2 #include <linux/sched.h>
3 #include <linux/sched/sysctl.h>
4 #include <linux/sched/rt.h>
5 #include <linux/sched/deadline.h>
6 #include <linux/mutex.h>
7 #include <linux/spinlock.h>
8 #include <linux/stop_machine.h>
9 #include <linux/tick.h>
10 #include <linux/slab.h>
13 #include "cpudeadline.h"
18 extern __read_mostly int scheduler_running;
20 extern unsigned long calc_load_update;
21 extern atomic_long_t calc_load_tasks;
23 extern long calc_load_fold_active(struct rq *this_rq);
24 extern void update_cpu_load_active(struct rq *this_rq);
27 * Helpers for converting nanosecond timing to jiffy resolution
29 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
32 * Increase resolution of nice-level calculations for 64-bit architectures.
33 * The extra resolution improves shares distribution and load balancing of
34 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
35 * hierarchies, especially on larger systems. This is not a user-visible change
36 * and does not change the user-interface for setting shares/weights.
38 * We increase resolution only if we have enough bits to allow this increased
39 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
40 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
43 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
44 # define SCHED_LOAD_RESOLUTION 10
45 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
46 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
48 # define SCHED_LOAD_RESOLUTION 0
49 # define scale_load(w) (w)
50 # define scale_load_down(w) (w)
53 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
54 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
56 #define NICE_0_LOAD SCHED_LOAD_SCALE
57 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
60 * Single value that decides SCHED_DEADLINE internal math precision.
61 * 10 -> just above 1us
62 * 9 -> just above 0.5us
67 * These are the 'tuning knobs' of the scheduler:
71 * single value that denotes runtime == period, ie unlimited time.
73 #define RUNTIME_INF ((u64)~0ULL)
75 static inline int fair_policy(int policy)
77 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
80 static inline int rt_policy(int policy)
82 return policy == SCHED_FIFO || policy == SCHED_RR;
85 static inline int dl_policy(int policy)
87 return policy == SCHED_DEADLINE;
90 static inline int task_has_rt_policy(struct task_struct *p)
92 return rt_policy(p->policy);
95 static inline int task_has_dl_policy(struct task_struct *p)
97 return dl_policy(p->policy);
100 static inline bool dl_time_before(u64 a, u64 b)
102 return (s64)(a - b) < 0;
106 * Tells if entity @a should preempt entity @b.
109 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
111 return dl_time_before(a->deadline, b->deadline);
115 * This is the priority-queue data structure of the RT scheduling class:
117 struct rt_prio_array {
118 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
119 struct list_head queue[MAX_RT_PRIO];
122 struct rt_bandwidth {
123 /* nests inside the rq lock: */
124 raw_spinlock_t rt_runtime_lock;
127 struct hrtimer rt_period_timer;
130 * To keep the bandwidth of -deadline tasks and groups under control
131 * we need some place where:
132 * - store the maximum -deadline bandwidth of the system (the group);
133 * - cache the fraction of that bandwidth that is currently allocated.
135 * This is all done in the data structure below. It is similar to the
136 * one used for RT-throttling (rt_bandwidth), with the main difference
137 * that, since here we are only interested in admission control, we
138 * do not decrease any runtime while the group "executes", neither we
139 * need a timer to replenish it.
141 * With respect to SMP, the bandwidth is given on a per-CPU basis,
143 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
144 * - dl_total_bw array contains, in the i-eth element, the currently
145 * allocated bandwidth on the i-eth CPU.
146 * Moreover, groups consume bandwidth on each CPU, while tasks only
147 * consume bandwidth on the CPU they're running on.
148 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
149 * that will be shown the next time the proc or cgroup controls will
150 * be red. It on its turn can be changed by writing on its own
153 struct dl_bandwidth {
154 raw_spinlock_t dl_runtime_lock;
159 static inline int dl_bandwidth_enabled(void)
161 return sysctl_sched_rt_runtime >= 0;
164 extern struct dl_bw *dl_bw_of(int i);
171 extern struct mutex sched_domains_mutex;
173 #ifdef CONFIG_CGROUP_SCHED
175 #include <linux/cgroup.h>
180 extern struct list_head task_groups;
182 struct cfs_bandwidth {
183 #ifdef CONFIG_CFS_BANDWIDTH
187 s64 hierarchal_quota;
190 int idle, timer_active;
191 struct hrtimer period_timer, slack_timer;
192 struct list_head throttled_cfs_rq;
195 int nr_periods, nr_throttled;
200 /* task group related information */
202 struct cgroup_subsys_state css;
204 #ifdef CONFIG_FAIR_GROUP_SCHED
205 /* schedulable entities of this group on each cpu */
206 struct sched_entity **se;
207 /* runqueue "owned" by this group on each cpu */
208 struct cfs_rq **cfs_rq;
209 unsigned long shares;
212 atomic_long_t load_avg;
213 atomic_t runnable_avg;
217 #ifdef CONFIG_RT_GROUP_SCHED
218 struct sched_rt_entity **rt_se;
219 struct rt_rq **rt_rq;
221 struct rt_bandwidth rt_bandwidth;
225 struct list_head list;
227 struct task_group *parent;
228 struct list_head siblings;
229 struct list_head children;
231 #ifdef CONFIG_SCHED_AUTOGROUP
232 struct autogroup *autogroup;
235 struct cfs_bandwidth cfs_bandwidth;
238 #ifdef CONFIG_FAIR_GROUP_SCHED
239 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
242 * A weight of 0 or 1 can cause arithmetics problems.
243 * A weight of a cfs_rq is the sum of weights of which entities
244 * are queued on this cfs_rq, so a weight of a entity should not be
245 * too large, so as the shares value of a task group.
246 * (The default weight is 1024 - so there's no practical
247 * limitation from this.)
249 #define MIN_SHARES (1UL << 1)
250 #define MAX_SHARES (1UL << 18)
253 typedef int (*tg_visitor)(struct task_group *, void *);
255 extern int walk_tg_tree_from(struct task_group *from,
256 tg_visitor down, tg_visitor up, void *data);
259 * Iterate the full tree, calling @down when first entering a node and @up when
260 * leaving it for the final time.
262 * Caller must hold rcu_lock or sufficient equivalent.
264 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
266 return walk_tg_tree_from(&root_task_group, down, up, data);
269 extern int tg_nop(struct task_group *tg, void *data);
271 extern void free_fair_sched_group(struct task_group *tg);
272 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
273 extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
274 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
275 struct sched_entity *se, int cpu,
276 struct sched_entity *parent);
277 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
278 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
280 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
281 extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force);
282 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
284 extern void free_rt_sched_group(struct task_group *tg);
285 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
286 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
287 struct sched_rt_entity *rt_se, int cpu,
288 struct sched_rt_entity *parent);
290 extern struct task_group *sched_create_group(struct task_group *parent);
291 extern void sched_online_group(struct task_group *tg,
292 struct task_group *parent);
293 extern void sched_destroy_group(struct task_group *tg);
294 extern void sched_offline_group(struct task_group *tg);
296 extern void sched_move_task(struct task_struct *tsk);
298 #ifdef CONFIG_FAIR_GROUP_SCHED
299 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
302 #else /* CONFIG_CGROUP_SCHED */
304 struct cfs_bandwidth { };
306 #endif /* CONFIG_CGROUP_SCHED */
308 /* CFS-related fields in a runqueue */
310 struct load_weight load;
311 unsigned int nr_running, h_nr_running;
316 u64 min_vruntime_copy;
319 struct rb_root tasks_timeline;
320 struct rb_node *rb_leftmost;
323 * 'curr' points to currently running entity on this cfs_rq.
324 * It is set to NULL otherwise (i.e when none are currently running).
326 struct sched_entity *curr, *next, *last, *skip;
328 #ifdef CONFIG_SCHED_DEBUG
329 unsigned int nr_spread_over;
335 * Under CFS, load is tracked on a per-entity basis and aggregated up.
336 * This allows for the description of both thread and group usage (in
337 * the FAIR_GROUP_SCHED case).
339 unsigned long runnable_load_avg, blocked_load_avg;
340 atomic64_t decay_counter;
342 atomic_long_t removed_load;
344 #ifdef CONFIG_FAIR_GROUP_SCHED
345 /* Required to track per-cpu representation of a task_group */
346 u32 tg_runnable_contrib;
347 unsigned long tg_load_contrib;
350 * h_load = weight * f(tg)
352 * Where f(tg) is the recursive weight fraction assigned to
355 unsigned long h_load;
356 u64 last_h_load_update;
357 struct sched_entity *h_load_next;
358 #endif /* CONFIG_FAIR_GROUP_SCHED */
359 #endif /* CONFIG_SMP */
361 #ifdef CONFIG_FAIR_GROUP_SCHED
362 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
365 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
366 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
367 * (like users, containers etc.)
369 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
370 * list is used during load balance.
373 struct list_head leaf_cfs_rq_list;
374 struct task_group *tg; /* group that "owns" this runqueue */
376 #ifdef CONFIG_CFS_BANDWIDTH
379 s64 runtime_remaining;
381 u64 throttled_clock, throttled_clock_task;
382 u64 throttled_clock_task_time;
383 int throttled, throttle_count;
384 struct list_head throttled_list;
385 #endif /* CONFIG_CFS_BANDWIDTH */
386 #endif /* CONFIG_FAIR_GROUP_SCHED */
389 static inline int rt_bandwidth_enabled(void)
391 return sysctl_sched_rt_runtime >= 0;
394 /* Real-Time classes' related field in a runqueue: */
396 struct rt_prio_array active;
397 unsigned int rt_nr_running;
398 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
400 int curr; /* highest queued rt task prio */
402 int next; /* next highest */
407 unsigned long rt_nr_migratory;
408 unsigned long rt_nr_total;
410 struct plist_head pushable_tasks;
417 /* Nests inside the rq lock: */
418 raw_spinlock_t rt_runtime_lock;
420 #ifdef CONFIG_RT_GROUP_SCHED
421 unsigned long rt_nr_boosted;
424 struct task_group *tg;
428 /* Deadline class' related fields in a runqueue */
430 /* runqueue is an rbtree, ordered by deadline */
431 struct rb_root rb_root;
432 struct rb_node *rb_leftmost;
434 unsigned long dl_nr_running;
438 * Deadline values of the currently executing and the
439 * earliest ready task on this rq. Caching these facilitates
440 * the decision wether or not a ready but not running task
441 * should migrate somewhere else.
448 unsigned long dl_nr_migratory;
452 * Tasks on this rq that can be pushed away. They are kept in
453 * an rb-tree, ordered by tasks' deadlines, with caching
454 * of the leftmost (earliest deadline) element.
456 struct rb_root pushable_dl_tasks_root;
457 struct rb_node *pushable_dl_tasks_leftmost;
466 * We add the notion of a root-domain which will be used to define per-domain
467 * variables. Each exclusive cpuset essentially defines an island domain by
468 * fully partitioning the member cpus from any other cpuset. Whenever a new
469 * exclusive cpuset is created, we also create and attach a new root-domain
478 cpumask_var_t online;
481 * The bit corresponding to a CPU gets set here if such CPU has more
482 * than one runnable -deadline task (as it is below for RT tasks).
484 cpumask_var_t dlo_mask;
490 * The "RT overload" flag: it gets set if a CPU has more than
491 * one runnable RT task.
493 cpumask_var_t rto_mask;
494 struct cpupri cpupri;
497 extern struct root_domain def_root_domain;
499 #endif /* CONFIG_SMP */
502 * This is the main, per-CPU runqueue data structure.
504 * Locking rule: those places that want to lock multiple runqueues
505 * (such as the load balancing or the thread migration code), lock
506 * acquire operations must be ordered by ascending &runqueue.
513 * nr_running and cpu_load should be in the same cacheline because
514 * remote CPUs use both these fields when doing load calculation.
516 unsigned int nr_running;
517 #ifdef CONFIG_NUMA_BALANCING
518 unsigned int nr_numa_running;
519 unsigned int nr_preferred_running;
521 #define CPU_LOAD_IDX_MAX 5
522 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
523 unsigned long last_load_update_tick;
524 #ifdef CONFIG_NO_HZ_COMMON
526 unsigned long nohz_flags;
528 #ifdef CONFIG_NO_HZ_FULL
529 unsigned long last_sched_tick;
531 int skip_clock_update;
533 /* capture load from *all* tasks on this cpu: */
534 struct load_weight load;
535 unsigned long nr_load_updates;
542 #ifdef CONFIG_FAIR_GROUP_SCHED
543 /* list of leaf cfs_rq on this cpu: */
544 struct list_head leaf_cfs_rq_list;
546 struct sched_avg avg;
547 #endif /* CONFIG_FAIR_GROUP_SCHED */
550 * This is part of a global counter where only the total sum
551 * over all CPUs matters. A task can increase this counter on
552 * one CPU and if it got migrated afterwards it may decrease
553 * it on another CPU. Always updated under the runqueue lock:
555 unsigned long nr_uninterruptible;
557 struct task_struct *curr, *idle, *stop;
558 unsigned long next_balance;
559 struct mm_struct *prev_mm;
567 struct root_domain *rd;
568 struct sched_domain *sd;
570 unsigned long cpu_power;
572 unsigned char idle_balance;
573 /* For active balancing */
577 struct cpu_stop_work active_balance_work;
578 /* cpu of this runqueue: */
582 struct list_head cfs_tasks;
589 /* This is used to determine avg_idle's max value */
590 u64 max_idle_balance_cost;
593 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
596 #ifdef CONFIG_PARAVIRT
599 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
600 u64 prev_steal_time_rq;
603 /* calc_load related fields */
604 unsigned long calc_load_update;
605 long calc_load_active;
607 #ifdef CONFIG_SCHED_HRTICK
609 int hrtick_csd_pending;
610 struct call_single_data hrtick_csd;
612 struct hrtimer hrtick_timer;
615 #ifdef CONFIG_SCHEDSTATS
617 struct sched_info rq_sched_info;
618 unsigned long long rq_cpu_time;
619 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
621 /* sys_sched_yield() stats */
622 unsigned int yld_count;
624 /* schedule() stats */
625 unsigned int sched_count;
626 unsigned int sched_goidle;
628 /* try_to_wake_up() stats */
629 unsigned int ttwu_count;
630 unsigned int ttwu_local;
634 struct llist_head wake_list;
638 static inline int cpu_of(struct rq *rq)
647 DECLARE_PER_CPU(struct rq, runqueues);
649 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
650 #define this_rq() (&__get_cpu_var(runqueues))
651 #define task_rq(p) cpu_rq(task_cpu(p))
652 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
653 #define raw_rq() (&__raw_get_cpu_var(runqueues))
655 static inline u64 rq_clock(struct rq *rq)
660 static inline u64 rq_clock_task(struct rq *rq)
662 return rq->clock_task;
665 #ifdef CONFIG_NUMA_BALANCING
666 extern void sched_setnuma(struct task_struct *p, int node);
667 extern int migrate_task_to(struct task_struct *p, int cpu);
668 extern int migrate_swap(struct task_struct *, struct task_struct *);
669 #endif /* CONFIG_NUMA_BALANCING */
673 #define rcu_dereference_check_sched_domain(p) \
674 rcu_dereference_check((p), \
675 lockdep_is_held(&sched_domains_mutex))
678 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
679 * See detach_destroy_domains: synchronize_sched for details.
681 * The domain tree of any CPU may only be accessed from within
682 * preempt-disabled sections.
684 #define for_each_domain(cpu, __sd) \
685 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
686 __sd; __sd = __sd->parent)
688 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
691 * highest_flag_domain - Return highest sched_domain containing flag.
692 * @cpu: The cpu whose highest level of sched domain is to
694 * @flag: The flag to check for the highest sched_domain
697 * Returns the highest sched_domain of a cpu which contains the given flag.
699 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
701 struct sched_domain *sd, *hsd = NULL;
703 for_each_domain(cpu, sd) {
704 if (!(sd->flags & flag))
712 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
714 struct sched_domain *sd;
716 for_each_domain(cpu, sd) {
717 if (sd->flags & flag)
724 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
725 DECLARE_PER_CPU(int, sd_llc_size);
726 DECLARE_PER_CPU(int, sd_llc_id);
727 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
728 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
729 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
731 struct sched_group_power {
734 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
737 unsigned int power, power_orig;
738 unsigned long next_update;
739 int imbalance; /* XXX unrelated to power but shared group state */
741 * Number of busy cpus in this group.
743 atomic_t nr_busy_cpus;
745 unsigned long cpumask[0]; /* iteration mask */
749 struct sched_group *next; /* Must be a circular list */
752 unsigned int group_weight;
753 struct sched_group_power *sgp;
756 * The CPUs this group covers.
758 * NOTE: this field is variable length. (Allocated dynamically
759 * by attaching extra space to the end of the structure,
760 * depending on how many CPUs the kernel has booted up with)
762 unsigned long cpumask[0];
765 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
767 return to_cpumask(sg->cpumask);
771 * cpumask masking which cpus in the group are allowed to iterate up the domain
774 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
776 return to_cpumask(sg->sgp->cpumask);
780 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
781 * @group: The group whose first cpu is to be returned.
783 static inline unsigned int group_first_cpu(struct sched_group *group)
785 return cpumask_first(sched_group_cpus(group));
788 extern int group_balance_cpu(struct sched_group *sg);
790 #endif /* CONFIG_SMP */
793 #include "auto_group.h"
795 #ifdef CONFIG_CGROUP_SCHED
798 * Return the group to which this tasks belongs.
800 * We cannot use task_css() and friends because the cgroup subsystem
801 * changes that value before the cgroup_subsys::attach() method is called,
802 * therefore we cannot pin it and might observe the wrong value.
804 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
805 * core changes this before calling sched_move_task().
807 * Instead we use a 'copy' which is updated from sched_move_task() while
808 * holding both task_struct::pi_lock and rq::lock.
810 static inline struct task_group *task_group(struct task_struct *p)
812 return p->sched_task_group;
815 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
816 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
818 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
819 struct task_group *tg = task_group(p);
822 #ifdef CONFIG_FAIR_GROUP_SCHED
823 p->se.cfs_rq = tg->cfs_rq[cpu];
824 p->se.parent = tg->se[cpu];
827 #ifdef CONFIG_RT_GROUP_SCHED
828 p->rt.rt_rq = tg->rt_rq[cpu];
829 p->rt.parent = tg->rt_se[cpu];
833 #else /* CONFIG_CGROUP_SCHED */
835 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
836 static inline struct task_group *task_group(struct task_struct *p)
841 #endif /* CONFIG_CGROUP_SCHED */
843 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
848 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
849 * successfuly executed on another CPU. We must ensure that updates of
850 * per-task data have been completed by this moment.
853 task_thread_info(p)->cpu = cpu;
859 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
861 #ifdef CONFIG_SCHED_DEBUG
862 # include <linux/static_key.h>
863 # define const_debug __read_mostly
865 # define const_debug const
868 extern const_debug unsigned int sysctl_sched_features;
870 #define SCHED_FEAT(name, enabled) \
871 __SCHED_FEAT_##name ,
874 #include "features.h"
880 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
881 static __always_inline bool static_branch__true(struct static_key *key)
883 return static_key_true(key); /* Not out of line branch. */
886 static __always_inline bool static_branch__false(struct static_key *key)
888 return static_key_false(key); /* Out of line branch. */
891 #define SCHED_FEAT(name, enabled) \
892 static __always_inline bool static_branch_##name(struct static_key *key) \
894 return static_branch__##enabled(key); \
897 #include "features.h"
901 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
902 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
903 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
904 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
905 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
907 #ifdef CONFIG_NUMA_BALANCING
908 #define sched_feat_numa(x) sched_feat(x)
909 #ifdef CONFIG_SCHED_DEBUG
910 #define numabalancing_enabled sched_feat_numa(NUMA)
912 extern bool numabalancing_enabled;
913 #endif /* CONFIG_SCHED_DEBUG */
915 #define sched_feat_numa(x) (0)
916 #define numabalancing_enabled (0)
917 #endif /* CONFIG_NUMA_BALANCING */
919 static inline u64 global_rt_period(void)
921 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
924 static inline u64 global_rt_runtime(void)
926 if (sysctl_sched_rt_runtime < 0)
929 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
932 static inline int task_current(struct rq *rq, struct task_struct *p)
934 return rq->curr == p;
937 static inline int task_running(struct rq *rq, struct task_struct *p)
942 return task_current(rq, p);
947 #ifndef prepare_arch_switch
948 # define prepare_arch_switch(next) do { } while (0)
950 #ifndef finish_arch_switch
951 # define finish_arch_switch(prev) do { } while (0)
953 #ifndef finish_arch_post_lock_switch
954 # define finish_arch_post_lock_switch() do { } while (0)
957 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
958 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
962 * We can optimise this out completely for !SMP, because the
963 * SMP rebalancing from interrupt is the only thing that cares
970 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
974 * After ->on_cpu is cleared, the task can be moved to a different CPU.
975 * We must ensure this doesn't happen until the switch is completely
981 #ifdef CONFIG_DEBUG_SPINLOCK
982 /* this is a valid case when another task releases the spinlock */
983 rq->lock.owner = current;
986 * If we are tracking spinlock dependencies then we have to
987 * fix up the runqueue lock - which gets 'carried over' from
990 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
992 raw_spin_unlock_irq(&rq->lock);
995 #else /* __ARCH_WANT_UNLOCKED_CTXSW */
996 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1000 * We can optimise this out completely for !SMP, because the
1001 * SMP rebalancing from interrupt is the only thing that cares
1006 raw_spin_unlock(&rq->lock);
1009 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1013 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1014 * We must ensure this doesn't happen until the switch is completely
1022 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */
1027 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1028 #define WF_FORK 0x02 /* child wakeup after fork */
1029 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1032 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1033 * of tasks with abnormal "nice" values across CPUs the contribution that
1034 * each task makes to its run queue's load is weighted according to its
1035 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1036 * scaled version of the new time slice allocation that they receive on time
1040 #define WEIGHT_IDLEPRIO 3
1041 #define WMULT_IDLEPRIO 1431655765
1044 * Nice levels are multiplicative, with a gentle 10% change for every
1045 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
1046 * nice 1, it will get ~10% less CPU time than another CPU-bound task
1047 * that remained on nice 0.
1049 * The "10% effect" is relative and cumulative: from _any_ nice level,
1050 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
1051 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
1052 * If a task goes up by ~10% and another task goes down by ~10% then
1053 * the relative distance between them is ~25%.)
1055 static const int prio_to_weight[40] = {
1056 /* -20 */ 88761, 71755, 56483, 46273, 36291,
1057 /* -15 */ 29154, 23254, 18705, 14949, 11916,
1058 /* -10 */ 9548, 7620, 6100, 4904, 3906,
1059 /* -5 */ 3121, 2501, 1991, 1586, 1277,
1060 /* 0 */ 1024, 820, 655, 526, 423,
1061 /* 5 */ 335, 272, 215, 172, 137,
1062 /* 10 */ 110, 87, 70, 56, 45,
1063 /* 15 */ 36, 29, 23, 18, 15,
1067 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
1069 * In cases where the weight does not change often, we can use the
1070 * precalculated inverse to speed up arithmetics by turning divisions
1071 * into multiplications:
1073 static const u32 prio_to_wmult[40] = {
1074 /* -20 */ 48388, 59856, 76040, 92818, 118348,
1075 /* -15 */ 147320, 184698, 229616, 287308, 360437,
1076 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
1077 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
1078 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
1079 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
1080 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
1081 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
1084 #define ENQUEUE_WAKEUP 1
1085 #define ENQUEUE_HEAD 2
1087 #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */
1089 #define ENQUEUE_WAKING 0
1091 #define ENQUEUE_REPLENISH 8
1093 #define DEQUEUE_SLEEP 1
1095 #define RETRY_TASK ((void *)-1UL)
1097 struct sched_class {
1098 const struct sched_class *next;
1100 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1101 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1102 void (*yield_task) (struct rq *rq);
1103 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1105 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1108 * It is the responsibility of the pick_next_task() method that will
1109 * return the next task to call put_prev_task() on the @prev task or
1110 * something equivalent.
1112 * May return RETRY_TASK when it finds a higher prio class has runnable
1115 struct task_struct * (*pick_next_task) (struct rq *rq,
1116 struct task_struct *prev);
1117 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1120 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1121 void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
1123 void (*post_schedule) (struct rq *this_rq);
1124 void (*task_waking) (struct task_struct *task);
1125 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1127 void (*set_cpus_allowed)(struct task_struct *p,
1128 const struct cpumask *newmask);
1130 void (*rq_online)(struct rq *rq);
1131 void (*rq_offline)(struct rq *rq);
1134 void (*set_curr_task) (struct rq *rq);
1135 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1136 void (*task_fork) (struct task_struct *p);
1137 void (*task_dead) (struct task_struct *p);
1139 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1140 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1141 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1144 unsigned int (*get_rr_interval) (struct rq *rq,
1145 struct task_struct *task);
1147 #ifdef CONFIG_FAIR_GROUP_SCHED
1148 void (*task_move_group) (struct task_struct *p, int on_rq);
1152 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1154 prev->sched_class->put_prev_task(rq, prev);
1157 #define sched_class_highest (&stop_sched_class)
1158 #define for_each_class(class) \
1159 for (class = sched_class_highest; class; class = class->next)
1161 extern const struct sched_class stop_sched_class;
1162 extern const struct sched_class dl_sched_class;
1163 extern const struct sched_class rt_sched_class;
1164 extern const struct sched_class fair_sched_class;
1165 extern const struct sched_class idle_sched_class;
1170 extern void update_group_power(struct sched_domain *sd, int cpu);
1172 extern void trigger_load_balance(struct rq *rq);
1174 extern void idle_enter_fair(struct rq *this_rq);
1175 extern void idle_exit_fair(struct rq *this_rq);
1179 static inline void idle_enter_fair(struct rq *rq) { }
1180 static inline void idle_exit_fair(struct rq *rq) { }
1184 extern void sysrq_sched_debug_show(void);
1185 extern void sched_init_granularity(void);
1186 extern void update_max_interval(void);
1188 extern void init_sched_dl_class(void);
1189 extern void init_sched_rt_class(void);
1190 extern void init_sched_fair_class(void);
1191 extern void init_sched_dl_class(void);
1193 extern void resched_task(struct task_struct *p);
1194 extern void resched_cpu(int cpu);
1196 extern struct rt_bandwidth def_rt_bandwidth;
1197 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1199 extern struct dl_bandwidth def_dl_bandwidth;
1200 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1201 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1203 unsigned long to_ratio(u64 period, u64 runtime);
1205 extern void update_idle_cpu_load(struct rq *this_rq);
1207 extern void init_task_runnable_average(struct task_struct *p);
1209 static inline void add_nr_running(struct rq *rq, unsigned count)
1211 unsigned prev_nr = rq->nr_running;
1213 rq->nr_running = prev_nr + count;
1215 #ifdef CONFIG_NO_HZ_FULL
1216 if (prev_nr < 2 && rq->nr_running >= 2) {
1217 if (tick_nohz_full_cpu(rq->cpu)) {
1218 /* Order rq->nr_running write against the IPI */
1220 smp_send_reschedule(rq->cpu);
1226 static inline void sub_nr_running(struct rq *rq, unsigned count)
1228 rq->nr_running -= count;
1231 static inline void rq_last_tick_reset(struct rq *rq)
1233 #ifdef CONFIG_NO_HZ_FULL
1234 rq->last_sched_tick = jiffies;
1238 extern void update_rq_clock(struct rq *rq);
1240 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1241 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1243 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1245 extern const_debug unsigned int sysctl_sched_time_avg;
1246 extern const_debug unsigned int sysctl_sched_nr_migrate;
1247 extern const_debug unsigned int sysctl_sched_migration_cost;
1249 static inline u64 sched_avg_period(void)
1251 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1254 #ifdef CONFIG_SCHED_HRTICK
1258 * - enabled by features
1259 * - hrtimer is actually high res
1261 static inline int hrtick_enabled(struct rq *rq)
1263 if (!sched_feat(HRTICK))
1265 if (!cpu_active(cpu_of(rq)))
1267 return hrtimer_is_hres_active(&rq->hrtick_timer);
1270 void hrtick_start(struct rq *rq, u64 delay);
1274 static inline int hrtick_enabled(struct rq *rq)
1279 #endif /* CONFIG_SCHED_HRTICK */
1282 extern void sched_avg_update(struct rq *rq);
1283 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1285 rq->rt_avg += rt_delta;
1286 sched_avg_update(rq);
1289 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1290 static inline void sched_avg_update(struct rq *rq) { }
1293 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
1296 #ifdef CONFIG_PREEMPT
1298 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1301 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1302 * way at the expense of forcing extra atomic operations in all
1303 * invocations. This assures that the double_lock is acquired using the
1304 * same underlying policy as the spinlock_t on this architecture, which
1305 * reduces latency compared to the unfair variant below. However, it
1306 * also adds more overhead and therefore may reduce throughput.
1308 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1309 __releases(this_rq->lock)
1310 __acquires(busiest->lock)
1311 __acquires(this_rq->lock)
1313 raw_spin_unlock(&this_rq->lock);
1314 double_rq_lock(this_rq, busiest);
1321 * Unfair double_lock_balance: Optimizes throughput at the expense of
1322 * latency by eliminating extra atomic operations when the locks are
1323 * already in proper order on entry. This favors lower cpu-ids and will
1324 * grant the double lock to lower cpus over higher ids under contention,
1325 * regardless of entry order into the function.
1327 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1328 __releases(this_rq->lock)
1329 __acquires(busiest->lock)
1330 __acquires(this_rq->lock)
1334 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1335 if (busiest < this_rq) {
1336 raw_spin_unlock(&this_rq->lock);
1337 raw_spin_lock(&busiest->lock);
1338 raw_spin_lock_nested(&this_rq->lock,
1339 SINGLE_DEPTH_NESTING);
1342 raw_spin_lock_nested(&busiest->lock,
1343 SINGLE_DEPTH_NESTING);
1348 #endif /* CONFIG_PREEMPT */
1351 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1353 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1355 if (unlikely(!irqs_disabled())) {
1356 /* printk() doesn't work good under rq->lock */
1357 raw_spin_unlock(&this_rq->lock);
1361 return _double_lock_balance(this_rq, busiest);
1364 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1365 __releases(busiest->lock)
1367 raw_spin_unlock(&busiest->lock);
1368 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1371 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1377 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1380 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1386 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1389 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1395 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1399 * double_rq_lock - safely lock two runqueues
1401 * Note this does not disable interrupts like task_rq_lock,
1402 * you need to do so manually before calling.
1404 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1405 __acquires(rq1->lock)
1406 __acquires(rq2->lock)
1408 BUG_ON(!irqs_disabled());
1410 raw_spin_lock(&rq1->lock);
1411 __acquire(rq2->lock); /* Fake it out ;) */
1414 raw_spin_lock(&rq1->lock);
1415 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1417 raw_spin_lock(&rq2->lock);
1418 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1424 * double_rq_unlock - safely unlock two runqueues
1426 * Note this does not restore interrupts like task_rq_unlock,
1427 * you need to do so manually after calling.
1429 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1430 __releases(rq1->lock)
1431 __releases(rq2->lock)
1433 raw_spin_unlock(&rq1->lock);
1435 raw_spin_unlock(&rq2->lock);
1437 __release(rq2->lock);
1440 #else /* CONFIG_SMP */
1443 * double_rq_lock - safely lock two runqueues
1445 * Note this does not disable interrupts like task_rq_lock,
1446 * you need to do so manually before calling.
1448 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1449 __acquires(rq1->lock)
1450 __acquires(rq2->lock)
1452 BUG_ON(!irqs_disabled());
1454 raw_spin_lock(&rq1->lock);
1455 __acquire(rq2->lock); /* Fake it out ;) */
1459 * double_rq_unlock - safely unlock two runqueues
1461 * Note this does not restore interrupts like task_rq_unlock,
1462 * you need to do so manually after calling.
1464 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1465 __releases(rq1->lock)
1466 __releases(rq2->lock)
1469 raw_spin_unlock(&rq1->lock);
1470 __release(rq2->lock);
1475 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1476 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1477 extern void print_cfs_stats(struct seq_file *m, int cpu);
1478 extern void print_rt_stats(struct seq_file *m, int cpu);
1480 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1481 extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1482 extern void init_dl_rq(struct dl_rq *dl_rq, struct rq *rq);
1484 extern void cfs_bandwidth_usage_inc(void);
1485 extern void cfs_bandwidth_usage_dec(void);
1487 #ifdef CONFIG_NO_HZ_COMMON
1488 enum rq_nohz_flag_bits {
1493 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1496 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1498 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1499 DECLARE_PER_CPU(u64, cpu_softirq_time);
1501 #ifndef CONFIG_64BIT
1502 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1504 static inline void irq_time_write_begin(void)
1506 __this_cpu_inc(irq_time_seq.sequence);
1510 static inline void irq_time_write_end(void)
1513 __this_cpu_inc(irq_time_seq.sequence);
1516 static inline u64 irq_time_read(int cpu)
1522 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1523 irq_time = per_cpu(cpu_softirq_time, cpu) +
1524 per_cpu(cpu_hardirq_time, cpu);
1525 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1529 #else /* CONFIG_64BIT */
1530 static inline void irq_time_write_begin(void)
1534 static inline void irq_time_write_end(void)
1538 static inline u64 irq_time_read(int cpu)
1540 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1542 #endif /* CONFIG_64BIT */
1543 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */