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/binfmts.h>
7 #include <linux/mutex.h>
8 #include <linux/spinlock.h>
9 #include <linux/stop_machine.h>
10 #include <linux/irq_work.h>
11 #include <linux/tick.h>
12 #include <linux/slab.h>
15 #include "cpudeadline.h"
21 /* task_struct::on_rq states: */
22 #define TASK_ON_RQ_QUEUED 1
23 #define TASK_ON_RQ_MIGRATING 2
25 extern __read_mostly int scheduler_running;
27 extern unsigned long calc_load_update;
28 extern atomic_long_t calc_load_tasks;
30 extern void calc_global_load_tick(struct rq *this_rq);
31 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
34 extern void cpu_load_update_active(struct rq *this_rq);
36 static inline void cpu_load_update_active(struct rq *this_rq) { }
40 * Helpers for converting nanosecond timing to jiffy resolution
42 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
45 * Increase resolution of nice-level calculations for 64-bit architectures.
46 * The extra resolution improves shares distribution and load balancing of
47 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
48 * hierarchies, especially on larger systems. This is not a user-visible change
49 * and does not change the user-interface for setting shares/weights.
51 * We increase resolution only if we have enough bits to allow this increased
52 * resolution (i.e. 64bit). The costs for increasing resolution when 32bit are
53 * pretty high and the returns do not justify the increased costs.
55 * Really only required when CONFIG_FAIR_GROUP_SCHED is also set, but to
56 * increase coverage and consistency always enable it on 64bit platforms.
59 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
60 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
61 # define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT)
63 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
64 # define scale_load(w) (w)
65 # define scale_load_down(w) (w)
69 * Task weight (visible to users) and its load (invisible to users) have
70 * independent resolution, but they should be well calibrated. We use
71 * scale_load() and scale_load_down(w) to convert between them. The
72 * following must be true:
74 * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
77 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
80 * Single value that decides SCHED_DEADLINE internal math precision.
81 * 10 -> just above 1us
82 * 9 -> just above 0.5us
87 * These are the 'tuning knobs' of the scheduler:
91 * single value that denotes runtime == period, ie unlimited time.
93 #define RUNTIME_INF ((u64)~0ULL)
95 static inline int idle_policy(int policy)
97 return policy == SCHED_IDLE;
99 static inline int fair_policy(int policy)
101 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
104 static inline int rt_policy(int policy)
106 return policy == SCHED_FIFO || policy == SCHED_RR;
109 static inline int dl_policy(int policy)
111 return policy == SCHED_DEADLINE;
113 static inline bool valid_policy(int policy)
115 return idle_policy(policy) || fair_policy(policy) ||
116 rt_policy(policy) || dl_policy(policy);
119 static inline int task_has_rt_policy(struct task_struct *p)
121 return rt_policy(p->policy);
124 static inline int task_has_dl_policy(struct task_struct *p)
126 return dl_policy(p->policy);
130 * Tells if entity @a should preempt entity @b.
133 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
135 return dl_time_before(a->deadline, b->deadline);
139 * This is the priority-queue data structure of the RT scheduling class:
141 struct rt_prio_array {
142 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
143 struct list_head queue[MAX_RT_PRIO];
146 struct rt_bandwidth {
147 /* nests inside the rq lock: */
148 raw_spinlock_t rt_runtime_lock;
151 struct hrtimer rt_period_timer;
152 unsigned int rt_period_active;
155 void __dl_clear_params(struct task_struct *p);
158 * To keep the bandwidth of -deadline tasks and groups under control
159 * we need some place where:
160 * - store the maximum -deadline bandwidth of the system (the group);
161 * - cache the fraction of that bandwidth that is currently allocated.
163 * This is all done in the data structure below. It is similar to the
164 * one used for RT-throttling (rt_bandwidth), with the main difference
165 * that, since here we are only interested in admission control, we
166 * do not decrease any runtime while the group "executes", neither we
167 * need a timer to replenish it.
169 * With respect to SMP, the bandwidth is given on a per-CPU basis,
171 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
172 * - dl_total_bw array contains, in the i-eth element, the currently
173 * allocated bandwidth on the i-eth CPU.
174 * Moreover, groups consume bandwidth on each CPU, while tasks only
175 * consume bandwidth on the CPU they're running on.
176 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
177 * that will be shown the next time the proc or cgroup controls will
178 * be red. It on its turn can be changed by writing on its own
181 struct dl_bandwidth {
182 raw_spinlock_t dl_runtime_lock;
187 static inline int dl_bandwidth_enabled(void)
189 return sysctl_sched_rt_runtime >= 0;
192 extern struct dl_bw *dl_bw_of(int i);
200 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
202 dl_b->total_bw -= tsk_bw;
206 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
208 dl_b->total_bw += tsk_bw;
212 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
214 return dl_b->bw != -1 &&
215 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
218 extern struct mutex sched_domains_mutex;
220 #ifdef CONFIG_CGROUP_SCHED
222 #include <linux/cgroup.h>
227 extern struct list_head task_groups;
229 struct cfs_bandwidth {
230 #ifdef CONFIG_CFS_BANDWIDTH
234 s64 hierarchical_quota;
237 int idle, period_active;
238 struct hrtimer period_timer, slack_timer;
239 struct list_head throttled_cfs_rq;
242 int nr_periods, nr_throttled;
247 /* task group related information */
249 struct cgroup_subsys_state css;
251 #ifdef CONFIG_FAIR_GROUP_SCHED
252 /* schedulable entities of this group on each cpu */
253 struct sched_entity **se;
254 /* runqueue "owned" by this group on each cpu */
255 struct cfs_rq **cfs_rq;
256 unsigned long shares;
260 * load_avg can be heavily contended at clock tick time, so put
261 * it in its own cacheline separated from the fields above which
262 * will also be accessed at each tick.
264 atomic_long_t load_avg ____cacheline_aligned;
268 #ifdef CONFIG_RT_GROUP_SCHED
269 struct sched_rt_entity **rt_se;
270 struct rt_rq **rt_rq;
272 struct rt_bandwidth rt_bandwidth;
276 struct list_head list;
278 struct task_group *parent;
279 struct list_head siblings;
280 struct list_head children;
282 #ifdef CONFIG_SCHED_AUTOGROUP
283 struct autogroup *autogroup;
286 struct cfs_bandwidth cfs_bandwidth;
289 #ifdef CONFIG_FAIR_GROUP_SCHED
290 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
293 * A weight of 0 or 1 can cause arithmetics problems.
294 * A weight of a cfs_rq is the sum of weights of which entities
295 * are queued on this cfs_rq, so a weight of a entity should not be
296 * too large, so as the shares value of a task group.
297 * (The default weight is 1024 - so there's no practical
298 * limitation from this.)
300 #define MIN_SHARES (1UL << 1)
301 #define MAX_SHARES (1UL << 18)
304 typedef int (*tg_visitor)(struct task_group *, void *);
306 extern int walk_tg_tree_from(struct task_group *from,
307 tg_visitor down, tg_visitor up, void *data);
310 * Iterate the full tree, calling @down when first entering a node and @up when
311 * leaving it for the final time.
313 * Caller must hold rcu_lock or sufficient equivalent.
315 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
317 return walk_tg_tree_from(&root_task_group, down, up, data);
320 extern int tg_nop(struct task_group *tg, void *data);
322 extern void free_fair_sched_group(struct task_group *tg);
323 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
324 extern void online_fair_sched_group(struct task_group *tg);
325 extern void unregister_fair_sched_group(struct task_group *tg);
326 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
327 struct sched_entity *se, int cpu,
328 struct sched_entity *parent);
329 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
331 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
332 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
333 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
335 extern void free_rt_sched_group(struct task_group *tg);
336 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
337 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
338 struct sched_rt_entity *rt_se, int cpu,
339 struct sched_rt_entity *parent);
341 extern struct task_group *sched_create_group(struct task_group *parent);
342 extern void sched_online_group(struct task_group *tg,
343 struct task_group *parent);
344 extern void sched_destroy_group(struct task_group *tg);
345 extern void sched_offline_group(struct task_group *tg);
347 extern void sched_move_task(struct task_struct *tsk);
349 #ifdef CONFIG_FAIR_GROUP_SCHED
350 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
353 extern void set_task_rq_fair(struct sched_entity *se,
354 struct cfs_rq *prev, struct cfs_rq *next);
355 #else /* !CONFIG_SMP */
356 static inline void set_task_rq_fair(struct sched_entity *se,
357 struct cfs_rq *prev, struct cfs_rq *next) { }
358 #endif /* CONFIG_SMP */
359 #endif /* CONFIG_FAIR_GROUP_SCHED */
361 #else /* CONFIG_CGROUP_SCHED */
363 struct cfs_bandwidth { };
365 #endif /* CONFIG_CGROUP_SCHED */
367 /* CFS-related fields in a runqueue */
369 struct load_weight load;
370 unsigned int nr_running, h_nr_running;
375 u64 min_vruntime_copy;
378 struct rb_root tasks_timeline;
379 struct rb_node *rb_leftmost;
382 * 'curr' points to currently running entity on this cfs_rq.
383 * It is set to NULL otherwise (i.e when none are currently running).
385 struct sched_entity *curr, *next, *last, *skip;
387 #ifdef CONFIG_SCHED_DEBUG
388 unsigned int nr_spread_over;
395 struct sched_avg avg;
396 u64 runnable_load_sum;
397 unsigned long runnable_load_avg;
398 #ifdef CONFIG_FAIR_GROUP_SCHED
399 unsigned long tg_load_avg_contrib;
401 atomic_long_t removed_load_avg, removed_util_avg;
403 u64 load_last_update_time_copy;
406 #ifdef CONFIG_FAIR_GROUP_SCHED
408 * h_load = weight * f(tg)
410 * Where f(tg) is the recursive weight fraction assigned to
413 unsigned long h_load;
414 u64 last_h_load_update;
415 struct sched_entity *h_load_next;
416 #endif /* CONFIG_FAIR_GROUP_SCHED */
417 #endif /* CONFIG_SMP */
419 #ifdef CONFIG_FAIR_GROUP_SCHED
420 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
423 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
424 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
425 * (like users, containers etc.)
427 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
428 * list is used during load balance.
431 struct list_head leaf_cfs_rq_list;
432 struct task_group *tg; /* group that "owns" this runqueue */
434 #ifdef CONFIG_CFS_BANDWIDTH
437 s64 runtime_remaining;
439 u64 throttled_clock, throttled_clock_task;
440 u64 throttled_clock_task_time;
441 int throttled, throttle_count;
442 struct list_head throttled_list;
443 #endif /* CONFIG_CFS_BANDWIDTH */
444 #endif /* CONFIG_FAIR_GROUP_SCHED */
447 static inline int rt_bandwidth_enabled(void)
449 return sysctl_sched_rt_runtime >= 0;
452 /* RT IPI pull logic requires IRQ_WORK */
453 #ifdef CONFIG_IRQ_WORK
454 # define HAVE_RT_PUSH_IPI
457 /* Real-Time classes' related field in a runqueue: */
459 struct rt_prio_array active;
460 unsigned int rt_nr_running;
461 unsigned int rr_nr_running;
462 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
464 int curr; /* highest queued rt task prio */
466 int next; /* next highest */
471 unsigned long rt_nr_migratory;
472 unsigned long rt_nr_total;
474 struct plist_head pushable_tasks;
475 #ifdef HAVE_RT_PUSH_IPI
478 struct irq_work push_work;
479 raw_spinlock_t push_lock;
481 #endif /* CONFIG_SMP */
487 /* Nests inside the rq lock: */
488 raw_spinlock_t rt_runtime_lock;
490 #ifdef CONFIG_RT_GROUP_SCHED
491 unsigned long rt_nr_boosted;
494 struct task_group *tg;
498 /* Deadline class' related fields in a runqueue */
500 /* runqueue is an rbtree, ordered by deadline */
501 struct rb_root rb_root;
502 struct rb_node *rb_leftmost;
504 unsigned long dl_nr_running;
508 * Deadline values of the currently executing and the
509 * earliest ready task on this rq. Caching these facilitates
510 * the decision wether or not a ready but not running task
511 * should migrate somewhere else.
518 unsigned long dl_nr_migratory;
522 * Tasks on this rq that can be pushed away. They are kept in
523 * an rb-tree, ordered by tasks' deadlines, with caching
524 * of the leftmost (earliest deadline) element.
526 struct rb_root pushable_dl_tasks_root;
527 struct rb_node *pushable_dl_tasks_leftmost;
536 * We add the notion of a root-domain which will be used to define per-domain
537 * variables. Each exclusive cpuset essentially defines an island domain by
538 * fully partitioning the member cpus from any other cpuset. Whenever a new
539 * exclusive cpuset is created, we also create and attach a new root-domain
548 cpumask_var_t online;
550 /* Indicate more than one runnable task for any CPU */
554 * The bit corresponding to a CPU gets set here if such CPU has more
555 * than one runnable -deadline task (as it is below for RT tasks).
557 cpumask_var_t dlo_mask;
563 * The "RT overload" flag: it gets set if a CPU has more than
564 * one runnable RT task.
566 cpumask_var_t rto_mask;
567 struct cpupri cpupri;
569 unsigned long max_cpu_capacity;
572 extern struct root_domain def_root_domain;
574 #endif /* CONFIG_SMP */
577 * This is the main, per-CPU runqueue data structure.
579 * Locking rule: those places that want to lock multiple runqueues
580 * (such as the load balancing or the thread migration code), lock
581 * acquire operations must be ordered by ascending &runqueue.
588 * nr_running and cpu_load should be in the same cacheline because
589 * remote CPUs use both these fields when doing load calculation.
591 unsigned int nr_running;
592 #ifdef CONFIG_NUMA_BALANCING
593 unsigned int nr_numa_running;
594 unsigned int nr_preferred_running;
596 #define CPU_LOAD_IDX_MAX 5
597 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
598 #ifdef CONFIG_NO_HZ_COMMON
600 unsigned long last_load_update_tick;
601 #endif /* CONFIG_SMP */
602 unsigned long nohz_flags;
603 #endif /* CONFIG_NO_HZ_COMMON */
604 #ifdef CONFIG_NO_HZ_FULL
605 unsigned long last_sched_tick;
607 /* capture load from *all* tasks on this cpu: */
608 struct load_weight load;
609 unsigned long nr_load_updates;
616 #ifdef CONFIG_FAIR_GROUP_SCHED
617 /* list of leaf cfs_rq on this cpu: */
618 struct list_head leaf_cfs_rq_list;
619 #endif /* CONFIG_FAIR_GROUP_SCHED */
622 * This is part of a global counter where only the total sum
623 * over all CPUs matters. A task can increase this counter on
624 * one CPU and if it got migrated afterwards it may decrease
625 * it on another CPU. Always updated under the runqueue lock:
627 unsigned long nr_uninterruptible;
629 struct task_struct *curr, *idle, *stop;
630 unsigned long next_balance;
631 struct mm_struct *prev_mm;
633 unsigned int clock_skip_update;
640 struct root_domain *rd;
641 struct sched_domain *sd;
643 unsigned long cpu_capacity;
644 unsigned long cpu_capacity_orig;
646 struct callback_head *balance_callback;
648 unsigned char idle_balance;
649 /* For active balancing */
652 struct cpu_stop_work active_balance_work;
653 /* cpu of this runqueue: */
657 struct list_head cfs_tasks;
664 /* This is used to determine avg_idle's max value */
665 u64 max_idle_balance_cost;
668 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
671 #ifdef CONFIG_PARAVIRT
674 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
675 u64 prev_steal_time_rq;
678 /* calc_load related fields */
679 unsigned long calc_load_update;
680 long calc_load_active;
682 #ifdef CONFIG_SCHED_HRTICK
684 int hrtick_csd_pending;
685 struct call_single_data hrtick_csd;
687 struct hrtimer hrtick_timer;
690 #ifdef CONFIG_SCHEDSTATS
692 struct sched_info rq_sched_info;
693 unsigned long long rq_cpu_time;
694 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
696 /* sys_sched_yield() stats */
697 unsigned int yld_count;
699 /* schedule() stats */
700 unsigned int sched_count;
701 unsigned int sched_goidle;
703 /* try_to_wake_up() stats */
704 unsigned int ttwu_count;
705 unsigned int ttwu_local;
709 struct llist_head wake_list;
712 #ifdef CONFIG_CPU_IDLE
713 /* Must be inspected within a rcu lock section */
714 struct cpuidle_state *idle_state;
718 static inline int cpu_of(struct rq *rq)
728 #ifdef CONFIG_SCHED_SMT
730 extern struct static_key_false sched_smt_present;
732 extern void __update_idle_core(struct rq *rq);
734 static inline void update_idle_core(struct rq *rq)
736 if (static_branch_unlikely(&sched_smt_present))
737 __update_idle_core(rq);
741 static inline void update_idle_core(struct rq *rq) { }
744 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
746 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
747 #define this_rq() this_cpu_ptr(&runqueues)
748 #define task_rq(p) cpu_rq(task_cpu(p))
749 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
750 #define raw_rq() raw_cpu_ptr(&runqueues)
752 static inline u64 __rq_clock_broken(struct rq *rq)
754 return READ_ONCE(rq->clock);
757 static inline u64 rq_clock(struct rq *rq)
759 lockdep_assert_held(&rq->lock);
763 static inline u64 rq_clock_task(struct rq *rq)
765 lockdep_assert_held(&rq->lock);
766 return rq->clock_task;
769 #define RQCF_REQ_SKIP 0x01
770 #define RQCF_ACT_SKIP 0x02
772 static inline void rq_clock_skip_update(struct rq *rq, bool skip)
774 lockdep_assert_held(&rq->lock);
776 rq->clock_skip_update |= RQCF_REQ_SKIP;
778 rq->clock_skip_update &= ~RQCF_REQ_SKIP;
782 enum numa_topology_type {
787 extern enum numa_topology_type sched_numa_topology_type;
788 extern int sched_max_numa_distance;
789 extern bool find_numa_distance(int distance);
792 #ifdef CONFIG_NUMA_BALANCING
793 /* The regions in numa_faults array from task_struct */
794 enum numa_faults_stats {
800 extern void sched_setnuma(struct task_struct *p, int node);
801 extern int migrate_task_to(struct task_struct *p, int cpu);
802 extern int migrate_swap(struct task_struct *, struct task_struct *);
803 #endif /* CONFIG_NUMA_BALANCING */
808 queue_balance_callback(struct rq *rq,
809 struct callback_head *head,
810 void (*func)(struct rq *rq))
812 lockdep_assert_held(&rq->lock);
814 if (unlikely(head->next))
817 head->func = (void (*)(struct callback_head *))func;
818 head->next = rq->balance_callback;
819 rq->balance_callback = head;
822 extern void sched_ttwu_pending(void);
824 #define rcu_dereference_check_sched_domain(p) \
825 rcu_dereference_check((p), \
826 lockdep_is_held(&sched_domains_mutex))
829 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
830 * See detach_destroy_domains: synchronize_sched for details.
832 * The domain tree of any CPU may only be accessed from within
833 * preempt-disabled sections.
835 #define for_each_domain(cpu, __sd) \
836 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
837 __sd; __sd = __sd->parent)
839 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
842 * highest_flag_domain - Return highest sched_domain containing flag.
843 * @cpu: The cpu whose highest level of sched domain is to
845 * @flag: The flag to check for the highest sched_domain
848 * Returns the highest sched_domain of a cpu which contains the given flag.
850 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
852 struct sched_domain *sd, *hsd = NULL;
854 for_each_domain(cpu, sd) {
855 if (!(sd->flags & flag))
863 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
865 struct sched_domain *sd;
867 for_each_domain(cpu, sd) {
868 if (sd->flags & flag)
875 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
876 DECLARE_PER_CPU(int, sd_llc_size);
877 DECLARE_PER_CPU(int, sd_llc_id);
878 DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
879 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
880 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
882 struct sched_group_capacity {
885 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
888 unsigned int capacity;
889 unsigned long next_update;
890 int imbalance; /* XXX unrelated to capacity but shared group state */
892 unsigned long cpumask[0]; /* iteration mask */
896 struct sched_group *next; /* Must be a circular list */
899 unsigned int group_weight;
900 struct sched_group_capacity *sgc;
903 * The CPUs this group covers.
905 * NOTE: this field is variable length. (Allocated dynamically
906 * by attaching extra space to the end of the structure,
907 * depending on how many CPUs the kernel has booted up with)
909 unsigned long cpumask[0];
912 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
914 return to_cpumask(sg->cpumask);
918 * cpumask masking which cpus in the group are allowed to iterate up the domain
921 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
923 return to_cpumask(sg->sgc->cpumask);
927 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
928 * @group: The group whose first cpu is to be returned.
930 static inline unsigned int group_first_cpu(struct sched_group *group)
932 return cpumask_first(sched_group_cpus(group));
935 extern int group_balance_cpu(struct sched_group *sg);
937 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
938 void register_sched_domain_sysctl(void);
939 void unregister_sched_domain_sysctl(void);
941 static inline void register_sched_domain_sysctl(void)
944 static inline void unregister_sched_domain_sysctl(void)
951 static inline void sched_ttwu_pending(void) { }
953 #endif /* CONFIG_SMP */
956 #include "auto_group.h"
958 #ifdef CONFIG_CGROUP_SCHED
961 * Return the group to which this tasks belongs.
963 * We cannot use task_css() and friends because the cgroup subsystem
964 * changes that value before the cgroup_subsys::attach() method is called,
965 * therefore we cannot pin it and might observe the wrong value.
967 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
968 * core changes this before calling sched_move_task().
970 * Instead we use a 'copy' which is updated from sched_move_task() while
971 * holding both task_struct::pi_lock and rq::lock.
973 static inline struct task_group *task_group(struct task_struct *p)
975 return p->sched_task_group;
978 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
979 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
981 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
982 struct task_group *tg = task_group(p);
985 #ifdef CONFIG_FAIR_GROUP_SCHED
986 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
987 p->se.cfs_rq = tg->cfs_rq[cpu];
988 p->se.parent = tg->se[cpu];
991 #ifdef CONFIG_RT_GROUP_SCHED
992 p->rt.rt_rq = tg->rt_rq[cpu];
993 p->rt.parent = tg->rt_se[cpu];
997 #else /* CONFIG_CGROUP_SCHED */
999 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
1000 static inline struct task_group *task_group(struct task_struct *p)
1005 #endif /* CONFIG_CGROUP_SCHED */
1007 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
1009 set_task_rq(p, cpu);
1012 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
1013 * successfuly executed on another CPU. We must ensure that updates of
1014 * per-task data have been completed by this moment.
1017 task_thread_info(p)->cpu = cpu;
1023 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
1025 #ifdef CONFIG_SCHED_DEBUG
1026 # include <linux/static_key.h>
1027 # define const_debug __read_mostly
1029 # define const_debug const
1032 extern const_debug unsigned int sysctl_sched_features;
1034 #define SCHED_FEAT(name, enabled) \
1035 __SCHED_FEAT_##name ,
1038 #include "features.h"
1044 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
1045 #define SCHED_FEAT(name, enabled) \
1046 static __always_inline bool static_branch_##name(struct static_key *key) \
1048 return static_key_##enabled(key); \
1051 #include "features.h"
1055 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1056 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1057 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1058 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1059 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1061 extern struct static_key_false sched_numa_balancing;
1062 extern struct static_key_false sched_schedstats;
1064 static inline u64 global_rt_period(void)
1066 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1069 static inline u64 global_rt_runtime(void)
1071 if (sysctl_sched_rt_runtime < 0)
1074 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1077 static inline int task_current(struct rq *rq, struct task_struct *p)
1079 return rq->curr == p;
1082 static inline int task_running(struct rq *rq, struct task_struct *p)
1087 return task_current(rq, p);
1091 static inline int task_on_rq_queued(struct task_struct *p)
1093 return p->on_rq == TASK_ON_RQ_QUEUED;
1096 static inline int task_on_rq_migrating(struct task_struct *p)
1098 return p->on_rq == TASK_ON_RQ_MIGRATING;
1101 #ifndef prepare_arch_switch
1102 # define prepare_arch_switch(next) do { } while (0)
1104 #ifndef finish_arch_post_lock_switch
1105 # define finish_arch_post_lock_switch() do { } while (0)
1108 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1112 * We can optimise this out completely for !SMP, because the
1113 * SMP rebalancing from interrupt is the only thing that cares
1120 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1124 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1125 * We must ensure this doesn't happen until the switch is completely
1128 * In particular, the load of prev->state in finish_task_switch() must
1129 * happen before this.
1131 * Pairs with the smp_cond_load_acquire() in try_to_wake_up().
1133 smp_store_release(&prev->on_cpu, 0);
1135 #ifdef CONFIG_DEBUG_SPINLOCK
1136 /* this is a valid case when another task releases the spinlock */
1137 rq->lock.owner = current;
1140 * If we are tracking spinlock dependencies then we have to
1141 * fix up the runqueue lock - which gets 'carried over' from
1142 * prev into current:
1144 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
1146 raw_spin_unlock_irq(&rq->lock);
1152 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1153 #define WF_FORK 0x02 /* child wakeup after fork */
1154 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1157 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1158 * of tasks with abnormal "nice" values across CPUs the contribution that
1159 * each task makes to its run queue's load is weighted according to its
1160 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1161 * scaled version of the new time slice allocation that they receive on time
1165 #define WEIGHT_IDLEPRIO 3
1166 #define WMULT_IDLEPRIO 1431655765
1168 extern const int sched_prio_to_weight[40];
1169 extern const u32 sched_prio_to_wmult[40];
1172 * {de,en}queue flags:
1174 * DEQUEUE_SLEEP - task is no longer runnable
1175 * ENQUEUE_WAKEUP - task just became runnable
1177 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
1178 * are in a known state which allows modification. Such pairs
1179 * should preserve as much state as possible.
1181 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
1184 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
1185 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
1186 * ENQUEUE_MIGRATED - the task was migrated during wakeup
1190 #define DEQUEUE_SLEEP 0x01
1191 #define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
1192 #define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
1194 #define ENQUEUE_WAKEUP 0x01
1195 #define ENQUEUE_RESTORE 0x02
1196 #define ENQUEUE_MOVE 0x04
1198 #define ENQUEUE_HEAD 0x08
1199 #define ENQUEUE_REPLENISH 0x10
1201 #define ENQUEUE_MIGRATED 0x20
1203 #define ENQUEUE_MIGRATED 0x00
1206 #define RETRY_TASK ((void *)-1UL)
1208 struct sched_class {
1209 const struct sched_class *next;
1211 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1212 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1213 void (*yield_task) (struct rq *rq);
1214 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1216 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1219 * It is the responsibility of the pick_next_task() method that will
1220 * return the next task to call put_prev_task() on the @prev task or
1221 * something equivalent.
1223 * May return RETRY_TASK when it finds a higher prio class has runnable
1226 struct task_struct * (*pick_next_task) (struct rq *rq,
1227 struct task_struct *prev,
1228 struct pin_cookie cookie);
1229 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1232 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1233 void (*migrate_task_rq)(struct task_struct *p);
1235 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1237 void (*set_cpus_allowed)(struct task_struct *p,
1238 const struct cpumask *newmask);
1240 void (*rq_online)(struct rq *rq);
1241 void (*rq_offline)(struct rq *rq);
1244 void (*set_curr_task) (struct rq *rq);
1245 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1246 void (*task_fork) (struct task_struct *p);
1247 void (*task_dead) (struct task_struct *p);
1250 * The switched_from() call is allowed to drop rq->lock, therefore we
1251 * cannot assume the switched_from/switched_to pair is serliazed by
1252 * rq->lock. They are however serialized by p->pi_lock.
1254 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1255 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1256 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1259 unsigned int (*get_rr_interval) (struct rq *rq,
1260 struct task_struct *task);
1262 void (*update_curr) (struct rq *rq);
1264 #define TASK_SET_GROUP 0
1265 #define TASK_MOVE_GROUP 1
1267 #ifdef CONFIG_FAIR_GROUP_SCHED
1268 void (*task_change_group) (struct task_struct *p, int type);
1272 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1274 prev->sched_class->put_prev_task(rq, prev);
1277 #define sched_class_highest (&stop_sched_class)
1278 #define for_each_class(class) \
1279 for (class = sched_class_highest; class; class = class->next)
1281 extern const struct sched_class stop_sched_class;
1282 extern const struct sched_class dl_sched_class;
1283 extern const struct sched_class rt_sched_class;
1284 extern const struct sched_class fair_sched_class;
1285 extern const struct sched_class idle_sched_class;
1290 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1292 extern void trigger_load_balance(struct rq *rq);
1294 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1298 #ifdef CONFIG_CPU_IDLE
1299 static inline void idle_set_state(struct rq *rq,
1300 struct cpuidle_state *idle_state)
1302 rq->idle_state = idle_state;
1305 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1307 WARN_ON(!rcu_read_lock_held());
1308 return rq->idle_state;
1311 static inline void idle_set_state(struct rq *rq,
1312 struct cpuidle_state *idle_state)
1316 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1322 extern void sysrq_sched_debug_show(void);
1323 extern void sched_init_granularity(void);
1324 extern void update_max_interval(void);
1326 extern void init_sched_dl_class(void);
1327 extern void init_sched_rt_class(void);
1328 extern void init_sched_fair_class(void);
1330 extern void resched_curr(struct rq *rq);
1331 extern void resched_cpu(int cpu);
1333 extern struct rt_bandwidth def_rt_bandwidth;
1334 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1336 extern struct dl_bandwidth def_dl_bandwidth;
1337 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1338 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1340 unsigned long to_ratio(u64 period, u64 runtime);
1342 extern void init_entity_runnable_average(struct sched_entity *se);
1343 extern void post_init_entity_util_avg(struct sched_entity *se);
1345 #ifdef CONFIG_NO_HZ_FULL
1346 extern bool sched_can_stop_tick(struct rq *rq);
1349 * Tick may be needed by tasks in the runqueue depending on their policy and
1350 * requirements. If tick is needed, lets send the target an IPI to kick it out of
1351 * nohz mode if necessary.
1353 static inline void sched_update_tick_dependency(struct rq *rq)
1357 if (!tick_nohz_full_enabled())
1362 if (!tick_nohz_full_cpu(cpu))
1365 if (sched_can_stop_tick(rq))
1366 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
1368 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
1371 static inline void sched_update_tick_dependency(struct rq *rq) { }
1374 static inline void add_nr_running(struct rq *rq, unsigned count)
1376 unsigned prev_nr = rq->nr_running;
1378 rq->nr_running = prev_nr + count;
1380 if (prev_nr < 2 && rq->nr_running >= 2) {
1382 if (!rq->rd->overload)
1383 rq->rd->overload = true;
1387 sched_update_tick_dependency(rq);
1390 static inline void sub_nr_running(struct rq *rq, unsigned count)
1392 rq->nr_running -= count;
1393 /* Check if we still need preemption */
1394 sched_update_tick_dependency(rq);
1397 static inline void rq_last_tick_reset(struct rq *rq)
1399 #ifdef CONFIG_NO_HZ_FULL
1400 rq->last_sched_tick = jiffies;
1404 extern void update_rq_clock(struct rq *rq);
1406 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1407 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1409 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1411 extern const_debug unsigned int sysctl_sched_time_avg;
1412 extern const_debug unsigned int sysctl_sched_nr_migrate;
1413 extern const_debug unsigned int sysctl_sched_migration_cost;
1415 static inline u64 sched_avg_period(void)
1417 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1420 #ifdef CONFIG_SCHED_HRTICK
1424 * - enabled by features
1425 * - hrtimer is actually high res
1427 static inline int hrtick_enabled(struct rq *rq)
1429 if (!sched_feat(HRTICK))
1431 if (!cpu_active(cpu_of(rq)))
1433 return hrtimer_is_hres_active(&rq->hrtick_timer);
1436 void hrtick_start(struct rq *rq, u64 delay);
1440 static inline int hrtick_enabled(struct rq *rq)
1445 #endif /* CONFIG_SCHED_HRTICK */
1448 extern void sched_avg_update(struct rq *rq);
1450 #ifndef arch_scale_freq_capacity
1451 static __always_inline
1452 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
1454 return SCHED_CAPACITY_SCALE;
1458 #ifndef arch_scale_cpu_capacity
1459 static __always_inline
1460 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
1462 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1463 return sd->smt_gain / sd->span_weight;
1465 return SCHED_CAPACITY_SCALE;
1469 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1471 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1472 sched_avg_update(rq);
1475 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1476 static inline void sched_avg_update(struct rq *rq) { }
1480 unsigned long flags;
1481 struct pin_cookie cookie;
1484 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1485 __acquires(rq->lock);
1486 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1487 __acquires(p->pi_lock)
1488 __acquires(rq->lock);
1490 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
1491 __releases(rq->lock)
1493 lockdep_unpin_lock(&rq->lock, rf->cookie);
1494 raw_spin_unlock(&rq->lock);
1498 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
1499 __releases(rq->lock)
1500 __releases(p->pi_lock)
1502 lockdep_unpin_lock(&rq->lock, rf->cookie);
1503 raw_spin_unlock(&rq->lock);
1504 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1508 #ifdef CONFIG_PREEMPT
1510 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1513 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1514 * way at the expense of forcing extra atomic operations in all
1515 * invocations. This assures that the double_lock is acquired using the
1516 * same underlying policy as the spinlock_t on this architecture, which
1517 * reduces latency compared to the unfair variant below. However, it
1518 * also adds more overhead and therefore may reduce throughput.
1520 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1521 __releases(this_rq->lock)
1522 __acquires(busiest->lock)
1523 __acquires(this_rq->lock)
1525 raw_spin_unlock(&this_rq->lock);
1526 double_rq_lock(this_rq, busiest);
1533 * Unfair double_lock_balance: Optimizes throughput at the expense of
1534 * latency by eliminating extra atomic operations when the locks are
1535 * already in proper order on entry. This favors lower cpu-ids and will
1536 * grant the double lock to lower cpus over higher ids under contention,
1537 * regardless of entry order into the function.
1539 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1540 __releases(this_rq->lock)
1541 __acquires(busiest->lock)
1542 __acquires(this_rq->lock)
1546 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1547 if (busiest < this_rq) {
1548 raw_spin_unlock(&this_rq->lock);
1549 raw_spin_lock(&busiest->lock);
1550 raw_spin_lock_nested(&this_rq->lock,
1551 SINGLE_DEPTH_NESTING);
1554 raw_spin_lock_nested(&busiest->lock,
1555 SINGLE_DEPTH_NESTING);
1560 #endif /* CONFIG_PREEMPT */
1563 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1565 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1567 if (unlikely(!irqs_disabled())) {
1568 /* printk() doesn't work good under rq->lock */
1569 raw_spin_unlock(&this_rq->lock);
1573 return _double_lock_balance(this_rq, busiest);
1576 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1577 __releases(busiest->lock)
1579 raw_spin_unlock(&busiest->lock);
1580 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1583 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1589 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1592 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1598 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1601 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1607 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1611 * double_rq_lock - safely lock two runqueues
1613 * Note this does not disable interrupts like task_rq_lock,
1614 * you need to do so manually before calling.
1616 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1617 __acquires(rq1->lock)
1618 __acquires(rq2->lock)
1620 BUG_ON(!irqs_disabled());
1622 raw_spin_lock(&rq1->lock);
1623 __acquire(rq2->lock); /* Fake it out ;) */
1626 raw_spin_lock(&rq1->lock);
1627 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1629 raw_spin_lock(&rq2->lock);
1630 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1636 * double_rq_unlock - safely unlock two runqueues
1638 * Note this does not restore interrupts like task_rq_unlock,
1639 * you need to do so manually after calling.
1641 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1642 __releases(rq1->lock)
1643 __releases(rq2->lock)
1645 raw_spin_unlock(&rq1->lock);
1647 raw_spin_unlock(&rq2->lock);
1649 __release(rq2->lock);
1652 #else /* CONFIG_SMP */
1655 * double_rq_lock - safely lock two runqueues
1657 * Note this does not disable interrupts like task_rq_lock,
1658 * you need to do so manually before calling.
1660 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1661 __acquires(rq1->lock)
1662 __acquires(rq2->lock)
1664 BUG_ON(!irqs_disabled());
1666 raw_spin_lock(&rq1->lock);
1667 __acquire(rq2->lock); /* Fake it out ;) */
1671 * double_rq_unlock - safely unlock two runqueues
1673 * Note this does not restore interrupts like task_rq_unlock,
1674 * you need to do so manually after calling.
1676 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1677 __releases(rq1->lock)
1678 __releases(rq2->lock)
1681 raw_spin_unlock(&rq1->lock);
1682 __release(rq2->lock);
1687 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1688 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1690 #ifdef CONFIG_SCHED_DEBUG
1691 extern void print_cfs_stats(struct seq_file *m, int cpu);
1692 extern void print_rt_stats(struct seq_file *m, int cpu);
1693 extern void print_dl_stats(struct seq_file *m, int cpu);
1695 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1697 #ifdef CONFIG_NUMA_BALANCING
1699 show_numa_stats(struct task_struct *p, struct seq_file *m);
1701 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1702 unsigned long tpf, unsigned long gsf, unsigned long gpf);
1703 #endif /* CONFIG_NUMA_BALANCING */
1704 #endif /* CONFIG_SCHED_DEBUG */
1706 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1707 extern void init_rt_rq(struct rt_rq *rt_rq);
1708 extern void init_dl_rq(struct dl_rq *dl_rq);
1710 extern void cfs_bandwidth_usage_inc(void);
1711 extern void cfs_bandwidth_usage_dec(void);
1713 #ifdef CONFIG_NO_HZ_COMMON
1714 enum rq_nohz_flag_bits {
1719 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1721 extern void nohz_balance_exit_idle(unsigned int cpu);
1723 static inline void nohz_balance_exit_idle(unsigned int cpu) { }
1726 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1728 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1729 DECLARE_PER_CPU(u64, cpu_softirq_time);
1731 #ifndef CONFIG_64BIT
1732 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1734 static inline void irq_time_write_begin(void)
1736 __this_cpu_inc(irq_time_seq.sequence);
1740 static inline void irq_time_write_end(void)
1743 __this_cpu_inc(irq_time_seq.sequence);
1746 static inline u64 irq_time_read(int cpu)
1752 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1753 irq_time = per_cpu(cpu_softirq_time, cpu) +
1754 per_cpu(cpu_hardirq_time, cpu);
1755 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1759 #else /* CONFIG_64BIT */
1760 static inline void irq_time_write_begin(void)
1764 static inline void irq_time_write_end(void)
1768 static inline u64 irq_time_read(int cpu)
1770 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1772 #endif /* CONFIG_64BIT */
1773 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
1775 #ifdef CONFIG_CPU_FREQ
1776 DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
1779 * cpufreq_update_util - Take a note about CPU utilization changes.
1780 * @time: Current time.
1781 * @util: Current utilization.
1782 * @max: Utilization ceiling.
1784 * This function is called by the scheduler on every invocation of
1785 * update_load_avg() on the CPU whose utilization is being updated.
1787 * It can only be called from RCU-sched read-side critical sections.
1789 static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
1791 struct update_util_data *data;
1793 data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
1795 data->func(data, time, util, max);
1799 * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
1800 * @time: Current time.
1802 * The way cpufreq is currently arranged requires it to evaluate the CPU
1803 * performance state (frequency/voltage) on a regular basis to prevent it from
1804 * being stuck in a completely inadequate performance level for too long.
1805 * That is not guaranteed to happen if the updates are only triggered from CFS,
1806 * though, because they may not be coming in if RT or deadline tasks are active
1807 * all the time (or there are RT and DL tasks only).
1809 * As a workaround for that issue, this function is called by the RT and DL
1810 * sched classes to trigger extra cpufreq updates to prevent it from stalling,
1811 * but that really is a band-aid. Going forward it should be replaced with
1812 * solutions targeted more specifically at RT and DL tasks.
1814 static inline void cpufreq_trigger_update(u64 time)
1816 cpufreq_update_util(time, ULONG_MAX, 0);
1819 static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
1820 static inline void cpufreq_trigger_update(u64 time) {}
1821 #endif /* CONFIG_CPU_FREQ */
1823 #ifdef arch_scale_freq_capacity
1824 #ifndef arch_scale_freq_invariant
1825 #define arch_scale_freq_invariant() (true)
1827 #else /* arch_scale_freq_capacity */
1828 #define arch_scale_freq_invariant() (false)