then
5269 * 'pushing' onto another runqueue.
5271 static int migration_cpu_stop(void *data
)
5273 struct migration_arg
*arg
= data
;
5276 * The original target cpu might have gone down and we might
5277 * be on another cpu but it doesn't matter.
5279 local_irq_disable();
5280 __migrate_task(arg
->task
, raw_smp_processor_id(), arg
->dest_cpu
);
5285 #ifdef CONFIG_HOTPLUG_CPU
5288 * Ensures that the idle task is using init_mm right before its cpu goes
5291 void idle_task_exit(void)
5293 struct mm_struct
*mm
= current
->active_mm
;
5295 BUG_ON(cpu_online(smp_processor_id()));
5298 switch_mm(mm
, &init_mm
, current
);
5303 * While a dead CPU has no uninterruptible tasks queued at this point,
5304 * it might still have a nonzero ->nr_uninterruptible counter, because
5305 * for performance reasons the counter is not stricly tracking tasks to
5306 * their home CPUs. So we just add the counter to another CPU's counter,
5307 * to keep the global sum constant after CPU-down:
5309 static void migrate_nr_uninterruptible(struct rq
*rq_src
)
5311 struct rq
*rq_dest
= cpu_rq(cpumask_any(cpu_active_mask
));
5313 rq_dest
->nr_uninterruptible
+= rq_src
->nr_uninterruptible
;
5314 rq_src
->nr_uninterruptible
= 0;
5318 * remove the tasks which were accounted by rq from calc_load_tasks.
5320 static void calc_global_load_remove(struct rq
*rq
)
5322 atomic_long_sub(rq
->calc_load_active
, &calc_load_tasks
);
5323 rq
->calc_load_active
= 0;
5327 * Migrate all tasks from the rq, sleeping tasks will be migrated by
5328 * try_to_wake_up()->select_task_rq().
5330 * Called with rq->lock held even though we'er in stop_machine() and
5331 * there's no concurrency possible, we hold the required locks anyway
5332 * because of lock validation efforts.
5334 static void migrate_tasks(unsigned int dead_cpu
)
5336 struct rq
*rq
= cpu_rq(dead_cpu
);
5337 struct task_struct
*next
, *stop
= rq
->stop
;
5341 * Fudge the rq selection such that the below task selection loop
5342 * doesn't get stuck on the currently eligible stop task.
5344 * We're currently inside stop_machine() and the rq is either stuck
5345 * in the stop_machine_cpu_stop() loop, or we're executing this code,
5346 * either way we should never end up calling schedule() until we're
5351 /* Ensure any throttled groups are reachable by pick_next_task */
5352 unthrottle_offline_cfs_rqs(rq
);
5356 * There's this thread running, bail when that's the only
5359 if (rq
->nr_running
== 1)
5362 next
= pick_next_task(rq
);
5364 next
->sched_class
->put_prev_task(rq
, next
);
5366 /* Find suitable destination for @next, with force if needed. */
5367 dest_cpu
= select_fallback_rq(dead_cpu
, next
);
5368 raw_spin_unlock(&rq
->lock
);
5370 __migrate_task(next
, dead_cpu
, dest_cpu
);
5372 raw_spin_lock(&rq
->lock
);
5378 #endif /* CONFIG_HOTPLUG_CPU */
5380 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
5382 static struct ctl_table sd_ctl_dir
[] = {
5384 .procname
= "sched_domain",
5390 static struct ctl_table sd_ctl_root
[] = {
5392 .procname
= "kernel",
5394 .child
= sd_ctl_dir
,
5399 static struct ctl_table
*sd_alloc_ctl_entry(int n
)
5401 struct ctl_table
*entry
=
5402 kcalloc(n
, sizeof(struct ctl_table
), GFP_KERNEL
);
5407 static void sd_free_ctl_entry(struct ctl_table
**tablep
)
5409 struct ctl_table
*entry
;
5412 * In the intermediate directories, both the child directory and
5413 * procname are dynamically allocated and could fail but the mode
5414 * will always be set. In the lowest directory the names are
5415 * static strings and all have proc handlers.
5417 for (entry
= *tablep
; entry
->mode
; entry
++) {
5419 sd_free_ctl_entry(&entry
->child
);
5420 if (entry
->proc_handler
== NULL
)
5421 kfree(entry
->procname
);
5429 set_table_entry(struct ctl_table
*entry
,
5430 const char *procname
, void *data
, int maxlen
,
5431 umode_t mode
, proc_handler
*proc_handler
)
5433 entry
->procname
= procname
;
5435 entry
->maxlen
= maxlen
;
5437 entry
->proc_handler
= proc_handler
;
5440 static struct ctl_table
*
5441 sd_alloc_ctl_domain_table(struct sched_domain
*sd
)
5443 struct ctl_table
*table
= sd_alloc_ctl_entry(13);
5448 set_table_entry(&table
[0], "min_interval", &sd
->min_interval
,
5449 sizeof(long), 0644, proc_doulongvec_minmax
);
5450 set_table_entry(&table
[1], "max_interval", &sd
->max_interval
,
5451 sizeof(long), 0644, proc_doulongvec_minmax
);
5452 set_table_entry(&table
[2], "busy_idx", &sd
->busy_idx
,
5453 sizeof(int), 0644, proc_dointvec_minmax
);
5454 set_table_entry(&table
[3], "idle_idx", &sd
->idle_idx
,
5455 sizeof(int), 0644, proc_dointvec_minmax
);
5456 set_table_entry(&table
[4], "newidle_idx", &sd
->newidle_idx
,
5457 sizeof(int), 0644, proc_dointvec_minmax
);
5458 set_table_entry(&table
[5], "wake_idx", &sd
->wake_idx
,
5459 sizeof(int), 0644, proc_dointvec_minmax
);
5460 set_table_entry(&table
[6], "forkexec_idx", &sd
->forkexec_idx
,
5461 sizeof(int), 0644, proc_dointvec_minmax
);
5462 set_table_entry(&table
[7], "busy_factor", &sd
->busy_factor
,
5463 sizeof(int), 0644, proc_dointvec_minmax
);
5464 set_table_entry(&table
[8], "imbalance_pct", &sd
->imbalance_pct
,
5465 sizeof(int), 0644, proc_dointvec_minmax
);
5466 set_table_entry(&table
[9], "cache_nice_tries",
5467 &sd
->cache_nice_tries
,
5468 sizeof(int), 0644, proc_dointvec_minmax
);
5469 set_table_entry(&table
[10], "flags", &sd
->flags
,
5470 sizeof(int), 0644, proc_dointvec_minmax
);
5471 set_table_entry(&table
[11], "name", sd
->name
,
5472 CORENAME_MAX_SIZE
, 0444, proc_dostring
);
5473 /* &table[12] is terminator */
5478 static ctl_table
*sd_alloc_ctl_cpu_table(int cpu
)
5480 struct ctl_table
*entry
, *table
;
5481 struct sched_domain
*sd
;
5482 int domain_num
= 0, i
;
5485 for_each_domain(cpu
, sd
)
5487 entry
= table
= sd_alloc_ctl_entry(domain_num
+ 1);
5492 for_each_domain(cpu
, sd
) {
5493 snprintf(buf
, 32, "domain%d", i
);
5494 entry
->procname
= kstrdup(buf
, GFP_KERNEL
);
5496 entry
->child
= sd_alloc_ctl_domain_table(sd
);
5503 static struct ctl_table_header
*sd_sysctl_header
;
5504 static void register_sched_domain_sysctl(void)
5506 int i
, cpu_num
= num_possible_cpus();
5507 struct ctl_table
*entry
= sd_alloc_ctl_entry(cpu_num
+ 1);
5510 WARN_ON(sd_ctl_dir
[0].child
);
5511 sd_ctl_dir
[0].child
= entry
;
5516 for_each_possible_cpu(i
) {
5517 snprintf(buf
, 32, "cpu%d", i
);
5518 entry
->procname
= kstrdup(buf
, GFP_KERNEL
);
5520 entry
->child
= sd_alloc_ctl_cpu_table(i
);
5524 WARN_ON(sd_sysctl_header
);
5525 sd_sysctl_header
= register_sysctl_table(sd_ctl_root
);
5528 /* may be called multiple times per register */
5529 static void unregister_sched_domain_sysctl(void)
5531 if (sd_sysctl_header
)
5532 unregister_sysctl_table(sd_sysctl_header
);
5533 sd_sysctl_header
= NULL
;
5534 if (sd_ctl_dir
[0].child
)
5535 sd_free_ctl_entry(&sd_ctl_dir
[0].child
);
5538 static void register_sched_domain_sysctl(void)
5541 static void unregister_sched_domain_sysctl(void)
5546 static void set_rq_online(struct rq
*rq
)
5549 const struct sched_class
*class;
5551 cpumask_set_cpu(rq
->cpu
, rq
->rd
->online
);
5554 for_each_class(class) {
5555 if (class->rq_online
)
5556 class->rq_online(rq
);
5561 static void set_rq_offline(struct rq
*rq
)
5564 const struct sched_class
*class;
5566 for_each_class(class) {
5567 if (class->rq_offline
)
5568 class->rq_offline(rq
);
5571 cpumask_clear_cpu(rq
->cpu
, rq
->rd
->online
);
5577 * migration_call - callback that gets triggered when a CPU is added.
5578 * Here we can start up the necessary migration thread for the new CPU.
5580 static int __cpuinit
5581 migration_call(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
)
5583 int cpu
= (long)hcpu
;
5584 unsigned long flags
;
5585 struct rq
*rq
= cpu_rq(cpu
);
5587 switch (action
& ~CPU_TASKS_FROZEN
) {
5589 case CPU_UP_PREPARE
:
5590 rq
->calc_load_update
= calc_load_update
;
5594 /* Update our root-domain */
5595 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5597 BUG_ON(!cpumask_test_cpu(cpu
, rq
->rd
->span
));
5601 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5604 #ifdef CONFIG_HOTPLUG_CPU
5606 sched_ttwu_pending();
5607 /* Update our root-domain */
5608 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5610 BUG_ON(!cpumask_test_cpu(cpu
, rq
->rd
->span
));
5614 BUG_ON(rq
->nr_running
!= 1); /* the migration thread */
5615 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5617 migrate_nr_uninterruptible(rq
);
5618 calc_global_load_remove(rq
);
5623 update_max_interval();
5629 * Register at high priority so that task migration (migrate_all_tasks)
5630 * happens before everything else. This has to be lower priority than
5631 * the notifier in the perf_event subsystem, though.
5633 static struct notifier_block __cpuinitdata migration_notifier
= {
5634 .notifier_call
= migration_call
,
5635 .priority
= CPU_PRI_MIGRATION
,
5638 static int __cpuinit
sched_cpu_active(struct notifier_block
*nfb
,
5639 unsigned long action
, void *hcpu
)
5641 switch (action
& ~CPU_TASKS_FROZEN
) {
5643 case CPU_DOWN_FAILED
:
5644 set_cpu_active((long)hcpu
, true);
5651 static int __cpuinit
sched_cpu_inactive(struct notifier_block
*nfb
,
5652 unsigned long action
, void *hcpu
)
5654 switch (action
& ~CPU_TASKS_FROZEN
) {
5655 case CPU_DOWN_PREPARE
:
5656 set_cpu_active((long)hcpu
, false);
5663 static int __init
migration_init(void)
5665 void *cpu
= (void *)(long)smp_processor_id();
5668 /* Initialize migration for the boot CPU */
5669 err
= migration_call(&migration_notifier
, CPU_UP_PREPARE
, cpu
);
5670 BUG_ON(err
== NOTIFY_BAD
);
5671 migration_call(&migration_notifier
, CPU_ONLINE
, cpu
);
5672 register_cpu_notifier(&migration_notifier
);
5674 /* Register cpu active notifiers */
5675 cpu_notifier(sched_cpu_active
, CPU_PRI_SCHED_ACTIVE
);
5676 cpu_notifier(sched_cpu_inactive
, CPU_PRI_SCHED_INACTIVE
);
5680 early_initcall(migration_init
);
5685 static cpumask_var_t sched_domains_tmpmask
; /* sched_domains_mutex */
5687 #ifdef CONFIG_SCHED_DEBUG
5689 static __read_mostly
int sched_debug_enabled
;
5691 static int __init
sched_debug_setup(char *str
)
5693 sched_debug_enabled
= 1;
5697 early_param("sched_debug", sched_debug_setup
);
5699 static inline bool sched_debug(void)
5701 return sched_debug_enabled
;
5704 static int sched_domain_debug_one(struct sched_domain
*sd
, int cpu
, int level
,
5705 struct cpumask
*groupmask
)
5707 struct sched_group
*group
= sd
->groups
;
5710 cpulist_scnprintf(str
, sizeof(str
), sched_domain_span(sd
));
5711 cpumask_clear(groupmask
);
5713 printk(KERN_DEBUG
"%*s domain %d: ", level
, "", level
);
5715 if (!(sd
->flags
& SD_LOAD_BALANCE
)) {
5716 printk("does not load-balance\n");
5718 printk(KERN_ERR
"ERROR: !SD_LOAD_BALANCE domain"
5723 printk(KERN_CONT
"span %s level %s\n", str
, sd
->name
);
5725 if (!cpumask_test_cpu(cpu
, sched_domain_span(sd
))) {
5726 printk(KERN_ERR
"ERROR: domain->span does not contain "
5729 if (!cpumask_test_cpu(cpu
, sched_group_cpus(group
))) {
5730 printk(KERN_ERR
"ERROR: domain->groups does not contain"
5734 printk(KERN_DEBUG
"%*s groups:", level
+ 1, "");
5738 printk(KERN_ERR
"ERROR: group is NULL\n");
5743 * Even though we initialize ->power to something semi-sane,
5744 * we leave power_orig unset. This allows us to detect if
5745 * domain iteration is still funny without causing /0 traps.
5747 if (!group
->sgp
->power_orig
) {
5748 printk(KERN_CONT
"\n");
5749 printk(KERN_ERR
"ERROR: domain->cpu_power not "
5754 if (!cpumask_weight(sched_group_cpus(group
))) {
5755 printk(KERN_CONT
"\n");
5756 printk(KERN_ERR
"ERROR: empty group\n");
5760 if (!(sd
->flags
& SD_OVERLAP
) &&
5761 cpumask_intersects(groupmask
, sched_group_cpus(group
))) {
5762 printk(KERN_CONT
"\n");
5763 printk(KERN_ERR
"ERROR: repeated CPUs\n");
5767 cpumask_or(groupmask
, groupmask
, sched_group_cpus(group
));
5769 cpulist_scnprintf(str
, sizeof(str
), sched_group_cpus(group
));
5771 printk(KERN_CONT
" %s", str
);
5772 if (group
->sgp
->power
!= SCHED_POWER_SCALE
) {
5773 printk(KERN_CONT
" (cpu_power = %d)",
5777 group
= group
->next
;
5778 } while (group
!= sd
->groups
);
5779 printk(KERN_CONT
"\n");
5781 if (!cpumask_equal(sched_domain_span(sd
), groupmask
))
5782 printk(KERN_ERR
"ERROR: groups don't span domain->span\n");
5785 !cpumask_subset(groupmask
, sched_domain_span(sd
->parent
)))
5786 printk(KERN_ERR
"ERROR: parent span is not a superset "
5787 "of domain->span\n");
5791 static void sched_domain_debug(struct sched_domain
*sd
, int cpu
)
5795 if (!sched_debug_enabled
)
5799 printk(KERN_DEBUG
"CPU%d attaching NULL sched-domain.\n", cpu
);
5803 printk(KERN_DEBUG
"CPU%d attaching sched-domain:\n", cpu
);
5806 if (sched_domain_debug_one(sd
, cpu
, level
, sched_domains_tmpmask
))
5814 #else /* !CONFIG_SCHED_DEBUG */
5815 # define sched_domain_debug(sd, cpu) do { } while (0)
5816 static inline bool sched_debug(void)
5820 #endif /* CONFIG_SCHED_DEBUG */
5822 static int sd_degenerate(struct sched_domain
*sd
)
5824 if (cpumask_weight(sched_domain_span(sd
)) == 1)
5827 /* Following flags need at least 2 groups */
5828 if (sd
->flags
& (SD_LOAD_BALANCE
|
5829 SD_BALANCE_NEWIDLE
|
5833 SD_SHARE_PKG_RESOURCES
)) {
5834 if (sd
->groups
!= sd
->groups
->next
)
5838 /* Following flags don't use groups */
5839 if (sd
->flags
& (SD_WAKE_AFFINE
))
5846 sd_parent_degenerate(struct sched_domain
*sd
, struct sched_domain
*parent
)
5848 unsigned long cflags
= sd
->flags
, pflags
= parent
->flags
;
5850 if (sd_degenerate(parent
))
5853 if (!cpumask_equal(sched_domain_span(sd
), sched_domain_span(parent
)))
5856 /* Flags needing groups don't count if only 1 group in parent */
5857 if (parent
->groups
== parent
->groups
->next
) {
5858 pflags
&= ~(SD_LOAD_BALANCE
|
5859 SD_BALANCE_NEWIDLE
|
5863 SD_SHARE_PKG_RESOURCES
);
5864 if (nr_node_ids
== 1)
5865 pflags
&= ~SD_SERIALIZE
;
5867 if (~cflags
& pflags
)
5873 static void free_rootdomain(struct rcu_head
*rcu
)
5875 struct root_domain
*rd
= container_of(rcu
, struct root_domain
, rcu
);
5877 cpupri_cleanup(&rd
->cpupri
);
5878 free_cpumask_var(rd
->rto_mask
);
5879 free_cpumask_var(rd
->online
);
5880 free_cpumask_var(rd
->span
);
5884 static void rq_attach_root(struct rq
*rq
, struct root_domain
*rd
)
5886 struct root_domain
*old_rd
= NULL
;
5887 unsigned long flags
;
5889 raw_spin_lock_irqsave(&rq
->lock
, flags
);
5894 if (cpumask_test_cpu(rq
->cpu
, old_rd
->online
))
5897 cpumask_clear_cpu(rq
->cpu
, old_rd
->span
);
5900 * If we dont want to free the old_rt yet then
5901 * set old_rd to NULL to skip the freeing later
5904 if (!atomic_dec_and_test(&old_rd
->refcount
))
5908 atomic_inc(&rd
->refcount
);
5911 cpumask_set_cpu(rq
->cpu
, rd
->span
);
5912 if (cpumask_test_cpu(rq
->cpu
, cpu_active_mask
))
5915 raw_spin_unlock_irqrestore(&rq
->lock
, flags
);
5918 call_rcu_sched(&old_rd
->rcu
, free_rootdomain
);
5921 static int init_rootdomain(struct root_domain
*rd
)
5923 memset(rd
, 0, sizeof(*rd
));
5925 if (!alloc_cpumask_var(&rd
->span
, GFP_KERNEL
))
5927 if (!alloc_cpumask_var(&rd
->online
, GFP_KERNEL
))
5929 if (!alloc_cpumask_var(&rd
->rto_mask
, GFP_KERNEL
))
5932 if (cpupri_init(&rd
->cpupri
) != 0)
5937 free_cpumask_var(rd
->rto_mask
);
5939 free_cpumask_var(rd
->online
);
5941 free_cpumask_var(rd
->span
);
5947 * By default the system creates a single root-domain with all cpus as
5948 * members (mimicking the global state we have today).
5950 struct root_domain def_root_domain
;
5952 static void init_defrootdomain(void)
5954 init_rootdomain(&def_root_domain
);
5956 atomic_set(&def_root_domain
.refcount
, 1);
5959 static struct root_domain
*alloc_rootdomain(void)
5961 struct root_domain
*rd
;
5963 rd
= kmalloc(sizeof(*rd
), GFP_KERNEL
);
5967 if (init_rootdomain(rd
) != 0) {
5975 static void free_sched_groups(struct sched_group
*sg
, int free_sgp
)
5977 struct sched_group
*tmp
, *first
;
5986 if (free_sgp
&& atomic_dec_and_test(&sg
->sgp
->ref
))
5991 } while (sg
!= first
);
5994 static void free_sched_domain(struct rcu_head
*rcu
)
5996 struct sched_domain
*sd
= container_of(rcu
, struct sched_domain
, rcu
);
5999 * If its an overlapping domain it has private groups, iterate and
6002 if (sd
->flags
& SD_OVERLAP
) {
6003 free_sched_groups(sd
->groups
, 1);
6004 } else if (atomic_dec_and_test(&sd
->groups
->ref
)) {
6005 kfree(sd
->groups
->sgp
);
6011 static void destroy_sched_domain(struct sched_domain
*sd
, int cpu
)
6013 call_rcu(&sd
->rcu
, free_sched_domain
);
6016 static void destroy_sched_domains(struct sched_domain
*sd
, int cpu
)
6018 for (; sd
; sd
= sd
->parent
)
6019 destroy_sched_domain(sd
, cpu
);
6023 * Keep a special pointer to the highest sched_domain that has
6024 * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
6025 * allows us to avoid some pointer chasing select_idle_sibling().
6027 * Also keep a unique ID per domain (we use the first cpu number in
6028 * the cpumask of the domain), this allows us to quickly tell if
6029 * two cpus are in the same cache domain, see cpus_share_cache().
6031 DEFINE_PER_CPU(struct sched_domain
*, sd_llc
);
6032 DEFINE_PER_CPU(int, sd_llc_id
);
6034 static void update_top_cache_domain(int cpu
)
6036 struct sched_domain
*sd
;
6039 sd
= highest_flag_domain(cpu
, SD_SHARE_PKG_RESOURCES
);
6041 id
= cpumask_first(sched_domain_span(sd
));
6043 rcu_assign_pointer(per_cpu(sd_llc
, cpu
), sd
);
6044 per_cpu(sd_llc_id
, cpu
) = id
;
6048 * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
6049 * hold the hotplug lock.
6052 cpu_attach_domain(struct sched_domain
*sd
, struct root_domain
*rd
, int cpu
)
6054 struct rq
*rq
= cpu_rq(cpu
);
6055 struct sched_domain
*tmp
;
6057 /* Remove the sched domains which do not contribute to scheduling. */
6058 for (tmp
= sd
; tmp
; ) {
6059 struct sched_domain
*parent
= tmp
->parent
;
6063 if (sd_parent_degenerate(tmp
, parent
)) {
6064 tmp
->parent
= parent
->parent
;
6066 parent
->parent
->child
= tmp
;
6067 destroy_sched_domain(parent
, cpu
);
6072 if (sd
&& sd_degenerate(sd
)) {
6075 destroy_sched_domain(tmp
, cpu
);
6080 sched_domain_debug(sd
, cpu
);
6082 rq_attach_root(rq
, rd
);
6084 rcu_assign_pointer(rq
->sd
, sd
);
6085 destroy_sched_domains(tmp
, cpu
);
6087 update_top_cache_domain(cpu
);
6090 /* cpus with isolated domains */
6091 static cpumask_var_t cpu_isolated_map
;
6093 /* Setup the mask of cpus configured for isolated domains */
6094 static int __init
isolated_cpu_setup(char *str
)
6096 alloc_bootmem_cpumask_var(&cpu_isolated_map
);
6097 cpulist_parse(str
, cpu_isolated_map
);
6101 __setup("isolcpus=", isolated_cpu_setup
);
6103 static const struct cpumask
*cpu_cpu_mask(int cpu
)
6105 return cpumask_of_node(cpu_to_node(cpu
));
6109 struct sched_domain
**__percpu sd
;
6110 struct sched_group
**__percpu sg
;
6111 struct sched_group_power
**__percpu sgp
;
6115 struct sched_domain
** __percpu sd
;
6116 struct root_domain
*rd
;
6126 struct sched_domain_topology_level
;
6128 typedef struct sched_domain
*(*sched_domain_init_f
)(struct sched_domain_topology_level
*tl
, int cpu
);
6129 typedef const struct cpumask
*(*sched_domain_mask_f
)(int cpu
);
6131 #define SDTL_OVERLAP 0x01
6133 struct sched_domain_topology_level
{
6134 sched_domain_init_f init
;
6135 sched_domain_mask_f mask
;
6138 struct sd_data data
;
6142 * Build an iteration mask that can exclude certain CPUs from the upwards
6145 * Asymmetric node setups can result in situations where the domain tree is of
6146 * unequal depth, make sure to skip domains that already cover the entire
6149 * In that case build_sched_domains() will have terminated the iteration early
6150 * and our sibling sd spans will be empty. Domains should always include the
6151 * cpu they're built on, so check that.
6154 static void build_group_mask(struct sched_domain
*sd
, struct sched_group
*sg
)
6156 const struct cpumask
*span
= sched_domain_span(sd
);
6157 struct sd_data
*sdd
= sd
->private;
6158 struct sched_domain
*sibling
;
6161 for_each_cpu(i
, span
) {
6162 sibling
= *per_cpu_ptr(sdd
->sd
, i
);
6163 if (!cpumask_test_cpu(i
, sched_domain_span(sibling
)))
6166 cpumask_set_cpu(i
, sched_group_mask(sg
));
6171 * Return the canonical balance cpu for this group, this is the first cpu
6172 * of this group that's also in the iteration mask.
6174 int group_balance_cpu(struct sched_group
*sg
)
6176 return cpumask_first_and(sched_group_cpus(sg
), sched_group_mask(sg
));
6180 build_overlap_sched_groups(struct sched_domain
*sd
, int cpu
)
6182 struct sched_group
*first
= NULL
, *last
= NULL
, *groups
= NULL
, *sg
;
6183 const struct cpumask
*span
= sched_domain_span(sd
);
6184 struct cpumask
*covered
= sched_domains_tmpmask
;
6185 struct sd_data
*sdd
= sd
->private;
6186 struct sched_domain
*child
;
6189 cpumask_clear(covered
);
6191 for_each_cpu(i
, span
) {
6192 struct cpumask
*sg_span
;
6194 if (cpumask_test_cpu(i
, covered
))
6197 child
= *per_cpu_ptr(sdd
->sd
, i
);
6199 /* See the comment near build_group_mask(). */
6200 if (!cpumask_test_cpu(i
, sched_domain_span(child
)))
6203 sg
= kzalloc_node(sizeof(struct sched_group
) + cpumask_size(),
6204 GFP_KERNEL
, cpu_to_node(cpu
));
6209 sg_span
= sched_group_cpus(sg
);
6211 child
= child
->child
;
6212 cpumask_copy(sg_span
, sched_domain_span(child
));
6214 cpumask_set_cpu(i
, sg_span
);
6216 cpumask_or(covered
, covered
, sg_span
);
6218 sg
->sgp
= *per_cpu_ptr(sdd
->sgp
, i
);
6219 if (atomic_inc_return(&sg
->sgp
->ref
) == 1)
6220 build_group_mask(sd
, sg
);
6223 * Initialize sgp->power such that even if we mess up the
6224 * domains and no possible iteration will get us here, we won't
6227 sg
->sgp
->power
= SCHED_POWER_SCALE
* cpumask_weight(sg_span
);
6230 * Make sure the first group of this domain contains the
6231 * canonical balance cpu. Otherwise the sched_domain iteration
6232 * breaks. See update_sg_lb_stats().
6234 if ((!groups
&& cpumask_test_cpu(cpu
, sg_span
)) ||
6235 group_balance_cpu(sg
) == cpu
)
6245 sd
->groups
= groups
;
6250 free_sched_groups(first
, 0);
6255 static int get_group(int cpu
, struct sd_data
*sdd
, struct sched_group
**sg
)
6257 struct sched_domain
*sd
= *per_cpu_ptr(sdd
->sd
, cpu
);
6258 struct sched_domain
*child
= sd
->child
;
6261 cpu
= cpumask_first(sched_domain_span(child
));
6264 *sg
= *per_cpu_ptr(sdd
->sg
, cpu
);
6265 (*sg
)->sgp
= *per_cpu_ptr(sdd
->sgp
, cpu
);
6266 atomic_set(&(*sg
)->sgp
->ref
, 1); /* for claim_allocations */
6273 * build_sched_groups will build a circular linked list of the groups
6274 * covered by the given span, and will set each group's ->cpumask correctly,
6275 * and ->cpu_power to 0.
6277 * Assumes the sched_domain tree is fully constructed
6280 build_sched_groups(struct sched_domain
*sd
, int cpu
)
6282 struct sched_group
*first
= NULL
, *last
= NULL
;
6283 struct sd_data
*sdd
= sd
->private;
6284 const struct cpumask
*span
= sched_domain_span(sd
);
6285 struct cpumask
*covered
;
6288 get_group(cpu
, sdd
, &sd
->groups
);
6289 atomic_inc(&sd
->groups
->ref
);
6291 if (cpu
!= cpumask_first(sched_domain_span(sd
)))
6294 lockdep_assert_held(&sched_domains_mutex
);
6295 covered
= sched_domains_tmpmask
;
6297 cpumask_clear(covered
);
6299 for_each_cpu(i
, span
) {
6300 struct sched_group
*sg
;
6301 int group
= get_group(i
, sdd
, &sg
);
6304 if (cpumask_test_cpu(i
, covered
))
6307 cpumask_clear(sched_group_cpus(sg
));
6309 cpumask_setall(sched_group_mask(sg
));
6311 for_each_cpu(j
, span
) {
6312 if (get_group(j
, sdd
, NULL
) != group
)
6315 cpumask_set_cpu(j
, covered
);
6316 cpumask_set_cpu(j
, sched_group_cpus(sg
));
6331 * Initialize sched groups cpu_power.
6333 * cpu_power indicates the capacity of sched group, which is used while
6334 * distributing the load between different sched groups in a sched domain.
6335 * Typically cpu_power for all the groups in a sched domain will be same unless
6336 * there are asymmetries in the topology. If there are asymmetries, group
6337 * having more cpu_power will pickup more load compared to the group having
6340 static void init_sched_groups_power(int cpu
, struct sched_domain
*sd
)
6342 struct sched_group
*sg
= sd
->groups
;
6344 WARN_ON(!sd
|| !sg
);
6347 sg
->group_weight
= cpumask_weight(sched_group_cpus(sg
));
6349 } while (sg
!= sd
->groups
);
6351 if (cpu
!= group_balance_cpu(sg
))
6354 update_group_power(sd
, cpu
);
6355 atomic_set(&sg
->sgp
->nr_busy_cpus
, sg
->group_weight
);
6358 int __weak
arch_sd_sibling_asym_packing(void)
6360 return 0*SD_ASYM_PACKING
;
6364 * Initializers for schedule domains
6365 * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
6368 #ifdef CONFIG_SCHED_DEBUG
6369 # define SD_INIT_NAME(sd, type) sd->name = #type
6371 # define SD_INIT_NAME(sd, type) do { } while (0)
6374 #define SD_INIT_FUNC(type) \
6375 static noinline struct sched_domain * \
6376 sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \
6378 struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \
6379 *sd = SD_##type##_INIT; \
6380 SD_INIT_NAME(sd, type); \
6381 sd->private = &tl->data; \
6386 #ifdef CONFIG_SCHED_SMT
6387 SD_INIT_FUNC(SIBLING
)
6389 #ifdef CONFIG_SCHED_MC
6392 #ifdef CONFIG_SCHED_BOOK
6396 static int default_relax_domain_level
= -1;
6397 int sched_domain_level_max
;
6399 static int __init
setup_relax_domain_level(char *str
)
6401 if (kstrtoint(str
, 0, &default_relax_domain_level
))
6402 pr_warn("Unable to set relax_domain_level\n");
6406 __setup("relax_domain_level=", setup_relax_domain_level
);
6408 static void set_domain_attribute(struct sched_domain
*sd
,
6409 struct sched_domain_attr
*attr
)
6413 if (!attr
|| attr
->relax_domain_level
< 0) {
6414 if (default_relax_domain_level
< 0)
6417 request
= default_relax_domain_level
;
6419 request
= attr
->relax_domain_level
;
6420 if (request
< sd
->level
) {
6421 /* turn off idle balance on this domain */
6422 sd
->flags
&= ~(SD_BALANCE_WAKE
|SD_BALANCE_NEWIDLE
);
6424 /* turn on idle balance on this domain */
6425 sd
->flags
|= (SD_BALANCE_WAKE
|SD_BALANCE_NEWIDLE
);
6429 static void __sdt_free(const struct cpumask
*cpu_map
);
6430 static int __sdt_alloc(const struct cpumask
*cpu_map
);
6432 static void __free_domain_allocs(struct s_data
*d
, enum s_alloc what
,
6433 const struct cpumask
*cpu_map
)
6437 if (!atomic_read(&d
->rd
->refcount
))
6438 free_rootdomain(&d
->rd
->rcu
); /* fall through */
6440 free_percpu(d
->sd
); /* fall through */
6442 __sdt_free(cpu_map
); /* fall through */
6448 static enum s_alloc
__visit_domain_allocation_hell(struct s_data
*d
,
6449 const struct cpumask
*cpu_map
)
6451 memset(d
, 0, sizeof(*d
));
6453 if (__sdt_alloc(cpu_map
))
6454 return sa_sd_storage
;
6455 d
->sd
= alloc_percpu(struct sched_domain
*);
6457 return sa_sd_storage
;
6458 d
->rd
= alloc_rootdomain();
6461 return sa_rootdomain
;
6465 * NULL the sd_data elements we've used to build the sched_domain and
6466 * sched_group structure so that the subsequent __free_domain_allocs()
6467 * will not free the data we're using.
6469 static void claim_allocations(int cpu
, struct sched_domain
*sd
)
6471 struct sd_data
*sdd
= sd
->private;
6473 WARN_ON_ONCE(*per_cpu_ptr(sdd
->sd
, cpu
) != sd
);
6474 *per_cpu_ptr(sdd
->sd
, cpu
) = NULL
;
6476 if (atomic_read(&(*per_cpu_ptr(sdd
->sg
, cpu
))->ref
))
6477 *per_cpu_ptr(sdd
->sg
, cpu
) = NULL
;
6479 if (atomic_read(&(*per_cpu_ptr(sdd
->sgp
, cpu
))->ref
))
6480 *per_cpu_ptr(sdd
->sgp
, cpu
) = NULL
;
6483 #ifdef CONFIG_SCHED_SMT
6484 static const struct cpumask
*cpu_smt_mask(int cpu
)
6486 return topology_thread_cpumask(cpu
);
6491 * Topology list, bottom-up.
6493 static struct sched_domain_topology_level default_topology
[] = {
6494 #ifdef CONFIG_SCHED_SMT
6495 { sd_init_SIBLING
, cpu_smt_mask
, },
6497 #ifdef CONFIG_SCHED_MC
6498 { sd_init_MC
, cpu_coregroup_mask
, },
6500 #ifdef CONFIG_SCHED_BOOK
6501 { sd_init_BOOK
, cpu_book_mask
, },
6503 { sd_init_CPU
, cpu_cpu_mask
, },
6507 static struct sched_domain_topology_level
*sched_domain_topology
= default_topology
;
6511 static int sched_domains_numa_levels
;
6512 static int *sched_domains_numa_distance
;
6513 static struct cpumask
***sched_domains_numa_masks
;
6514 static int sched_domains_curr_level
;
6516 static inline int sd_local_flags(int level
)
6518 if (sched_domains_numa_distance
[level
] > RECLAIM_DISTANCE
)
6521 return SD_BALANCE_EXEC
| SD_BALANCE_FORK
| SD_WAKE_AFFINE
;
6524 static struct sched_domain
*
6525 sd_numa_init(struct sched_domain_topology_level
*tl
, int cpu
)
6527 struct sched_domain
*sd
= *per_cpu_ptr(tl
->data
.sd
, cpu
);
6528 int level
= tl
->numa_level
;
6529 int sd_weight
= cpumask_weight(
6530 sched_domains_numa_masks
[level
][cpu_to_node(cpu
)]);
6532 *sd
= (struct sched_domain
){
6533 .min_interval
= sd_weight
,
6534 .max_interval
= 2*sd_weight
,
6536 .imbalance_pct
= 125,
6537 .cache_nice_tries
= 2,
6544 .flags
= 1*SD_LOAD_BALANCE
6545 | 1*SD_BALANCE_NEWIDLE
6551 | 0*SD_SHARE_CPUPOWER
6552 | 0*SD_SHARE_PKG_RESOURCES
6554 | 0*SD_PREFER_SIBLING
6555 | sd_local_flags(level
)
6557 .last_balance
= jiffies
,
6558 .balance_interval
= sd_weight
,
6560 SD_INIT_NAME(sd
, NUMA
);
6561 sd
->private = &tl
->data
;
6564 * Ugly hack to pass state to sd_numa_mask()...
6566 sched_domains_curr_level
= tl
->numa_level
;
6571 static const struct cpumask
*sd_numa_mask(int cpu
)
6573 return sched_domains_numa_masks
[sched_domains_curr_level
][cpu_to_node(cpu
)];
6576 static void sched_numa_warn(const char *str
)
6578 static int done
= false;
6586 printk(KERN_WARNING
"ERROR: %s\n\n", str
);
6588 for (i
= 0; i
< nr_node_ids
; i
++) {
6589 printk(KERN_WARNING
" ");
6590 for (j
= 0; j
< nr_node_ids
; j
++)
6591 printk(KERN_CONT
"%02d ", node_distance(i
,j
));
6592 printk(KERN_CONT
"\n");
6594 printk(KERN_WARNING
"\n");
6597 static bool find_numa_distance(int distance
)
6601 if (distance
== node_distance(0, 0))
6604 for (i
= 0; i
< sched_domains_numa_levels
; i
++) {
6605 if (sched_domains_numa_distance
[i
] == distance
)
6612 static void sched_init_numa(void)
6614 int next_distance
, curr_distance
= node_distance(0, 0);
6615 struct sched_domain_topology_level
*tl
;
6619 sched_domains_numa_distance
= kzalloc(sizeof(int) * nr_node_ids
, GFP_KERNEL
);
6620 if (!sched_domains_numa_distance
)
6624 * O(nr_nodes^2) deduplicating selection sort -- in order to find the
6625 * unique distances in the node_distance() table.
6627 * Assumes node_distance(0,j) includes all distances in
6628 * node_distance(i,j) in order to avoid cubic time.
6630 next_distance
= curr_distance
;
6631 for (i
= 0; i
< nr_node_ids
; i
++) {
6632 for (j
= 0; j
< nr_node_ids
; j
++) {
6633 for (k
= 0; k
< nr_node_ids
; k
++) {
6634 int distance
= node_distance(i
, k
);
6636 if (distance
> curr_distance
&&
6637 (distance
< next_distance
||
6638 next_distance
== curr_distance
))
6639 next_distance
= distance
;
6642 * While not a strong assumption it would be nice to know
6643 * about cases where if node A is connected to B, B is not
6644 * equally connected to A.
6646 if (sched_debug() && node_distance(k
, i
) != distance
)
6647 sched_numa_warn("Node-distance not symmetric");
6649 if (sched_debug() && i
&& !find_numa_distance(distance
))
6650 sched_numa_warn("Node-0 not representative");
6652 if (next_distance
!= curr_distance
) {
6653 sched_domains_numa_distance
[level
++] = next_distance
;
6654 sched_domains_numa_levels
= level
;
6655 curr_distance
= next_distance
;
6660 * In case of sched_debug() we verify the above assumption.
6666 * 'level' contains the number of unique distances, excluding the
6667 * identity distance node_distance(i,i).
6669 * The sched_domains_nume_distance[] array includes the actual distance
6673 sched_domains_numa_masks
= kzalloc(sizeof(void *) * level
, GFP_KERNEL
);
6674 if (!sched_domains_numa_masks
)
6678 * Now for each level, construct a mask per node which contains all
6679 * cpus of nodes that are that many hops away from us.
6681 for (i
= 0; i
< level
; i
++) {
6682 sched_domains_numa_masks
[i
] =
6683 kzalloc(nr_node_ids
* sizeof(void *), GFP_KERNEL
);
6684 if (!sched_domains_numa_masks
[i
])
6687 for (j
= 0; j
< nr_node_ids
; j
++) {
6688 struct cpumask
*mask
= kzalloc(cpumask_size(), GFP_KERNEL
);
6692 sched_domains_numa_masks
[i
][j
] = mask
;
6694 for (k
= 0; k
< nr_node_ids
; k
++) {
6695 if (node_distance(j
, k
) > sched_domains_numa_distance
[i
])
6698 cpumask_or(mask
, mask
, cpumask_of_node(k
));
6703 tl
= kzalloc((ARRAY_SIZE(default_topology
) + level
) *
6704 sizeof(struct sched_domain_topology_level
), GFP_KERNEL
);
6709 * Copy the default topology bits..
6711 for (i
= 0; default_topology
[i
].init
; i
++)
6712 tl
[i
] = default_topology
[i
];
6715 * .. and append 'j' levels of NUMA goodness.
6717 for (j
= 0; j
< level
; i
++, j
++) {
6718 tl
[i
] = (struct sched_domain_topology_level
){
6719 .init
= sd_numa_init
,
6720 .mask
= sd_numa_mask
,
6721 .flags
= SDTL_OVERLAP
,
6726 sched_domain_topology
= tl
;
6729 static inline void sched_init_numa(void)
6732 #endif /* CONFIG_NUMA */
6734 static int __sdt_alloc(const struct cpumask
*cpu_map
)
6736 struct sched_domain_topology_level
*tl
;
6739 for (tl
= sched_domain_topology
; tl
->init
; tl
++) {
6740 struct sd_data
*sdd
= &tl
->data
;
6742 sdd
->sd
= alloc_percpu(struct sched_domain
*);
6746 sdd
->sg
= alloc_percpu(struct sched_group
*);
6750 sdd
->sgp
= alloc_percpu(struct sched_group_power
*);
6754 for_each_cpu(j
, cpu_map
) {
6755 struct sched_domain
*sd
;
6756 struct sched_group
*sg
;
6757 struct sched_group_power
*sgp
;
6759 sd
= kzalloc_node(sizeof(struct sched_domain
) + cpumask_size(),
6760 GFP_KERNEL
, cpu_to_node(j
));
6764 *per_cpu_ptr(sdd
->sd
, j
) = sd
;
6766 sg
= kzalloc_node(sizeof(struct sched_group
) + cpumask_size(),
6767 GFP_KERNEL
, cpu_to_node(j
));
6773 *per_cpu_ptr(sdd
->sg
, j
) = sg
;
6775 sgp
= kzalloc_node(sizeof(struct sched_group_power
) + cpumask_size(),
6776 GFP_KERNEL
, cpu_to_node(j
));
6780 *per_cpu_ptr(sdd
->sgp
, j
) = sgp
;
6787 static void __sdt_free(const struct cpumask
*cpu_map
)
6789 struct sched_domain_topology_level
*tl
;
6792 for (tl
= sched_domain_topology
; tl
->init
; tl
++) {
6793 struct sd_data
*sdd
= &tl
->data
;
6795 for_each_cpu(j
, cpu_map
) {
6796 struct sched_domain
*sd
;
6799 sd
= *per_cpu_ptr(sdd
->sd
, j
);
6800 if (sd
&& (sd
->flags
& SD_OVERLAP
))
6801 free_sched_groups(sd
->groups
, 0);
6802 kfree(*per_cpu_ptr(sdd
->sd
, j
));
6806 kfree(*per_cpu_ptr(sdd
->sg
, j
));
6808 kfree(*per_cpu_ptr(sdd
->sgp
, j
));
6810 free_percpu(sdd
->sd
);
6812 free_percpu(sdd
->sg
);
6814 free_percpu(sdd
->sgp
);
6819 struct sched_domain
*build_sched_domain(struct sched_domain_topology_level
*tl
,
6820 struct s_data
*d
, const struct cpumask
*cpu_map
,
6821 struct sched_domain_attr
*attr
, struct sched_domain
*child
,
6824 struct sched_domain
*sd
= tl
->init(tl
, cpu
);
6828 cpumask_and(sched_domain_span(sd
), cpu_map
, tl
->mask(cpu
));
6830 sd
->level
= child
->level
+ 1;
6831 sched_domain_level_max
= max(sched_domain_level_max
, sd
->level
);
6835 set_domain_attribute(sd
, attr
);
6841 * Build sched domains for a given set of cpus and attach the sched domains
6842 * to the individual cpus
6844 static int build_sched_domains(const struct cpumask
*cpu_map
,
6845 struct sched_domain_attr
*attr
)
6847 enum s_alloc alloc_state
= sa_none
;
6848 struct sched_domain
*sd
;
6850 int i
, ret
= -ENOMEM
;
6852 alloc_state
= __visit_domain_allocation_hell(&d
, cpu_map
);
6853 if (alloc_state
!= sa_rootdomain
)
6856 /* Set up domains for cpus specified by the cpu_map. */
6857 for_each_cpu(i
, cpu_map
) {
6858 struct sched_domain_topology_level
*tl
;
6861 for (tl
= sched_domain_topology
; tl
->init
; tl
++) {
6862 sd
= build_sched_domain(tl
, &d
, cpu_map
, attr
, sd
, i
);
6863 if (tl
->flags
& SDTL_OVERLAP
|| sched_feat(FORCE_SD_OVERLAP
))
6864 sd
->flags
|= SD_OVERLAP
;
6865 if (cpumask_equal(cpu_map
, sched_domain_span(sd
)))
6872 *per_cpu_ptr(d
.sd
, i
) = sd
;
6875 /* Build the groups for the domains */
6876 for_each_cpu(i
, cpu_map
) {
6877 for (sd
= *per_cpu_ptr(d
.sd
, i
); sd
; sd
= sd
->parent
) {
6878 sd
->span_weight
= cpumask_weight(sched_domain_span(sd
));
6879 if (sd
->flags
& SD_OVERLAP
) {
6880 if (build_overlap_sched_groups(sd
, i
))
6883 if (build_sched_groups(sd
, i
))
6889 /* Calculate CPU power for physical packages and nodes */
6890 for (i
= nr_cpumask_bits
-1; i
>= 0; i
--) {
6891 if (!cpumask_test_cpu(i
, cpu_map
))
6894 for (sd
= *per_cpu_ptr(d
.sd
, i
); sd
; sd
= sd
->parent
) {
6895 claim_allocations(i
, sd
);
6896 init_sched_groups_power(i
, sd
);
6900 /* Attach the domains */
6902 for_each_cpu(i
, cpu_map
) {
6903 sd
= *per_cpu_ptr(d
.sd
, i
);
6904 cpu_attach_domain(sd
, d
.rd
, i
);
6910 __free_domain_allocs(&d
, alloc_state
, cpu_map
);
6914 static cpumask_var_t
*doms_cur
; /* current sched domains */
6915 static int ndoms_cur
; /* number of sched domains in 'doms_cur' */
6916 static struct sched_domain_attr
*dattr_cur
;
6917 /* attribues of custom domains in 'doms_cur' */
6920 * Special case: If a kmalloc of a doms_cur partition (array of
6921 * cpumask) fails, then fallback to a single sched domain,
6922 * as determined by the single cpumask fallback_doms.
6924 static cpumask_var_t fallback_doms
;
6927 * arch_update_cpu_topology lets virtualized architectures update the
6928 * cpu core maps. It is supposed to return 1 if the topology changed
6929 * or 0 if it stayed the same.
6931 int __attribute__((weak
)) arch_update_cpu_topology(void)
6936 cpumask_var_t
*alloc_sched_domains(unsigned int ndoms
)
6939 cpumask_var_t
*doms
;
6941 doms
= kmalloc(sizeof(*doms
) * ndoms
, GFP_KERNEL
);
6944 for (i
= 0; i
< ndoms
; i
++) {
6945 if (!alloc_cpumask_var(&doms
[i
], GFP_KERNEL
)) {
6946 free_sched_domains(doms
, i
);
6953 void free_sched_domains(cpumask_var_t doms
[], unsigned int ndoms
)
6956 for (i
= 0; i
< ndoms
; i
++)
6957 free_cpumask_var(doms
[i
]);
6962 * Set up scheduler domains and groups. Callers must hold the hotplug lock.
6963 * For now this just excludes isolated cpus, but could be used to
6964 * exclude other special cases in the future.
6966 static int init_sched_domains(const struct cpumask
*cpu_map
)
6970 arch_update_cpu_topology();
6972 doms_cur
= alloc_sched_domains(ndoms_cur
);
6974 doms_cur
= &fallback_doms
;
6975 cpumask_andnot(doms_cur
[0], cpu_map
, cpu_isolated_map
);
6976 err
= build_sched_domains(doms_cur
[0], NULL
);
6977 register_sched_domain_sysctl();
6983 * Detach sched domains from a group of cpus specified in cpu_map
6984 * These cpus will now be attached to the NULL domain
6986 static void detach_destroy_domains(const struct cpumask
*cpu_map
)
6991 for_each_cpu(i
, cpu_map
)
6992 cpu_attach_domain(NULL
, &def_root_domain
, i
);
6996 /* handle null as "default" */
6997 static int dattrs_equal(struct sched_domain_attr
*cur
, int idx_cur
,
6998 struct sched_domain_attr
*new, int idx_new
)
7000 struct sched_domain_attr tmp
;
7007 return !memcmp(cur
? (cur
+ idx_cur
) : &tmp
,
7008 new ? (new + idx_new
) : &tmp
,
7009 sizeof(struct sched_domain_attr
));
7013 * Partition sched domains as specified by the 'ndoms_new'
7014 * cpumasks in the array doms_new[] of cpumasks. This compares
7015 * doms_new[] to the current sched domain partitioning, doms_cur[].
7016 * It destroys each deleted domain and builds each new domain.
7018 * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
7019 * The masks don't intersect (don't overlap.) We should setup one
7020 * sched domain for each mask. CPUs not in any of the cpumasks will
7021 * not be load balanced. If the same cpumask appears both in the
7022 * current 'doms_cur' domains and in the new 'doms_new', we can leave
7025 * The passed in 'doms_new' should be allocated using
7026 * alloc_sched_domains. This routine takes ownership of it and will
7027 * free_sched_domains it when done with it. If the caller failed the
7028 * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
7029 * and partition_sched_domains() will fallback to the single partition
7030 * 'fallback_doms', it also forces the domains to be rebuilt.
7032 * If doms_new == NULL it will be replaced with cpu_online_mask.
7033 * ndoms_new == 0 is a special case for destroying existing domains,
7034 * and it will not create the default domain.
7036 * Call with hotplug lock held
7038 void partition_sched_domains(int ndoms_new
, cpumask_var_t doms_new
[],
7039 struct sched_domain_attr
*dattr_new
)
7044 mutex_lock(&sched_domains_mutex
);
7046 /* always unregister in case we don't destroy any domains */
7047 unregister_sched_domain_sysctl();
7049 /* Let architecture update cpu core mappings. */
7050 new_topology
= arch_update_cpu_topology();
7052 n
= doms_new
? ndoms_new
: 0;
7054 /* Destroy deleted domains */
7055 for (i
= 0; i
< ndoms_cur
; i
++) {
7056 for (j
= 0; j
< n
&& !new_topology
; j
++) {
7057 if (cpumask_equal(doms_cur
[i
], doms_new
[j
])
7058 && dattrs_equal(dattr_cur
, i
, dattr_new
, j
))
7061 /* no match - a current sched domain not in new doms_new[] */
7062 detach_destroy_domains(doms_cur
[i
]);
7067 if (doms_new
== NULL
) {
7069 doms_new
= &fallback_doms
;
7070 cpumask_andnot(doms_new
[0], cpu_active_mask
, cpu_isolated_map
);
7071 WARN_ON_ONCE(dattr_new
);
7074 /* Build new domains */
7075 for (i
= 0; i
< ndoms_new
; i
++) {
7076 for (j
= 0; j
< ndoms_cur
&& !new_topology
; j
++) {
7077 if (cpumask_equal(doms_new
[i
], doms_cur
[j
])
7078 && dattrs_equal(dattr_new
, i
, dattr_cur
, j
))
7081 /* no match - add a new doms_new */
7082 build_sched_domains(doms_new
[i
], dattr_new
? dattr_new
+ i
: NULL
);
7087 /* Remember the new sched domains */
7088 if (doms_cur
!= &fallback_doms
)
7089 free_sched_domains(doms_cur
, ndoms_cur
);
7090 kfree(dattr_cur
); /* kfree(NULL) is safe */
7091 doms_cur
= doms_new
;
7092 dattr_cur
= dattr_new
;
7093 ndoms_cur
= ndoms_new
;
7095 register_sched_domain_sysctl();
7097 mutex_unlock(&sched_domains_mutex
);
7101 * Update cpusets according to cpu_active mask. If cpusets are
7102 * disabled, cpuset_update_active_cpus() becomes a simple wrapper
7103 * around partition_sched_domains().
7105 static int cpuset_cpu_active(struct notifier_block
*nfb
, unsigned long action
,
7108 switch (action
& ~CPU_TASKS_FROZEN
) {
7110 case CPU_DOWN_FAILED
:
7111 cpuset_update_active_cpus();
7118 static int cpuset_cpu_inactive(struct notifier_block
*nfb
, unsigned long action
,
7121 switch (action
& ~CPU_TASKS_FROZEN
) {
7122 case CPU_DOWN_PREPARE
:
7123 cpuset_update_active_cpus();
7130 void __init
sched_init_smp(void)
7132 cpumask_var_t non_isolated_cpus
;
7134 alloc_cpumask_var(&non_isolated_cpus
, GFP_KERNEL
);
7135 alloc_cpumask_var(&fallback_doms
, GFP_KERNEL
);
7140 mutex_lock(&sched_domains_mutex
);
7141 init_sched_domains(cpu_active_mask
);
7142 cpumask_andnot(non_isolated_cpus
, cpu_possible_mask
, cpu_isolated_map
);
7143 if (cpumask_empty(non_isolated_cpus
))
7144 cpumask_set_cpu(smp_processor_id(), non_isolated_cpus
);
7145 mutex_unlock(&sched_domains_mutex
);
7148 hotcpu_notifier(cpuset_cpu_active
, CPU_PRI_CPUSET_ACTIVE
);
7149 hotcpu_notifier(cpuset_cpu_inactive
, CPU_PRI_CPUSET_INACTIVE
);
7151 /* RT runtime code needs to handle some hotplug events */
7152 hotcpu_notifier(update_runtime
, 0);
7156 /* Move init over to a non-isolated CPU */
7157 if (set_cpus_allowed_ptr(current
, non_isolated_cpus
) < 0)
7159 sched_init_granularity();
7160 free_cpumask_var(non_isolated_cpus
);
7162 init_sched_rt_class();
7165 void __init
sched_init_smp(void)
7167 sched_init_granularity();
7169 #endif /* CONFIG_SMP */
7171 const_debug
unsigned int sysctl_timer_migration
= 1;
7173 int in_sched_functions(unsigned long addr
)
7175 return in_lock_functions(addr
) ||
7176 (addr
>= (unsigned long)__sched_text_start
7177 && addr
< (unsigned long)__sched_text_end
);
7180 #ifdef CONFIG_CGROUP_SCHED
7181 struct task_group root_task_group
;
7184 DECLARE_PER_CPU(cpumask_var_t
, load_balance_tmpmask
);
7186 void __init
sched_init(void)
7189 unsigned long alloc_size
= 0, ptr
;
7191 #ifdef CONFIG_FAIR_GROUP_SCHED
7192 alloc_size
+= 2 * nr_cpu_ids
* sizeof(void **);
7194 #ifdef CONFIG_RT_GROUP_SCHED
7195 alloc_size
+= 2 * nr_cpu_ids
* sizeof(void **);
7197 #ifdef CONFIG_CPUMASK_OFFSTACK
7198 alloc_size
+= num_possible_cpus() * cpumask_size();
7201 ptr
= (unsigned long)kzalloc(alloc_size
, GFP_NOWAIT
);
7203 #ifdef CONFIG_FAIR_GROUP_SCHED
7204 root_task_group
.se
= (struct sched_entity
**)ptr
;
7205 ptr
+= nr_cpu_ids
* sizeof(void **);
7207 root_task_group
.cfs_rq
= (struct cfs_rq
**)ptr
;
7208 ptr
+= nr_cpu_ids
* sizeof(void **);
7210 #endif /* CONFIG_FAIR_GROUP_SCHED */
7211 #ifdef CONFIG_RT_GROUP_SCHED
7212 root_task_group
.rt_se
= (struct sched_rt_entity
**)ptr
;
7213 ptr
+= nr_cpu_ids
* sizeof(void **);
7215 root_task_group
.rt_rq
= (struct rt_rq
**)ptr
;
7216 ptr
+= nr_cpu_ids
* sizeof(void **);
7218 #endif /* CONFIG_RT_GROUP_SCHED */
7219 #ifdef CONFIG_CPUMASK_OFFSTACK
7220 for_each_possible_cpu(i
) {
7221 per_cpu(load_balance_tmpmask
, i
) = (void *)ptr
;
7222 ptr
+= cpumask_size();
7224 #endif /* CONFIG_CPUMASK_OFFSTACK */
7228 init_defrootdomain();
7231 init_rt_bandwidth(&def_rt_bandwidth
,
7232 global_rt_period(), global_rt_runtime());
7234 #ifdef CONFIG_RT_GROUP_SCHED
7235 init_rt_bandwidth(&root_task_group
.rt_bandwidth
,
7236 global_rt_period(), global_rt_runtime());
7237 #endif /* CONFIG_RT_GROUP_SCHED */
7239 #ifdef CONFIG_CGROUP_SCHED
7240 list_add(&root_task_group
.list
, &task_groups
);
7241 INIT_LIST_HEAD(&root_task_group
.children
);
7242 INIT_LIST_HEAD(&root_task_group
.siblings
);
7243 autogroup_init(&init_task
);
7245 #endif /* CONFIG_CGROUP_SCHED */
7247 #ifdef CONFIG_CGROUP_CPUACCT
7248 root_cpuacct
.cpustat
= &kernel_cpustat
;
7249 root_cpuacct
.cpuusage
= alloc_percpu(u64
);
7250 /* Too early, not expected to fail */
7251 BUG_ON(!root_cpuacct
.cpuusage
);
7253 for_each_possible_cpu(i
) {
7257 raw_spin_lock_init(&rq
->lock
);
7259 rq
->calc_load_active
= 0;
7260 rq
->calc_load_update
= jiffies
+ LOAD_FREQ
;
7261 init_cfs_rq(&rq
->cfs
);
7262 init_rt_rq(&rq
->rt
, rq
);
7263 #ifdef CONFIG_FAIR_GROUP_SCHED
7264 root_task_group
.shares
= ROOT_TASK_GROUP_LOAD
;
7265 INIT_LIST_HEAD(&rq
->leaf_cfs_rq_list
);
7267 * How much cpu bandwidth does root_task_group get?
7269 * In case of task-groups formed thr' the cgroup filesystem, it
7270 * gets 100% of the cpu resources in the system. This overall
7271 * system cpu resource is divided among the tasks of
7272 * root_task_group and its child task-groups in a fair manner,
7273 * based on each entity's (task or task-group's) weight
7274 * (se->load.weight).
7276 * In other words, if root_task_group has 10 tasks of weight
7277 * 1024) and two child groups A0 and A1 (of weight 1024 each),
7278 * then A0's share of the cpu resource is:
7280 * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
7282 * We achieve this by letting root_task_group's tasks sit
7283 * directly in rq->cfs (i.e root_task_group->se[] = NULL).
7285 init_cfs_bandwidth(&root_task_group
.cfs_bandwidth
);
7286 init_tg_cfs_entry(&root_task_group
, &rq
->cfs
, NULL
, i
, NULL
);
7287 #endif /* CONFIG_FAIR_GROUP_SCHED */
7289 rq
->rt
.rt_runtime
= def_rt_bandwidth
.rt_runtime
;
7290 #ifdef CONFIG_RT_GROUP_SCHED
7291 INIT_LIST_HEAD(&rq
->leaf_rt_rq_list
);
7292 init_tg_rt_entry(&root_task_group
, &rq
->rt
, NULL
, i
, NULL
);
7295 for (j
= 0; j
< CPU_LOAD_IDX_MAX
; j
++)
7296 rq
->cpu_load
[j
] = 0;
7298 rq
->last_load_update_tick
= jiffies
;
7303 rq
->cpu_power
= SCHED_POWER_SCALE
;
7304 rq
->post_schedule
= 0;
7305 rq
->active_balance
= 0;
7306 rq
->next_balance
= jiffies
;
7311 rq
->avg_idle
= 2*sysctl_sched_migration_cost
;
7313 INIT_LIST_HEAD(&rq
->cfs_tasks
);
7315 rq_attach_root(rq
, &def_root_domain
);
7321 atomic_set(&rq
->nr_iowait
, 0);
7324 set_load_weight(&init_task
);
7326 #ifdef CONFIG_PREEMPT_NOTIFIERS
7327 INIT_HLIST_HEAD(&init_task
.preempt_notifiers
);
7330 #ifdef CONFIG_RT_MUTEXES
7331 plist_head_init(&init_task
.pi_waiters
);
7335 * The boot idle thread does lazy MMU switching as well:
7337 atomic_inc(&init_mm
.mm_count
);
7338 enter_lazy_tlb(&init_mm
, current
);
7341 * Make us the idle thread. Technically, schedule() should not be
7342 * called from this thread, however somewhere below it might be,
7343 * but because we are the idle thread, we just pick up running again
7344 * when this runqueue becomes "idle".
7346 init_idle(current
, smp_processor_id());
7348 calc_load_update
= jiffies
+ LOAD_FREQ
;
7351 * During early bootup we pretend to be a normal task:
7353 current
->sched_class
= &fair_sched_class
;
7356 zalloc_cpumask_var(&sched_domains_tmpmask
, GFP_NOWAIT
);
7357 /* May be allocated at isolcpus cmdline parse time */
7358 if (cpu_isolated_map
== NULL
)
7359 zalloc_cpumask_var(&cpu_isolated_map
, GFP_NOWAIT
);
7360 idle_thread_set_boot_cpu();
7362 init_sched_fair_class();
7364 scheduler_running
= 1;
7367 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
7368 static inline int preempt_count_equals(int preempt_offset
)
7370 int nested
= (preempt_count() & ~PREEMPT_ACTIVE
) + rcu_preempt_depth();
7372 return (nested
== preempt_offset
);
7375 void __might_sleep(const char *file
, int line
, int preempt_offset
)
7377 static unsigned long prev_jiffy
; /* ratelimiting */
7379 rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
7380 if ((preempt_count_equals(preempt_offset
) && !irqs_disabled()) ||
7381 system_state
!= SYSTEM_RUNNING
|| oops_in_progress
)
7383 if (time_before(jiffies
, prev_jiffy
+ HZ
) && prev_jiffy
)
7385 prev_jiffy
= jiffies
;
7388 "BUG: sleeping function called from invalid context at %s:%d\n",
7391 "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
7392 in_atomic(), irqs_disabled(),
7393 current
->pid
, current
->comm
);
7395 debug_show_held_locks(current
);
7396 if (irqs_disabled())
7397 print_irqtrace_events(current
);
7400 EXPORT_SYMBOL(__might_sleep
);
7403 #ifdef CONFIG_MAGIC_SYSRQ
7404 static void normalize_task(struct rq
*rq
, struct task_struct
*p
)
7406 const struct sched_class
*prev_class
= p
->sched_class
;
7407 int old_prio
= p
->prio
;
7412 dequeue_task(rq
, p
, 0);
7413 __setscheduler(rq
, p
, SCHED_NORMAL
, 0);
7415 enqueue_task(rq
, p
, 0);
7416 resched_task(rq
->curr
);
7419 check_class_changed(rq
, p
, prev_class
, old_prio
);
7422 void normalize_rt_tasks(void)
7424 struct task_struct
*g
, *p
;
7425 unsigned long flags
;
7428 read_lock_irqsave(&tasklist_lock
, flags
);
7429 do_each_thread(g
, p
) {
7431 * Only normalize user tasks:
7436 p
->se
.exec_start
= 0;
7437 #ifdef CONFIG_SCHEDSTATS
7438 p
->se
.statistics
.wait_start
= 0;
7439 p
->se
.statistics
.sleep_start
= 0;
7440 p
->se
.statistics
.block_start
= 0;
7445 * Renice negative nice level userspace
7448 if (TASK_NICE(p
) < 0 && p
->mm
)
7449 set_user_nice(p
, 0);
7453 raw_spin_lock(&p
->pi_lock
);
7454 rq
= __task_rq_lock(p
);
7456 normalize_task(rq
, p
);
7458 __task_rq_unlock(rq
);
7459 raw_spin_unlock(&p
->pi_lock
);
7460 } while_each_thread(g
, p
);
7462 read_unlock_irqrestore(&tasklist_lock
, flags
);
7465 #endif /* CONFIG_MAGIC_SYSRQ */
7467 #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
7469 * These functions are only useful for the IA64 MCA handling, or kdb.
7471 * They can only be called when the whole system has been
7472 * stopped - every CPU needs to be quiescent, and no scheduling
7473 * activity can take place. Using them for anything else would
7474 * be a serious bug, and as a result, they aren't even visible
7475 * under any other configuration.
7479 * curr_task - return the current task for a given cpu.
7480 * @cpu: the processor in question.
7482 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
7484 struct task_struct
*curr_task(int cpu
)
7486 return cpu_curr(cpu
);
7489 #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
7493 * set_curr_task - set the current task for a given cpu.
7494 * @cpu: the processor in question.
7495 * @p: the task pointer to set.
7497 * Description: This function must only be used when non-maskable interrupts
7498 * are serviced on a separate stack. It allows the architecture to switch the
7499 * notion of the current task on a cpu in a non-blocking manner. This function
7500 * must be called with all CPU's synchronized, and interrupts disabled, the
7501 * and caller must save the original value of the current task (see
7502 * curr_task() above) and restore that value before reenabling interrupts and
7503 * re-starting the system.
7505 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
7507 void set_curr_task(int cpu
, struct task_struct
*p
)
7514 #ifdef CONFIG_CGROUP_SCHED
7515 /* task_group_lock serializes the addition/removal of task groups */
7516 static DEFINE_SPINLOCK(task_group_lock
);
7518 static void free_sched_group(struct task_group
*tg
)
7520 free_fair_sched_group(tg
);
7521 free_rt_sched_group(tg
);
7526 /* allocate runqueue etc for a new task group */
7527 struct task_group
*sched_create_group(struct task_group
*parent
)
7529 struct task_group
*tg
;
7530 unsigned long flags
;
7532 tg
= kzalloc(sizeof(*tg
), GFP_KERNEL
);
7534 return ERR_PTR(-ENOMEM
);
7536 if (!alloc_fair_sched_group(tg
, parent
))
7539 if (!alloc_rt_sched_group(tg
, parent
))
7542 spin_lock_irqsave(&task_group_lock
, flags
);
7543 list_add_rcu(&tg
->list
, &task_groups
);
7545 WARN_ON(!parent
); /* root should already exist */
7547 tg
->parent
= parent
;
7548 INIT_LIST_HEAD(&tg
->children
);
7549 list_add_rcu(&tg
->siblings
, &parent
->children
);
7550 spin_unlock_irqrestore(&task_group_lock
, flags
);
7555 free_sched_group(tg
);
7556 return ERR_PTR(-ENOMEM
);
7559 /* rcu callback to free various structures associated with a task group */
7560 static void free_sched_group_rcu(struct rcu_head
*rhp
)
7562 /* now it should be safe to free those cfs_rqs */
7563 free_sched_group(container_of(rhp
, struct task_group
, rcu
));
7566 /* Destroy runqueue etc associated with a task group */
7567 void sched_destroy_group(struct task_group
*tg
)
7569 unsigned long flags
;
7572 /* end participation in shares distribution */
7573 for_each_possible_cpu(i
)
7574 unregister_fair_sched_group(tg
, i
);
7576 spin_lock_irqsave(&task_group_lock
, flags
);
7577 list_del_rcu(&tg
->list
);
7578 list_del_rcu(&tg
->siblings
);
7579 spin_unlock_irqrestore(&task_group_lock
, flags
);
7581 /* wait for possible concurrent references to cfs_rqs complete */
7582 call_rcu(&tg
->rcu
, free_sched_group_rcu
);
7585 /* change task's runqueue when it moves between groups.
7586 * The caller of this function should have put the task in its new group
7587 * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
7588 * reflect its new group.
7590 void sched_move_task(struct task_struct
*tsk
)
7593 unsigned long flags
;
7596 rq
= task_rq_lock(tsk
, &flags
);
7598 running
= task_current(rq
, tsk
);
7602 dequeue_task(rq
, tsk
, 0);
7603 if (unlikely(running
))
7604 tsk
->sched_class
->put_prev_task(rq
, tsk
);
7606 #ifdef CONFIG_FAIR_GROUP_SCHED
7607 if (tsk
->sched_class
->task_move_group
)
7608 tsk
->sched_class
->task_move_group(tsk
, on_rq
);
7611 set_task_rq(tsk
, task_cpu(tsk
));
7613 if (unlikely(running
))
7614 tsk
->sched_class
->set_curr_task(rq
);
7616 enqueue_task(rq
, tsk
, 0);
7618 task_rq_unlock(rq
, tsk
, &flags
);
7620 #endif /* CONFIG_CGROUP_SCHED */
7622 #if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH)
7623 static unsigned long to_ratio(u64 period
, u64 runtime
)
7625 if (runtime
== RUNTIME_INF
)
7628 return div64_u64(runtime
<< 20, period
);
7632 #ifdef CONFIG_RT_GROUP_SCHED
7634 * Ensure that the real time constraints are schedulable.
7636 static DEFINE_MUTEX(rt_constraints_mutex
);
7638 /* Must be called with tasklist_lock held */
7639 static inline int tg_has_rt_tasks(struct task_group
*tg
)
7641 struct task_struct
*g
, *p
;
7643 do_each_thread(g
, p
) {
7644 if (rt_task(p
) && task_rq(p
)->rt
.tg
== tg
)
7646 } while_each_thread(g
, p
);
7651 struct rt_schedulable_data
{
7652 struct task_group
*tg
;
7657 static int tg_rt_schedulable(struct task_group
*tg
, void *data
)
7659 struct rt_schedulable_data
*d
= data
;
7660 struct task_group
*child
;
7661 unsigned long total
, sum
= 0;
7662 u64 period
, runtime
;
7664 period
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7665 runtime
= tg
->rt_bandwidth
.rt_runtime
;
7668 period
= d
->rt_period
;
7669 runtime
= d
->rt_runtime
;
7673 * Cannot have more runtime than the period.
7675 if (runtime
> period
&& runtime
!= RUNTIME_INF
)
7679 * Ensure we don't starve existing RT tasks.
7681 if (rt_bandwidth_enabled() && !runtime
&& tg_has_rt_tasks(tg
))
7684 total
= to_ratio(period
, runtime
);
7687 * Nobody can have more than the global setting allows.
7689 if (total
> to_ratio(global_rt_period(), global_rt_runtime()))
7693 * The sum of our children's runtime should not exceed our own.
7695 list_for_each_entry_rcu(child
, &tg
->children
, siblings
) {
7696 period
= ktime_to_ns(child
->rt_bandwidth
.rt_period
);
7697 runtime
= child
->rt_bandwidth
.rt_runtime
;
7699 if (child
== d
->tg
) {
7700 period
= d
->rt_period
;
7701 runtime
= d
->rt_runtime
;
7704 sum
+= to_ratio(period
, runtime
);
7713 static int __rt_schedulable(struct task_group
*tg
, u64 period
, u64 runtime
)
7717 struct rt_schedulable_data data
= {
7719 .rt_period
= period
,
7720 .rt_runtime
= runtime
,
7724 ret
= walk_tg_tree(tg_rt_schedulable
, tg_nop
, &data
);
7730 static int tg_set_rt_bandwidth(struct task_group
*tg
,
7731 u64 rt_period
, u64 rt_runtime
)
7735 mutex_lock(&rt_constraints_mutex
);
7736 read_lock(&tasklist_lock
);
7737 err
= __rt_schedulable(tg
, rt_period
, rt_runtime
);
7741 raw_spin_lock_irq(&tg
->rt_bandwidth
.rt_runtime_lock
);
7742 tg
->rt_bandwidth
.rt_period
= ns_to_ktime(rt_period
);
7743 tg
->rt_bandwidth
.rt_runtime
= rt_runtime
;
7745 for_each_possible_cpu(i
) {
7746 struct rt_rq
*rt_rq
= tg
->rt_rq
[i
];
7748 raw_spin_lock(&rt_rq
->rt_runtime_lock
);
7749 rt_rq
->rt_runtime
= rt_runtime
;
7750 raw_spin_unlock(&rt_rq
->rt_runtime_lock
);
7752 raw_spin_unlock_irq(&tg
->rt_bandwidth
.rt_runtime_lock
);
7754 read_unlock(&tasklist_lock
);
7755 mutex_unlock(&rt_constraints_mutex
);
7760 int sched_group_set_rt_runtime(struct task_group
*tg
, long rt_runtime_us
)
7762 u64 rt_runtime
, rt_period
;
7764 rt_period
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7765 rt_runtime
= (u64
)rt_runtime_us
* NSEC_PER_USEC
;
7766 if (rt_runtime_us
< 0)
7767 rt_runtime
= RUNTIME_INF
;
7769 return tg_set_rt_bandwidth(tg
, rt_period
, rt_runtime
);
7772 long sched_group_rt_runtime(struct task_group
*tg
)
7776 if (tg
->rt_bandwidth
.rt_runtime
== RUNTIME_INF
)
7779 rt_runtime_us
= tg
->rt_bandwidth
.rt_runtime
;
7780 do_div(rt_runtime_us
, NSEC_PER_USEC
);
7781 return rt_runtime_us
;
7784 int sched_group_set_rt_period(struct task_group
*tg
, long rt_period_us
)
7786 u64 rt_runtime
, rt_period
;
7788 rt_period
= (u64
)rt_period_us
* NSEC_PER_USEC
;
7789 rt_runtime
= tg
->rt_bandwidth
.rt_runtime
;
7794 return tg_set_rt_bandwidth(tg
, rt_period
, rt_runtime
);
7797 long sched_group_rt_period(struct task_group
*tg
)
7801 rt_period_us
= ktime_to_ns(tg
->rt_bandwidth
.rt_period
);
7802 do_div(rt_period_us
, NSEC_PER_USEC
);
7803 return rt_period_us
;
7806 static int sched_rt_global_constraints(void)
7808 u64 runtime
, period
;
7811 if (sysctl_sched_rt_period
<= 0)
7814 runtime
= global_rt_runtime();
7815 period
= global_rt_period();
7818 * Sanity check on the sysctl variables.
7820 if (runtime
> period
&& runtime
!= RUNTIME_INF
)
7823 mutex_lock(&rt_constraints_mutex
);
7824 read_lock(&tasklist_lock
);
7825 ret
= __rt_schedulable(NULL
, 0, 0);
7826 read_unlock(&tasklist_lock
);
7827 mutex_unlock(&rt_constraints_mutex
);
7832 int sched_rt_can_attach(struct task_group
*tg
, struct task_struct
*tsk
)
7834 /* Don't accept realtime tasks when there is no way for them to run */
7835 if (rt_task(tsk
) && tg
->rt_bandwidth
.rt_runtime
== 0)
7841 #else /* !CONFIG_RT_GROUP_SCHED */
7842 static int sched_rt_global_constraints(void)
7844 unsigned long flags
;
7847 if (sysctl_sched_rt_period
<= 0)
7851 * There's always some RT tasks in the root group
7852 * -- migration, kstopmachine etc..
7854 if (sysctl_sched_rt_runtime
== 0)
7857 raw_spin_lock_irqsave(&def_rt_bandwidth
.rt_runtime_lock
, flags
);
7858 for_each_possible_cpu(i
) {
7859 struct rt_rq
*rt_rq
= &cpu_rq(i
)->rt
;
7861 raw_spin_lock(&rt_rq
->rt_runtime_lock
);
7862 rt_rq
->rt_runtime
= global_rt_runtime();
7863 raw_spin_unlock(&rt_rq
->rt_runtime_lock
);
7865 raw_spin_unlock_irqrestore(&def_rt_bandwidth
.rt_runtime_lock
, flags
);
7869 #endif /* CONFIG_RT_GROUP_SCHED */
7871 int sched_rt_handler(struct ctl_table
*table
, int write
,
7872 void __user
*buffer
, size_t *lenp
,
7876 int old_period
, old_runtime
;
7877 static DEFINE_MUTEX(mutex
);
7880 old_period
= sysctl_sched_rt_period
;
7881 old_runtime
= sysctl_sched_rt_runtime
;
7883 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
7885 if (!ret
&& write
) {
7886 ret
= sched_rt_global_constraints();
7888 sysctl_sched_rt_period
= old_period
;
7889 sysctl_sched_rt_runtime
= old_runtime
;
7891 def_rt_bandwidth
.rt_runtime
= global_rt_runtime();
7892 def_rt_bandwidth
.rt_period
=
7893 ns_to_ktime(global_rt_period());
7896 mutex_unlock(&mutex
);
7901 #ifdef CONFIG_CGROUP_SCHED
7903 /* return corresponding task_group object of a cgroup */
7904 static inline struct task_group
*cgroup_tg(struct cgroup
*cgrp
)
7906 return container_of(cgroup_subsys_state(cgrp
, cpu_cgroup_subsys_id
),
7907 struct task_group
, css
);
7910 static struct cgroup_subsys_state
*cpu_cgroup_create(struct cgroup
*cgrp
)
7912 struct task_group
*tg
, *parent
;
7914 if (!cgrp
->parent
) {
7915 /* This is early initialization for the top cgroup */
7916 return &root_task_group
.css
;
7919 parent
= cgroup_tg(cgrp
->parent
);
7920 tg
= sched_create_group(parent
);
7922 return ERR_PTR(-ENOMEM
);
7927 static void cpu_cgroup_destroy(struct cgroup
*cgrp
)
7929 struct task_group
*tg
= cgroup_tg(cgrp
);
7931 sched_destroy_group(tg
);
7934 static int cpu_cgroup_can_attach(struct cgroup
*cgrp
,
7935 struct cgroup_taskset
*tset
)
7937 struct task_struct
*task
;
7939 cgroup_taskset_for_each(task
, cgrp
, tset
) {
7940 #ifdef CONFIG_RT_GROUP_SCHED
7941 if (!sched_rt_can_attach(cgroup_tg(cgrp
), task
))
7944 /* We don't support RT-tasks being in separate groups */
7945 if (task
->sched_class
!= &fair_sched_class
)
7952 static void cpu_cgroup_attach(struct cgroup
*cgrp
,
7953 struct cgroup_taskset
*tset
)
7955 struct task_struct
*task
;
7957 cgroup_taskset_for_each(task
, cgrp
, tset
)
7958 sched_move_task(task
);
7962 cpu_cgroup_exit(struct cgroup
*cgrp
, struct cgroup
*old_cgrp
,
7963 struct task_struct
*task
)
7966 * cgroup_exit() is called in the copy_process() failure path.
7967 * Ignore this case since the task hasn't ran yet, this avoids
7968 * trying to poke a half freed task state from generic code.
7970 if (!(task
->flags
& PF_EXITING
))
7973 sched_move_task(task
);
7976 #ifdef CONFIG_FAIR_GROUP_SCHED
7977 static int cpu_shares_write_u64(struct cgroup
*cgrp
, struct cftype
*cftype
,
7980 return sched_group_set_shares(cgroup_tg(cgrp
), scale_load(shareval
));
7983 static u64
cpu_shares_read_u64(struct cgroup
*cgrp
, struct cftype
*cft
)
7985 struct task_group
*tg
= cgroup_tg(cgrp
);
7987 return (u64
) scale_load_down(tg
->shares
);
7990 #ifdef CONFIG_CFS_BANDWIDTH
7991 static DEFINE_MUTEX(cfs_constraints_mutex
);
7993 const u64 max_cfs_quota_period
= 1 * NSEC_PER_SEC
; /* 1s */
7994 const u64 min_cfs_quota_period
= 1 * NSEC_PER_MSEC
; /* 1ms */
7996 static int __cfs_schedulable(struct task_group
*tg
, u64 period
, u64 runtime
);
7998 static int tg_set_cfs_bandwidth(struct task_group
*tg
, u64 period
, u64 quota
)
8000 int i
, ret
= 0, runtime_enabled
, runtime_was_enabled
;
8001 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8003 if (tg
== &root_task_group
)
8007 * Ensure we have at some amount of bandwidth every period. This is
8008 * to prevent reaching a state of large arrears when throttled via
8009 * entity_tick() resulting in prolonged exit starvation.
8011 if (quota
< min_cfs_quota_period
|| period
< min_cfs_quota_period
)
8015 * Likewise, bound things on the otherside by preventing insane quota
8016 * periods. This also allows us to normalize in computing quota
8019 if (period
> max_cfs_quota_period
)
8022 mutex_lock(&cfs_constraints_mutex
);
8023 ret
= __cfs_schedulable(tg
, period
, quota
);
8027 runtime_enabled
= quota
!= RUNTIME_INF
;
8028 runtime_was_enabled
= cfs_b
->quota
!= RUNTIME_INF
;
8029 account_cfs_bandwidth_used(runtime_enabled
, runtime_was_enabled
);
8030 raw_spin_lock_irq(&cfs_b
->lock
);
8031 cfs_b
->period
= ns_to_ktime(period
);
8032 cfs_b
->quota
= quota
;
8034 __refill_cfs_bandwidth_runtime(cfs_b
);
8035 /* restart the period timer (if active) to handle new period expiry */
8036 if (runtime_enabled
&& cfs_b
->timer_active
) {
8037 /* force a reprogram */
8038 cfs_b
->timer_active
= 0;
8039 __start_cfs_bandwidth(cfs_b
);
8041 raw_spin_unlock_irq(&cfs_b
->lock
);
8043 for_each_possible_cpu(i
) {
8044 struct cfs_rq
*cfs_rq
= tg
->cfs_rq
[i
];
8045 struct rq
*rq
= cfs_rq
->rq
;
8047 raw_spin_lock_irq(&rq
->lock
);
8048 cfs_rq
->runtime_enabled
= runtime_enabled
;
8049 cfs_rq
->runtime_remaining
= 0;
8051 if (cfs_rq
->throttled
)
8052 unthrottle_cfs_rq(cfs_rq
);
8053 raw_spin_unlock_irq(&rq
->lock
);
8056 mutex_unlock(&cfs_constraints_mutex
);
8061 int tg_set_cfs_quota(struct task_group
*tg
, long cfs_quota_us
)
8065 period
= ktime_to_ns(tg
->cfs_bandwidth
.period
);
8066 if (cfs_quota_us
< 0)
8067 quota
= RUNTIME_INF
;
8069 quota
= (u64
)cfs_quota_us
* NSEC_PER_USEC
;
8071 return tg_set_cfs_bandwidth(tg
, period
, quota
);
8074 long tg_get_cfs_quota(struct task_group
*tg
)
8078 if (tg
->cfs_bandwidth
.quota
== RUNTIME_INF
)
8081 quota_us
= tg
->cfs_bandwidth
.quota
;
8082 do_div(quota_us
, NSEC_PER_USEC
);
8087 int tg_set_cfs_period(struct task_group
*tg
, long cfs_period_us
)
8091 period
= (u64
)cfs_period_us
* NSEC_PER_USEC
;
8092 quota
= tg
->cfs_bandwidth
.quota
;
8094 return tg_set_cfs_bandwidth(tg
, period
, quota
);
8097 long tg_get_cfs_period(struct task_group
*tg
)
8101 cfs_period_us
= ktime_to_ns(tg
->cfs_bandwidth
.period
);
8102 do_div(cfs_period_us
, NSEC_PER_USEC
);
8104 return cfs_period_us
;
8107 static s64
cpu_cfs_quota_read_s64(struct cgroup
*cgrp
, struct cftype
*cft
)
8109 return tg_get_cfs_quota(cgroup_tg(cgrp
));
8112 static int cpu_cfs_quota_write_s64(struct cgroup
*cgrp
, struct cftype
*cftype
,
8115 return tg_set_cfs_quota(cgroup_tg(cgrp
), cfs_quota_us
);
8118 static u64
cpu_cfs_period_read_u64(struct cgroup
*cgrp
, struct cftype
*cft
)
8120 return tg_get_cfs_period(cgroup_tg(cgrp
));
8123 static int cpu_cfs_period_write_u64(struct cgroup
*cgrp
, struct cftype
*cftype
,
8126 return tg_set_cfs_period(cgroup_tg(cgrp
), cfs_period_us
);
8129 struct cfs_schedulable_data
{
8130 struct task_group
*tg
;
8135 * normalize group quota/period to be quota/max_period
8136 * note: units are usecs
8138 static u64
normalize_cfs_quota(struct task_group
*tg
,
8139 struct cfs_schedulable_data
*d
)
8147 period
= tg_get_cfs_period(tg
);
8148 quota
= tg_get_cfs_quota(tg
);
8151 /* note: these should typically be equivalent */
8152 if (quota
== RUNTIME_INF
|| quota
== -1)
8155 return to_ratio(period
, quota
);
8158 static int tg_cfs_schedulable_down(struct task_group
*tg
, void *data
)
8160 struct cfs_schedulable_data
*d
= data
;
8161 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8162 s64 quota
= 0, parent_quota
= -1;
8165 quota
= RUNTIME_INF
;
8167 struct cfs_bandwidth
*parent_b
= &tg
->parent
->cfs_bandwidth
;
8169 quota
= normalize_cfs_quota(tg
, d
);
8170 parent_quota
= parent_b
->hierarchal_quota
;
8173 * ensure max(child_quota) <= parent_quota, inherit when no
8176 if (quota
== RUNTIME_INF
)
8177 quota
= parent_quota
;
8178 else if (parent_quota
!= RUNTIME_INF
&& quota
> parent_quota
)
8181 cfs_b
->hierarchal_quota
= quota
;
8186 static int __cfs_schedulable(struct task_group
*tg
, u64 period
, u64 quota
)
8189 struct cfs_schedulable_data data
= {
8195 if (quota
!= RUNTIME_INF
) {
8196 do_div(data
.period
, NSEC_PER_USEC
);
8197 do_div(data
.quota
, NSEC_PER_USEC
);
8201 ret
= walk_tg_tree(tg_cfs_schedulable_down
, tg_nop
, &data
);
8207 static int cpu_stats_show(struct cgroup
*cgrp
, struct cftype
*cft
,
8208 struct cgroup_map_cb
*cb
)
8210 struct task_group
*tg
= cgroup_tg(cgrp
);
8211 struct cfs_bandwidth
*cfs_b
= &tg
->cfs_bandwidth
;
8213 cb
->fill(cb
, "nr_periods", cfs_b
->nr_periods
);
8214 cb
->fill(cb
, "nr_throttled", cfs_b
->nr_throttled
);
8215 cb
->fill(cb
, "throttled_time", cfs_b
->throttled_time
);
8219 #endif /* CONFIG_CFS_BANDWIDTH */
8220 #endif /* CONFIG_FAIR_GROUP_SCHED */
8222 #ifdef CONFIG_RT_GROUP_SCHED
8223 static int cpu_rt_runtime_write(struct cgroup
*cgrp
, struct cftype
*cft
,
8226 return sched_group_set_rt_runtime(cgroup_tg(cgrp
), val
);
8229 static s64
cpu_rt_runtime_read(struct cgroup
*cgrp
, struct cftype
*cft
)
8231 return sched_group_rt_runtime(cgroup_tg(cgrp
));
8234 static int cpu_rt_period_write_uint(struct cgroup
*cgrp
, struct cftype
*cftype
,
8237 return sched_group_set_rt_period(cgroup_tg(cgrp
), rt_period_us
);
8240 static u64
cpu_rt_period_read_uint(struct cgroup
*cgrp
, struct cftype
*cft
)
8242 return sched_group_rt_period(cgroup_tg(cgrp
));
8244 #endif /* CONFIG_RT_GROUP_SCHED */
8246 static struct cftype cpu_files
[] = {
8247 #ifdef CONFIG_FAIR_GROUP_SCHED
8250 .read_u64
= cpu_shares_read_u64
,
8251 .write_u64
= cpu_shares_write_u64
,
8254 #ifdef CONFIG_CFS_BANDWIDTH
8256 .name
= "cfs_quota_us",
8257 .read_s64
= cpu_cfs_quota_read_s64
,
8258 .write_s64
= cpu_cfs_quota_write_s64
,
8261 .name
= "cfs_period_us",
8262 .read_u64
= cpu_cfs_period_read_u64
,
8263 .write_u64
= cpu_cfs_period_write_u64
,
8267 .read_map
= cpu_stats_show
,
8270 #ifdef CONFIG_RT_GROUP_SCHED
8272 .name
= "rt_runtime_us",
8273 .read_s64
= cpu_rt_runtime_read
,
8274 .write_s64
= cpu_rt_runtime_write
,
8277 .name
= "rt_period_us",
8278 .read_u64
= cpu_rt_period_read_uint
,
8279 .write_u64
= cpu_rt_period_write_uint
,
8285 struct cgroup_subsys cpu_cgroup_subsys
= {
8287 .create
= cpu_cgroup_create
,
8288 .destroy
= cpu_cgroup_destroy
,
8289 .can_attach
= cpu_cgroup_can_attach
,
8290 .attach
= cpu_cgroup_attach
,
8291 .exit
= cpu_cgroup_exit
,
8292 .subsys_id
= cpu_cgroup_subsys_id
,
8293 .base_cftypes
= cpu_files
,
8297 #endif /* CONFIG_CGROUP_SCHED */
8299 #ifdef CONFIG_CGROUP_CPUACCT
8302 * CPU accounting code for task groups.
8304 * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
8305 * (balbir@in.ibm.com).
8308 /* create a new cpu accounting group */
8309 static struct cgroup_subsys_state
*cpuacct_create(struct cgroup
*cgrp
)
8314 return &root_cpuacct
.css
;
8316 ca
= kzalloc(sizeof(*ca
), GFP_KERNEL
);
8320 ca
->cpuusage
= alloc_percpu(u64
);
8324 ca
->cpustat
= alloc_percpu(struct kernel_cpustat
);
8326 goto out_free_cpuusage
;
8331 free_percpu(ca
->cpuusage
);
8335 return ERR_PTR(-ENOMEM
);
8338 /* destroy an existing cpu accounting group */
8339 static void cpuacct_destroy(struct cgroup
*cgrp
)
8341 struct cpuacct
*ca
= cgroup_ca(cgrp
);
8343 free_percpu(ca
->cpustat
);
8344 free_percpu(ca
->cpuusage
);
8348 static u64
cpuacct_cpuusage_read(struct cpuacct
*ca
, int cpu
)
8350 u64
*cpuusage
= per_cpu_ptr(ca
->cpuusage
, cpu
);
8353 #ifndef CONFIG_64BIT
8355 * Take rq->lock to make 64-bit read safe on 32-bit platforms.
8357 raw_spin_lock_irq(&cpu_rq(cpu
)->lock
);
8359 raw_spin_unlock_irq(&cpu_rq(cpu
)->lock
);
8367 static void cpuacct_cpuusage_write(struct cpuacct
*ca
, int cpu
, u64 val
)
8369 u64
*cpuusage
= per_cpu_ptr(ca
->cpuusage
, cpu
);
8371 #ifndef CONFIG_64BIT
8373 * Take rq->lock to make 64-bit write safe on 32-bit platforms.
8375 raw_spin_lock_irq(&cpu_rq(cpu
)->lock
);
8377 raw_spin_unlock_irq(&cpu_rq(cpu
)->lock
);
8383 /* return total cpu usage (in nanoseconds) of a group */
8384 static u64
cpuusage_read(struct cgroup
*cgrp
, struct cftype
*cft
)
8386 struct cpuacct
*ca
= cgroup_ca(cgrp
);
8387 u64 totalcpuusage
= 0;
8390 for_each_present_cpu(i
)
8391 totalcpuusage
+= cpuacct_cpuusage_read(ca
, i
);
8393 return totalcpuusage
;
8396 static int cpuusage_write(struct cgroup
*cgrp
, struct cftype
*cftype
,
8399 struct cpuacct
*ca
= cgroup_ca(cgrp
);
8408 for_each_present_cpu(i
)
8409 cpuacct_cpuusage_write(ca
, i
, 0);
8415 static int cpuacct_percpu_seq_read(struct cgroup
*cgroup
, struct cftype
*cft
,
8418 struct cpuacct
*ca
= cgroup_ca(cgroup
);
8422 for_each_present_cpu(i
) {
8423 percpu
= cpuacct_cpuusage_read(ca
, i
);
8424 seq_printf(m
, "%llu ", (unsigned long long) percpu
);
8426 seq_printf(m
, "\n");
8430 static const char *cpuacct_stat_desc
[] = {
8431 [CPUACCT_STAT_USER
] = "user",
8432 [CPUACCT_STAT_SYSTEM
] = "system",
8435 static int cpuacct_stats_show(struct cgroup
*cgrp
, struct cftype
*cft
,
8436 struct cgroup_map_cb
*cb
)
8438 struct cpuacct
*ca
= cgroup_ca(cgrp
);
8442 for_each_online_cpu(cpu
) {
8443 struct kernel_cpustat
*kcpustat
= per_cpu_ptr(ca
->cpustat
, cpu
);
8444 val
+= kcpustat
->cpustat
[CPUTIME_USER
];
8445 val
+= kcpustat
->cpustat
[CPUTIME_NICE
];
8447 val
= cputime64_to_clock_t(val
);
8448 cb
->fill(cb
, cpuacct_stat_desc
[CPUACCT_STAT_USER
], val
);
8451 for_each_online_cpu(cpu
) {
8452 struct kernel_cpustat
*kcpustat
= per_cpu_ptr(ca
->cpustat
, cpu
);
8453 val
+= kcpustat
->cpustat
[CPUTIME_SYSTEM
];
8454 val
+= kcpustat
->cpustat
[CPUTIME_IRQ
];
8455 val
+= kcpustat
->cpustat
[CPUTIME_SOFTIRQ
];
8458 val
= cputime64_to_clock_t(val
);
8459 cb
->fill(cb
, cpuacct_stat_desc
[CPUACCT_STAT_SYSTEM
], val
);
8464 static struct cftype files
[] = {
8467 .read_u64
= cpuusage_read
,
8468 .write_u64
= cpuusage_write
,
8471 .name
= "usage_percpu",
8472 .read_seq_string
= cpuacct_percpu_seq_read
,
8476 .read_map
= cpuacct_stats_show
,
8482 * charge this task's execution time to its accounting group.
8484 * called with rq->lock held.
8486 void cpuacct_charge(struct task_struct
*tsk
, u64 cputime
)
8491 if (unlikely(!cpuacct_subsys
.active
))
8494 cpu
= task_cpu(tsk
);
8500 for (; ca
; ca
= parent_ca(ca
)) {
8501 u64
*cpuusage
= per_cpu_ptr(ca
->cpuusage
, cpu
);
8502 *cpuusage
+= cputime
;
8508 struct cgroup_subsys cpuacct_subsys
= {
8510 .create
= cpuacct_create
,
8511 .destroy
= cpuacct_destroy
,
8512 .subsys_id
= cpuacct_subsys_id
,
8513 .base_cftypes
= files
,
8515 #endif /* CONFIG_CGROUP_CPUACCT */