2 #include <linux/sched.h>
3 #include <linux/sched/sysctl.h>
4 #include <linux/sched/rt.h>
5 #include <linux/mutex.h>
6 #include <linux/spinlock.h>
7 #include <linux/stop_machine.h>
11 extern __read_mostly
int scheduler_running
;
14 * Convert user-nice values [ -20 ... 0 ... 19 ]
15 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
18 #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
19 #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
20 #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
23 * 'User priority' is the nice value converted to something we
24 * can work with better when scaling various scheduler parameters,
25 * it's a [ 0 ... 39 ] range.
27 #define USER_PRIO(p) ((p)-MAX_RT_PRIO)
28 #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
29 #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
32 * Helpers for converting nanosecond timing to jiffy resolution
34 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
37 * Increase resolution of nice-level calculations for 64-bit architectures.
38 * The extra resolution improves shares distribution and load balancing of
39 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
40 * hierarchies, especially on larger systems. This is not a user-visible change
41 * and does not change the user-interface for setting shares/weights.
43 * We increase resolution only if we have enough bits to allow this increased
44 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
45 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
48 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
49 # define SCHED_LOAD_RESOLUTION 10
50 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
51 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
53 # define SCHED_LOAD_RESOLUTION 0
54 # define scale_load(w) (w)
55 # define scale_load_down(w) (w)
58 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
59 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
61 #define NICE_0_LOAD SCHED_LOAD_SCALE
62 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
65 * These are the 'tuning knobs' of the scheduler:
69 * single value that denotes runtime == period, ie unlimited time.
71 #define RUNTIME_INF ((u64)~0ULL)
73 static inline int rt_policy(int policy
)
75 if (policy
== SCHED_FIFO
|| policy
== SCHED_RR
)
80 static inline int task_has_rt_policy(struct task_struct
*p
)
82 return rt_policy(p
->policy
);
86 * This is the priority-queue data structure of the RT scheduling class:
88 struct rt_prio_array
{
89 DECLARE_BITMAP(bitmap
, MAX_RT_PRIO
+1); /* include 1 bit for delimiter */
90 struct list_head queue
[MAX_RT_PRIO
];
94 /* nests inside the rq lock: */
95 raw_spinlock_t rt_runtime_lock
;
98 struct hrtimer rt_period_timer
;
101 extern struct mutex sched_domains_mutex
;
103 #ifdef CONFIG_CGROUP_SCHED
105 #include <linux/cgroup.h>
110 extern struct list_head task_groups
;
112 struct cfs_bandwidth
{
113 #ifdef CONFIG_CFS_BANDWIDTH
117 s64 hierarchal_quota
;
120 int idle
, timer_active
;
121 struct hrtimer period_timer
, slack_timer
;
122 struct list_head throttled_cfs_rq
;
125 int nr_periods
, nr_throttled
;
130 /* task group related information */
132 struct cgroup_subsys_state css
;
134 #ifdef CONFIG_FAIR_GROUP_SCHED
135 /* schedulable entities of this group on each cpu */
136 struct sched_entity
**se
;
137 /* runqueue "owned" by this group on each cpu */
138 struct cfs_rq
**cfs_rq
;
139 unsigned long shares
;
141 atomic_t load_weight
;
143 atomic_t runnable_avg
;
146 #ifdef CONFIG_RT_GROUP_SCHED
147 struct sched_rt_entity
**rt_se
;
148 struct rt_rq
**rt_rq
;
150 struct rt_bandwidth rt_bandwidth
;
154 struct list_head list
;
156 struct task_group
*parent
;
157 struct list_head siblings
;
158 struct list_head children
;
160 #ifdef CONFIG_SCHED_AUTOGROUP
161 struct autogroup
*autogroup
;
164 struct cfs_bandwidth cfs_bandwidth
;
167 #ifdef CONFIG_FAIR_GROUP_SCHED
168 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
171 * A weight of 0 or 1 can cause arithmetics problems.
172 * A weight of a cfs_rq is the sum of weights of which entities
173 * are queued on this cfs_rq, so a weight of a entity should not be
174 * too large, so as the shares value of a task group.
175 * (The default weight is 1024 - so there's no practical
176 * limitation from this.)
178 #define MIN_SHARES (1UL << 1)
179 #define MAX_SHARES (1UL << 18)
182 /* Default task group.
183 * Every task in system belong to this group at bootup.
185 extern struct task_group root_task_group
;
187 typedef int (*tg_visitor
)(struct task_group
*, void *);
189 extern int walk_tg_tree_from(struct task_group
*from
,
190 tg_visitor down
, tg_visitor up
, void *data
);
193 * Iterate the full tree, calling @down when first entering a node and @up when
194 * leaving it for the final time.
196 * Caller must hold rcu_lock or sufficient equivalent.
198 static inline int walk_tg_tree(tg_visitor down
, tg_visitor up
, void *data
)
200 return walk_tg_tree_from(&root_task_group
, down
, up
, data
);
203 extern int tg_nop(struct task_group
*tg
, void *data
);
205 extern void free_fair_sched_group(struct task_group
*tg
);
206 extern int alloc_fair_sched_group(struct task_group
*tg
, struct task_group
*parent
);
207 extern void unregister_fair_sched_group(struct task_group
*tg
, int cpu
);
208 extern void init_tg_cfs_entry(struct task_group
*tg
, struct cfs_rq
*cfs_rq
,
209 struct sched_entity
*se
, int cpu
,
210 struct sched_entity
*parent
);
211 extern void init_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
);
212 extern int sched_group_set_shares(struct task_group
*tg
, unsigned long shares
);
214 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth
*cfs_b
);
215 extern void __start_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
);
216 extern void unthrottle_cfs_rq(struct cfs_rq
*cfs_rq
);
218 extern void free_rt_sched_group(struct task_group
*tg
);
219 extern int alloc_rt_sched_group(struct task_group
*tg
, struct task_group
*parent
);
220 extern void init_tg_rt_entry(struct task_group
*tg
, struct rt_rq
*rt_rq
,
221 struct sched_rt_entity
*rt_se
, int cpu
,
222 struct sched_rt_entity
*parent
);
224 #else /* CONFIG_CGROUP_SCHED */
226 struct cfs_bandwidth
{ };
228 #endif /* CONFIG_CGROUP_SCHED */
230 /* CFS-related fields in a runqueue */
232 struct load_weight load
;
233 unsigned int nr_running
, h_nr_running
;
238 u64 min_vruntime_copy
;
241 struct rb_root tasks_timeline
;
242 struct rb_node
*rb_leftmost
;
245 * 'curr' points to currently running entity on this cfs_rq.
246 * It is set to NULL otherwise (i.e when none are currently running).
248 struct sched_entity
*curr
, *next
, *last
, *skip
;
250 #ifdef CONFIG_SCHED_DEBUG
251 unsigned int nr_spread_over
;
256 * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
257 * removed when useful for applications beyond shares distribution (e.g.
260 #ifdef CONFIG_FAIR_GROUP_SCHED
263 * Under CFS, load is tracked on a per-entity basis and aggregated up.
264 * This allows for the description of both thread and group usage (in
265 * the FAIR_GROUP_SCHED case).
267 u64 runnable_load_avg
, blocked_load_avg
;
268 atomic64_t decay_counter
, removed_load
;
270 #endif /* CONFIG_FAIR_GROUP_SCHED */
271 /* These always depend on CONFIG_FAIR_GROUP_SCHED */
272 #ifdef CONFIG_FAIR_GROUP_SCHED
273 u32 tg_runnable_contrib
;
275 #endif /* CONFIG_FAIR_GROUP_SCHED */
278 * h_load = weight * f(tg)
280 * Where f(tg) is the recursive weight fraction assigned to
283 unsigned long h_load
;
284 #endif /* CONFIG_SMP */
286 #ifdef CONFIG_FAIR_GROUP_SCHED
287 struct rq
*rq
; /* cpu runqueue to which this cfs_rq is attached */
290 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
291 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
292 * (like users, containers etc.)
294 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
295 * list is used during load balance.
298 struct list_head leaf_cfs_rq_list
;
299 struct task_group
*tg
; /* group that "owns" this runqueue */
301 #ifdef CONFIG_CFS_BANDWIDTH
304 s64 runtime_remaining
;
306 u64 throttled_clock
, throttled_clock_task
;
307 u64 throttled_clock_task_time
;
308 int throttled
, throttle_count
;
309 struct list_head throttled_list
;
310 #endif /* CONFIG_CFS_BANDWIDTH */
311 #endif /* CONFIG_FAIR_GROUP_SCHED */
314 static inline int rt_bandwidth_enabled(void)
316 return sysctl_sched_rt_runtime
>= 0;
319 /* Real-Time classes' related field in a runqueue: */
321 struct rt_prio_array active
;
322 unsigned int rt_nr_running
;
323 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
325 int curr
; /* highest queued rt task prio */
327 int next
; /* next highest */
332 unsigned long rt_nr_migratory
;
333 unsigned long rt_nr_total
;
335 struct plist_head pushable_tasks
;
340 /* Nests inside the rq lock: */
341 raw_spinlock_t rt_runtime_lock
;
343 #ifdef CONFIG_RT_GROUP_SCHED
344 unsigned long rt_nr_boosted
;
347 struct list_head leaf_rt_rq_list
;
348 struct task_group
*tg
;
355 * We add the notion of a root-domain which will be used to define per-domain
356 * variables. Each exclusive cpuset essentially defines an island domain by
357 * fully partitioning the member cpus from any other cpuset. Whenever a new
358 * exclusive cpuset is created, we also create and attach a new root-domain
367 cpumask_var_t online
;
370 * The "RT overload" flag: it gets set if a CPU has more than
371 * one runnable RT task.
373 cpumask_var_t rto_mask
;
374 struct cpupri cpupri
;
377 extern struct root_domain def_root_domain
;
379 #endif /* CONFIG_SMP */
382 * This is the main, per-CPU runqueue data structure.
384 * Locking rule: those places that want to lock multiple runqueues
385 * (such as the load balancing or the thread migration code), lock
386 * acquire operations must be ordered by ascending &runqueue.
393 * nr_running and cpu_load should be in the same cacheline because
394 * remote CPUs use both these fields when doing load calculation.
396 unsigned int nr_running
;
397 #define CPU_LOAD_IDX_MAX 5
398 unsigned long cpu_load
[CPU_LOAD_IDX_MAX
];
399 unsigned long last_load_update_tick
;
402 unsigned long nohz_flags
;
404 int skip_clock_update
;
406 /* capture load from *all* tasks on this cpu: */
407 struct load_weight load
;
408 unsigned long nr_load_updates
;
414 #ifdef CONFIG_FAIR_GROUP_SCHED
415 /* list of leaf cfs_rq on this cpu: */
416 struct list_head leaf_cfs_rq_list
;
418 unsigned long h_load_throttle
;
419 #endif /* CONFIG_SMP */
420 #endif /* CONFIG_FAIR_GROUP_SCHED */
422 #ifdef CONFIG_RT_GROUP_SCHED
423 struct list_head leaf_rt_rq_list
;
427 * This is part of a global counter where only the total sum
428 * over all CPUs matters. A task can increase this counter on
429 * one CPU and if it got migrated afterwards it may decrease
430 * it on another CPU. Always updated under the runqueue lock:
432 unsigned long nr_uninterruptible
;
434 struct task_struct
*curr
, *idle
, *stop
;
435 unsigned long next_balance
;
436 struct mm_struct
*prev_mm
;
444 struct root_domain
*rd
;
445 struct sched_domain
*sd
;
447 unsigned long cpu_power
;
449 unsigned char idle_balance
;
450 /* For active balancing */
454 struct cpu_stop_work active_balance_work
;
455 /* cpu of this runqueue: */
459 struct list_head cfs_tasks
;
467 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
470 #ifdef CONFIG_PARAVIRT
473 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
474 u64 prev_steal_time_rq
;
477 /* calc_load related fields */
478 unsigned long calc_load_update
;
479 long calc_load_active
;
481 #ifdef CONFIG_SCHED_HRTICK
483 int hrtick_csd_pending
;
484 struct call_single_data hrtick_csd
;
486 struct hrtimer hrtick_timer
;
489 #ifdef CONFIG_SCHEDSTATS
491 struct sched_info rq_sched_info
;
492 unsigned long long rq_cpu_time
;
493 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
495 /* sys_sched_yield() stats */
496 unsigned int yld_count
;
498 /* schedule() stats */
499 unsigned int sched_count
;
500 unsigned int sched_goidle
;
502 /* try_to_wake_up() stats */
503 unsigned int ttwu_count
;
504 unsigned int ttwu_local
;
508 struct llist_head wake_list
;
511 struct sched_avg avg
;
514 static inline int cpu_of(struct rq
*rq
)
523 DECLARE_PER_CPU(struct rq
, runqueues
);
525 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
526 #define this_rq() (&__get_cpu_var(runqueues))
527 #define task_rq(p) cpu_rq(task_cpu(p))
528 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
529 #define raw_rq() (&__raw_get_cpu_var(runqueues))
533 #define rcu_dereference_check_sched_domain(p) \
534 rcu_dereference_check((p), \
535 lockdep_is_held(&sched_domains_mutex))
538 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
539 * See detach_destroy_domains: synchronize_sched for details.
541 * The domain tree of any CPU may only be accessed from within
542 * preempt-disabled sections.
544 #define for_each_domain(cpu, __sd) \
545 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
546 __sd; __sd = __sd->parent)
548 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
551 * highest_flag_domain - Return highest sched_domain containing flag.
552 * @cpu: The cpu whose highest level of sched domain is to
554 * @flag: The flag to check for the highest sched_domain
557 * Returns the highest sched_domain of a cpu which contains the given flag.
559 static inline struct sched_domain
*highest_flag_domain(int cpu
, int flag
)
561 struct sched_domain
*sd
, *hsd
= NULL
;
563 for_each_domain(cpu
, sd
) {
564 if (!(sd
->flags
& flag
))
572 DECLARE_PER_CPU(struct sched_domain
*, sd_llc
);
573 DECLARE_PER_CPU(int, sd_llc_id
);
575 extern int group_balance_cpu(struct sched_group
*sg
);
577 #endif /* CONFIG_SMP */
580 #include "auto_group.h"
582 #ifdef CONFIG_CGROUP_SCHED
585 * Return the group to which this tasks belongs.
587 * We cannot use task_subsys_state() and friends because the cgroup
588 * subsystem changes that value before the cgroup_subsys::attach() method
589 * is called, therefore we cannot pin it and might observe the wrong value.
591 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
592 * core changes this before calling sched_move_task().
594 * Instead we use a 'copy' which is updated from sched_move_task() while
595 * holding both task_struct::pi_lock and rq::lock.
597 static inline struct task_group
*task_group(struct task_struct
*p
)
599 return p
->sched_task_group
;
602 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
603 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
)
605 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
606 struct task_group
*tg
= task_group(p
);
609 #ifdef CONFIG_FAIR_GROUP_SCHED
610 p
->se
.cfs_rq
= tg
->cfs_rq
[cpu
];
611 p
->se
.parent
= tg
->se
[cpu
];
614 #ifdef CONFIG_RT_GROUP_SCHED
615 p
->rt
.rt_rq
= tg
->rt_rq
[cpu
];
616 p
->rt
.parent
= tg
->rt_se
[cpu
];
620 #else /* CONFIG_CGROUP_SCHED */
622 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
) { }
623 static inline struct task_group
*task_group(struct task_struct
*p
)
628 #endif /* CONFIG_CGROUP_SCHED */
630 static inline void __set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
635 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
636 * successfuly executed on another CPU. We must ensure that updates of
637 * per-task data have been completed by this moment.
640 task_thread_info(p
)->cpu
= cpu
;
645 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
647 #ifdef CONFIG_SCHED_DEBUG
648 # include <linux/static_key.h>
649 # define const_debug __read_mostly
651 # define const_debug const
654 extern const_debug
unsigned int sysctl_sched_features
;
656 #define SCHED_FEAT(name, enabled) \
657 __SCHED_FEAT_##name ,
660 #include "features.h"
666 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
667 static __always_inline
bool static_branch__true(struct static_key
*key
)
669 return static_key_true(key
); /* Not out of line branch. */
672 static __always_inline
bool static_branch__false(struct static_key
*key
)
674 return static_key_false(key
); /* Out of line branch. */
677 #define SCHED_FEAT(name, enabled) \
678 static __always_inline bool static_branch_##name(struct static_key *key) \
680 return static_branch__##enabled(key); \
683 #include "features.h"
687 extern struct static_key sched_feat_keys
[__SCHED_FEAT_NR
];
688 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
689 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
690 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
691 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
693 #ifdef CONFIG_NUMA_BALANCING
694 #define sched_feat_numa(x) sched_feat(x)
695 #ifdef CONFIG_SCHED_DEBUG
696 #define numabalancing_enabled sched_feat_numa(NUMA)
698 extern bool numabalancing_enabled
;
699 #endif /* CONFIG_SCHED_DEBUG */
701 #define sched_feat_numa(x) (0)
702 #define numabalancing_enabled (0)
703 #endif /* CONFIG_NUMA_BALANCING */
705 static inline u64
global_rt_period(void)
707 return (u64
)sysctl_sched_rt_period
* NSEC_PER_USEC
;
710 static inline u64
global_rt_runtime(void)
712 if (sysctl_sched_rt_runtime
< 0)
715 return (u64
)sysctl_sched_rt_runtime
* NSEC_PER_USEC
;
720 static inline int task_current(struct rq
*rq
, struct task_struct
*p
)
722 return rq
->curr
== p
;
725 static inline int task_running(struct rq
*rq
, struct task_struct
*p
)
730 return task_current(rq
, p
);
735 #ifndef prepare_arch_switch
736 # define prepare_arch_switch(next) do { } while (0)
738 #ifndef finish_arch_switch
739 # define finish_arch_switch(prev) do { } while (0)
741 #ifndef finish_arch_post_lock_switch
742 # define finish_arch_post_lock_switch() do { } while (0)
745 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
746 static inline void prepare_lock_switch(struct rq
*rq
, struct task_struct
*next
)
750 * We can optimise this out completely for !SMP, because the
751 * SMP rebalancing from interrupt is the only thing that cares
758 static inline void finish_lock_switch(struct rq
*rq
, struct task_struct
*prev
)
762 * After ->on_cpu is cleared, the task can be moved to a different CPU.
763 * We must ensure this doesn't happen until the switch is completely
769 #ifdef CONFIG_DEBUG_SPINLOCK
770 /* this is a valid case when another task releases the spinlock */
771 rq
->lock
.owner
= current
;
774 * If we are tracking spinlock dependencies then we have to
775 * fix up the runqueue lock - which gets 'carried over' from
778 spin_acquire(&rq
->lock
.dep_map
, 0, 0, _THIS_IP_
);
780 raw_spin_unlock_irq(&rq
->lock
);
783 #else /* __ARCH_WANT_UNLOCKED_CTXSW */
784 static inline void prepare_lock_switch(struct rq
*rq
, struct task_struct
*next
)
788 * We can optimise this out completely for !SMP, because the
789 * SMP rebalancing from interrupt is the only thing that cares
794 raw_spin_unlock(&rq
->lock
);
797 static inline void finish_lock_switch(struct rq
*rq
, struct task_struct
*prev
)
801 * After ->on_cpu is cleared, the task can be moved to a different CPU.
802 * We must ensure this doesn't happen until the switch is completely
810 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */
812 static inline void update_load_add(struct load_weight
*lw
, unsigned long inc
)
818 static inline void update_load_sub(struct load_weight
*lw
, unsigned long dec
)
824 static inline void update_load_set(struct load_weight
*lw
, unsigned long w
)
831 * To aid in avoiding the subversion of "niceness" due to uneven distribution
832 * of tasks with abnormal "nice" values across CPUs the contribution that
833 * each task makes to its run queue's load is weighted according to its
834 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
835 * scaled version of the new time slice allocation that they receive on time
839 #define WEIGHT_IDLEPRIO 3
840 #define WMULT_IDLEPRIO 1431655765
843 * Nice levels are multiplicative, with a gentle 10% change for every
844 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
845 * nice 1, it will get ~10% less CPU time than another CPU-bound task
846 * that remained on nice 0.
848 * The "10% effect" is relative and cumulative: from _any_ nice level,
849 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
850 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
851 * If a task goes up by ~10% and another task goes down by ~10% then
852 * the relative distance between them is ~25%.)
854 static const int prio_to_weight
[40] = {
855 /* -20 */ 88761, 71755, 56483, 46273, 36291,
856 /* -15 */ 29154, 23254, 18705, 14949, 11916,
857 /* -10 */ 9548, 7620, 6100, 4904, 3906,
858 /* -5 */ 3121, 2501, 1991, 1586, 1277,
859 /* 0 */ 1024, 820, 655, 526, 423,
860 /* 5 */ 335, 272, 215, 172, 137,
861 /* 10 */ 110, 87, 70, 56, 45,
862 /* 15 */ 36, 29, 23, 18, 15,
866 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
868 * In cases where the weight does not change often, we can use the
869 * precalculated inverse to speed up arithmetics by turning divisions
870 * into multiplications:
872 static const u32 prio_to_wmult
[40] = {
873 /* -20 */ 48388, 59856, 76040, 92818, 118348,
874 /* -15 */ 147320, 184698, 229616, 287308, 360437,
875 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
876 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
877 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
878 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
879 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
880 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
883 /* Time spent by the tasks of the cpu accounting group executing in ... */
884 enum cpuacct_stat_index
{
885 CPUACCT_STAT_USER
, /* ... user mode */
886 CPUACCT_STAT_SYSTEM
, /* ... kernel mode */
892 #define sched_class_highest (&stop_sched_class)
893 #define for_each_class(class) \
894 for (class = sched_class_highest; class; class = class->next)
896 extern const struct sched_class stop_sched_class
;
897 extern const struct sched_class rt_sched_class
;
898 extern const struct sched_class fair_sched_class
;
899 extern const struct sched_class idle_sched_class
;
904 extern void trigger_load_balance(struct rq
*rq
, int cpu
);
905 extern void idle_balance(int this_cpu
, struct rq
*this_rq
);
907 #else /* CONFIG_SMP */
909 static inline void idle_balance(int cpu
, struct rq
*rq
)
915 extern void sysrq_sched_debug_show(void);
916 extern void sched_init_granularity(void);
917 extern void update_max_interval(void);
918 extern void update_group_power(struct sched_domain
*sd
, int cpu
);
919 extern int update_runtime(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
);
920 extern void init_sched_rt_class(void);
921 extern void init_sched_fair_class(void);
923 extern void resched_task(struct task_struct
*p
);
924 extern void resched_cpu(int cpu
);
926 extern struct rt_bandwidth def_rt_bandwidth
;
927 extern void init_rt_bandwidth(struct rt_bandwidth
*rt_b
, u64 period
, u64 runtime
);
929 extern void update_idle_cpu_load(struct rq
*this_rq
);
931 #ifdef CONFIG_CGROUP_CPUACCT
932 #include <linux/cgroup.h>
933 /* track cpu usage of a group of tasks and its child groups */
935 struct cgroup_subsys_state css
;
936 /* cpuusage holds pointer to a u64-type object on every cpu */
937 u64 __percpu
*cpuusage
;
938 struct kernel_cpustat __percpu
*cpustat
;
941 extern struct cgroup_subsys cpuacct_subsys
;
942 extern struct cpuacct root_cpuacct
;
944 /* return cpu accounting group corresponding to this container */
945 static inline struct cpuacct
*cgroup_ca(struct cgroup
*cgrp
)
947 return container_of(cgroup_subsys_state(cgrp
, cpuacct_subsys_id
),
948 struct cpuacct
, css
);
951 /* return cpu accounting group to which this task belongs */
952 static inline struct cpuacct
*task_ca(struct task_struct
*tsk
)
954 return container_of(task_subsys_state(tsk
, cpuacct_subsys_id
),
955 struct cpuacct
, css
);
958 static inline struct cpuacct
*parent_ca(struct cpuacct
*ca
)
960 if (!ca
|| !ca
->css
.cgroup
->parent
)
962 return cgroup_ca(ca
->css
.cgroup
->parent
);
965 extern void cpuacct_charge(struct task_struct
*tsk
, u64 cputime
);
967 static inline void cpuacct_charge(struct task_struct
*tsk
, u64 cputime
) {}
970 #ifdef CONFIG_PARAVIRT
971 static inline u64
steal_ticks(u64 steal
)
973 if (unlikely(steal
> NSEC_PER_SEC
))
974 return div_u64(steal
, TICK_NSEC
);
976 return __iter_div_u64_rem(steal
, TICK_NSEC
, &steal
);
980 static inline void inc_nr_running(struct rq
*rq
)
985 static inline void dec_nr_running(struct rq
*rq
)
990 extern void update_rq_clock(struct rq
*rq
);
992 extern void activate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
993 extern void deactivate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
995 extern void check_preempt_curr(struct rq
*rq
, struct task_struct
*p
, int flags
);
997 extern const_debug
unsigned int sysctl_sched_time_avg
;
998 extern const_debug
unsigned int sysctl_sched_nr_migrate
;
999 extern const_debug
unsigned int sysctl_sched_migration_cost
;
1001 static inline u64
sched_avg_period(void)
1003 return (u64
)sysctl_sched_time_avg
* NSEC_PER_MSEC
/ 2;
1006 #ifdef CONFIG_SCHED_HRTICK
1010 * - enabled by features
1011 * - hrtimer is actually high res
1013 static inline int hrtick_enabled(struct rq
*rq
)
1015 if (!sched_feat(HRTICK
))
1017 if (!cpu_active(cpu_of(rq
)))
1019 return hrtimer_is_hres_active(&rq
->hrtick_timer
);
1022 void hrtick_start(struct rq
*rq
, u64 delay
);
1026 static inline int hrtick_enabled(struct rq
*rq
)
1031 #endif /* CONFIG_SCHED_HRTICK */
1034 extern void sched_avg_update(struct rq
*rq
);
1035 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
)
1037 rq
->rt_avg
+= rt_delta
;
1038 sched_avg_update(rq
);
1041 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
) { }
1042 static inline void sched_avg_update(struct rq
*rq
) { }
1045 extern void start_bandwidth_timer(struct hrtimer
*period_timer
, ktime_t period
);
1048 #ifdef CONFIG_PREEMPT
1050 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
);
1053 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1054 * way at the expense of forcing extra atomic operations in all
1055 * invocations. This assures that the double_lock is acquired using the
1056 * same underlying policy as the spinlock_t on this architecture, which
1057 * reduces latency compared to the unfair variant below. However, it
1058 * also adds more overhead and therefore may reduce throughput.
1060 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1061 __releases(this_rq
->lock
)
1062 __acquires(busiest
->lock
)
1063 __acquires(this_rq
->lock
)
1065 raw_spin_unlock(&this_rq
->lock
);
1066 double_rq_lock(this_rq
, busiest
);
1073 * Unfair double_lock_balance: Optimizes throughput at the expense of
1074 * latency by eliminating extra atomic operations when the locks are
1075 * already in proper order on entry. This favors lower cpu-ids and will
1076 * grant the double lock to lower cpus over higher ids under contention,
1077 * regardless of entry order into the function.
1079 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1080 __releases(this_rq
->lock
)
1081 __acquires(busiest
->lock
)
1082 __acquires(this_rq
->lock
)
1086 if (unlikely(!raw_spin_trylock(&busiest
->lock
))) {
1087 if (busiest
< this_rq
) {
1088 raw_spin_unlock(&this_rq
->lock
);
1089 raw_spin_lock(&busiest
->lock
);
1090 raw_spin_lock_nested(&this_rq
->lock
,
1091 SINGLE_DEPTH_NESTING
);
1094 raw_spin_lock_nested(&busiest
->lock
,
1095 SINGLE_DEPTH_NESTING
);
1100 #endif /* CONFIG_PREEMPT */
1103 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1105 static inline int double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1107 if (unlikely(!irqs_disabled())) {
1108 /* printk() doesn't work good under rq->lock */
1109 raw_spin_unlock(&this_rq
->lock
);
1113 return _double_lock_balance(this_rq
, busiest
);
1116 static inline void double_unlock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1117 __releases(busiest
->lock
)
1119 raw_spin_unlock(&busiest
->lock
);
1120 lock_set_subclass(&this_rq
->lock
.dep_map
, 0, _RET_IP_
);
1124 * double_rq_lock - safely lock two runqueues
1126 * Note this does not disable interrupts like task_rq_lock,
1127 * you need to do so manually before calling.
1129 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1130 __acquires(rq1
->lock
)
1131 __acquires(rq2
->lock
)
1133 BUG_ON(!irqs_disabled());
1135 raw_spin_lock(&rq1
->lock
);
1136 __acquire(rq2
->lock
); /* Fake it out ;) */
1139 raw_spin_lock(&rq1
->lock
);
1140 raw_spin_lock_nested(&rq2
->lock
, SINGLE_DEPTH_NESTING
);
1142 raw_spin_lock(&rq2
->lock
);
1143 raw_spin_lock_nested(&rq1
->lock
, SINGLE_DEPTH_NESTING
);
1149 * double_rq_unlock - safely unlock two runqueues
1151 * Note this does not restore interrupts like task_rq_unlock,
1152 * you need to do so manually after calling.
1154 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1155 __releases(rq1
->lock
)
1156 __releases(rq2
->lock
)
1158 raw_spin_unlock(&rq1
->lock
);
1160 raw_spin_unlock(&rq2
->lock
);
1162 __release(rq2
->lock
);
1165 #else /* CONFIG_SMP */
1168 * double_rq_lock - safely lock two runqueues
1170 * Note this does not disable interrupts like task_rq_lock,
1171 * you need to do so manually before calling.
1173 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1174 __acquires(rq1
->lock
)
1175 __acquires(rq2
->lock
)
1177 BUG_ON(!irqs_disabled());
1179 raw_spin_lock(&rq1
->lock
);
1180 __acquire(rq2
->lock
); /* Fake it out ;) */
1184 * double_rq_unlock - safely unlock two runqueues
1186 * Note this does not restore interrupts like task_rq_unlock,
1187 * you need to do so manually after calling.
1189 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1190 __releases(rq1
->lock
)
1191 __releases(rq2
->lock
)
1194 raw_spin_unlock(&rq1
->lock
);
1195 __release(rq2
->lock
);
1200 extern struct sched_entity
*__pick_first_entity(struct cfs_rq
*cfs_rq
);
1201 extern struct sched_entity
*__pick_last_entity(struct cfs_rq
*cfs_rq
);
1202 extern void print_cfs_stats(struct seq_file
*m
, int cpu
);
1203 extern void print_rt_stats(struct seq_file
*m
, int cpu
);
1205 extern void init_cfs_rq(struct cfs_rq
*cfs_rq
);
1206 extern void init_rt_rq(struct rt_rq
*rt_rq
, struct rq
*rq
);
1208 extern void account_cfs_bandwidth_used(int enabled
, int was_enabled
);
1211 enum rq_nohz_flag_bits
{
1217 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1220 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1222 DECLARE_PER_CPU(u64
, cpu_hardirq_time
);
1223 DECLARE_PER_CPU(u64
, cpu_softirq_time
);
1225 #ifndef CONFIG_64BIT
1226 DECLARE_PER_CPU(seqcount_t
, irq_time_seq
);
1228 static inline void irq_time_write_begin(void)
1230 __this_cpu_inc(irq_time_seq
.sequence
);
1234 static inline void irq_time_write_end(void)
1237 __this_cpu_inc(irq_time_seq
.sequence
);
1240 static inline u64
irq_time_read(int cpu
)
1246 seq
= read_seqcount_begin(&per_cpu(irq_time_seq
, cpu
));
1247 irq_time
= per_cpu(cpu_softirq_time
, cpu
) +
1248 per_cpu(cpu_hardirq_time
, cpu
);
1249 } while (read_seqcount_retry(&per_cpu(irq_time_seq
, cpu
), seq
));
1253 #else /* CONFIG_64BIT */
1254 static inline void irq_time_write_begin(void)
1258 static inline void irq_time_write_end(void)
1262 static inline u64
irq_time_read(int cpu
)
1264 return per_cpu(cpu_softirq_time
, cpu
) + per_cpu(cpu_hardirq_time
, cpu
);
1266 #endif /* CONFIG_64BIT */
1267 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */