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>
8 #include <linux/tick.h>
9 #include <linux/slab.h>
16 extern __read_mostly
int scheduler_running
;
18 extern unsigned long calc_load_update
;
19 extern atomic_long_t calc_load_tasks
;
21 extern long calc_load_fold_active(struct rq
*this_rq
);
22 extern void update_cpu_load_active(struct rq
*this_rq
);
25 * Convert user-nice values [ -20 ... 0 ... 19 ]
26 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
29 #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
30 #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
31 #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
34 * 'User priority' is the nice value converted to something we
35 * can work with better when scaling various scheduler parameters,
36 * it's a [ 0 ... 39 ] range.
38 #define USER_PRIO(p) ((p)-MAX_RT_PRIO)
39 #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
40 #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
43 * Helpers for converting nanosecond timing to jiffy resolution
45 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
48 * Increase resolution of nice-level calculations for 64-bit architectures.
49 * The extra resolution improves shares distribution and load balancing of
50 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
51 * hierarchies, especially on larger systems. This is not a user-visible change
52 * and does not change the user-interface for setting shares/weights.
54 * We increase resolution only if we have enough bits to allow this increased
55 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
56 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
59 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
60 # define SCHED_LOAD_RESOLUTION 10
61 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
62 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
64 # define SCHED_LOAD_RESOLUTION 0
65 # define scale_load(w) (w)
66 # define scale_load_down(w) (w)
69 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
70 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
72 #define NICE_0_LOAD SCHED_LOAD_SCALE
73 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
76 * These are the 'tuning knobs' of the scheduler:
80 * single value that denotes runtime == period, ie unlimited time.
82 #define RUNTIME_INF ((u64)~0ULL)
84 static inline int rt_policy(int policy
)
86 if (policy
== SCHED_FIFO
|| policy
== SCHED_RR
)
91 static inline int task_has_rt_policy(struct task_struct
*p
)
93 return rt_policy(p
->policy
);
97 * This is the priority-queue data structure of the RT scheduling class:
99 struct rt_prio_array
{
100 DECLARE_BITMAP(bitmap
, MAX_RT_PRIO
+1); /* include 1 bit for delimiter */
101 struct list_head queue
[MAX_RT_PRIO
];
104 struct rt_bandwidth
{
105 /* nests inside the rq lock: */
106 raw_spinlock_t rt_runtime_lock
;
109 struct hrtimer rt_period_timer
;
112 extern struct mutex sched_domains_mutex
;
114 #ifdef CONFIG_CGROUP_SCHED
116 #include <linux/cgroup.h>
121 extern struct list_head task_groups
;
123 struct cfs_bandwidth
{
124 #ifdef CONFIG_CFS_BANDWIDTH
128 s64 hierarchal_quota
;
131 int idle
, timer_active
;
132 struct hrtimer period_timer
, slack_timer
;
133 struct list_head throttled_cfs_rq
;
136 int nr_periods
, nr_throttled
;
141 /* task group related information */
143 struct cgroup_subsys_state css
;
145 #ifdef CONFIG_FAIR_GROUP_SCHED
146 /* schedulable entities of this group on each cpu */
147 struct sched_entity
**se
;
148 /* runqueue "owned" by this group on each cpu */
149 struct cfs_rq
**cfs_rq
;
150 unsigned long shares
;
153 atomic_long_t load_avg
;
154 atomic_t runnable_avg
;
158 #ifdef CONFIG_RT_GROUP_SCHED
159 struct sched_rt_entity
**rt_se
;
160 struct rt_rq
**rt_rq
;
162 struct rt_bandwidth rt_bandwidth
;
166 struct list_head list
;
168 struct task_group
*parent
;
169 struct list_head siblings
;
170 struct list_head children
;
172 #ifdef CONFIG_SCHED_AUTOGROUP
173 struct autogroup
*autogroup
;
176 struct cfs_bandwidth cfs_bandwidth
;
179 #ifdef CONFIG_FAIR_GROUP_SCHED
180 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
183 * A weight of 0 or 1 can cause arithmetics problems.
184 * A weight of a cfs_rq is the sum of weights of which entities
185 * are queued on this cfs_rq, so a weight of a entity should not be
186 * too large, so as the shares value of a task group.
187 * (The default weight is 1024 - so there's no practical
188 * limitation from this.)
190 #define MIN_SHARES (1UL << 1)
191 #define MAX_SHARES (1UL << 18)
194 typedef int (*tg_visitor
)(struct task_group
*, void *);
196 extern int walk_tg_tree_from(struct task_group
*from
,
197 tg_visitor down
, tg_visitor up
, void *data
);
200 * Iterate the full tree, calling @down when first entering a node and @up when
201 * leaving it for the final time.
203 * Caller must hold rcu_lock or sufficient equivalent.
205 static inline int walk_tg_tree(tg_visitor down
, tg_visitor up
, void *data
)
207 return walk_tg_tree_from(&root_task_group
, down
, up
, data
);
210 extern int tg_nop(struct task_group
*tg
, void *data
);
212 extern void free_fair_sched_group(struct task_group
*tg
);
213 extern int alloc_fair_sched_group(struct task_group
*tg
, struct task_group
*parent
);
214 extern void unregister_fair_sched_group(struct task_group
*tg
, int cpu
);
215 extern void init_tg_cfs_entry(struct task_group
*tg
, struct cfs_rq
*cfs_rq
,
216 struct sched_entity
*se
, int cpu
,
217 struct sched_entity
*parent
);
218 extern void init_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
);
219 extern int sched_group_set_shares(struct task_group
*tg
, unsigned long shares
);
221 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth
*cfs_b
);
222 extern void __start_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
);
223 extern void unthrottle_cfs_rq(struct cfs_rq
*cfs_rq
);
225 extern void free_rt_sched_group(struct task_group
*tg
);
226 extern int alloc_rt_sched_group(struct task_group
*tg
, struct task_group
*parent
);
227 extern void init_tg_rt_entry(struct task_group
*tg
, struct rt_rq
*rt_rq
,
228 struct sched_rt_entity
*rt_se
, int cpu
,
229 struct sched_rt_entity
*parent
);
231 extern struct task_group
*sched_create_group(struct task_group
*parent
);
232 extern void sched_online_group(struct task_group
*tg
,
233 struct task_group
*parent
);
234 extern void sched_destroy_group(struct task_group
*tg
);
235 extern void sched_offline_group(struct task_group
*tg
);
237 extern void sched_move_task(struct task_struct
*tsk
);
239 #ifdef CONFIG_FAIR_GROUP_SCHED
240 extern int sched_group_set_shares(struct task_group
*tg
, unsigned long shares
);
243 #else /* CONFIG_CGROUP_SCHED */
245 struct cfs_bandwidth
{ };
247 #endif /* CONFIG_CGROUP_SCHED */
249 /* CFS-related fields in a runqueue */
251 struct load_weight load
;
252 unsigned int nr_running
, h_nr_running
;
257 u64 min_vruntime_copy
;
260 struct rb_root tasks_timeline
;
261 struct rb_node
*rb_leftmost
;
264 * 'curr' points to currently running entity on this cfs_rq.
265 * It is set to NULL otherwise (i.e when none are currently running).
267 struct sched_entity
*curr
, *next
, *last
, *skip
;
269 #ifdef CONFIG_SCHED_DEBUG
270 unsigned int nr_spread_over
;
276 * Under CFS, load is tracked on a per-entity basis and aggregated up.
277 * This allows for the description of both thread and group usage (in
278 * the FAIR_GROUP_SCHED case).
280 unsigned long runnable_load_avg
, blocked_load_avg
;
281 atomic64_t decay_counter
;
283 atomic_long_t removed_load
;
285 #ifdef CONFIG_FAIR_GROUP_SCHED
286 /* Required to track per-cpu representation of a task_group */
287 u32 tg_runnable_contrib
;
288 unsigned long tg_load_contrib
;
291 * h_load = weight * f(tg)
293 * Where f(tg) is the recursive weight fraction assigned to
296 unsigned long h_load
;
297 u64 last_h_load_update
;
298 struct sched_entity
*h_load_next
;
299 #endif /* CONFIG_FAIR_GROUP_SCHED */
300 #endif /* CONFIG_SMP */
302 #ifdef CONFIG_FAIR_GROUP_SCHED
303 struct rq
*rq
; /* cpu runqueue to which this cfs_rq is attached */
306 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
307 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
308 * (like users, containers etc.)
310 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
311 * list is used during load balance.
314 struct list_head leaf_cfs_rq_list
;
315 struct task_group
*tg
; /* group that "owns" this runqueue */
317 #ifdef CONFIG_CFS_BANDWIDTH
320 s64 runtime_remaining
;
322 u64 throttled_clock
, throttled_clock_task
;
323 u64 throttled_clock_task_time
;
324 int throttled
, throttle_count
;
325 struct list_head throttled_list
;
326 #endif /* CONFIG_CFS_BANDWIDTH */
327 #endif /* CONFIG_FAIR_GROUP_SCHED */
330 static inline int rt_bandwidth_enabled(void)
332 return sysctl_sched_rt_runtime
>= 0;
335 /* Real-Time classes' related field in a runqueue: */
337 struct rt_prio_array active
;
338 unsigned int rt_nr_running
;
339 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
341 int curr
; /* highest queued rt task prio */
343 int next
; /* next highest */
348 unsigned long rt_nr_migratory
;
349 unsigned long rt_nr_total
;
351 struct plist_head pushable_tasks
;
356 /* Nests inside the rq lock: */
357 raw_spinlock_t rt_runtime_lock
;
359 #ifdef CONFIG_RT_GROUP_SCHED
360 unsigned long rt_nr_boosted
;
363 struct task_group
*tg
;
370 * We add the notion of a root-domain which will be used to define per-domain
371 * variables. Each exclusive cpuset essentially defines an island domain by
372 * fully partitioning the member cpus from any other cpuset. Whenever a new
373 * exclusive cpuset is created, we also create and attach a new root-domain
382 cpumask_var_t online
;
385 * The "RT overload" flag: it gets set if a CPU has more than
386 * one runnable RT task.
388 cpumask_var_t rto_mask
;
389 struct cpupri cpupri
;
392 extern struct root_domain def_root_domain
;
394 #endif /* CONFIG_SMP */
397 * This is the main, per-CPU runqueue data structure.
399 * Locking rule: those places that want to lock multiple runqueues
400 * (such as the load balancing or the thread migration code), lock
401 * acquire operations must be ordered by ascending &runqueue.
408 * nr_running and cpu_load should be in the same cacheline because
409 * remote CPUs use both these fields when doing load calculation.
411 unsigned int nr_running
;
412 #define CPU_LOAD_IDX_MAX 5
413 unsigned long cpu_load
[CPU_LOAD_IDX_MAX
];
414 unsigned long last_load_update_tick
;
415 #ifdef CONFIG_NO_HZ_COMMON
417 unsigned long nohz_flags
;
419 #ifdef CONFIG_NO_HZ_FULL
420 unsigned long last_sched_tick
;
422 int skip_clock_update
;
424 /* capture load from *all* tasks on this cpu: */
425 struct load_weight load
;
426 unsigned long nr_load_updates
;
432 #ifdef CONFIG_FAIR_GROUP_SCHED
433 /* list of leaf cfs_rq on this cpu: */
434 struct list_head leaf_cfs_rq_list
;
435 #endif /* CONFIG_FAIR_GROUP_SCHED */
437 #ifdef CONFIG_RT_GROUP_SCHED
438 struct list_head leaf_rt_rq_list
;
442 * This is part of a global counter where only the total sum
443 * over all CPUs matters. A task can increase this counter on
444 * one CPU and if it got migrated afterwards it may decrease
445 * it on another CPU. Always updated under the runqueue lock:
447 unsigned long nr_uninterruptible
;
449 struct task_struct
*curr
, *idle
, *stop
;
450 unsigned long next_balance
;
451 struct mm_struct
*prev_mm
;
459 struct root_domain
*rd
;
460 struct sched_domain
*sd
;
462 unsigned long cpu_power
;
464 unsigned char idle_balance
;
465 /* For active balancing */
469 struct cpu_stop_work active_balance_work
;
470 /* cpu of this runqueue: */
474 struct list_head cfs_tasks
;
481 /* This is used to determine avg_idle's max value */
482 u64 max_idle_balance_cost
;
485 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
488 #ifdef CONFIG_PARAVIRT
491 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
492 u64 prev_steal_time_rq
;
495 /* calc_load related fields */
496 unsigned long calc_load_update
;
497 long calc_load_active
;
499 #ifdef CONFIG_SCHED_HRTICK
501 int hrtick_csd_pending
;
502 struct call_single_data hrtick_csd
;
504 struct hrtimer hrtick_timer
;
507 #ifdef CONFIG_SCHEDSTATS
509 struct sched_info rq_sched_info
;
510 unsigned long long rq_cpu_time
;
511 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
513 /* sys_sched_yield() stats */
514 unsigned int yld_count
;
516 /* schedule() stats */
517 unsigned int sched_count
;
518 unsigned int sched_goidle
;
520 /* try_to_wake_up() stats */
521 unsigned int ttwu_count
;
522 unsigned int ttwu_local
;
526 struct llist_head wake_list
;
529 struct sched_avg avg
;
532 static inline int cpu_of(struct rq
*rq
)
541 DECLARE_PER_CPU(struct rq
, runqueues
);
543 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
544 #define this_rq() (&__get_cpu_var(runqueues))
545 #define task_rq(p) cpu_rq(task_cpu(p))
546 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
547 #define raw_rq() (&__raw_get_cpu_var(runqueues))
549 static inline u64
rq_clock(struct rq
*rq
)
554 static inline u64
rq_clock_task(struct rq
*rq
)
556 return rq
->clock_task
;
559 #ifdef CONFIG_NUMA_BALANCING
560 extern int migrate_task_to(struct task_struct
*p
, int cpu
);
561 static inline void task_numa_free(struct task_struct
*p
)
563 kfree(p
->numa_faults
);
565 #else /* CONFIG_NUMA_BALANCING */
566 static inline void task_numa_free(struct task_struct
*p
)
569 #endif /* CONFIG_NUMA_BALANCING */
573 #define rcu_dereference_check_sched_domain(p) \
574 rcu_dereference_check((p), \
575 lockdep_is_held(&sched_domains_mutex))
578 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
579 * See detach_destroy_domains: synchronize_sched for details.
581 * The domain tree of any CPU may only be accessed from within
582 * preempt-disabled sections.
584 #define for_each_domain(cpu, __sd) \
585 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
586 __sd; __sd = __sd->parent)
588 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
591 * highest_flag_domain - Return highest sched_domain containing flag.
592 * @cpu: The cpu whose highest level of sched domain is to
594 * @flag: The flag to check for the highest sched_domain
597 * Returns the highest sched_domain of a cpu which contains the given flag.
599 static inline struct sched_domain
*highest_flag_domain(int cpu
, int flag
)
601 struct sched_domain
*sd
, *hsd
= NULL
;
603 for_each_domain(cpu
, sd
) {
604 if (!(sd
->flags
& flag
))
612 DECLARE_PER_CPU(struct sched_domain
*, sd_llc
);
613 DECLARE_PER_CPU(int, sd_llc_size
);
614 DECLARE_PER_CPU(int, sd_llc_id
);
616 struct sched_group_power
{
619 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
622 unsigned int power
, power_orig
;
623 unsigned long next_update
;
624 int imbalance
; /* XXX unrelated to power but shared group state */
626 * Number of busy cpus in this group.
628 atomic_t nr_busy_cpus
;
630 unsigned long cpumask
[0]; /* iteration mask */
634 struct sched_group
*next
; /* Must be a circular list */
637 unsigned int group_weight
;
638 struct sched_group_power
*sgp
;
641 * The CPUs this group covers.
643 * NOTE: this field is variable length. (Allocated dynamically
644 * by attaching extra space to the end of the structure,
645 * depending on how many CPUs the kernel has booted up with)
647 unsigned long cpumask
[0];
650 static inline struct cpumask
*sched_group_cpus(struct sched_group
*sg
)
652 return to_cpumask(sg
->cpumask
);
656 * cpumask masking which cpus in the group are allowed to iterate up the domain
659 static inline struct cpumask
*sched_group_mask(struct sched_group
*sg
)
661 return to_cpumask(sg
->sgp
->cpumask
);
665 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
666 * @group: The group whose first cpu is to be returned.
668 static inline unsigned int group_first_cpu(struct sched_group
*group
)
670 return cpumask_first(sched_group_cpus(group
));
673 extern int group_balance_cpu(struct sched_group
*sg
);
675 #endif /* CONFIG_SMP */
678 #include "auto_group.h"
680 #ifdef CONFIG_CGROUP_SCHED
683 * Return the group to which this tasks belongs.
685 * We cannot use task_css() and friends because the cgroup subsystem
686 * changes that value before the cgroup_subsys::attach() method is called,
687 * therefore we cannot pin it and might observe the wrong value.
689 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
690 * core changes this before calling sched_move_task().
692 * Instead we use a 'copy' which is updated from sched_move_task() while
693 * holding both task_struct::pi_lock and rq::lock.
695 static inline struct task_group
*task_group(struct task_struct
*p
)
697 return p
->sched_task_group
;
700 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
701 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
)
703 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
704 struct task_group
*tg
= task_group(p
);
707 #ifdef CONFIG_FAIR_GROUP_SCHED
708 p
->se
.cfs_rq
= tg
->cfs_rq
[cpu
];
709 p
->se
.parent
= tg
->se
[cpu
];
712 #ifdef CONFIG_RT_GROUP_SCHED
713 p
->rt
.rt_rq
= tg
->rt_rq
[cpu
];
714 p
->rt
.parent
= tg
->rt_se
[cpu
];
718 #else /* CONFIG_CGROUP_SCHED */
720 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
) { }
721 static inline struct task_group
*task_group(struct task_struct
*p
)
726 #endif /* CONFIG_CGROUP_SCHED */
728 static inline void __set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
733 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
734 * successfuly executed on another CPU. We must ensure that updates of
735 * per-task data have been completed by this moment.
738 task_thread_info(p
)->cpu
= cpu
;
743 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
745 #ifdef CONFIG_SCHED_DEBUG
746 # include <linux/static_key.h>
747 # define const_debug __read_mostly
749 # define const_debug const
752 extern const_debug
unsigned int sysctl_sched_features
;
754 #define SCHED_FEAT(name, enabled) \
755 __SCHED_FEAT_##name ,
758 #include "features.h"
764 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
765 static __always_inline
bool static_branch__true(struct static_key
*key
)
767 return static_key_true(key
); /* Not out of line branch. */
770 static __always_inline
bool static_branch__false(struct static_key
*key
)
772 return static_key_false(key
); /* Out of line branch. */
775 #define SCHED_FEAT(name, enabled) \
776 static __always_inline bool static_branch_##name(struct static_key *key) \
778 return static_branch__##enabled(key); \
781 #include "features.h"
785 extern struct static_key sched_feat_keys
[__SCHED_FEAT_NR
];
786 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
787 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
788 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
789 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
791 #ifdef CONFIG_NUMA_BALANCING
792 #define sched_feat_numa(x) sched_feat(x)
793 #ifdef CONFIG_SCHED_DEBUG
794 #define numabalancing_enabled sched_feat_numa(NUMA)
796 extern bool numabalancing_enabled
;
797 #endif /* CONFIG_SCHED_DEBUG */
799 #define sched_feat_numa(x) (0)
800 #define numabalancing_enabled (0)
801 #endif /* CONFIG_NUMA_BALANCING */
803 static inline u64
global_rt_period(void)
805 return (u64
)sysctl_sched_rt_period
* NSEC_PER_USEC
;
808 static inline u64
global_rt_runtime(void)
810 if (sysctl_sched_rt_runtime
< 0)
813 return (u64
)sysctl_sched_rt_runtime
* NSEC_PER_USEC
;
818 static inline int task_current(struct rq
*rq
, struct task_struct
*p
)
820 return rq
->curr
== p
;
823 static inline int task_running(struct rq
*rq
, struct task_struct
*p
)
828 return task_current(rq
, p
);
833 #ifndef prepare_arch_switch
834 # define prepare_arch_switch(next) do { } while (0)
836 #ifndef finish_arch_switch
837 # define finish_arch_switch(prev) do { } while (0)
839 #ifndef finish_arch_post_lock_switch
840 # define finish_arch_post_lock_switch() do { } while (0)
843 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
844 static inline void prepare_lock_switch(struct rq
*rq
, struct task_struct
*next
)
848 * We can optimise this out completely for !SMP, because the
849 * SMP rebalancing from interrupt is the only thing that cares
856 static inline void finish_lock_switch(struct rq
*rq
, struct task_struct
*prev
)
860 * After ->on_cpu is cleared, the task can be moved to a different CPU.
861 * We must ensure this doesn't happen until the switch is completely
867 #ifdef CONFIG_DEBUG_SPINLOCK
868 /* this is a valid case when another task releases the spinlock */
869 rq
->lock
.owner
= current
;
872 * If we are tracking spinlock dependencies then we have to
873 * fix up the runqueue lock - which gets 'carried over' from
876 spin_acquire(&rq
->lock
.dep_map
, 0, 0, _THIS_IP_
);
878 raw_spin_unlock_irq(&rq
->lock
);
881 #else /* __ARCH_WANT_UNLOCKED_CTXSW */
882 static inline void prepare_lock_switch(struct rq
*rq
, struct task_struct
*next
)
886 * We can optimise this out completely for !SMP, because the
887 * SMP rebalancing from interrupt is the only thing that cares
892 raw_spin_unlock(&rq
->lock
);
895 static inline void finish_lock_switch(struct rq
*rq
, struct task_struct
*prev
)
899 * After ->on_cpu is cleared, the task can be moved to a different CPU.
900 * We must ensure this doesn't happen until the switch is completely
908 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */
913 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
914 #define WF_FORK 0x02 /* child wakeup after fork */
915 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
918 * To aid in avoiding the subversion of "niceness" due to uneven distribution
919 * of tasks with abnormal "nice" values across CPUs the contribution that
920 * each task makes to its run queue's load is weighted according to its
921 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
922 * scaled version of the new time slice allocation that they receive on time
926 #define WEIGHT_IDLEPRIO 3
927 #define WMULT_IDLEPRIO 1431655765
930 * Nice levels are multiplicative, with a gentle 10% change for every
931 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
932 * nice 1, it will get ~10% less CPU time than another CPU-bound task
933 * that remained on nice 0.
935 * The "10% effect" is relative and cumulative: from _any_ nice level,
936 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
937 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
938 * If a task goes up by ~10% and another task goes down by ~10% then
939 * the relative distance between them is ~25%.)
941 static const int prio_to_weight
[40] = {
942 /* -20 */ 88761, 71755, 56483, 46273, 36291,
943 /* -15 */ 29154, 23254, 18705, 14949, 11916,
944 /* -10 */ 9548, 7620, 6100, 4904, 3906,
945 /* -5 */ 3121, 2501, 1991, 1586, 1277,
946 /* 0 */ 1024, 820, 655, 526, 423,
947 /* 5 */ 335, 272, 215, 172, 137,
948 /* 10 */ 110, 87, 70, 56, 45,
949 /* 15 */ 36, 29, 23, 18, 15,
953 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
955 * In cases where the weight does not change often, we can use the
956 * precalculated inverse to speed up arithmetics by turning divisions
957 * into multiplications:
959 static const u32 prio_to_wmult
[40] = {
960 /* -20 */ 48388, 59856, 76040, 92818, 118348,
961 /* -15 */ 147320, 184698, 229616, 287308, 360437,
962 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
963 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
964 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
965 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
966 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
967 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
970 #define ENQUEUE_WAKEUP 1
971 #define ENQUEUE_HEAD 2
973 #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */
975 #define ENQUEUE_WAKING 0
978 #define DEQUEUE_SLEEP 1
981 const struct sched_class
*next
;
983 void (*enqueue_task
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
984 void (*dequeue_task
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
985 void (*yield_task
) (struct rq
*rq
);
986 bool (*yield_to_task
) (struct rq
*rq
, struct task_struct
*p
, bool preempt
);
988 void (*check_preempt_curr
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
990 struct task_struct
* (*pick_next_task
) (struct rq
*rq
);
991 void (*put_prev_task
) (struct rq
*rq
, struct task_struct
*p
);
994 int (*select_task_rq
)(struct task_struct
*p
, int sd_flag
, int flags
);
995 void (*migrate_task_rq
)(struct task_struct
*p
, int next_cpu
);
997 void (*pre_schedule
) (struct rq
*this_rq
, struct task_struct
*task
);
998 void (*post_schedule
) (struct rq
*this_rq
);
999 void (*task_waking
) (struct task_struct
*task
);
1000 void (*task_woken
) (struct rq
*this_rq
, struct task_struct
*task
);
1002 void (*set_cpus_allowed
)(struct task_struct
*p
,
1003 const struct cpumask
*newmask
);
1005 void (*rq_online
)(struct rq
*rq
);
1006 void (*rq_offline
)(struct rq
*rq
);
1009 void (*set_curr_task
) (struct rq
*rq
);
1010 void (*task_tick
) (struct rq
*rq
, struct task_struct
*p
, int queued
);
1011 void (*task_fork
) (struct task_struct
*p
);
1013 void (*switched_from
) (struct rq
*this_rq
, struct task_struct
*task
);
1014 void (*switched_to
) (struct rq
*this_rq
, struct task_struct
*task
);
1015 void (*prio_changed
) (struct rq
*this_rq
, struct task_struct
*task
,
1018 unsigned int (*get_rr_interval
) (struct rq
*rq
,
1019 struct task_struct
*task
);
1021 #ifdef CONFIG_FAIR_GROUP_SCHED
1022 void (*task_move_group
) (struct task_struct
*p
, int on_rq
);
1026 #define sched_class_highest (&stop_sched_class)
1027 #define for_each_class(class) \
1028 for (class = sched_class_highest; class; class = class->next)
1030 extern const struct sched_class stop_sched_class
;
1031 extern const struct sched_class rt_sched_class
;
1032 extern const struct sched_class fair_sched_class
;
1033 extern const struct sched_class idle_sched_class
;
1038 extern void update_group_power(struct sched_domain
*sd
, int cpu
);
1040 extern void trigger_load_balance(struct rq
*rq
, int cpu
);
1041 extern void idle_balance(int this_cpu
, struct rq
*this_rq
);
1043 extern void idle_enter_fair(struct rq
*this_rq
);
1044 extern void idle_exit_fair(struct rq
*this_rq
);
1046 #else /* CONFIG_SMP */
1048 static inline void idle_balance(int cpu
, struct rq
*rq
)
1054 extern void sysrq_sched_debug_show(void);
1055 extern void sched_init_granularity(void);
1056 extern void update_max_interval(void);
1057 extern void init_sched_rt_class(void);
1058 extern void init_sched_fair_class(void);
1060 extern void resched_task(struct task_struct
*p
);
1061 extern void resched_cpu(int cpu
);
1063 extern struct rt_bandwidth def_rt_bandwidth
;
1064 extern void init_rt_bandwidth(struct rt_bandwidth
*rt_b
, u64 period
, u64 runtime
);
1066 extern void update_idle_cpu_load(struct rq
*this_rq
);
1068 extern void init_task_runnable_average(struct task_struct
*p
);
1070 #ifdef CONFIG_PARAVIRT
1071 static inline u64
steal_ticks(u64 steal
)
1073 if (unlikely(steal
> NSEC_PER_SEC
))
1074 return div_u64(steal
, TICK_NSEC
);
1076 return __iter_div_u64_rem(steal
, TICK_NSEC
, &steal
);
1080 static inline void inc_nr_running(struct rq
*rq
)
1084 #ifdef CONFIG_NO_HZ_FULL
1085 if (rq
->nr_running
== 2) {
1086 if (tick_nohz_full_cpu(rq
->cpu
)) {
1087 /* Order rq->nr_running write against the IPI */
1089 smp_send_reschedule(rq
->cpu
);
1095 static inline void dec_nr_running(struct rq
*rq
)
1100 static inline void rq_last_tick_reset(struct rq
*rq
)
1102 #ifdef CONFIG_NO_HZ_FULL
1103 rq
->last_sched_tick
= jiffies
;
1107 extern void update_rq_clock(struct rq
*rq
);
1109 extern void activate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
1110 extern void deactivate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
1112 extern void check_preempt_curr(struct rq
*rq
, struct task_struct
*p
, int flags
);
1114 extern const_debug
unsigned int sysctl_sched_time_avg
;
1115 extern const_debug
unsigned int sysctl_sched_nr_migrate
;
1116 extern const_debug
unsigned int sysctl_sched_migration_cost
;
1118 static inline u64
sched_avg_period(void)
1120 return (u64
)sysctl_sched_time_avg
* NSEC_PER_MSEC
/ 2;
1123 #ifdef CONFIG_SCHED_HRTICK
1127 * - enabled by features
1128 * - hrtimer is actually high res
1130 static inline int hrtick_enabled(struct rq
*rq
)
1132 if (!sched_feat(HRTICK
))
1134 if (!cpu_active(cpu_of(rq
)))
1136 return hrtimer_is_hres_active(&rq
->hrtick_timer
);
1139 void hrtick_start(struct rq
*rq
, u64 delay
);
1143 static inline int hrtick_enabled(struct rq
*rq
)
1148 #endif /* CONFIG_SCHED_HRTICK */
1151 extern void sched_avg_update(struct rq
*rq
);
1152 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
)
1154 rq
->rt_avg
+= rt_delta
;
1155 sched_avg_update(rq
);
1158 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
) { }
1159 static inline void sched_avg_update(struct rq
*rq
) { }
1162 extern void start_bandwidth_timer(struct hrtimer
*period_timer
, ktime_t period
);
1165 #ifdef CONFIG_PREEMPT
1167 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
);
1170 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1171 * way at the expense of forcing extra atomic operations in all
1172 * invocations. This assures that the double_lock is acquired using the
1173 * same underlying policy as the spinlock_t on this architecture, which
1174 * reduces latency compared to the unfair variant below. However, it
1175 * also adds more overhead and therefore may reduce throughput.
1177 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1178 __releases(this_rq
->lock
)
1179 __acquires(busiest
->lock
)
1180 __acquires(this_rq
->lock
)
1182 raw_spin_unlock(&this_rq
->lock
);
1183 double_rq_lock(this_rq
, busiest
);
1190 * Unfair double_lock_balance: Optimizes throughput at the expense of
1191 * latency by eliminating extra atomic operations when the locks are
1192 * already in proper order on entry. This favors lower cpu-ids and will
1193 * grant the double lock to lower cpus over higher ids under contention,
1194 * regardless of entry order into the function.
1196 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1197 __releases(this_rq
->lock
)
1198 __acquires(busiest
->lock
)
1199 __acquires(this_rq
->lock
)
1203 if (unlikely(!raw_spin_trylock(&busiest
->lock
))) {
1204 if (busiest
< this_rq
) {
1205 raw_spin_unlock(&this_rq
->lock
);
1206 raw_spin_lock(&busiest
->lock
);
1207 raw_spin_lock_nested(&this_rq
->lock
,
1208 SINGLE_DEPTH_NESTING
);
1211 raw_spin_lock_nested(&busiest
->lock
,
1212 SINGLE_DEPTH_NESTING
);
1217 #endif /* CONFIG_PREEMPT */
1220 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1222 static inline int double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1224 if (unlikely(!irqs_disabled())) {
1225 /* printk() doesn't work good under rq->lock */
1226 raw_spin_unlock(&this_rq
->lock
);
1230 return _double_lock_balance(this_rq
, busiest
);
1233 static inline void double_unlock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1234 __releases(busiest
->lock
)
1236 raw_spin_unlock(&busiest
->lock
);
1237 lock_set_subclass(&this_rq
->lock
.dep_map
, 0, _RET_IP_
);
1241 * double_rq_lock - safely lock two runqueues
1243 * Note this does not disable interrupts like task_rq_lock,
1244 * you need to do so manually before calling.
1246 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1247 __acquires(rq1
->lock
)
1248 __acquires(rq2
->lock
)
1250 BUG_ON(!irqs_disabled());
1252 raw_spin_lock(&rq1
->lock
);
1253 __acquire(rq2
->lock
); /* Fake it out ;) */
1256 raw_spin_lock(&rq1
->lock
);
1257 raw_spin_lock_nested(&rq2
->lock
, SINGLE_DEPTH_NESTING
);
1259 raw_spin_lock(&rq2
->lock
);
1260 raw_spin_lock_nested(&rq1
->lock
, SINGLE_DEPTH_NESTING
);
1266 * double_rq_unlock - safely unlock two runqueues
1268 * Note this does not restore interrupts like task_rq_unlock,
1269 * you need to do so manually after calling.
1271 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1272 __releases(rq1
->lock
)
1273 __releases(rq2
->lock
)
1275 raw_spin_unlock(&rq1
->lock
);
1277 raw_spin_unlock(&rq2
->lock
);
1279 __release(rq2
->lock
);
1282 #else /* CONFIG_SMP */
1285 * double_rq_lock - safely lock two runqueues
1287 * Note this does not disable interrupts like task_rq_lock,
1288 * you need to do so manually before calling.
1290 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1291 __acquires(rq1
->lock
)
1292 __acquires(rq2
->lock
)
1294 BUG_ON(!irqs_disabled());
1296 raw_spin_lock(&rq1
->lock
);
1297 __acquire(rq2
->lock
); /* Fake it out ;) */
1301 * double_rq_unlock - safely unlock two runqueues
1303 * Note this does not restore interrupts like task_rq_unlock,
1304 * you need to do so manually after calling.
1306 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1307 __releases(rq1
->lock
)
1308 __releases(rq2
->lock
)
1311 raw_spin_unlock(&rq1
->lock
);
1312 __release(rq2
->lock
);
1317 extern struct sched_entity
*__pick_first_entity(struct cfs_rq
*cfs_rq
);
1318 extern struct sched_entity
*__pick_last_entity(struct cfs_rq
*cfs_rq
);
1319 extern void print_cfs_stats(struct seq_file
*m
, int cpu
);
1320 extern void print_rt_stats(struct seq_file
*m
, int cpu
);
1322 extern void init_cfs_rq(struct cfs_rq
*cfs_rq
);
1323 extern void init_rt_rq(struct rt_rq
*rt_rq
, struct rq
*rq
);
1325 extern void account_cfs_bandwidth_used(int enabled
, int was_enabled
);
1327 #ifdef CONFIG_NO_HZ_COMMON
1328 enum rq_nohz_flag_bits
{
1333 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1336 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1338 DECLARE_PER_CPU(u64
, cpu_hardirq_time
);
1339 DECLARE_PER_CPU(u64
, cpu_softirq_time
);
1341 #ifndef CONFIG_64BIT
1342 DECLARE_PER_CPU(seqcount_t
, irq_time_seq
);
1344 static inline void irq_time_write_begin(void)
1346 __this_cpu_inc(irq_time_seq
.sequence
);
1350 static inline void irq_time_write_end(void)
1353 __this_cpu_inc(irq_time_seq
.sequence
);
1356 static inline u64
irq_time_read(int cpu
)
1362 seq
= read_seqcount_begin(&per_cpu(irq_time_seq
, cpu
));
1363 irq_time
= per_cpu(cpu_softirq_time
, cpu
) +
1364 per_cpu(cpu_hardirq_time
, cpu
);
1365 } while (read_seqcount_retry(&per_cpu(irq_time_seq
, cpu
), seq
));
1369 #else /* CONFIG_64BIT */
1370 static inline void irq_time_write_begin(void)
1374 static inline void irq_time_write_end(void)
1378 static inline u64
irq_time_read(int cpu
)
1380 return per_cpu(cpu_softirq_time
, cpu
) + per_cpu(cpu_hardirq_time
, cpu
);
1382 #endif /* CONFIG_64BIT */
1383 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */