OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / kernel / sched / sched.h
blob98c0c2623db86019e464cb63caf49a7a253ee733
2 #include <linux/sched.h>
3 #include <linux/mutex.h>
4 #include <linux/spinlock.h>
5 #include <linux/stop_machine.h>
7 #include "cpupri.h"
9 extern __read_mostly int scheduler_running;
12 * Convert user-nice values [ -20 ... 0 ... 19 ]
13 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
14 * and back.
16 #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
17 #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
18 #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
21 * 'User priority' is the nice value converted to something we
22 * can work with better when scaling various scheduler parameters,
23 * it's a [ 0 ... 39 ] range.
25 #define USER_PRIO(p) ((p)-MAX_RT_PRIO)
26 #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
27 #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
30 * Helpers for converting nanosecond timing to jiffy resolution
32 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
34 #define NICE_0_LOAD SCHED_LOAD_SCALE
35 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
38 * These are the 'tuning knobs' of the scheduler:
40 * default timeslice is 100 msecs (used only for SCHED_RR tasks).
41 * Timeslices get refilled after they expire.
43 #define DEF_TIMESLICE (100 * HZ / 1000)
46 * single value that denotes runtime == period, ie unlimited time.
48 #define RUNTIME_INF ((u64)~0ULL)
50 static inline int rt_policy(int policy)
52 if (policy == SCHED_FIFO || policy == SCHED_RR)
53 return 1;
54 return 0;
57 static inline int task_has_rt_policy(struct task_struct *p)
59 return rt_policy(p->policy);
63 * This is the priority-queue data structure of the RT scheduling class:
65 struct rt_prio_array {
66 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
67 struct list_head queue[MAX_RT_PRIO];
70 struct rt_bandwidth {
71 /* nests inside the rq lock: */
72 raw_spinlock_t rt_runtime_lock;
73 ktime_t rt_period;
74 u64 rt_runtime;
75 struct hrtimer rt_period_timer;
78 extern struct mutex sched_domains_mutex;
80 #ifdef CONFIG_CGROUP_SCHED
82 #include <linux/cgroup.h>
84 struct cfs_rq;
85 struct rt_rq;
87 static LIST_HEAD(task_groups);
89 struct cfs_bandwidth {
90 #ifdef CONFIG_CFS_BANDWIDTH
91 raw_spinlock_t lock;
92 ktime_t period;
93 u64 quota, runtime;
94 s64 hierarchal_quota;
95 u64 runtime_expires;
97 int idle, timer_active;
98 struct hrtimer period_timer, slack_timer;
99 struct list_head throttled_cfs_rq;
101 /* statistics */
102 int nr_periods, nr_throttled;
103 u64 throttled_time;
104 #endif
107 /* task group related information */
108 struct task_group {
109 struct cgroup_subsys_state css;
111 #ifdef CONFIG_FAIR_GROUP_SCHED
112 /* schedulable entities of this group on each cpu */
113 struct sched_entity **se;
114 /* runqueue "owned" by this group on each cpu */
115 struct cfs_rq **cfs_rq;
116 unsigned long shares;
118 atomic_t load_weight;
119 #endif
121 #ifdef CONFIG_RT_GROUP_SCHED
122 struct sched_rt_entity **rt_se;
123 struct rt_rq **rt_rq;
125 struct rt_bandwidth rt_bandwidth;
126 #endif
128 struct rcu_head rcu;
129 struct list_head list;
131 struct task_group *parent;
132 struct list_head siblings;
133 struct list_head children;
135 #ifdef CONFIG_SCHED_AUTOGROUP
136 struct autogroup *autogroup;
137 #endif
139 struct cfs_bandwidth cfs_bandwidth;
142 #ifdef CONFIG_FAIR_GROUP_SCHED
143 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
146 * A weight of 0 or 1 can cause arithmetics problems.
147 * A weight of a cfs_rq is the sum of weights of which entities
148 * are queued on this cfs_rq, so a weight of a entity should not be
149 * too large, so as the shares value of a task group.
150 * (The default weight is 1024 - so there's no practical
151 * limitation from this.)
153 #define MIN_SHARES (1UL << 1)
154 #define MAX_SHARES (1UL << 18)
155 #endif
157 /* Default task group.
158 * Every task in system belong to this group at bootup.
160 extern struct task_group root_task_group;
162 typedef int (*tg_visitor)(struct task_group *, void *);
164 extern int walk_tg_tree_from(struct task_group *from,
165 tg_visitor down, tg_visitor up, void *data);
168 * Iterate the full tree, calling @down when first entering a node and @up when
169 * leaving it for the final time.
171 * Caller must hold rcu_lock or sufficient equivalent.
173 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
175 return walk_tg_tree_from(&root_task_group, down, up, data);
178 extern int tg_nop(struct task_group *tg, void *data);
180 extern void free_fair_sched_group(struct task_group *tg);
181 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
182 extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
183 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
184 struct sched_entity *se, int cpu,
185 struct sched_entity *parent);
186 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
187 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
189 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
190 extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
191 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
193 extern void free_rt_sched_group(struct task_group *tg);
194 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
195 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
196 struct sched_rt_entity *rt_se, int cpu,
197 struct sched_rt_entity *parent);
199 #else /* CONFIG_CGROUP_SCHED */
201 struct cfs_bandwidth { };
203 #endif /* CONFIG_CGROUP_SCHED */
205 /* CFS-related fields in a runqueue */
206 struct cfs_rq {
207 struct load_weight load;
208 unsigned long nr_running, h_nr_running;
210 u64 exec_clock;
211 u64 min_vruntime;
212 #ifndef CONFIG_64BIT
213 u64 min_vruntime_copy;
214 #endif
216 struct rb_root tasks_timeline;
217 struct rb_node *rb_leftmost;
219 struct list_head tasks;
220 struct list_head *balance_iterator;
223 * 'curr' points to currently running entity on this cfs_rq.
224 * It is set to NULL otherwise (i.e when none are currently running).
226 struct sched_entity *curr, *next, *last, *skip;
228 #ifdef CONFIG_SCHED_DEBUG
229 unsigned int nr_spread_over;
230 #endif
232 #ifdef CONFIG_FAIR_GROUP_SCHED
233 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
236 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
237 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
238 * (like users, containers etc.)
240 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
241 * list is used during load balance.
243 int on_list;
244 struct list_head leaf_cfs_rq_list;
245 struct task_group *tg; /* group that "owns" this runqueue */
247 #ifdef CONFIG_SMP
249 * the part of load.weight contributed by tasks
251 unsigned long task_weight;
254 * h_load = weight * f(tg)
256 * Where f(tg) is the recursive weight fraction assigned to
257 * this group.
259 unsigned long h_load;
262 * Maintaining per-cpu shares distribution for group scheduling
264 * load_stamp is the last time we updated the load average
265 * load_last is the last time we updated the load average and saw load
266 * load_unacc_exec_time is currently unaccounted execution time
268 u64 load_avg;
269 u64 load_period;
270 u64 load_stamp, load_last, load_unacc_exec_time;
272 unsigned long load_contribution;
273 #endif /* CONFIG_SMP */
274 #ifdef CONFIG_CFS_BANDWIDTH
275 int runtime_enabled;
276 u64 runtime_expires;
277 s64 runtime_remaining;
279 u64 throttled_timestamp;
280 int throttled, throttle_count;
281 struct list_head throttled_list;
282 #endif /* CONFIG_CFS_BANDWIDTH */
283 #endif /* CONFIG_FAIR_GROUP_SCHED */
286 static inline int rt_bandwidth_enabled(void)
288 return sysctl_sched_rt_runtime >= 0;
291 /* Real-Time classes' related field in a runqueue: */
292 struct rt_rq {
293 struct rt_prio_array active;
294 unsigned long rt_nr_running;
295 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
296 struct {
297 int curr; /* highest queued rt task prio */
298 #ifdef CONFIG_SMP
299 int next; /* next highest */
300 #endif
301 } highest_prio;
302 #endif
303 #ifdef CONFIG_SMP
304 unsigned long rt_nr_migratory;
305 unsigned long rt_nr_total;
306 int overloaded;
307 struct plist_head pushable_tasks;
308 #endif
309 int rt_throttled;
310 u64 rt_time;
311 u64 rt_runtime;
312 /* Nests inside the rq lock: */
313 raw_spinlock_t rt_runtime_lock;
315 #ifdef CONFIG_RT_GROUP_SCHED
316 unsigned long rt_nr_boosted;
318 struct rq *rq;
319 struct list_head leaf_rt_rq_list;
320 struct task_group *tg;
321 #endif
324 #ifdef CONFIG_SMP
327 * We add the notion of a root-domain which will be used to define per-domain
328 * variables. Each exclusive cpuset essentially defines an island domain by
329 * fully partitioning the member cpus from any other cpuset. Whenever a new
330 * exclusive cpuset is created, we also create and attach a new root-domain
331 * object.
334 struct root_domain {
335 atomic_t refcount;
336 atomic_t rto_count;
337 struct rcu_head rcu;
338 cpumask_var_t span;
339 cpumask_var_t online;
342 * The "RT overload" flag: it gets set if a CPU has more than
343 * one runnable RT task.
345 cpumask_var_t rto_mask;
346 struct cpupri cpupri;
349 extern struct root_domain def_root_domain;
351 #endif /* CONFIG_SMP */
354 * This is the main, per-CPU runqueue data structure.
356 * Locking rule: those places that want to lock multiple runqueues
357 * (such as the load balancing or the thread migration code), lock
358 * acquire operations must be ordered by ascending &runqueue.
360 struct rq {
361 /* runqueue lock: */
362 raw_spinlock_t lock;
365 * nr_running and cpu_load should be in the same cacheline because
366 * remote CPUs use both these fields when doing load calculation.
368 unsigned long nr_running;
369 #define CPU_LOAD_IDX_MAX 5
370 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
371 unsigned long last_load_update_tick;
372 #ifdef CONFIG_NO_HZ
373 u64 nohz_stamp;
374 unsigned long nohz_flags;
375 #endif
376 int skip_clock_update;
378 /* capture load from *all* tasks on this cpu: */
379 struct load_weight load;
380 unsigned long nr_load_updates;
381 u64 nr_switches;
383 struct cfs_rq cfs;
384 struct rt_rq rt;
386 #ifdef CONFIG_FAIR_GROUP_SCHED
387 /* list of leaf cfs_rq on this cpu: */
388 struct list_head leaf_cfs_rq_list;
389 #endif
390 #ifdef CONFIG_RT_GROUP_SCHED
391 struct list_head leaf_rt_rq_list;
392 #endif
395 * This is part of a global counter where only the total sum
396 * over all CPUs matters. A task can increase this counter on
397 * one CPU and if it got migrated afterwards it may decrease
398 * it on another CPU. Always updated under the runqueue lock:
400 unsigned long nr_uninterruptible;
402 struct task_struct *curr, *idle, *stop;
403 unsigned long next_balance;
404 struct mm_struct *prev_mm;
406 u64 clock;
407 u64 clock_task;
409 atomic_t nr_iowait;
411 #ifdef CONFIG_SMP
412 struct root_domain *rd;
413 struct sched_domain *sd;
415 unsigned long cpu_power;
417 unsigned char idle_balance;
418 /* For active balancing */
419 int post_schedule;
420 int active_balance;
421 int push_cpu;
422 struct cpu_stop_work active_balance_work;
423 /* cpu of this runqueue: */
424 int cpu;
425 int online;
427 u64 rt_avg;
428 u64 age_stamp;
429 u64 idle_stamp;
430 u64 avg_idle;
431 #endif
433 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
434 u64 prev_irq_time;
435 #endif
436 #ifdef CONFIG_PARAVIRT
437 u64 prev_steal_time;
438 #endif
439 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
440 u64 prev_steal_time_rq;
441 #endif
443 /* calc_load related fields */
444 unsigned long calc_load_update;
445 long calc_load_active;
447 #ifdef CONFIG_SCHED_HRTICK
448 #ifdef CONFIG_SMP
449 int hrtick_csd_pending;
450 struct call_single_data hrtick_csd;
451 #endif
452 struct hrtimer hrtick_timer;
453 #endif
455 #ifdef CONFIG_SCHEDSTATS
456 /* latency stats */
457 struct sched_info rq_sched_info;
458 unsigned long long rq_cpu_time;
459 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
461 /* sys_sched_yield() stats */
462 unsigned int yld_count;
464 /* schedule() stats */
465 unsigned int sched_switch;
466 unsigned int sched_count;
467 unsigned int sched_goidle;
469 /* try_to_wake_up() stats */
470 unsigned int ttwu_count;
471 unsigned int ttwu_local;
472 #endif
474 #ifdef CONFIG_SMP
475 struct llist_head wake_list;
476 #endif
479 static inline int cpu_of(struct rq *rq)
481 #ifdef CONFIG_SMP
482 return rq->cpu;
483 #else
484 return 0;
485 #endif
488 DECLARE_PER_CPU(struct rq, runqueues);
490 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
491 #define this_rq() (&__get_cpu_var(runqueues))
492 #define task_rq(p) cpu_rq(task_cpu(p))
493 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
494 #define raw_rq() (&__raw_get_cpu_var(runqueues))
496 #ifdef CONFIG_SMP
498 #define rcu_dereference_check_sched_domain(p) \
499 rcu_dereference_check((p), \
500 lockdep_is_held(&sched_domains_mutex))
503 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
504 * See detach_destroy_domains: synchronize_sched for details.
506 * The domain tree of any CPU may only be accessed from within
507 * preempt-disabled sections.
509 #define for_each_domain(cpu, __sd) \
510 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
511 __sd; __sd = __sd->parent)
513 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
516 * highest_flag_domain - Return highest sched_domain containing flag.
517 * @cpu: The cpu whose highest level of sched domain is to
518 * be returned.
519 * @flag: The flag to check for the highest sched_domain
520 * for the given cpu.
522 * Returns the highest sched_domain of a cpu which contains the given flag.
524 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
526 struct sched_domain *sd, *hsd = NULL;
528 for_each_domain(cpu, sd) {
529 if (!(sd->flags & flag))
530 break;
531 hsd = sd;
534 return hsd;
537 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
538 DECLARE_PER_CPU(int, sd_llc_id);
540 #endif /* CONFIG_SMP */
542 #include "stats.h"
543 #include "auto_group.h"
545 #ifdef CONFIG_CGROUP_SCHED
548 * Return the group to which this tasks belongs.
550 * We use task_subsys_state_check() and extend the RCU verification with
551 * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each
552 * task it moves into the cgroup. Therefore by holding either of those locks,
553 * we pin the task to the current cgroup.
555 static inline struct task_group *task_group(struct task_struct *p)
557 struct task_group *tg;
558 struct cgroup_subsys_state *css;
560 css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
561 lockdep_is_held(&p->pi_lock) ||
562 lockdep_is_held(&task_rq(p)->lock));
563 tg = container_of(css, struct task_group, css);
565 return autogroup_task_group(p, tg);
568 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
569 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
571 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
572 struct task_group *tg = task_group(p);
573 #endif
575 #ifdef CONFIG_FAIR_GROUP_SCHED
576 p->se.cfs_rq = tg->cfs_rq[cpu];
577 p->se.parent = tg->se[cpu];
578 #endif
580 #ifdef CONFIG_RT_GROUP_SCHED
581 p->rt.rt_rq = tg->rt_rq[cpu];
582 p->rt.parent = tg->rt_se[cpu];
583 #endif
586 #else /* CONFIG_CGROUP_SCHED */
588 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
589 static inline struct task_group *task_group(struct task_struct *p)
591 return NULL;
594 #endif /* CONFIG_CGROUP_SCHED */
596 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
598 set_task_rq(p, cpu);
599 #ifdef CONFIG_SMP
601 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
602 * successfuly executed on another CPU. We must ensure that updates of
603 * per-task data have been completed by this moment.
605 smp_wmb();
606 task_thread_info(p)->cpu = cpu;
607 #endif
611 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
613 #ifdef CONFIG_SCHED_DEBUG
614 # include <linux/jump_label.h>
615 # define const_debug __read_mostly
616 #else
617 # define const_debug const
618 #endif
620 extern const_debug unsigned int sysctl_sched_features;
622 #define SCHED_FEAT(name, enabled) \
623 __SCHED_FEAT_##name ,
625 enum {
626 #include "features.h"
627 __SCHED_FEAT_NR,
630 #undef SCHED_FEAT
632 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
633 static __always_inline bool static_branch__true(struct jump_label_key *key)
635 return likely(static_branch(key)); /* Not out of line branch. */
638 static __always_inline bool static_branch__false(struct jump_label_key *key)
640 return unlikely(static_branch(key)); /* Out of line branch. */
643 #define SCHED_FEAT(name, enabled) \
644 static __always_inline bool static_branch_##name(struct jump_label_key *key) \
646 return static_branch__##enabled(key); \
649 #include "features.h"
651 #undef SCHED_FEAT
653 extern struct jump_label_key sched_feat_keys[__SCHED_FEAT_NR];
654 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
655 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
656 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
657 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
659 static inline u64 global_rt_period(void)
661 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
664 static inline u64 global_rt_runtime(void)
666 if (sysctl_sched_rt_runtime < 0)
667 return RUNTIME_INF;
669 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
674 static inline int task_current(struct rq *rq, struct task_struct *p)
676 return rq->curr == p;
679 static inline int task_running(struct rq *rq, struct task_struct *p)
681 #ifdef CONFIG_SMP
682 return p->on_cpu;
683 #else
684 return task_current(rq, p);
685 #endif
689 #ifndef prepare_arch_switch
690 # define prepare_arch_switch(next) do { } while (0)
691 #endif
692 #ifndef finish_arch_switch
693 # define finish_arch_switch(prev) do { } while (0)
694 #endif
696 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
697 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
699 #ifdef CONFIG_SMP
701 * We can optimise this out completely for !SMP, because the
702 * SMP rebalancing from interrupt is the only thing that cares
703 * here.
705 next->on_cpu = 1;
706 #endif
709 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
711 #ifdef CONFIG_SMP
713 * After ->on_cpu is cleared, the task can be moved to a different CPU.
714 * We must ensure this doesn't happen until the switch is completely
715 * finished.
717 smp_wmb();
718 prev->on_cpu = 0;
719 #endif
720 #ifdef CONFIG_DEBUG_SPINLOCK
721 /* this is a valid case when another task releases the spinlock */
722 rq->lock.owner = current;
723 #endif
725 * If we are tracking spinlock dependencies then we have to
726 * fix up the runqueue lock - which gets 'carried over' from
727 * prev into current:
729 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
731 raw_spin_unlock_irq(&rq->lock);
734 #else /* __ARCH_WANT_UNLOCKED_CTXSW */
735 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
737 #ifdef CONFIG_SMP
739 * We can optimise this out completely for !SMP, because the
740 * SMP rebalancing from interrupt is the only thing that cares
741 * here.
743 next->on_cpu = 1;
744 #endif
745 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
746 raw_spin_unlock_irq(&rq->lock);
747 #else
748 raw_spin_unlock(&rq->lock);
749 #endif
752 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
754 #ifdef CONFIG_SMP
756 * After ->on_cpu is cleared, the task can be moved to a different CPU.
757 * We must ensure this doesn't happen until the switch is completely
758 * finished.
760 smp_wmb();
761 prev->on_cpu = 0;
762 #endif
763 #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
764 local_irq_enable();
765 #endif
767 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */
770 static inline void update_load_add(struct load_weight *lw, unsigned long inc)
772 lw->weight += inc;
773 lw->inv_weight = 0;
776 static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
778 lw->weight -= dec;
779 lw->inv_weight = 0;
782 static inline void update_load_set(struct load_weight *lw, unsigned long w)
784 lw->weight = w;
785 lw->inv_weight = 0;
789 * To aid in avoiding the subversion of "niceness" due to uneven distribution
790 * of tasks with abnormal "nice" values across CPUs the contribution that
791 * each task makes to its run queue's load is weighted according to its
792 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
793 * scaled version of the new time slice allocation that they receive on time
794 * slice expiry etc.
797 #define WEIGHT_IDLEPRIO 3
798 #define WMULT_IDLEPRIO 1431655765
801 * Nice levels are multiplicative, with a gentle 10% change for every
802 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
803 * nice 1, it will get ~10% less CPU time than another CPU-bound task
804 * that remained on nice 0.
806 * The "10% effect" is relative and cumulative: from _any_ nice level,
807 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
808 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
809 * If a task goes up by ~10% and another task goes down by ~10% then
810 * the relative distance between them is ~25%.)
812 static const int prio_to_weight[40] = {
813 /* -20 */ 88761, 71755, 56483, 46273, 36291,
814 /* -15 */ 29154, 23254, 18705, 14949, 11916,
815 /* -10 */ 9548, 7620, 6100, 4904, 3906,
816 /* -5 */ 3121, 2501, 1991, 1586, 1277,
817 /* 0 */ 1024, 820, 655, 526, 423,
818 /* 5 */ 335, 272, 215, 172, 137,
819 /* 10 */ 110, 87, 70, 56, 45,
820 /* 15 */ 36, 29, 23, 18, 15,
824 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
826 * In cases where the weight does not change often, we can use the
827 * precalculated inverse to speed up arithmetics by turning divisions
828 * into multiplications:
830 static const u32 prio_to_wmult[40] = {
831 /* -20 */ 48388, 59856, 76040, 92818, 118348,
832 /* -15 */ 147320, 184698, 229616, 287308, 360437,
833 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
834 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
835 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
836 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
837 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
838 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
841 /* Time spent by the tasks of the cpu accounting group executing in ... */
842 enum cpuacct_stat_index {
843 CPUACCT_STAT_USER, /* ... user mode */
844 CPUACCT_STAT_SYSTEM, /* ... kernel mode */
846 CPUACCT_STAT_NSTATS,
850 #define sched_class_highest (&stop_sched_class)
851 #define for_each_class(class) \
852 for (class = sched_class_highest; class; class = class->next)
854 extern const struct sched_class stop_sched_class;
855 extern const struct sched_class rt_sched_class;
856 extern const struct sched_class fair_sched_class;
857 extern const struct sched_class idle_sched_class;
860 #ifdef CONFIG_SMP
862 extern void trigger_load_balance(struct rq *rq, int cpu);
863 extern void idle_balance(int this_cpu, struct rq *this_rq);
865 #else /* CONFIG_SMP */
867 static inline void idle_balance(int cpu, struct rq *rq)
871 #endif
873 extern void sysrq_sched_debug_show(void);
874 extern void sched_init_granularity(void);
875 extern void update_max_interval(void);
876 extern void update_group_power(struct sched_domain *sd, int cpu);
877 extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu);
878 extern void init_sched_rt_class(void);
879 extern void init_sched_fair_class(void);
881 extern void resched_task(struct task_struct *p);
882 extern void resched_cpu(int cpu);
884 extern struct rt_bandwidth def_rt_bandwidth;
885 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
887 extern void update_cpu_load(struct rq *this_rq);
889 #ifdef CONFIG_CGROUP_CPUACCT
890 #include <linux/cgroup.h>
891 /* track cpu usage of a group of tasks and its child groups */
892 struct cpuacct {
893 struct cgroup_subsys_state css;
894 /* cpuusage holds pointer to a u64-type object on every cpu */
895 u64 __percpu *cpuusage;
896 struct kernel_cpustat __percpu *cpustat;
899 /* return cpu accounting group corresponding to this container */
900 static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
902 return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
903 struct cpuacct, css);
906 /* return cpu accounting group to which this task belongs */
907 static inline struct cpuacct *task_ca(struct task_struct *tsk)
909 return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
910 struct cpuacct, css);
913 static inline struct cpuacct *parent_ca(struct cpuacct *ca)
915 if (!ca || !ca->css.cgroup->parent)
916 return NULL;
917 return cgroup_ca(ca->css.cgroup->parent);
920 extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
921 #else
922 static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
923 #endif
925 static inline void inc_nr_running(struct rq *rq)
927 rq->nr_running++;
930 static inline void dec_nr_running(struct rq *rq)
932 rq->nr_running--;
935 extern void update_rq_clock(struct rq *rq);
937 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
938 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
940 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
942 extern const_debug unsigned int sysctl_sched_time_avg;
943 extern const_debug unsigned int sysctl_sched_nr_migrate;
944 extern const_debug unsigned int sysctl_sched_migration_cost;
946 static inline u64 sched_avg_period(void)
948 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
951 void calc_load_account_idle(struct rq *this_rq);
953 #ifdef CONFIG_SCHED_HRTICK
956 * Use hrtick when:
957 * - enabled by features
958 * - hrtimer is actually high res
960 static inline int hrtick_enabled(struct rq *rq)
962 if (!sched_feat(HRTICK))
963 return 0;
964 if (!cpu_active(cpu_of(rq)))
965 return 0;
966 return hrtimer_is_hres_active(&rq->hrtick_timer);
969 void hrtick_start(struct rq *rq, u64 delay);
971 #else
973 static inline int hrtick_enabled(struct rq *rq)
975 return 0;
978 #endif /* CONFIG_SCHED_HRTICK */
980 #ifdef CONFIG_SMP
981 extern void sched_avg_update(struct rq *rq);
982 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
984 rq->rt_avg += rt_delta;
985 sched_avg_update(rq);
987 #else
988 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
989 static inline void sched_avg_update(struct rq *rq) { }
990 #endif
992 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
994 #ifdef CONFIG_SMP
995 #ifdef CONFIG_PREEMPT
997 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1000 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1001 * way at the expense of forcing extra atomic operations in all
1002 * invocations. This assures that the double_lock is acquired using the
1003 * same underlying policy as the spinlock_t on this architecture, which
1004 * reduces latency compared to the unfair variant below. However, it
1005 * also adds more overhead and therefore may reduce throughput.
1007 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1008 __releases(this_rq->lock)
1009 __acquires(busiest->lock)
1010 __acquires(this_rq->lock)
1012 raw_spin_unlock(&this_rq->lock);
1013 double_rq_lock(this_rq, busiest);
1015 return 1;
1018 #else
1020 * Unfair double_lock_balance: Optimizes throughput at the expense of
1021 * latency by eliminating extra atomic operations when the locks are
1022 * already in proper order on entry. This favors lower cpu-ids and will
1023 * grant the double lock to lower cpus over higher ids under contention,
1024 * regardless of entry order into the function.
1026 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1027 __releases(this_rq->lock)
1028 __acquires(busiest->lock)
1029 __acquires(this_rq->lock)
1031 int ret = 0;
1033 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1034 if (busiest < this_rq) {
1035 raw_spin_unlock(&this_rq->lock);
1036 raw_spin_lock(&busiest->lock);
1037 raw_spin_lock_nested(&this_rq->lock,
1038 SINGLE_DEPTH_NESTING);
1039 ret = 1;
1040 } else
1041 raw_spin_lock_nested(&busiest->lock,
1042 SINGLE_DEPTH_NESTING);
1044 return ret;
1047 #endif /* CONFIG_PREEMPT */
1050 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1052 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1054 if (unlikely(!irqs_disabled())) {
1055 /* printk() doesn't work good under rq->lock */
1056 raw_spin_unlock(&this_rq->lock);
1057 BUG_ON(1);
1060 return _double_lock_balance(this_rq, busiest);
1063 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1064 __releases(busiest->lock)
1066 raw_spin_unlock(&busiest->lock);
1067 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1071 * double_rq_lock - safely lock two runqueues
1073 * Note this does not disable interrupts like task_rq_lock,
1074 * you need to do so manually before calling.
1076 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1077 __acquires(rq1->lock)
1078 __acquires(rq2->lock)
1080 BUG_ON(!irqs_disabled());
1081 if (rq1 == rq2) {
1082 raw_spin_lock(&rq1->lock);
1083 __acquire(rq2->lock); /* Fake it out ;) */
1084 } else {
1085 if (rq1 < rq2) {
1086 raw_spin_lock(&rq1->lock);
1087 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1088 } else {
1089 raw_spin_lock(&rq2->lock);
1090 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1096 * double_rq_unlock - safely unlock two runqueues
1098 * Note this does not restore interrupts like task_rq_unlock,
1099 * you need to do so manually after calling.
1101 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1102 __releases(rq1->lock)
1103 __releases(rq2->lock)
1105 raw_spin_unlock(&rq1->lock);
1106 if (rq1 != rq2)
1107 raw_spin_unlock(&rq2->lock);
1108 else
1109 __release(rq2->lock);
1112 #else /* CONFIG_SMP */
1115 * double_rq_lock - safely lock two runqueues
1117 * Note this does not disable interrupts like task_rq_lock,
1118 * you need to do so manually before calling.
1120 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1121 __acquires(rq1->lock)
1122 __acquires(rq2->lock)
1124 BUG_ON(!irqs_disabled());
1125 BUG_ON(rq1 != rq2);
1126 raw_spin_lock(&rq1->lock);
1127 __acquire(rq2->lock); /* Fake it out ;) */
1131 * double_rq_unlock - safely unlock two runqueues
1133 * Note this does not restore interrupts like task_rq_unlock,
1134 * you need to do so manually after calling.
1136 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1137 __releases(rq1->lock)
1138 __releases(rq2->lock)
1140 BUG_ON(rq1 != rq2);
1141 raw_spin_unlock(&rq1->lock);
1142 __release(rq2->lock);
1145 #endif
1147 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1148 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1149 extern void print_cfs_stats(struct seq_file *m, int cpu);
1150 extern void print_rt_stats(struct seq_file *m, int cpu);
1152 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1153 extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1154 extern void unthrottle_offline_cfs_rqs(struct rq *rq);
1156 extern void account_cfs_bandwidth_used(int enabled, int was_enabled);
1158 #ifdef CONFIG_NO_HZ
1159 enum rq_nohz_flag_bits {
1160 NOHZ_TICK_STOPPED,
1161 NOHZ_BALANCE_KICK,
1162 NOHZ_IDLE,
1165 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1166 #endif