1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Scheduler internal types and methods:
4 */
5 #ifndef COMMON_SDK_LINUX_KERNEL_SCHED_SCHED_H
6 #define COMMON_SDK_LINUX_KERNEL_SCHED_SCHED_H
7
8 #include <linux/sched.h>
9 #include <linux/sched/autogroup.h>
10 #include <linux/sched/clock.h>
11 #include <linux/sched/coredump.h>
12 #include <linux/sched/cpufreq.h>
13 #include <linux/sched/cputime.h>
14 #include <linux/sched/deadline.h>
15 #include <linux/sched/debug.h>
16 #include <linux/sched/hotplug.h>
17 #include <linux/sched/idle.h>
18 #include <linux/sched/init.h>
19 #include <linux/sched/isolation.h>
20 #include <linux/sched/jobctl.h>
21 #include <linux/sched/loadavg.h>
22 #include <linux/sched/mm.h>
23 #include <linux/sched/nohz.h>
24 #include <linux/sched/numa_balancing.h>
25 #include <linux/sched/prio.h>
26 #include <linux/sched/rt.h>
27 #include <linux/sched/signal.h>
28 #include <linux/sched/smt.h>
29 #include <linux/sched/stat.h>
30 #include <linux/sched/sysctl.h>
31 #include <linux/sched/task.h>
32 #include <linux/sched/task_stack.h>
33 #include <linux/sched/topology.h>
34 #include <linux/sched/user.h>
35 #include <linux/sched/wake_q.h>
36 #include <linux/sched/xacct.h>
37
38 #include <uapi/linux/sched/types.h>
39
40 #include <linux/binfmts.h>
41 #include <linux/blkdev.h>
42 #include <linux/compat.h>
43 #include <linux/context_tracking.h>
44 #include <linux/cpufreq.h>
45 #include <linux/cpuidle.h>
46 #include <linux/cpuset.h>
47 #include <linux/ctype.h>
48 #include <linux/debugfs.h>
49 #include <linux/delayacct.h>
50 #include <linux/energy_model.h>
51 #include <linux/init_task.h>
52 #include <linux/kprobes.h>
53 #include <linux/kthread.h>
54 #include <linux/membarrier.h>
55 #include <linux/migrate.h>
56 #include <linux/mmu_context.h>
57 #include <linux/nmi.h>
58 #include <linux/proc_fs.h>
59 #include <linux/prefetch.h>
60 #include <linux/profile.h>
61 #include <linux/psi.h>
62 #include <linux/rcupdate_wait.h>
63 #include <linux/security.h>
64 #include <linux/stop_machine.h>
65 #include <linux/suspend.h>
66 #include <linux/swait.h>
67 #include <linux/syscalls.h>
68 #include <linux/task_work.h>
69 #include <linux/tsacct_kern.h>
70
71 #include <asm/tlb.h>
72 #include <asm-generic/vmlinux.lds.h>
73
74 #ifdef CONFIG_PARAVIRT
75 #include <asm/paravirt.h>
76 #endif
77
78 #include "cpupri.h"
79 #include "cpudeadline.h"
80
81 #include <trace/events/sched.h>
82
83 #ifdef CONFIG_SCHED_DEBUG
84 #define SCHED_WARN_ON(x) (WARN_ONCE(x, #x))
85 #else
86 #define SCHED_WARN_ON(x) ( { \
87 (void)(x), 0; })
88 #endif
89
90 struct rq;
91 struct cpuidle_state;
92
93 #ifdef CONFIG_SCHED_RT_CAS
94 extern unsigned long uclamp_task_util(struct task_struct *p);
95 #endif
96
97 #ifdef CONFIG_SCHED_WALT
98 extern unsigned int sched_ravg_window;
99 extern unsigned int walt_cpu_util_freq_divisor;
100
101 struct walt_sched_stats {
102 u64 cumulative_runnable_avg_scaled;
103 };
104
105 struct load_subtractions {
106 u64 window_start;
107 u64 subs;
108 u64 new_subs;
109 };
110
111 #define NUM_TRACKED_WINDOWS 2
112
113 struct sched_cluster {
114 raw_spinlock_t load_lock;
115 struct list_head list;
116 struct cpumask cpus;
117 int id;
118 int max_power_cost;
119 int min_power_cost;
120 int max_possible_capacity;
121 int capacity;
122 int efficiency; /* Differentiate cpus with different IPC capability */
123 int load_scale_factor;
124 unsigned int exec_scale_factor;
125 /*
126 * max_freq = user maximum
127 * max_possible_freq = maximum supported by hardware
128 */
129 unsigned int cur_freq, max_freq, min_freq;
130 unsigned int max_possible_freq;
131 bool freq_init_done;
132 };
133
134 extern unsigned int sched_disable_window_stats;
135 #endif /* CONFIG_SCHED_WALT */
136
137 /* task_struct::on_rq states: */
138 #define TASK_ON_RQ_QUEUED 1
139 #define TASK_ON_RQ_MIGRATING 2
140
141 extern __read_mostly int scheduler_running;
142
143 extern unsigned long calc_load_update;
144 extern atomic_long_t calc_load_tasks;
145
146 extern const u64 max_cfs_quota_period;
147
148 extern void calc_global_load_tick(struct rq *this_rq);
149 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
150
151 #ifdef CONFIG_SMP
152 extern void init_sched_groups_capacity(int cpu, struct sched_domain *sd);
153 #endif
154
155 extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
156 /*
157 * Helpers for converting nanosecond timing to jiffy resolution
158 */
159 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
160 #ifdef CONFIG_SCHED_LATENCY_NICE
161 #define MAX_LATENCY_NICE 19
162 #define MIN_LATENCY_NICE -20
163 #define LATENCY_NICE_WIDTH \
164 (MAX_LATENCY_NICE - MIN_LATENCY_NICE + 1)
165 #define DEFAULT_LATENCY_NICE 0
166 #define DEFAULT_LATENCY_PRIO (DEFAULT_LATENCY_NICE + LATENCY_NICE_WIDTH/2)
167 #define NICE_TO_LATENCY(nice) ((nice) + DEFAULT_LATENCY_PRIO)
168 #define LATENCY_TO_NICE(prio) ((prio) - DEFAULT_LATENCY_PRIO)
169 #define NICE_LATENCY_SHIFT (SCHED_FIXEDPOINT_SHIFT)
170 #define NICE_LATENCY_WEIGHT_MAX (1L << NICE_LATENCY_SHIFT)
171 #endif /* CONFIG_SCHED_LATENCY_NICE */
172
173 /*
174 * Increase resolution of nice-level calculations for 64-bit architectures.
175 * The extra resolution improves shares distribution and load balancing of
176 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
177 * hierarchies, especially on larger systems. This is not a user-visible change
178 * and does not change the user-interface for setting shares/weights.
179 *
180 * We increase resolution only if we have enough bits to allow this increased
181 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
182 * are pretty high and the returns do not justify the increased costs.
183 *
184 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
185 * increase coverage and consistency always enable it on 64-bit platforms.
186 */
187 #ifdef CONFIG_64BIT
188 #define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
189 #define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
190 #define scale_load_down(w) \
191 ( { \
192 unsigned long __w = (w); \
193 if (__w) \
194 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
195 __w; \
196 })
197 #else
198 #define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
199 #define scale_load(w) (w)
200 #define scale_load_down(w) (w)
201 #endif
202
203 /*
204 * Task weight (visible to users) and its load (invisible to users) have
205 * independent resolution, but they should be well calibrated. We use
206 * scale_load() and scale_load_down(w) to convert between them. The
207 * following must be true:
208 *
209 * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
210 *
211 */
212 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
213 #define CPU_FREQ_1K 1024
214 #define CPU_SAMPLE_ARTE 8
215
216 extern struct cpufreq_governor schedutil_gov;
217
218 /*
219 * Single value that decides SCHED_DEADLINE internal math precision.
220 * 10 -> just above 1us
221 * 9 -> just above 0.5us
222 */
223 #define DL_SCALE 10
224
225 /*
226 * Single value that denotes runtime == period, ie unlimited time.
227 */
228 #define RUNTIME_INF ((u64)~0ULL)
229
idle_policy(int policy)230 static inline int idle_policy(int policy)
231 {
232 return policy == SCHED_IDLE;
233 }
fair_policy(int policy)234 static inline int fair_policy(int policy)
235 {
236 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
237 }
238
rt_policy(int policy)239 static inline int rt_policy(int policy)
240 {
241 return policy == SCHED_FIFO || policy == SCHED_RR;
242 }
243
dl_policy(int policy)244 static inline int dl_policy(int policy)
245 {
246 return policy == SCHED_DEADLINE;
247 }
valid_policy(int policy)248 static inline bool valid_policy(int policy)
249 {
250 return idle_policy(policy) || fair_policy(policy) || rt_policy(policy) || dl_policy(policy);
251 }
252
task_has_idle_policy(struct task_struct * p)253 static inline int task_has_idle_policy(struct task_struct *p)
254 {
255 return idle_policy(p->policy);
256 }
257
task_has_rt_policy(struct task_struct * p)258 static inline int task_has_rt_policy(struct task_struct *p)
259 {
260 return rt_policy(p->policy);
261 }
262
task_has_dl_policy(struct task_struct * p)263 static inline int task_has_dl_policy(struct task_struct *p)
264 {
265 return dl_policy(p->policy);
266 }
267
268 #define cap_scale(v, s) (((v) * (s)) >> SCHED_CAPACITY_SHIFT)
269
update_avg(u64 * avg,u64 sample)270 static inline void update_avg(u64 *avg, u64 sample)
271 {
272 s64 diff = sample - *avg;
273 *avg += diff / CPU_SAMPLE_ARTE;
274 }
275
276 /*
277 * Shifting a value by an exponent greater *or equal* to the size of said value
278 * is UB; cap at size-1.
279 */
280 #define shr_bound(val, shift) ((val) >> min_t(typeof(shift), (shift), BITS_PER_TYPE(typeof(val)) - 1))
281
282 /*
283 * !! For sched_setattr_nocheck() (kernel) only !!
284 *
285 * This is actually gross. :(
286 *
287 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
288 * tasks, but still be able to sleep. We need this on platforms that cannot
289 * atomically change clock frequency. Remove once fast switching will be
290 * available on such platforms.
291 *
292 * SUGOV stands for SchedUtil GOVernor.
293 */
294 #define SCHED_FLAG_SUGOV 0x10000000
295
296 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
297
dl_entity_is_special(struct sched_dl_entity * dl_se)298 static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se)
299 {
300 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
301 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV);
302 #else
303 return false;
304 #endif
305 }
306
307 /*
308 * Tells if entity @a should preempt entity @b.
309 */
dl_entity_preempt(struct sched_dl_entity * a,struct sched_dl_entity * b)310 static inline bool dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
311 {
312 return dl_entity_is_special(a) || dl_time_before(a->deadline, b->deadline);
313 }
314
315 /*
316 * This is the priority-queue data structure of the RT scheduling class:
317 */
318 struct rt_prio_array {
319 DECLARE_BITMAP(bitmap, MAX_RT_PRIO + 1); /* include 1 bit for delimiter */
320 struct list_head queue[MAX_RT_PRIO];
321 };
322
323 struct rt_bandwidth {
324 /* nests inside the rq lock: */
325 raw_spinlock_t rt_runtime_lock;
326 ktime_t rt_period;
327 u64 rt_runtime;
328 struct hrtimer rt_period_timer;
329 unsigned int rt_period_active;
330 };
331
332 void __dl_clear_params(struct task_struct *p);
333
334 struct dl_bandwidth {
335 raw_spinlock_t dl_runtime_lock;
336 u64 dl_runtime;
337 u64 dl_period;
338 };
339
dl_bandwidth_enabled(void)340 static inline int dl_bandwidth_enabled(void)
341 {
342 return sysctl_sched_rt_runtime >= 0;
343 }
344
345 /*
346 * To keep the bandwidth of -deadline tasks under control
347 * we need some place where:
348 * - store the maximum -deadline bandwidth of each cpu;
349 * - cache the fraction of bandwidth that is currently allocated in
350 * each root domain;
351 *
352 * This is all done in the data structure below. It is similar to the
353 * one used for RT-throttling (rt_bandwidth), with the main difference
354 * that, since here we are only interested in admission control, we
355 * do not decrease any runtime while the group "executes", neither we
356 * need a timer to replenish it.
357 *
358 * With respect to SMP, bandwidth is given on a per root domain basis,
359 * meaning that:
360 * - bw (< 100%) is the deadline bandwidth of each CPU;
361 * - total_bw is the currently allocated bandwidth in each root domain;
362 */
363 struct dl_bw {
364 raw_spinlock_t lock;
365 u64 bw;
366 u64 total_bw;
367 };
368
369 static inline void __dl_update(struct dl_bw *dl_b, s64 bw);
370
__dl_sub(struct dl_bw * dl_b,u64 tsk_bw,int cpus)371 static inline void __dl_sub(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
372 {
373 dl_b->total_bw -= tsk_bw;
374 __dl_update(dl_b, (s32)tsk_bw / cpus);
375 }
376
__dl_add(struct dl_bw * dl_b,u64 tsk_bw,int cpus)377 static inline void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
378 {
379 dl_b->total_bw += tsk_bw;
380 __dl_update(dl_b, -((s32)tsk_bw / cpus));
381 }
382
__dl_overflow(struct dl_bw * dl_b,unsigned long cap,u64 old_bw,u64 new_bw)383 static inline bool __dl_overflow(struct dl_bw *dl_b, unsigned long cap, u64 old_bw, u64 new_bw)
384 {
385 return (dl_b->bw != -1) && (cap_scale(dl_b->bw, cap) < (dl_b->total_bw - old_bw + new_bw));
386 }
387
388 /*
389 * Verify the fitness of task @p to run on @cpu taking into account the
390 * CPU original capacity and the runtime/deadline ratio of the task.
391 *
392 * The function will return true if the CPU original capacity of the
393 * @cpu scaled by SCHED_CAPACITY_SCALE >= runtime/deadline ratio of the
394 * task and false otherwise.
395 */
dl_task_fits_capacity(struct task_struct * p,int cpu)396 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu)
397 {
398 unsigned long cap = arch_scale_cpu_capacity(cpu);
399
400 return ((cap_scale(p->dl.dl_deadline, cap)) >= (p->dl.dl_runtime));
401 }
402
403 extern void init_dl_bw(struct dl_bw *dl_b);
404 extern int sched_dl_global_validate(void);
405 extern void sched_dl_do_global(void);
406 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr);
407 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
408 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
409 extern bool __checkparam_dl(const struct sched_attr *attr);
410 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
411 extern int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
412 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
413 extern int dl_cpu_busy(int cpu, struct task_struct *p);
414
415 #ifdef CONFIG_CGROUP_SCHED
416
417 #include <linux/cgroup.h>
418 #include <linux/psi.h>
419
420 struct cfs_rq;
421 struct rt_rq;
422
423 extern struct list_head task_groups;
424
425 struct cfs_bandwidth {
426 #ifdef CONFIG_CFS_BANDWIDTH
427 raw_spinlock_t lock;
428 ktime_t period;
429 u64 quota;
430 u64 runtime;
431 s64 hierarchical_quota;
432
433 u8 idle;
434 u8 period_active;
435 u8 slack_started;
436 struct hrtimer period_timer;
437 struct hrtimer slack_timer;
438 struct list_head throttled_cfs_rq;
439
440 /* Statistics: */
441 int nr_periods;
442 int nr_throttled;
443 u64 throttled_time;
444 #endif
445 };
446
447 /* Task group related information */
448 struct task_group {
449 struct cgroup_subsys_state css;
450
451 #ifdef CONFIG_FAIR_GROUP_SCHED
452 /* schedulable entities of this group on each CPU */
453 struct sched_entity **se;
454 /* runqueue "owned" by this group on each CPU */
455 struct cfs_rq **cfs_rq;
456 unsigned long shares;
457
458 #ifdef CONFIG_SMP
459 /*
460 * load_avg can be heavily contended at clock tick time, so put
461 * it in its own cacheline separated from the fields above which
462 * will also be accessed at each tick.
463 */
464 atomic_long_t load_avg ____cacheline_aligned;
465 #endif
466 #endif
467
468 #ifdef CONFIG_RT_GROUP_SCHED
469 struct sched_rt_entity **rt_se;
470 struct rt_rq **rt_rq;
471
472 struct rt_bandwidth rt_bandwidth;
473 #endif
474
475 struct rcu_head rcu;
476 struct list_head list;
477
478 struct task_group *parent;
479 struct list_head siblings;
480 struct list_head children;
481
482 #ifdef CONFIG_SCHED_AUTOGROUP
483 struct autogroup *autogroup;
484 #endif
485
486 struct cfs_bandwidth cfs_bandwidth;
487
488 #ifdef CONFIG_UCLAMP_TASK_GROUP
489 /* The two decimal precision [%] value requested from user-space */
490 unsigned int uclamp_pct[UCLAMP_CNT];
491 /* Clamp values requested for a task group */
492 struct uclamp_se uclamp_req[UCLAMP_CNT];
493 /* Effective clamp values used for a task group */
494 struct uclamp_se uclamp[UCLAMP_CNT];
495 #endif
496
497 #ifdef CONFIG_SCHED_RTG_CGROUP
498 /*
499 * Controls whether tasks of this cgroup should be colocated with each
500 * other and tasks of other cgroups that have the same flag turned on.
501 */
502 bool colocate;
503
504 /* Controls whether further updates are allowed to the colocate flag */
505 bool colocate_update_disabled;
506 #endif
507 };
508
509 #ifdef CONFIG_FAIR_GROUP_SCHED
510 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
511
512 /*
513 * A weight of 0 or 1 can cause arithmetics problems.
514 * A weight of a cfs_rq is the sum of weights of which entities
515 * are queued on this cfs_rq, so a weight of a entity should not be
516 * too large, so as the shares value of a task group.
517 * (The default weight is 1024 - so there's no practical
518 * limitation from this.)
519 */
520 #define MIN_SHARES (1UL << 1)
521 #define MAX_SHARES (1UL << 18)
522 #endif
523
524 typedef int (*tg_visitor)(struct task_group *, void *);
525
526 extern int walk_tg_tree_from(struct task_group *from, tg_visitor down, tg_visitor up, void *data);
527
528 /*
529 * Iterate the full tree, calling @down when first entering a node and @up when
530 * leaving it for the final time.
531 *
532 * Caller must hold rcu_lock or sufficient equivalent.
533 */
walk_tg_tree(tg_visitor down,tg_visitor up,void * data)534 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
535 {
536 return walk_tg_tree_from(&root_task_group, down, up, data);
537 }
538
539 extern int tg_nop(struct task_group *tg, void *data);
540
541 extern void free_fair_sched_group(struct task_group *tg);
542 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
543 extern void online_fair_sched_group(struct task_group *tg);
544 extern void unregister_fair_sched_group(struct task_group *tg);
545 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, struct sched_entity *se, int cpu,
546 struct sched_entity *parent);
547 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
548
549 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
550 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
551 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
552
553 extern void free_rt_sched_group(struct task_group *tg);
554 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
555 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int cpu,
556 struct sched_rt_entity *parent);
557 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
558 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
559 extern long sched_group_rt_runtime(struct task_group *tg);
560 extern long sched_group_rt_period(struct task_group *tg);
561 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
562
563 extern struct task_group *sched_create_group(struct task_group *parent);
564 extern void sched_online_group(struct task_group *tg, struct task_group *parent);
565 extern void sched_destroy_group(struct task_group *tg);
566 extern void sched_offline_group(struct task_group *tg);
567
568 extern void sched_move_task(struct task_struct *tsk);
569
570 #ifdef CONFIG_FAIR_GROUP_SCHED
571 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
572
573 #ifdef CONFIG_SMP
574 extern void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next);
575 #else /* !CONFIG_SMP */
set_task_rq_fair(struct sched_entity * se,struct cfs_rq * prev,struct cfs_rq * next)576 static inline void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next)
577 {
578 }
579 #endif /* CONFIG_SMP */
580 #endif /* CONFIG_FAIR_GROUP_SCHED */
581
582 #else /* CONFIG_CGROUP_SCHED */
583
584 struct cfs_bandwidth {
585 };
586
587 #endif /* CONFIG_CGROUP_SCHED */
588
589 /* CFS-related fields in a runqueue */
590 struct cfs_rq {
591 struct load_weight load;
592 unsigned int nr_running;
593 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */
594 unsigned int idle_h_nr_running; /* SCHED_IDLE */
595
596 u64 exec_clock;
597 u64 min_vruntime;
598 #ifndef CONFIG_64BIT
599 u64 min_vruntime_copy;
600 #endif
601
602 struct rb_root_cached tasks_timeline;
603
604 /*
605 * 'curr' points to currently running entity on this cfs_rq.
606 * It is set to NULL otherwise (i.e when none are currently running).
607 */
608 struct sched_entity *curr;
609 struct sched_entity *next;
610 struct sched_entity *last;
611 struct sched_entity *skip;
612
613 #ifdef CONFIG_SCHED_DEBUG
614 unsigned int nr_spread_over;
615 #endif
616
617 #ifdef CONFIG_SMP
618 /*
619 * CFS load tracking
620 */
621 struct sched_avg avg;
622 #ifndef CONFIG_64BIT
623 u64 load_last_update_time_copy;
624 #endif
625 struct {
626 raw_spinlock_t lock ____cacheline_aligned;
627 int nr;
628 unsigned long load_avg;
629 unsigned long util_avg;
630 unsigned long runnable_avg;
631 } removed;
632
633 #ifdef CONFIG_FAIR_GROUP_SCHED
634 unsigned long tg_load_avg_contrib;
635 long propagate;
636 long prop_runnable_sum;
637
638 /*
639 * h_load = weight * f(tg)
640 *
641 * Where f(tg) is the recursive weight fraction assigned to
642 * this group.
643 */
644 unsigned long h_load;
645 u64 last_h_load_update;
646 struct sched_entity *h_load_next;
647 #endif /* CONFIG_FAIR_GROUP_SCHED */
648 #endif /* CONFIG_SMP */
649
650 #ifdef CONFIG_FAIR_GROUP_SCHED
651 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */
652
653 /*
654 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
655 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
656 * (like users, containers etc.)
657 *
658 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU.
659 * This list is used during load balance.
660 */
661 int on_list;
662 struct list_head leaf_cfs_rq_list;
663 struct task_group *tg; /* group that "owns" this runqueue */
664
665 #ifdef CONFIG_SCHED_WALT
666 struct walt_sched_stats walt_stats;
667 #endif
668
669 #ifdef CONFIG_CFS_BANDWIDTH
670 int runtime_enabled;
671 s64 runtime_remaining;
672
673 u64 throttled_clock;
674 u64 throttled_clock_pelt;
675 u64 throttled_clock_pelt_time;
676 int throttled;
677 int throttle_count;
678 struct list_head throttled_list;
679 #ifdef CONFIG_SCHED_WALT
680 u64 cumulative_runnable_avg;
681 #endif
682 #endif /* CONFIG_CFS_BANDWIDTH */
683 #endif /* CONFIG_FAIR_GROUP_SCHED */
684 };
685
rt_bandwidth_enabled(void)686 static inline int rt_bandwidth_enabled(void)
687 {
688 return sysctl_sched_rt_runtime >= 0;
689 }
690
691 /* RT IPI pull logic requires IRQ_WORK */
692 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP)
693 #define HAVE_RT_PUSH_IPI
694 #endif
695
696 /* Real-Time classes' related field in a runqueue: */
697 struct rt_rq {
698 struct rt_prio_array active;
699 unsigned int rt_nr_running;
700 unsigned int rr_nr_running;
701 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
702 struct {
703 int curr; /* highest queued rt task prio */
704 #ifdef CONFIG_SMP
705 int next; /* next highest */
706 #endif
707 } highest_prio;
708 #endif
709 #ifdef CONFIG_SMP
710 unsigned long rt_nr_migratory;
711 unsigned long rt_nr_total;
712 int overloaded;
713 struct plist_head pushable_tasks;
714
715 #endif /* CONFIG_SMP */
716 int rt_queued;
717
718 int rt_throttled;
719 u64 rt_time;
720 u64 rt_runtime;
721 /* Nests inside the rq lock: */
722 raw_spinlock_t rt_runtime_lock;
723
724 #ifdef CONFIG_RT_GROUP_SCHED
725 unsigned long rt_nr_boosted;
726
727 struct rq *rq;
728 struct task_group *tg;
729 #endif
730 };
731
rt_rq_is_runnable(struct rt_rq * rt_rq)732 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
733 {
734 return rt_rq->rt_queued && rt_rq->rt_nr_running;
735 }
736
737 /* Deadline class' related fields in a runqueue */
738 struct dl_rq {
739 /* runqueue is an rbtree, ordered by deadline */
740 struct rb_root_cached root;
741
742 unsigned long dl_nr_running;
743
744 #ifdef CONFIG_SMP
745 /*
746 * Deadline values of the currently executing and the
747 * earliest ready task on this rq. Caching these facilitates
748 * the decision whether or not a ready but not running task
749 * should migrate somewhere else.
750 */
751 struct {
752 u64 curr;
753 u64 next;
754 } earliest_dl;
755
756 unsigned long dl_nr_migratory;
757 int overloaded;
758
759 /*
760 * Tasks on this rq that can be pushed away. They are kept in
761 * an rb-tree, ordered by tasks' deadlines, with caching
762 * of the leftmost (earliest deadline) element.
763 */
764 struct rb_root_cached pushable_dl_tasks_root;
765 #else
766 struct dl_bw dl_bw;
767 #endif
768 /*
769 * "Active utilization" for this runqueue: increased when a
770 * task wakes up (becomes TASK_RUNNING) and decreased when a
771 * task blocks
772 */
773 u64 running_bw;
774
775 /*
776 * Utilization of the tasks "assigned" to this runqueue (including
777 * the tasks that are in runqueue and the tasks that executed on this
778 * CPU and blocked). Increased when a task moves to this runqueue, and
779 * decreased when the task moves away (migrates, changes scheduling
780 * policy, or terminates).
781 * This is needed to compute the "inactive utilization" for the
782 * runqueue (inactive utilization = this_bw - running_bw).
783 */
784 u64 this_bw;
785 u64 extra_bw;
786
787 /*
788 * Inverse of the fraction of CPU utilization that can be reclaimed
789 * by the GRUB algorithm.
790 */
791 u64 bw_ratio;
792 };
793
794 #ifdef CONFIG_FAIR_GROUP_SCHED
795 /* An entity is a task if it doesn't "own" a runqueue */
796 #define entity_is_task(se) (!se->my_q)
797
se_update_runnable(struct sched_entity * se)798 static inline void se_update_runnable(struct sched_entity *se)
799 {
800 if (!entity_is_task(se)) {
801 se->runnable_weight = se->my_q->h_nr_running;
802 }
803 }
804
se_runnable(struct sched_entity * se)805 static inline long se_runnable(struct sched_entity *se)
806 {
807 if (entity_is_task(se)) {
808 return !!se->on_rq;
809 } else {
810 return se->runnable_weight;
811 }
812 }
813
814 #else
815 #define entity_is_task(se) 1
816
se_update_runnable(struct sched_entity * se)817 static inline void se_update_runnable(struct sched_entity *se)
818 {
819 }
820
se_runnable(struct sched_entity * se)821 static inline long se_runnable(struct sched_entity *se)
822 {
823 return !!se->on_rq;
824 }
825 #endif
826
827 #ifdef CONFIG_SMP
828 /*
829 * XXX we want to get rid of these helpers and use the full load resolution.
830 */
se_weight(struct sched_entity * se)831 static inline long se_weight(struct sched_entity *se)
832 {
833 return scale_load_down(se->load.weight);
834 }
835
sched_asym_prefer(int a,int b)836 static inline bool sched_asym_prefer(int a, int b)
837 {
838 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
839 }
840
841 struct perf_domain {
842 struct em_perf_domain *em_pd;
843 struct perf_domain *next;
844 struct rcu_head rcu;
845 };
846
847 /* Scheduling group status flags */
848 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */
849 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */
850
851 /*
852 * We add the notion of a root-domain which will be used to define per-domain
853 * variables. Each exclusive cpuset essentially defines an island domain by
854 * fully partitioning the member CPUs from any other cpuset. Whenever a new
855 * exclusive cpuset is created, we also create and attach a new root-domain
856 * object.
857 *
858 */
859 struct root_domain {
860 atomic_t refcount;
861 atomic_t rto_count;
862 struct rcu_head rcu;
863 cpumask_var_t span;
864 cpumask_var_t online;
865
866 /*
867 * Indicate pullable load on at least one CPU, e.g:
868 * - More than one runnable task
869 * - Running task is misfit
870 */
871 int overload;
872
873 /* Indicate one or more cpus over-utilized (tipping point) */
874 int overutilized;
875
876 /*
877 * The bit corresponding to a CPU gets set here if such CPU has more
878 * than one runnable -deadline task (as it is below for RT tasks).
879 */
880 cpumask_var_t dlo_mask;
881 atomic_t dlo_count;
882 struct dl_bw dl_bw;
883 struct cpudl cpudl;
884
885 #ifdef HAVE_RT_PUSH_IPI
886 /*
887 * For IPI pull requests, loop across the rto_mask.
888 */
889 struct irq_work rto_push_work;
890 raw_spinlock_t rto_lock;
891 /* These are only updated and read within rto_lock */
892 int rto_loop;
893 int rto_cpu;
894 /* These atomics are updated outside of a lock */
895 atomic_t rto_loop_next;
896 atomic_t rto_loop_start;
897 #endif
898 /*
899 * The "RT overload" flag: it gets set if a CPU has more than
900 * one runnable RT task.
901 */
902 cpumask_var_t rto_mask;
903 struct cpupri cpupri;
904
905 unsigned long max_cpu_capacity;
906
907 /*
908 * NULL-terminated list of performance domains intersecting with the
909 * CPUs of the rd. Protected by RCU.
910 */
911 struct perf_domain __rcu *pd;
912 #ifdef CONFIG_SCHED_RT_CAS
913 int max_cap_orig_cpu;
914 #endif
915 };
916
917 extern void init_defrootdomain(void);
918 extern int sched_init_domains(const struct cpumask *cpu_map);
919 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
920 extern void sched_get_rd(struct root_domain *rd);
921 extern void sched_put_rd(struct root_domain *rd);
922
923 #ifdef HAVE_RT_PUSH_IPI
924 extern void rto_push_irq_work_func(struct irq_work *work);
925 #endif
926 #endif /* CONFIG_SMP */
927
928 #ifdef CONFIG_UCLAMP_TASK
929 /*
930 * struct uclamp_bucket - Utilization clamp bucket
931 * @value: utilization clamp value for tasks on this clamp bucket
932 * @tasks: number of RUNNABLE tasks on this clamp bucket
933 *
934 * Keep track of how many tasks are RUNNABLE for a given utilization
935 * clamp value.
936 */
937 struct uclamp_bucket {
938 unsigned long value : bits_per(SCHED_CAPACITY_SCALE);
939 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE);
940 };
941
942 /*
943 * struct uclamp_rq - rq's utilization clamp
944 * @value: currently active clamp values for a rq
945 * @bucket: utilization clamp buckets affecting a rq
946 *
947 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values.
948 * A clamp value is affecting a rq when there is at least one task RUNNABLE
949 * (or actually running) with that value.
950 *
951 * There are up to UCLAMP_CNT possible different clamp values, currently there
952 * are only two: minimum utilization and maximum utilization.
953 *
954 * All utilization clamping values are MAX aggregated, since:
955 * - for util_min: we want to run the CPU at least at the max of the minimum
956 * utilization required by its currently RUNNABLE tasks.
957 * - for util_max: we want to allow the CPU to run up to the max of the
958 * maximum utilization allowed by its currently RUNNABLE tasks.
959 *
960 * Since on each system we expect only a limited number of different
961 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track
962 * the metrics required to compute all the per-rq utilization clamp values.
963 */
964 struct uclamp_rq {
965 unsigned int value;
966 struct uclamp_bucket bucket[UCLAMP_BUCKETS];
967 };
968
969 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used);
970 #endif /* CONFIG_UCLAMP_TASK */
971
972 /*
973 * This is the main, per-CPU runqueue data structure.
974 *
975 * Locking rule: those places that want to lock multiple runqueues
976 * (such as the load balancing or the thread migration code), lock
977 * acquire operations must be ordered by ascending &runqueue.
978 */
979 struct rq {
980 /* runqueue lock: */
981 raw_spinlock_t lock;
982
983 /*
984 * nr_running and cpu_load should be in the same cacheline because
985 * remote CPUs use both these fields when doing load calculation.
986 */
987 unsigned int nr_running;
988 #ifdef CONFIG_NUMA_BALANCING
989 unsigned int nr_numa_running;
990 unsigned int nr_preferred_running;
991 unsigned int numa_migrate_on;
992 #endif
993 #ifdef CONFIG_NO_HZ_COMMON
994 #ifdef CONFIG_SMP
995 unsigned long last_blocked_load_update_tick;
996 unsigned int has_blocked_load;
997 call_single_data_t nohz_csd;
998 #endif /* CONFIG_SMP */
999 unsigned int nohz_tick_stopped;
1000 atomic_t nohz_flags;
1001 #endif /* CONFIG_NO_HZ_COMMON */
1002
1003 #ifdef CONFIG_SMP
1004 unsigned int ttwu_pending;
1005 #endif
1006 u64 nr_switches;
1007
1008 #ifdef CONFIG_UCLAMP_TASK
1009 /* Utilization clamp values based on CPU's RUNNABLE tasks */
1010 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned;
1011 unsigned int uclamp_flags;
1012 #define UCLAMP_FLAG_IDLE 0x01
1013 #endif
1014
1015 struct cfs_rq cfs;
1016 struct rt_rq rt;
1017 struct dl_rq dl;
1018
1019 #ifdef CONFIG_FAIR_GROUP_SCHED
1020 /* list of leaf cfs_rq on this CPU: */
1021 struct list_head leaf_cfs_rq_list;
1022 struct list_head *tmp_alone_branch;
1023 #endif /* CONFIG_FAIR_GROUP_SCHED */
1024
1025 /*
1026 * This is part of a global counter where only the total sum
1027 * over all CPUs matters. A task can increase this counter on
1028 * one CPU and if it got migrated afterwards it may decrease
1029 * it on another CPU. Always updated under the runqueue lock:
1030 */
1031 unsigned long nr_uninterruptible;
1032
1033 struct task_struct __rcu *curr;
1034 struct task_struct *idle;
1035 struct task_struct *stop;
1036 unsigned long next_balance;
1037 struct mm_struct *prev_mm;
1038
1039 unsigned int clock_update_flags;
1040 u64 clock;
1041 /* Ensure that all clocks are in the same cache line */
1042 u64 clock_task ____cacheline_aligned;
1043 u64 clock_pelt;
1044 unsigned long lost_idle_time;
1045
1046 atomic_t nr_iowait;
1047
1048 #ifdef CONFIG_MEMBARRIER
1049 int membarrier_state;
1050 #endif
1051
1052 #ifdef CONFIG_SMP
1053 struct root_domain *rd;
1054 struct sched_domain __rcu *sd;
1055
1056 unsigned long cpu_capacity;
1057 unsigned long cpu_capacity_orig;
1058
1059 struct callback_head *balance_callback;
1060
1061 unsigned char nohz_idle_balance;
1062 unsigned char idle_balance;
1063
1064 unsigned long misfit_task_load;
1065
1066 /* For active balancing */
1067 int active_balance;
1068 int push_cpu;
1069 #ifdef CONFIG_SCHED_EAS
1070 struct task_struct *push_task;
1071 #endif
1072 struct cpu_stop_work active_balance_work;
1073
1074 /* For rt active balancing */
1075 #ifdef CONFIG_SCHED_RT_ACTIVE_LB
1076 int rt_active_balance;
1077 struct task_struct *rt_push_task;
1078 struct cpu_stop_work rt_active_balance_work;
1079 #endif
1080
1081 /* CPU of this runqueue: */
1082 int cpu;
1083 int online;
1084
1085 struct list_head cfs_tasks;
1086
1087 struct sched_avg avg_rt;
1088 struct sched_avg avg_dl;
1089 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
1090 struct sched_avg avg_irq;
1091 #endif
1092 #ifdef CONFIG_SCHED_THERMAL_PRESSURE
1093 struct sched_avg avg_thermal;
1094 #endif
1095 u64 idle_stamp;
1096 u64 avg_idle;
1097
1098 /* This is used to determine avg_idle's max value */
1099 u64 max_idle_balance_cost;
1100 #endif /* CONFIG_SMP */
1101
1102 #ifdef CONFIG_SCHED_WALT
1103 struct sched_cluster *cluster;
1104 struct cpumask freq_domain_cpumask;
1105 struct walt_sched_stats walt_stats;
1106
1107 u64 window_start;
1108 unsigned long walt_flags;
1109
1110 u64 cur_irqload;
1111 u64 avg_irqload;
1112 u64 irqload_ts;
1113 u64 curr_runnable_sum;
1114 u64 prev_runnable_sum;
1115 u64 nt_curr_runnable_sum;
1116 u64 nt_prev_runnable_sum;
1117 u64 cum_window_demand_scaled;
1118 struct load_subtractions load_subs[NUM_TRACKED_WINDOWS];
1119 #ifdef CONFIG_SCHED_RTG
1120 struct group_cpu_time grp_time;
1121 #endif
1122 #endif /* CONFIG_SCHED_WALT */
1123
1124 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1125 u64 prev_irq_time;
1126 #endif
1127 #ifdef CONFIG_PARAVIRT
1128 u64 prev_steal_time;
1129 #endif
1130 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
1131 u64 prev_steal_time_rq;
1132 #endif
1133
1134 /* calc_load related fields */
1135 unsigned long calc_load_update;
1136 long calc_load_active;
1137
1138 #ifdef CONFIG_SCHED_HRTICK
1139 #ifdef CONFIG_SMP
1140 call_single_data_t hrtick_csd;
1141 #endif
1142 struct hrtimer hrtick_timer;
1143 ktime_t hrtick_time;
1144 #endif
1145
1146 #ifdef CONFIG_SCHEDSTATS
1147 /* latency stats */
1148 struct sched_info rq_sched_info;
1149 unsigned long long rq_cpu_time;
1150 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
1151
1152 /* sys_sched_yield() stats */
1153 unsigned int yld_count;
1154
1155 /* schedule() stats */
1156 unsigned int sched_count;
1157 unsigned int sched_goidle;
1158
1159 /* try_to_wake_up() stats */
1160 unsigned int ttwu_count;
1161 unsigned int ttwu_local;
1162 #endif
1163
1164 #ifdef CONFIG_CPU_IDLE
1165 /* Must be inspected within a rcu lock section */
1166 struct cpuidle_state *idle_state;
1167 #endif
1168 };
1169
1170 #ifdef CONFIG_FAIR_GROUP_SCHED
1171
1172 /* CPU runqueue to which this cfs_rq is attached */
rq_of(struct cfs_rq * cfs_rq)1173 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1174 {
1175 return cfs_rq->rq;
1176 }
1177
1178 #else
1179
rq_of(struct cfs_rq * cfs_rq)1180 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1181 {
1182 return container_of(cfs_rq, struct rq, cfs);
1183 }
1184 #endif
1185
cpu_of(struct rq * rq)1186 static inline int cpu_of(struct rq *rq)
1187 {
1188 #ifdef CONFIG_SMP
1189 return rq->cpu;
1190 #else
1191 return 0;
1192 #endif
1193 }
1194
1195 #ifdef CONFIG_SCHED_SMT
1196 extern void __update_idle_core(struct rq *rq);
1197
update_idle_core(struct rq * rq)1198 static inline void update_idle_core(struct rq *rq)
1199 {
1200 if (static_branch_unlikely(&sched_smt_present)) {
1201 __update_idle_core(rq);
1202 }
1203 }
1204
1205 #else
update_idle_core(struct rq * rq)1206 static inline void update_idle_core(struct rq *rq)
1207 {
1208 }
1209 #endif
1210
1211 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
1212
1213 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
1214 #define this_rq() this_cpu_ptr(&runqueues)
1215 #define task_rq(p) cpu_rq(task_cpu(p))
1216 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
1217 #define raw_rq() raw_cpu_ptr(&runqueues)
1218
1219 extern void update_rq_clock(struct rq *rq);
1220
__rq_clock_broken(struct rq * rq)1221 static inline u64 __rq_clock_broken(struct rq *rq)
1222 {
1223 return READ_ONCE(rq->clock);
1224 }
1225
1226 /*
1227 * rq::clock_update_flags bits
1228 *
1229 * %RQCF_REQ_SKIP - will request skipping of clock update on the next
1230 * call to __schedule(). This is an optimisation to avoid
1231 * neighbouring rq clock updates.
1232 *
1233 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is
1234 * in effect and calls to update_rq_clock() are being ignored.
1235 *
1236 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been
1237 * made to update_rq_clock() since the last time rq::lock was pinned.
1238 *
1239 * If inside of __schedule(), clock_update_flags will have been
1240 * shifted left (a left shift is a cheap operation for the fast path
1241 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use,
1242 *
1243 * if (rq-clock_update_flags >= RQCF_UPDATED)
1244 *
1245 * to check if %RQCF_UPADTED is set. It'll never be shifted more than
1246 * one position though, because the next rq_unpin_lock() will shift it
1247 * back.
1248 */
1249 #define RQCF_REQ_SKIP 0x01
1250 #define RQCF_ACT_SKIP 0x02
1251 #define RQCF_UPDATED 0x04
1252
assert_clock_updated(struct rq * rq)1253 static inline void assert_clock_updated(struct rq *rq)
1254 {
1255 /*
1256 * The only reason for not seeing a clock update since the
1257 * last rq_pin_lock() is if we're currently skipping updates.
1258 */
1259 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP);
1260 }
1261
rq_clock(struct rq * rq)1262 static inline u64 rq_clock(struct rq *rq)
1263 {
1264 lockdep_assert_held(&rq->lock);
1265 assert_clock_updated(rq);
1266
1267 return rq->clock;
1268 }
1269
rq_clock_task(struct rq * rq)1270 static inline u64 rq_clock_task(struct rq *rq)
1271 {
1272 lockdep_assert_held(&rq->lock);
1273 assert_clock_updated(rq);
1274
1275 return rq->clock_task;
1276 }
1277
1278 /**
1279 * By default the decay is the default pelt decay period.
1280 * The decay shift can change the decay period in
1281 * multiples of 32.
1282 * Decay shift Decay period(ms)
1283 * 0 32
1284 * 1 64
1285 * 2 128
1286 * 3 256
1287 * 4 512
1288 */
1289 extern int sched_thermal_decay_shift;
1290
rq_clock_thermal(struct rq * rq)1291 static inline u64 rq_clock_thermal(struct rq *rq)
1292 {
1293 return rq_clock_task(rq) >> sched_thermal_decay_shift;
1294 }
1295
rq_clock_skip_update(struct rq * rq)1296 static inline void rq_clock_skip_update(struct rq *rq)
1297 {
1298 lockdep_assert_held(&rq->lock);
1299 rq->clock_update_flags |= RQCF_REQ_SKIP;
1300 }
1301
1302 /*
1303 * See rt task throttling, which is the only time a skip
1304 * request is cancelled.
1305 */
rq_clock_cancel_skipupdate(struct rq * rq)1306 static inline void rq_clock_cancel_skipupdate(struct rq *rq)
1307 {
1308 lockdep_assert_held(&rq->lock);
1309 rq->clock_update_flags &= ~RQCF_REQ_SKIP;
1310 }
1311
1312 struct rq_flags {
1313 unsigned long flags;
1314 struct pin_cookie cookie;
1315 #ifdef CONFIG_SCHED_DEBUG
1316 /*
1317 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
1318 * current pin context is stashed here in case it needs to be
1319 * restored in rq_repin_lock().
1320 */
1321 unsigned int clock_update_flags;
1322 #endif
1323 };
1324
1325 /*
1326 * Lockdep annotation that avoids accidental unlocks; it's like a
1327 * sticky/continuous lockdep_assert_held().
1328 *
1329 * This avoids code that has access to 'struct rq *rq' (basically everything in
1330 * the scheduler) from accidentally unlocking the rq if they do not also have a
1331 * copy of the (on-stack) 'struct rq_flags rf'.
1332 *
1333 * Also see Documentation/locking/lockdep-design.rst.
1334 */
rq_pin_lock(struct rq * rq,struct rq_flags * rf)1335 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
1336 {
1337 rf->cookie = lockdep_pin_lock(&rq->lock);
1338
1339 #ifdef CONFIG_SCHED_DEBUG
1340 rq->clock_update_flags &= (RQCF_REQ_SKIP | RQCF_ACT_SKIP);
1341 rf->clock_update_flags = 0;
1342 #endif
1343 }
1344
rq_unpin_lock(struct rq * rq,struct rq_flags * rf)1345 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
1346 {
1347 #ifdef CONFIG_SCHED_DEBUG
1348 if (rq->clock_update_flags > RQCF_ACT_SKIP) {
1349 rf->clock_update_flags = RQCF_UPDATED;
1350 }
1351 #endif
1352
1353 lockdep_unpin_lock(&rq->lock, rf->cookie);
1354 }
1355
rq_repin_lock(struct rq * rq,struct rq_flags * rf)1356 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
1357 {
1358 lockdep_repin_lock(&rq->lock, rf->cookie);
1359
1360 #ifdef CONFIG_SCHED_DEBUG
1361 /*
1362 * Restore the value we stashed in @rf for this pin context.
1363 */
1364 rq->clock_update_flags |= rf->clock_update_flags;
1365 #endif
1366 }
1367
1368 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(rq->lock);
1369
1370 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(p->pi_lock) __acquires(rq->lock);
1371
__task_rq_unlock(struct rq * rq,struct rq_flags * rf)1372 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock)
1373 {
1374 rq_unpin_lock(rq, rf);
1375 raw_spin_unlock(&rq->lock);
1376 }
1377
task_rq_unlock(struct rq * rq,struct task_struct * p,struct rq_flags * rf)1378 static inline void task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) __releases(rq->lock)
1379 __releases(p->pi_lock)
1380 {
1381 rq_unpin_lock(rq, rf);
1382 raw_spin_unlock(&rq->lock);
1383 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1384 }
1385
rq_lock_irqsave(struct rq * rq,struct rq_flags * rf)1386 static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock)
1387 {
1388 raw_spin_lock_irqsave(&rq->lock, rf->flags);
1389 rq_pin_lock(rq, rf);
1390 }
1391
rq_lock_irq(struct rq * rq,struct rq_flags * rf)1392 static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock)
1393 {
1394 raw_spin_lock_irq(&rq->lock);
1395 rq_pin_lock(rq, rf);
1396 }
1397
rq_lock(struct rq * rq,struct rq_flags * rf)1398 static inline void rq_lock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock)
1399 {
1400 raw_spin_lock(&rq->lock);
1401 rq_pin_lock(rq, rf);
1402 }
1403
rq_relock(struct rq * rq,struct rq_flags * rf)1404 static inline void rq_relock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock)
1405 {
1406 raw_spin_lock(&rq->lock);
1407 rq_repin_lock(rq, rf);
1408 }
1409
rq_unlock_irqrestore(struct rq * rq,struct rq_flags * rf)1410 static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) __releases(rq->lock)
1411 {
1412 rq_unpin_lock(rq, rf);
1413 raw_spin_unlock_irqrestore(&rq->lock, rf->flags);
1414 }
1415
rq_unlock_irq(struct rq * rq,struct rq_flags * rf)1416 static inline void rq_unlock_irq(struct rq *rq, struct rq_flags *rf) __releases(rq->lock)
1417 {
1418 rq_unpin_lock(rq, rf);
1419 raw_spin_unlock_irq(&rq->lock);
1420 }
1421
rq_unlock(struct rq * rq,struct rq_flags * rf)1422 static inline void rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock)
1423 {
1424 rq_unpin_lock(rq, rf);
1425 raw_spin_unlock(&rq->lock);
1426 }
1427
this_rq_lock_irq(struct rq_flags * rf)1428 static inline struct rq *this_rq_lock_irq(struct rq_flags *rf) __acquires(rq->lock)
1429 {
1430 struct rq *rq;
1431
1432 local_irq_disable();
1433 rq = this_rq();
1434 rq_lock(rq, rf);
1435 return rq;
1436 }
1437
1438 #ifdef CONFIG_NUMA
1439 enum numa_topology_type {
1440 NUMA_DIRECT,
1441 NUMA_GLUELESS_MESH,
1442 NUMA_BACKPLANE,
1443 };
1444 extern enum numa_topology_type sched_numa_topology_type;
1445 extern int sched_max_numa_distance;
1446 extern bool find_numa_distance(int distance);
1447 extern void sched_init_numa(void);
1448 extern void sched_domains_numa_masks_set(unsigned int cpu);
1449 extern void sched_domains_numa_masks_clear(unsigned int cpu);
1450 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
1451 #else
sched_init_numa(void)1452 static inline void sched_init_numa(void)
1453 {
1454 }
sched_domains_numa_masks_set(unsigned int cpu)1455 static inline void sched_domains_numa_masks_set(unsigned int cpu)
1456 {
1457 }
sched_domains_numa_masks_clear(unsigned int cpu)1458 static inline void sched_domains_numa_masks_clear(unsigned int cpu)
1459 {
1460 }
sched_numa_find_closest(const struct cpumask * cpus,int cpu)1461 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
1462 {
1463 return nr_cpu_ids;
1464 }
1465 #endif
1466
1467 #ifdef CONFIG_NUMA_BALANCING
1468 /* The regions in numa_faults array from task_struct */
1469 enum numa_faults_stats { NUMA_MEM = 0, NUMA_CPU, NUMA_MEMBUF, NUMA_CPUBUF };
1470 extern void sched_setnuma(struct task_struct *p, int node);
1471 extern int migrate_task_to(struct task_struct *p, int cpu);
1472 extern int migrate_swap(struct task_struct *p, struct task_struct *t, int cpu, int scpu);
1473 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
1474 #else
init_numa_balancing(unsigned long clone_flags,struct task_struct * p)1475 static inline void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
1476 {
1477 }
1478 #endif /* CONFIG_NUMA_BALANCING */
1479
1480 #ifdef CONFIG_SMP
1481
queue_balance_callback(struct rq * rq,struct callback_head * head,void (* func)(struct rq * rq))1482 static inline void queue_balance_callback(struct rq *rq, struct callback_head *head, void (*func)(struct rq *rq))
1483 {
1484 lockdep_assert_held(&rq->lock);
1485
1486 if (unlikely(head->next)) {
1487 return;
1488 }
1489
1490 head->func = (void (*)(struct callback_head *))func;
1491 head->next = rq->balance_callback;
1492 rq->balance_callback = head;
1493 }
1494
1495 #define rcu_dereference_check_sched_domain(p) rcu_dereference_check((p), lockdep_is_held(&sched_domains_mutex))
1496
1497 /*
1498 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
1499 * See destroy_sched_domains: call_rcu for details.
1500 *
1501 * The domain tree of any CPU may only be accessed from within
1502 * preempt-disabled sections.
1503 */
1504 #define for_each_domain(cpu, __sd) \
1505 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
1506
1507 /**
1508 * highest_flag_domain - Return highest sched_domain containing flag.
1509 * @cpu: The CPU whose highest level of sched domain is to
1510 * be returned.
1511 * @flag: The flag to check for the highest sched_domain
1512 * for the given CPU.
1513 *
1514 * Returns the highest sched_domain of a CPU which contains the given flag.
1515 */
highest_flag_domain(int cpu,int flag)1516 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
1517 {
1518 struct sched_domain *sd, *hsd = NULL;
1519
1520 for (sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); sd; sd = sd->parent) {
1521 if (!(sd->flags & flag)) {
1522 break;
1523 }
1524 hsd = sd;
1525 }
1526
1527 return hsd;
1528 }
1529
lowest_flag_domain(int cpu,int flag)1530 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
1531 {
1532 struct sched_domain *sd;
1533
1534 for (sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); sd; sd = sd->parent) {
1535 if (sd->flags & flag) {
1536 break;
1537 }
1538 }
1539
1540 return sd;
1541 }
1542
1543 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);
1544 DECLARE_PER_CPU(int, sd_llc_size);
1545 DECLARE_PER_CPU(int, sd_llc_id);
1546 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
1547 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);
1548 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
1549 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
1550 extern struct static_key_false sched_asym_cpucapacity;
1551
1552 struct sched_group_capacity {
1553 atomic_t ref;
1554 /*
1555 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
1556 * for a single CPU.
1557 */
1558 unsigned long capacity;
1559 unsigned long min_capacity; /* Min per-CPU capacity in group */
1560 unsigned long max_capacity; /* Max per-CPU capacity in group */
1561 unsigned long next_update;
1562 int imbalance; /* XXX unrelated to capacity but shared group state */
1563
1564 #ifdef CONFIG_SCHED_DEBUG
1565 int id;
1566 #endif
1567
1568 unsigned long cpumask[]; /* Balance mask */
1569 };
1570
1571 struct sched_group {
1572 struct sched_group *next; /* Must be a circular list */
1573 atomic_t ref;
1574
1575 unsigned int group_weight;
1576 struct sched_group_capacity *sgc;
1577 int asym_prefer_cpu; /* CPU of highest priority in group */
1578
1579 /*
1580 * The CPUs this group covers.
1581 *
1582 * NOTE: this field is variable length. (Allocated dynamically
1583 * by attaching extra space to the end of the structure,
1584 * depending on how many CPUs the kernel has booted up with)
1585 */
1586 unsigned long cpumask[];
1587 };
1588
sched_group_span(struct sched_group * sg)1589 static inline struct cpumask *sched_group_span(struct sched_group *sg)
1590 {
1591 return to_cpumask(sg->cpumask);
1592 }
1593
1594 /*
1595 * See build_balance_mask().
1596 */
group_balance_mask(struct sched_group * sg)1597 static inline struct cpumask *group_balance_mask(struct sched_group *sg)
1598 {
1599 return to_cpumask(sg->sgc->cpumask);
1600 }
1601
1602 /**
1603 * group_first_cpu - Returns the first CPU in the cpumask of a sched_group.
1604 * @group: The group whose first CPU is to be returned.
1605 */
group_first_cpu(struct sched_group * group)1606 static inline unsigned int group_first_cpu(struct sched_group *group)
1607 {
1608 return cpumask_first(sched_group_span(group));
1609 }
1610
1611 extern int group_balance_cpu(struct sched_group *sg);
1612
1613 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
1614 void register_sched_domain_sysctl(void);
1615 void dirty_sched_domain_sysctl(int cpu);
1616 void unregister_sched_domain_sysctl(void);
1617 #else
register_sched_domain_sysctl(void)1618 static inline void register_sched_domain_sysctl(void)
1619 {
1620 }
dirty_sched_domain_sysctl(int cpu)1621 static inline void dirty_sched_domain_sysctl(int cpu)
1622 {
1623 }
unregister_sched_domain_sysctl(void)1624 static inline void unregister_sched_domain_sysctl(void)
1625 {
1626 }
1627 #endif
1628
1629 extern void flush_smp_call_function_from_idle(void);
1630
1631 #else /* !CONFIG_SMP: */
flush_smp_call_function_from_idle(void)1632 static inline void flush_smp_call_function_from_idle(void)
1633 {
1634 }
1635 #endif
1636
1637 #include "stats.h"
1638 #include "autogroup.h"
1639
1640 #ifdef CONFIG_CGROUP_SCHED
1641
1642 /*
1643 * Return the group to which this tasks belongs.
1644 *
1645 * We cannot use task_css() and friends because the cgroup subsystem
1646 * changes that value before the cgroup_subsys::attach() method is called,
1647 * therefore we cannot pin it and might observe the wrong value.
1648 *
1649 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
1650 * core changes this before calling sched_move_task().
1651 *
1652 * Instead we use a 'copy' which is updated from sched_move_task() while
1653 * holding both task_struct::pi_lock and rq::lock.
1654 */
task_group(struct task_struct * p)1655 static inline struct task_group *task_group(struct task_struct *p)
1656 {
1657 return p->sched_task_group;
1658 }
1659
1660 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
set_task_rq(struct task_struct * p,unsigned int cpu)1661 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
1662 {
1663 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
1664 struct task_group *tg = task_group(p);
1665 #endif
1666
1667 #ifdef CONFIG_FAIR_GROUP_SCHED
1668 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
1669 p->se.cfs_rq = tg->cfs_rq[cpu];
1670 p->se.parent = tg->se[cpu];
1671 #endif
1672
1673 #ifdef CONFIG_RT_GROUP_SCHED
1674 p->rt.rt_rq = tg->rt_rq[cpu];
1675 p->rt.parent = tg->rt_se[cpu];
1676 #endif
1677 }
1678
1679 #else /* CONFIG_CGROUP_SCHED */
1680
set_task_rq(struct task_struct * p,unsigned int cpu)1681 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
1682 {
1683 }
task_group(struct task_struct * p)1684 static inline struct task_group *task_group(struct task_struct *p)
1685 {
1686 return NULL;
1687 }
1688
1689 #endif /* CONFIG_CGROUP_SCHED */
1690
__set_task_cpu(struct task_struct * p,unsigned int cpu)1691 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
1692 {
1693 set_task_rq(p, cpu);
1694 #ifdef CONFIG_SMP
1695 /*
1696 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
1697 * successfully executed on another CPU. We must ensure that updates of
1698 * per-task data have been completed by this moment.
1699 */
1700 smp_wmb();
1701 #ifdef CONFIG_THREAD_INFO_IN_TASK
1702 WRITE_ONCE(p->cpu, cpu);
1703 #else
1704 WRITE_ONCE(task_thread_info(p)->cpu, cpu);
1705 #endif
1706 p->wake_cpu = cpu;
1707 #endif
1708 }
1709
1710 /*
1711 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
1712 */
1713 #ifdef CONFIG_SCHED_DEBUG
1714 #include <linux/static_key.h>
1715 #define const_debug __read_mostly
1716 #else
1717 #define const_debug const
1718 #endif
1719
1720 #define SCHED_FEAT(name, enabled) __SCHED_FEAT_##name,
1721
1722 enum {
1723 #include "features.h"
1724 __SCHED_FEAT_NR,
1725 };
1726
1727 #undef SCHED_FEAT
1728
1729 #ifdef CONFIG_SCHED_DEBUG
1730
1731 /*
1732 * To support run-time toggling of sched features, all the translation units
1733 * (but core.c) reference the sysctl_sched_features defined in core.c.
1734 */
1735 extern const_debug unsigned int sysctl_sched_features;
1736
1737 #ifdef CONFIG_JUMP_LABEL
1738 #define SCHED_FEAT(name, enabled) \
1739 static __always_inline bool static_branch_##name(struct static_key *key) \
1740 { \
1741 return static_key_##enabled(key); \
1742 }
1743
1744 #include "features.h"
1745 #undef SCHED_FEAT
1746
1747 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1748 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1749
1750 #else /* !CONFIG_JUMP_LABEL */
1751
1752 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1753
1754 #endif /* CONFIG_JUMP_LABEL */
1755
1756 #else /* !SCHED_DEBUG */
1757
1758 /*
1759 * Each translation unit has its own copy of sysctl_sched_features to allow
1760 * constants propagation at compile time and compiler optimization based on
1761 * features default.
1762 */
1763 #define SCHED_FEAT(name, enabled) (1UL << __SCHED_FEAT_##name) * (enabled) |
1764 static const_debug __maybe_unused unsigned int sysctl_sched_features =
1765 #include "features.h"
1766 0;
1767 #undef SCHED_FEAT
1768
1769 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1770
1771 #endif /* SCHED_DEBUG */
1772
1773 extern struct static_key_false sched_numa_balancing;
1774 extern struct static_key_false sched_schedstats;
1775
global_rt_period(void)1776 static inline u64 global_rt_period(void)
1777 {
1778 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1779 }
1780
global_rt_runtime(void)1781 static inline u64 global_rt_runtime(void)
1782 {
1783 if (sysctl_sched_rt_runtime < 0) {
1784 return RUNTIME_INF;
1785 }
1786
1787 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1788 }
1789
task_current(struct rq * rq,struct task_struct * p)1790 static inline int task_current(struct rq *rq, struct task_struct *p)
1791 {
1792 return rq->curr == p;
1793 }
1794
task_running(struct rq * rq,struct task_struct * p)1795 static inline int task_running(struct rq *rq, struct task_struct *p)
1796 {
1797 #ifdef CONFIG_SMP
1798 return p->on_cpu;
1799 #else
1800 return task_current(rq, p);
1801 #endif
1802 }
1803
task_on_rq_queued(struct task_struct * p)1804 static inline int task_on_rq_queued(struct task_struct *p)
1805 {
1806 return p->on_rq == TASK_ON_RQ_QUEUED;
1807 }
1808
task_on_rq_migrating(struct task_struct * p)1809 static inline int task_on_rq_migrating(struct task_struct *p)
1810 {
1811 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
1812 }
1813
1814 /*
1815 * wake flags
1816 */
1817 #define WF_SYNC 0x01 /* Waker goes to sleep after wakeup */
1818 #define WF_FORK 0x02 /* Child wakeup after fork */
1819 #define WF_MIGRATED 0x04 /* Internal use, task got migrated */
1820 #define WF_ON_CPU 0x08 /* Wakee is on_cpu */
1821
1822 /*
1823 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1824 * of tasks with abnormal "nice" values across CPUs the contribution that
1825 * each task makes to its run queue's load is weighted according to its
1826 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1827 * scaled version of the new time slice allocation that they receive on time
1828 * slice expiry etc.
1829 */
1830
1831 #define WEIGHT_IDLEPRIO 3
1832 #define WMULT_IDLEPRIO 1431655765
1833
1834 extern const int sched_prio_to_weight[40];
1835 extern const u32 sched_prio_to_wmult[40];
1836 #ifdef CONFIG_SCHED_LATENCY_NICE
1837 extern const int sched_latency_to_weight[40];
1838 #endif
1839
1840 /*
1841 * {de,en}queue flags:
1842 *
1843 * DEQUEUE_SLEEP - task is no longer runnable
1844 * ENQUEUE_WAKEUP - task just became runnable
1845 *
1846 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
1847 * are in a known state which allows modification. Such pairs
1848 * should preserve as much state as possible.
1849 *
1850 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
1851 * in the runqueue.
1852 *
1853 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
1854 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
1855 * ENQUEUE_MIGRATED - the task was migrated during wakeup
1856 *
1857 */
1858
1859 #define DEQUEUE_SLEEP 0x01
1860 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */
1861 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */
1862 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */
1863
1864 #define ENQUEUE_WAKEUP 0x01
1865 #define ENQUEUE_RESTORE 0x02
1866 #define ENQUEUE_MOVE 0x04
1867 #define ENQUEUE_NOCLOCK 0x08
1868
1869 #define ENQUEUE_HEAD 0x10
1870 #define ENQUEUE_REPLENISH 0x20
1871 #ifdef CONFIG_SMP
1872 #define ENQUEUE_MIGRATED 0x40
1873 #else
1874 #define ENQUEUE_MIGRATED 0x00
1875 #endif
1876
1877 #define ENQUEUE_WAKEUP_SYNC 0x80
1878
1879 #define RETRY_TASK ((void *)-1UL)
1880
1881 struct sched_class {
1882 #ifdef CONFIG_UCLAMP_TASK
1883 int uclamp_enabled;
1884 #endif
1885
1886 void (*enqueue_task)(struct rq *rq, struct task_struct *p, int flags);
1887 void (*dequeue_task)(struct rq *rq, struct task_struct *p, int flags);
1888 void (*yield_task)(struct rq *rq);
1889 bool (*yield_to_task)(struct rq *rq, struct task_struct *p);
1890
1891 void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
1892
1893 struct task_struct *(*pick_next_task)(struct rq *rq);
1894
1895 void (*put_prev_task)(struct rq *rq, struct task_struct *p);
1896 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
1897
1898 #ifdef CONFIG_SMP
1899 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
1900 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1901 void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
1902
1903 void (*task_woken)(struct rq *this_rq, struct task_struct *task);
1904
1905 void (*set_cpus_allowed)(struct task_struct *p, const struct cpumask *newmask);
1906
1907 void (*rq_online)(struct rq *rq);
1908 void (*rq_offline)(struct rq *rq);
1909 #endif
1910
1911 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued);
1912 void (*task_fork)(struct task_struct *p);
1913 void (*task_dead)(struct task_struct *p);
1914
1915 /*
1916 * The switched_from() call is allowed to drop rq->lock, therefore we
1917 * cannot assume the switched_from/switched_to pair is serliazed by
1918 * rq->lock. They are however serialized by p->pi_lock.
1919 */
1920 void (*switched_from)(struct rq *this_rq, struct task_struct *task);
1921 void (*switched_to)(struct rq *this_rq, struct task_struct *task);
1922 void (*prio_changed)(struct rq *this_rq, struct task_struct *task, int oldprio);
1923
1924 unsigned int (*get_rr_interval)(struct rq *rq, struct task_struct *task);
1925
1926 void (*update_curr)(struct rq *rq);
1927
1928 #define TASK_SET_GROUP 0
1929 #define TASK_MOVE_GROUP 1
1930
1931 #ifdef CONFIG_FAIR_GROUP_SCHED
1932 void (*task_change_group)(struct task_struct *p, int type);
1933 #endif
1934 #ifdef CONFIG_SCHED_WALT
1935 void (*fixup_walt_sched_stats)(struct rq *rq, struct task_struct *p, u16 updated_demand_scaled);
1936 #endif
1937 #ifdef CONFIG_SCHED_EAS
1938 void (*check_for_migration)(struct rq *rq, struct task_struct *p);
1939 #endif
1940 } __aligned(STRUCT_ALIGNMENT); /* STRUCT_ALIGN(), vmlinux.lds.h */
1941
put_prev_task(struct rq * rq,struct task_struct * prev)1942 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1943 {
1944 WARN_ON_ONCE(rq->curr != prev);
1945 prev->sched_class->put_prev_task(rq, prev);
1946 }
1947
set_next_task(struct rq * rq,struct task_struct * next)1948 static inline void set_next_task(struct rq *rq, struct task_struct *next)
1949 {
1950 WARN_ON_ONCE(rq->curr != next);
1951 next->sched_class->set_next_task(rq, next, false);
1952 }
1953
1954 /* Defined in include/asm-generic/vmlinux.lds.h */
1955 extern struct sched_class __begin_sched_classes[];
1956 extern struct sched_class __end_sched_classes[];
1957
1958 #define sched_class_highest (__end_sched_classes - 1)
1959 #define sched_class_lowest (__begin_sched_classes - 1)
1960
1961 #define for_class_range(class, _from, _to) for (class = (_from); class != (_to); (class)--)
1962
1963 #define for_each_class(class) for_class_range(class, sched_class_highest, sched_class_lowest)
1964
1965 extern const struct sched_class stop_sched_class;
1966 extern const struct sched_class dl_sched_class;
1967 extern const struct sched_class rt_sched_class;
1968 extern const struct sched_class fair_sched_class;
1969 extern const struct sched_class idle_sched_class;
1970
sched_stop_runnable(struct rq * rq)1971 static inline bool sched_stop_runnable(struct rq *rq)
1972 {
1973 return rq->stop && task_on_rq_queued(rq->stop);
1974 }
1975
sched_dl_runnable(struct rq * rq)1976 static inline bool sched_dl_runnable(struct rq *rq)
1977 {
1978 return rq->dl.dl_nr_running > 0;
1979 }
1980
sched_rt_runnable(struct rq * rq)1981 static inline bool sched_rt_runnable(struct rq *rq)
1982 {
1983 return rq->rt.rt_queued > 0;
1984 }
1985
sched_fair_runnable(struct rq * rq)1986 static inline bool sched_fair_runnable(struct rq *rq)
1987 {
1988 return rq->cfs.nr_running > 0;
1989 }
1990
1991 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
1992 extern struct task_struct *pick_next_task_idle(struct rq *rq);
1993
1994 #ifdef CONFIG_SMP
1995
1996 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1997
1998 extern void trigger_load_balance(struct rq *rq);
1999
2000 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
2001
2002 #endif
2003
2004 #ifdef CONFIG_CPU_IDLE
idle_set_state(struct rq * rq,struct cpuidle_state * idle_state)2005 static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state)
2006 {
2007 rq->idle_state = idle_state;
2008 }
2009
idle_get_state(struct rq * rq)2010 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
2011 {
2012 SCHED_WARN_ON(!rcu_read_lock_held());
2013
2014 return rq->idle_state;
2015 }
2016 #else
idle_set_state(struct rq * rq,struct cpuidle_state * idle_state)2017 static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state)
2018 {
2019 }
2020
idle_get_state(struct rq * rq)2021 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
2022 {
2023 return NULL;
2024 }
2025 #endif
2026
2027 extern void schedule_idle(void);
2028
2029 extern void sysrq_sched_debug_show(void);
2030 extern void sched_init_granularity(void);
2031 extern void update_max_interval(void);
2032
2033 extern void init_sched_dl_class(void);
2034 extern void init_sched_rt_class(void);
2035 extern void init_sched_fair_class(void);
2036
2037 extern void reweight_task(struct task_struct *p, int prio);
2038
2039 extern void resched_curr(struct rq *rq);
2040 extern void resched_cpu(int cpu);
2041
2042 extern struct rt_bandwidth def_rt_bandwidth;
2043 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
2044
2045 extern struct dl_bandwidth def_dl_bandwidth;
2046 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
2047 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
2048 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
2049
2050 #define BW_SHIFT 20
2051 #define BW_UNIT (1 << BW_SHIFT)
2052 #define RATIO_SHIFT 8
2053 #define MAX_BW_BITS (64 - BW_SHIFT)
2054 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1)
2055 unsigned long to_ratio(u64 period, u64 runtime);
2056
2057 extern void init_entity_runnable_average(struct sched_entity *se);
2058 extern void post_init_entity_util_avg(struct task_struct *p);
2059
2060 #ifdef CONFIG_NO_HZ_FULL
2061 extern bool sched_can_stop_tick(struct rq *rq);
2062 extern int __init sched_tick_offload_init(void);
2063
2064 /*
2065 * Tick may be needed by tasks in the runqueue depending on their policy and
2066 * requirements. If tick is needed, lets send the target an IPI to kick it out of
2067 * nohz mode if necessary.
2068 */
sched_update_tick_dependency(struct rq * rq)2069 static inline void sched_update_tick_dependency(struct rq *rq)
2070 {
2071 int cpu = cpu_of(rq);
2072 if (!tick_nohz_full_cpu(cpu)) {
2073 return;
2074 }
2075
2076 if (sched_can_stop_tick(rq)) {
2077 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
2078 } else {
2079 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
2080 }
2081 }
2082 #else
sched_tick_offload_init(void)2083 static inline int sched_tick_offload_init(void)
2084 {
2085 return 0;
2086 }
sched_update_tick_dependency(struct rq * rq)2087 static inline void sched_update_tick_dependency(struct rq *rq)
2088 {
2089 }
2090 #endif
2091
add_nr_running(struct rq * rq,unsigned count)2092 static inline void add_nr_running(struct rq *rq, unsigned count)
2093 {
2094 unsigned prev_nr = rq->nr_running;
2095
2096 rq->nr_running = prev_nr + count;
2097 if (trace_sched_update_nr_running_tp_enabled()) {
2098 call_trace_sched_update_nr_running(rq, count);
2099 }
2100
2101 #ifdef CONFIG_SMP
2102 if (prev_nr < TASK_ON_RQ_MIGRATING && rq->nr_running >= TASK_ON_RQ_MIGRATING) {
2103 if (!READ_ONCE(rq->rd->overload)) {
2104 WRITE_ONCE(rq->rd->overload, 1);
2105 }
2106 }
2107 #endif
2108
2109 sched_update_tick_dependency(rq);
2110 }
2111
sub_nr_running(struct rq * rq,unsigned count)2112 static inline void sub_nr_running(struct rq *rq, unsigned count)
2113 {
2114 rq->nr_running -= count;
2115 if (trace_sched_update_nr_running_tp_enabled()) {
2116 call_trace_sched_update_nr_running(rq, -count);
2117 }
2118
2119 /* Check if we still need preemption */
2120 sched_update_tick_dependency(rq);
2121 }
2122
2123 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
2124 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
2125
2126 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
2127
2128 extern const_debug unsigned int sysctl_sched_nr_migrate;
2129 extern const_debug unsigned int sysctl_sched_migration_cost;
2130
2131 #ifdef CONFIG_SCHED_HRTICK
2132
2133 /*
2134 * Use hrtick when:
2135 * - enabled by features
2136 * - hrtimer is actually high res
2137 */
hrtick_enabled(struct rq * rq)2138 static inline int hrtick_enabled(struct rq *rq)
2139 {
2140 if (!sched_feat(HRTICK)) {
2141 return 0;
2142 }
2143 if (!cpu_active(cpu_of(rq))) {
2144 return 0;
2145 }
2146 return hrtimer_is_hres_active(&rq->hrtick_timer);
2147 }
2148
2149 void hrtick_start(struct rq *rq, u64 delay);
2150
2151 #else
2152
hrtick_enabled(struct rq * rq)2153 static inline int hrtick_enabled(struct rq *rq)
2154 {
2155 return 0;
2156 }
2157
2158 #endif /* CONFIG_SCHED_HRTICK */
2159
2160 #ifdef CONFIG_SCHED_WALT
2161 u64 sched_ktime_clock(void);
2162 #else
sched_ktime_clock(void)2163 static inline u64 sched_ktime_clock(void)
2164 {
2165 return sched_clock();
2166 }
2167 #endif
2168
2169 #ifndef arch_scale_freq_tick
arch_scale_freq_tick(void)2170 static __always_inline void arch_scale_freq_tick(void)
2171 {
2172 }
2173 #endif
2174
2175 #ifndef arch_scale_freq_capacity
2176 /**
2177 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
2178 * @cpu: the CPU in question.
2179 *
2180 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e.
2181 *
2182 * f_curr
2183 * ------ * SCHED_CAPACITY_SCALE
2184 * f_max
2185 */
arch_scale_freq_capacity(int cpu)2186 static __always_inline unsigned long arch_scale_freq_capacity(int cpu)
2187 {
2188 return SCHED_CAPACITY_SCALE;
2189 }
2190 #endif
2191
2192 unsigned long capacity_curr_of(int cpu);
2193 unsigned long cpu_util(int cpu);
2194
2195 #ifdef CONFIG_SMP
2196 #ifdef CONFIG_SCHED_WALT
2197 extern unsigned int sysctl_sched_use_walt_cpu_util;
2198 extern unsigned int walt_disabled;
2199 #endif
2200 #ifdef CONFIG_PREEMPTION
2201
2202 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
2203
2204 /*
2205 * fair double_lock_balance: Safely acquires both rq->locks in a fair
2206 * way at the expense of forcing extra atomic operations in all
2207 * invocations. This assures that the double_lock is acquired using the
2208 * same underlying policy as the spinlock_t on this architecture, which
2209 * reduces latency compared to the unfair variant below. However, it
2210 * also adds more overhead and therefore may reduce throughput.
2211 */
_double_lock_balance(struct rq * this_rq,struct rq * busiest)2212 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __releases(this_rq->lock)
2213 __acquires(busiest->lock) __acquires(this_rq->lock)
2214 {
2215 raw_spin_unlock(&this_rq->lock);
2216 double_rq_lock(this_rq, busiest);
2217
2218 return 1;
2219 }
2220
2221 #else
2222 /*
2223 * Unfair double_lock_balance: Optimizes throughput at the expense of
2224 * latency by eliminating extra atomic operations when the locks are
2225 * already in proper order on entry. This favors lower CPU-ids and will
2226 * grant the double lock to lower CPUs over higher ids under contention,
2227 * regardless of entry order into the function.
2228 */
_double_lock_balance(struct rq * this_rq,struct rq * busiest)2229 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __releases(this_rq->lock)
2230 __acquires(busiest->lock) __acquires(this_rq->lock)
2231 {
2232 int ret = 0;
2233
2234 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
2235 if (busiest < this_rq) {
2236 raw_spin_unlock(&this_rq->lock);
2237 raw_spin_lock(&busiest->lock);
2238 raw_spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
2239 ret = 1;
2240 } else {
2241 raw_spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
2242 }
2243 }
2244 return ret;
2245 }
2246
2247 #endif /* CONFIG_PREEMPTION */
2248
2249 /*
2250 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
2251 */
double_lock_balance(struct rq * this_rq,struct rq * busiest)2252 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
2253 {
2254 if (unlikely(!irqs_disabled())) {
2255 /* printk() doesn't work well under rq->lock */
2256 raw_spin_unlock(&this_rq->lock);
2257 BUG_ON(1);
2258 }
2259
2260 return _double_lock_balance(this_rq, busiest);
2261 }
2262
double_unlock_balance(struct rq * this_rq,struct rq * busiest)2263 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) __releases(busiest->lock)
2264 {
2265 raw_spin_unlock(&busiest->lock);
2266 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
2267 }
2268
double_lock(spinlock_t * l1,spinlock_t * l2)2269 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
2270 {
2271 if (l1 > l2) {
2272 swap(l1, l2);
2273 }
2274
2275 spin_lock(l1);
2276 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2277 }
2278
double_lock_irq(spinlock_t * l1,spinlock_t * l2)2279 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
2280 {
2281 if (l1 > l2) {
2282 swap(l1, l2);
2283 }
2284
2285 spin_lock_irq(l1);
2286 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2287 }
2288
double_raw_lock(raw_spinlock_t * l1,raw_spinlock_t * l2)2289 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
2290 {
2291 if (l1 > l2) {
2292 swap(l1, l2);
2293 }
2294
2295 raw_spin_lock(l1);
2296 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2297 }
2298
2299 /*
2300 * double_rq_lock - safely lock two runqueues
2301 *
2302 * Note this does not disable interrupts like task_rq_lock,
2303 * you need to do so manually before calling.
2304 */
double_rq_lock(struct rq * rq1,struct rq * rq2)2305 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) __acquires(rq1->lock) __acquires(rq2->lock)
2306 {
2307 BUG_ON(!irqs_disabled());
2308 if (rq1 == rq2) {
2309 raw_spin_lock(&rq1->lock);
2310 __acquire(rq2->lock); /* Fake it out ;) */
2311 } else {
2312 if (rq1 < rq2) {
2313 raw_spin_lock(&rq1->lock);
2314 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
2315 } else {
2316 raw_spin_lock(&rq2->lock);
2317 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
2318 }
2319 }
2320 }
2321
2322 /*
2323 * double_rq_unlock - safely unlock two runqueues
2324 *
2325 * Note this does not restore interrupts like task_rq_unlock,
2326 * you need to do so manually after calling.
2327 */
double_rq_unlock(struct rq * rq1,struct rq * rq2)2328 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq1->lock) __releases(rq2->lock)
2329 {
2330 raw_spin_unlock(&rq1->lock);
2331 if (rq1 != rq2) {
2332 raw_spin_unlock(&rq2->lock);
2333 } else {
2334 __release(rq2->lock);
2335 }
2336 }
2337
2338 extern void set_rq_online(struct rq *rq);
2339 extern void set_rq_offline(struct rq *rq);
2340 extern bool sched_smp_initialized;
2341
2342 #else /* CONFIG_SMP */
2343
2344 /*
2345 * double_rq_lock - safely lock two runqueues
2346 *
2347 * Note this does not disable interrupts like task_rq_lock,
2348 * you need to do so manually before calling.
2349 */
double_rq_lock(struct rq * rq1,struct rq * rq2)2350 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) __acquires(rq1->lock) __acquires(rq2->lock)
2351 {
2352 BUG_ON(!irqs_disabled());
2353 BUG_ON(rq1 != rq2);
2354 raw_spin_lock(&rq1->lock);
2355 __acquire(rq2->lock); /* Fake it out ;) */
2356 }
2357
2358 /*
2359 * double_rq_unlock - safely unlock two runqueues
2360 *
2361 * Note this does not restore interrupts like task_rq_unlock,
2362 * you need to do so manually after calling.
2363 */
double_rq_unlock(struct rq * rq1,struct rq * rq2)2364 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq1->lock) __releases(rq2->lock)
2365 {
2366 BUG_ON(rq1 != rq2);
2367 raw_spin_unlock(&rq1->lock);
2368 __release(rq2->lock);
2369 }
2370
2371 #endif
2372
2373 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
2374 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
2375
2376 #ifdef CONFIG_SCHED_DEBUG
2377 extern bool sched_debug_enabled;
2378
2379 extern void print_cfs_stats(struct seq_file *m, int cpu);
2380 extern void print_rt_stats(struct seq_file *m, int cpu);
2381 extern void print_dl_stats(struct seq_file *m, int cpu);
2382 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
2383 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
2384 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
2385 #ifdef CONFIG_NUMA_BALANCING
2386 extern void show_numa_stats(struct task_struct *p, struct seq_file *m);
2387 extern void print_numa_stats(struct seq_file *m, int node, unsigned long tsf, unsigned long tpf, unsigned long gsf,
2388 unsigned long gpf);
2389 #endif /* CONFIG_NUMA_BALANCING */
2390 #endif /* CONFIG_SCHED_DEBUG */
2391
2392 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
2393 extern void init_rt_rq(struct rt_rq *rt_rq);
2394 extern void init_dl_rq(struct dl_rq *dl_rq);
2395
2396 extern void cfs_bandwidth_usage_inc(void);
2397 extern void cfs_bandwidth_usage_dec(void);
2398
2399 #ifdef CONFIG_NO_HZ_COMMON
2400 #define NOHZ_BALANCE_KICK_BIT 0
2401 #define NOHZ_STATS_KICK_BIT 1
2402
2403 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT)
2404 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT)
2405
2406 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK)
2407
2408 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
2409
2410 extern void nohz_balance_exit_idle(struct rq *rq);
2411 #else
nohz_balance_exit_idle(struct rq * rq)2412 static inline void nohz_balance_exit_idle(struct rq *rq)
2413 {
2414 }
2415 #endif
2416
2417 #ifdef CONFIG_SMP
__dl_update(struct dl_bw * dl_b,s64 bw)2418 static inline void __dl_update(struct dl_bw *dl_b, s64 bw)
2419 {
2420 struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw);
2421 int i;
2422
2423 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), "sched RCU must be held");
2424 for_each_cpu_and(i, rd->span, cpu_active_mask)
2425 {
2426 struct rq *rq = cpu_rq(i);
2427
2428 rq->dl.extra_bw += bw;
2429 }
2430 }
2431 #else
__dl_update(struct dl_bw * dl_b,s64 bw)2432 static inline void __dl_update(struct dl_bw *dl_b, s64 bw)
2433 {
2434 struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw);
2435
2436 dl->extra_bw += bw;
2437 }
2438 #endif
2439
2440 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2441 struct irqtime {
2442 u64 total;
2443 u64 tick_delta;
2444 u64 irq_start_time;
2445 struct u64_stats_sync sync;
2446 };
2447
2448 DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
2449
2450 /*
2451 * Returns the irqtime minus the softirq time computed by ksoftirqd.
2452 * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime
2453 * and never move forward.
2454 */
irq_time_read(int cpu)2455 static inline u64 irq_time_read(int cpu)
2456 {
2457 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
2458 unsigned int seq;
2459 u64 total;
2460
2461 do {
2462 seq = __u64_stats_fetch_begin(&irqtime->sync);
2463 total = irqtime->total;
2464 } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
2465
2466 return total;
2467 }
2468 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
2469
2470 #ifdef CONFIG_CPU_FREQ
2471 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
2472
2473 /**
2474 * cpufreq_update_util - Take a note about CPU utilization changes.
2475 * @rq: Runqueue to carry out the update for.
2476 * @flags: Update reason flags.
2477 *
2478 * This function is called by the scheduler on the CPU whose utilization is
2479 * being updated.
2480 *
2481 * It can only be called from RCU-sched read-side critical sections.
2482 *
2483 * The way cpufreq is currently arranged requires it to evaluate the CPU
2484 * performance state (frequency/voltage) on a regular basis to prevent it from
2485 * being stuck in a completely inadequate performance level for too long.
2486 * That is not guaranteed to happen if the updates are only triggered from CFS
2487 * and DL, though, because they may not be coming in if only RT tasks are
2488 * active all the time (or there are RT tasks only).
2489 *
2490 * As a workaround for that issue, this function is called periodically by the
2491 * RT sched class to trigger extra cpufreq updates to prevent it from stalling,
2492 * but that really is a band-aid. Going forward it should be replaced with
2493 * solutions targeted more specifically at RT tasks.
2494 */
cpufreq_update_util(struct rq * rq,unsigned int flags)2495 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
2496 {
2497 struct update_util_data *data;
2498 u64 clock;
2499
2500 #ifdef CONFIG_SCHED_WALT
2501 if (!(flags & SCHED_CPUFREQ_WALT)) {
2502 return;
2503 }
2504
2505 clock = sched_ktime_clock();
2506 #else
2507 clock = rq_clock(rq);
2508 #endif
2509 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, cpu_of(rq)));
2510 if (data) {
2511 data->func(data, clock, flags);
2512 }
2513 }
2514 #else
cpufreq_update_util(struct rq * rq,unsigned int flags)2515 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
2516 {
2517 }
2518 #endif /* CONFIG_CPU_FREQ */
2519
2520 #ifdef CONFIG_UCLAMP_TASK
2521 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
2522
2523 /**
2524 * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values.
2525 * @rq: The rq to clamp against. Must not be NULL.
2526 * @util: The util value to clamp.
2527 * @p: The task to clamp against. Can be NULL if you want to clamp
2528 * against @rq only.
2529 *
2530 * Clamps the passed @util to the max(@rq, @p) effective uclamp values.
2531 *
2532 * If sched_uclamp_used static key is disabled, then just return the util
2533 * without any clamping since uclamp aggregation at the rq level in the fast
2534 * path is disabled, rendering this operation a NOP.
2535 *
2536 * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It
2537 * will return the correct effective uclamp value of the task even if the
2538 * static key is disabled.
2539 */
uclamp_rq_util_with(struct rq * rq,unsigned long util,struct task_struct * p)2540 static __always_inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, struct task_struct *p)
2541 {
2542 unsigned long min_util = 0;
2543 unsigned long max_util = 0;
2544
2545 if (!static_branch_likely(&sched_uclamp_used)) {
2546 return util;
2547 }
2548
2549 if (p) {
2550 min_util = uclamp_eff_value(p, UCLAMP_MIN);
2551 max_util = uclamp_eff_value(p, UCLAMP_MAX);
2552
2553 /*
2554 * Ignore last runnable task's max clamp, as this task will
2555 * reset it. Similarly, no need to read the rq's min clamp.
2556 */
2557 if (rq->uclamp_flags & UCLAMP_FLAG_IDLE) {
2558 goto out;
2559 }
2560 }
2561
2562 min_util = max_t(unsigned long, min_util, READ_ONCE(rq->uclamp[UCLAMP_MIN].value));
2563 max_util = max_t(unsigned long, max_util, READ_ONCE(rq->uclamp[UCLAMP_MAX].value));
2564 out:
2565 /*
2566 * Since CPU's {min,max}_util clamps are MAX aggregated considering
2567 * RUNNABLE tasks with _different_ clamps, we can end up with an
2568 * inversion. Fix it now when the clamps are applied.
2569 */
2570 if (unlikely(min_util >= max_util)) {
2571 return min_util;
2572 }
2573
2574 return clamp(util, min_util, max_util);
2575 }
2576
uclamp_boosted(struct task_struct * p)2577 static inline bool uclamp_boosted(struct task_struct *p)
2578 {
2579 return uclamp_eff_value(p, UCLAMP_MIN) > 0;
2580 }
2581
2582 /*
2583 * When uclamp is compiled in, the aggregation at rq level is 'turned off'
2584 * by default in the fast path and only gets turned on once userspace performs
2585 * an operation that requires it.
2586 *
2587 * Returns true if userspace opted-in to use uclamp and aggregation at rq level
2588 * hence is active.
2589 */
uclamp_is_used(void)2590 static inline bool uclamp_is_used(void)
2591 {
2592 return static_branch_likely(&sched_uclamp_used);
2593 }
2594 #else /* CONFIG_UCLAMP_TASK */
uclamp_rq_util_with(struct rq * rq,unsigned long util,struct task_struct * p)2595 static inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, struct task_struct *p)
2596 {
2597 return util;
2598 }
2599
uclamp_boosted(struct task_struct * p)2600 static inline bool uclamp_boosted(struct task_struct *p)
2601 {
2602 return false;
2603 }
2604
uclamp_is_used(void)2605 static inline bool uclamp_is_used(void)
2606 {
2607 return false;
2608 }
2609 #endif /* CONFIG_UCLAMP_TASK */
2610
2611 #ifdef arch_scale_freq_capacity
2612 #ifndef arch_scale_freq_invariant
2613 #define arch_scale_freq_invariant() true
2614 #endif
2615 #else
2616 #define arch_scale_freq_invariant() false
2617 #endif
2618
2619 #ifdef CONFIG_SMP
capacity_of(int cpu)2620 static inline unsigned long capacity_of(int cpu)
2621 {
2622 return cpu_rq(cpu)->cpu_capacity;
2623 }
2624
capacity_orig_of(int cpu)2625 static inline unsigned long capacity_orig_of(int cpu)
2626 {
2627 return cpu_rq(cpu)->cpu_capacity_orig;
2628 }
2629 #endif
2630
2631 /**
2632 * enum schedutil_type - CPU utilization type
2633 * @FREQUENCY_UTIL: Utilization used to select frequency
2634 * @ENERGY_UTIL: Utilization used during energy calculation
2635 *
2636 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
2637 * need to be aggregated differently depending on the usage made of them. This
2638 * enum is used within schedutil_freq_util() to differentiate the types of
2639 * utilization expected by the callers, and adjust the aggregation accordingly.
2640 */
2641 enum schedutil_type {
2642 FREQUENCY_UTIL,
2643 ENERGY_UTIL,
2644 };
2645
2646 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
2647
2648 unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs, unsigned long max, enum schedutil_type type,
2649 struct task_struct *p);
2650
cpu_bw_dl(struct rq * rq)2651 static inline unsigned long cpu_bw_dl(struct rq *rq)
2652 {
2653 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
2654 }
2655
cpu_util_dl(struct rq * rq)2656 static inline unsigned long cpu_util_dl(struct rq *rq)
2657 {
2658 return READ_ONCE(rq->avg_dl.util_avg);
2659 }
2660
cpu_util_cfs(struct rq * rq)2661 static inline unsigned long cpu_util_cfs(struct rq *rq)
2662 {
2663 unsigned long util = READ_ONCE(rq->cfs.avg.util_avg);
2664
2665 if (sched_feat(UTIL_EST)) {
2666 util = max_t(unsigned long, util, READ_ONCE(rq->cfs.avg.util_est.enqueued));
2667 }
2668
2669 return util;
2670 }
2671
cpu_util_rt(struct rq * rq)2672 static inline unsigned long cpu_util_rt(struct rq *rq)
2673 {
2674 return READ_ONCE(rq->avg_rt.util_avg);
2675 }
2676 #else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
schedutil_cpu_util(int cpu,unsigned long util_cfs,unsigned long max,enum schedutil_type type,struct task_struct * p)2677 static inline unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs, unsigned long max,
2678 enum schedutil_type type, struct task_struct *p)
2679 {
2680 return 0;
2681 }
2682 #endif /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
2683
2684 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
cpu_util_irq(struct rq * rq)2685 static inline unsigned long cpu_util_irq(struct rq *rq)
2686 {
2687 return rq->avg_irq.util_avg;
2688 }
2689
scale_irq_capacity(unsigned long util,unsigned long irq,unsigned long max)2690 static inline unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
2691 {
2692 util *= (max - irq);
2693 util /= max;
2694
2695 return util;
2696 }
2697 #else
cpu_util_irq(struct rq * rq)2698 static inline unsigned long cpu_util_irq(struct rq *rq)
2699 {
2700 return 0;
2701 }
2702
scale_irq_capacity(unsigned long util,unsigned long irq,unsigned long max)2703 static inline unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
2704 {
2705 return util;
2706 }
2707 #endif
2708
2709 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
2710
2711 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
2712
2713 DECLARE_STATIC_KEY_FALSE(sched_energy_present);
2714
sched_energy_enabled(void)2715 static inline bool sched_energy_enabled(void)
2716 {
2717 return static_branch_unlikely(&sched_energy_present);
2718 }
2719
2720 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */
2721
2722 #define perf_domain_span(pd) NULL
sched_energy_enabled(void)2723 static inline bool sched_energy_enabled(void)
2724 {
2725 return false;
2726 }
2727
2728 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
2729
2730 #ifdef CONFIG_MEMBARRIER
2731 /*
2732 * The scheduler provides memory barriers required by membarrier between:
2733 * - prior user-space memory accesses and store to rq->membarrier_state,
2734 * - store to rq->membarrier_state and following user-space memory accesses.
2735 * In the same way it provides those guarantees around store to rq->curr.
2736 */
membarrier_switch_mm(struct rq * rq,struct mm_struct * prev_mm,struct mm_struct * next_mm)2737 static inline void membarrier_switch_mm(struct rq *rq, struct mm_struct *prev_mm, struct mm_struct *next_mm)
2738 {
2739 int membarrier_state;
2740
2741 if (prev_mm == next_mm) {
2742 return;
2743 }
2744
2745 membarrier_state = atomic_read(&next_mm->membarrier_state);
2746 if (READ_ONCE(rq->membarrier_state) == membarrier_state) {
2747 return;
2748 }
2749
2750 WRITE_ONCE(rq->membarrier_state, membarrier_state);
2751 }
2752 #else
membarrier_switch_mm(struct rq * rq,struct mm_struct * prev_mm,struct mm_struct * next_mm)2753 static inline void membarrier_switch_mm(struct rq *rq, struct mm_struct *prev_mm, struct mm_struct *next_mm)
2754 {
2755 }
2756 #endif
2757
2758 #ifdef CONFIG_SMP
is_per_cpu_kthread(struct task_struct * p)2759 static inline bool is_per_cpu_kthread(struct task_struct *p)
2760 {
2761 if (!(p->flags & PF_KTHREAD)) {
2762 return false;
2763 }
2764
2765 if (p->nr_cpus_allowed != 1) {
2766 return false;
2767 }
2768
2769 return true;
2770 }
2771 #endif
2772
2773 void swake_up_all_locked(struct swait_queue_head *q);
2774 void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
2775
2776 #ifdef CONFIG_SCHED_RTG
2777 extern bool task_fits_max(struct task_struct *p, int cpu);
2778 extern unsigned long capacity_spare_without(int cpu, struct task_struct *p);
2779 extern int update_preferred_cluster(struct related_thread_group *grp, struct task_struct *p, u32 old_load,
2780 bool from_tick);
2781 extern struct cpumask *find_rtg_target(struct task_struct *p);
2782 #endif
2783
2784 #ifdef CONFIG_SCHED_WALT
cluster_first_cpu(struct sched_cluster * cluster)2785 static inline int cluster_first_cpu(struct sched_cluster *cluster)
2786 {
2787 return cpumask_first(&cluster->cpus);
2788 }
2789
2790 extern struct list_head cluster_head;
2791 extern struct sched_cluster *sched_cluster[NR_CPUS];
2792
2793 #define for_each_sched_cluster(cluster) list_for_each_entry_rcu(cluster, &cluster_head, list)
2794
2795 extern struct mutex policy_mutex;
2796 extern unsigned int sched_disable_window_stats;
2797 extern unsigned int max_possible_freq;
2798 extern unsigned int min_max_freq;
2799 extern unsigned int max_possible_efficiency;
2800 extern unsigned int min_possible_efficiency;
2801 extern unsigned int max_capacity;
2802 extern unsigned int min_capacity;
2803 extern unsigned int max_load_scale_factor;
2804 extern unsigned int max_possible_capacity;
2805 extern unsigned int min_max_possible_capacity;
2806 extern unsigned int max_power_cost;
2807 extern unsigned int __read_mostly sched_init_task_load_windows;
2808 extern unsigned int sysctl_sched_restrict_cluster_spill;
2809 extern unsigned int sched_pred_alert_load;
2810 extern struct sched_cluster init_cluster;
2811
walt_fixup_cum_window_demand(struct rq * rq,s64 scaled_delta)2812 static inline void walt_fixup_cum_window_demand(struct rq *rq, s64 scaled_delta)
2813 {
2814 rq->cum_window_demand_scaled += scaled_delta;
2815 if (unlikely((s64)rq->cum_window_demand_scaled < 0)) {
2816 rq->cum_window_demand_scaled = 0;
2817 }
2818 }
2819
2820 /* Is frequency of two cpus synchronized with each other? */
same_freq_domain(int src_cpu,int dst_cpu)2821 static inline int same_freq_domain(int src_cpu, int dst_cpu)
2822 {
2823 struct rq *rq = cpu_rq(src_cpu);
2824
2825 if (src_cpu == dst_cpu) {
2826 return 1;
2827 }
2828
2829 return cpumask_test_cpu(dst_cpu, &rq->freq_domain_cpumask);
2830 }
2831
2832 extern void reset_task_stats(struct task_struct *p);
2833
2834 #define CPU_RESERVED 1
is_reserved(int cpu)2835 static inline int is_reserved(int cpu)
2836 {
2837 struct rq *rq = cpu_rq(cpu);
2838
2839 return test_bit(CPU_RESERVED, &rq->walt_flags);
2840 }
2841
mark_reserved(int cpu)2842 static inline int mark_reserved(int cpu)
2843 {
2844 struct rq *rq = cpu_rq(cpu);
2845
2846 return test_and_set_bit(CPU_RESERVED, &rq->walt_flags);
2847 }
2848
clear_reserved(int cpu)2849 static inline void clear_reserved(int cpu)
2850 {
2851 struct rq *rq = cpu_rq(cpu);
2852
2853 clear_bit(CPU_RESERVED, &rq->walt_flags);
2854 }
2855
cpu_capacity(int cpu)2856 static inline int cpu_capacity(int cpu)
2857 {
2858 return cpu_rq(cpu)->cluster->capacity;
2859 }
2860
cpu_max_possible_capacity(int cpu)2861 static inline int cpu_max_possible_capacity(int cpu)
2862 {
2863 return cpu_rq(cpu)->cluster->max_possible_capacity;
2864 }
2865
cpu_load_scale_factor(int cpu)2866 static inline int cpu_load_scale_factor(int cpu)
2867 {
2868 return cpu_rq(cpu)->cluster->load_scale_factor;
2869 }
2870
cluster_max_freq(struct sched_cluster * cluster)2871 static inline unsigned int cluster_max_freq(struct sched_cluster *cluster)
2872 {
2873 /*
2874 * Governor and thermal driver don't know the other party's mitigation
2875 * voting. So struct cluster saves both and return min() for current
2876 * cluster fmax.
2877 */
2878 return cluster->max_freq;
2879 }
2880
2881 /* Keep track of max/min capacity possible across CPUs "currently" */
__update_min_max_capacity(void)2882 static inline void __update_min_max_capacity(void)
2883 {
2884 int i;
2885 int max_cap = 0, min_cap = INT_MAX;
2886
2887 for_each_possible_cpu(i)
2888 {
2889 if (!cpu_active(i)) {
2890 continue;
2891 }
2892
2893 max_cap = max(max_cap, cpu_capacity(i));
2894 min_cap = min(min_cap, cpu_capacity(i));
2895 }
2896
2897 max_capacity = max_cap;
2898 min_capacity = min_cap;
2899 }
2900
2901 /*
2902 * Return load_scale_factor of a cpu in reference to "most" efficient cpu, so
2903 * that "most" efficient cpu gets a load_scale_factor of 1
2904 */
load_scale_cpu_efficiency(struct sched_cluster * cluster)2905 static inline unsigned long load_scale_cpu_efficiency(struct sched_cluster *cluster)
2906 {
2907 return DIV_ROUND_UP(CPU_FREQ_1K * max_possible_efficiency, cluster->efficiency);
2908 }
2909
2910 /*
2911 * Return load_scale_factor of a cpu in reference to cpu with best max_freq
2912 * (max_possible_freq), so that one with best max_freq gets a load_scale_factor
2913 * of 1.
2914 */
load_scale_cpu_freq(struct sched_cluster * cluster)2915 static inline unsigned long load_scale_cpu_freq(struct sched_cluster *cluster)
2916 {
2917 return DIV_ROUND_UP(CPU_FREQ_1K * max_possible_freq, cluster_max_freq(cluster));
2918 }
2919
compute_load_scale_factor(struct sched_cluster * cluster)2920 static inline int compute_load_scale_factor(struct sched_cluster *cluster)
2921 {
2922 int load_scale = CPU_FREQ_1K;
2923
2924 /*
2925 * load_scale_factor accounts for the fact that task load
2926 * is in reference to "best" performing cpu. Task's load will need to be
2927 * scaled (up) by a factor to determine suitability to be placed on a
2928 * (little) cpu.
2929 */
2930 load_scale *= load_scale_cpu_efficiency(cluster);
2931 load_scale >>= 0xa;
2932
2933 load_scale *= load_scale_cpu_freq(cluster);
2934 load_scale >>= 0xa;
2935
2936 return load_scale;
2937 }
2938
is_max_capacity_cpu(int cpu)2939 static inline bool is_max_capacity_cpu(int cpu)
2940 {
2941 return cpu_max_possible_capacity(cpu) == max_possible_capacity;
2942 }
2943
is_min_capacity_cpu(int cpu)2944 static inline bool is_min_capacity_cpu(int cpu)
2945 {
2946 return cpu_max_possible_capacity(cpu) == min_max_possible_capacity;
2947 }
2948
2949 /*
2950 * Return 'capacity' of a cpu in reference to "least" efficient cpu, such that
2951 * least efficient cpu gets capacity of 1024
2952 */
capacity_scale_cpu_efficiency(struct sched_cluster * cluster)2953 static unsigned long capacity_scale_cpu_efficiency(struct sched_cluster *cluster)
2954 {
2955 return (0x400 * cluster->efficiency) / min_possible_efficiency;
2956 }
2957
2958 /*
2959 * Return 'capacity' of a cpu in reference to cpu with lowest max_freq
2960 * (min_max_freq), such that one with lowest max_freq gets capacity of 1024.
2961 */
capacity_scale_cpu_freq(struct sched_cluster * cluster)2962 static unsigned long capacity_scale_cpu_freq(struct sched_cluster *cluster)
2963 {
2964 return (0x400 * cluster_max_freq(cluster)) / min_max_freq;
2965 }
2966
compute_capacity(struct sched_cluster * cluster)2967 static inline int compute_capacity(struct sched_cluster *cluster)
2968 {
2969 int capacity = 0x400;
2970
2971 capacity *= capacity_scale_cpu_efficiency(cluster);
2972 capacity >>= 0xa;
2973
2974 capacity *= capacity_scale_cpu_freq(cluster);
2975 capacity >>= 0xa;
2976
2977 return capacity;
2978 }
2979
power_cost(int cpu,u64 demand)2980 static inline unsigned int power_cost(int cpu, u64 demand)
2981 {
2982 return cpu_max_possible_capacity(cpu);
2983 }
2984
cpu_util_freq_walt(int cpu)2985 static inline unsigned long cpu_util_freq_walt(int cpu)
2986 {
2987 u64 util;
2988 struct rq *rq = cpu_rq(cpu);
2989 unsigned long capacity = capacity_orig_of(cpu);
2990
2991 if (unlikely(walt_disabled || !sysctl_sched_use_walt_cpu_util)) {
2992 return cpu_util(cpu);
2993 }
2994
2995 util = rq->prev_runnable_sum << SCHED_CAPACITY_SHIFT;
2996 util = div_u64(util, sched_ravg_window);
2997
2998 return (util >= capacity) ? capacity : util;
2999 }
3000
hmp_capable(void)3001 static inline bool hmp_capable(void)
3002 {
3003 return max_possible_capacity != min_max_possible_capacity;
3004 }
3005 #else /* CONFIG_SCHED_WALT */
walt_fixup_cum_window_demand(struct rq * rq,s64 scaled_delta)3006 static inline void walt_fixup_cum_window_demand(struct rq *rq, s64 scaled_delta)
3007 {
3008 }
3009
same_freq_domain(int src_cpu,int dst_cpu)3010 static inline int same_freq_domain(int src_cpu, int dst_cpu)
3011 {
3012 return 1;
3013 }
3014
is_reserved(int cpu)3015 static inline int is_reserved(int cpu)
3016 {
3017 return 0;
3018 }
3019
clear_reserved(int cpu)3020 static inline void clear_reserved(int cpu)
3021 {
3022 }
3023
hmp_capable(void)3024 static inline bool hmp_capable(void)
3025 {
3026 return false;
3027 }
3028 #endif /* CONFIG_SCHED_WALT */
3029
3030 struct sched_avg_stats {
3031 int nr;
3032 int nr_misfit;
3033 int nr_max;
3034 int nr_scaled;
3035 };
3036 #ifdef CONFIG_SCHED_RUNNING_AVG
3037 extern void sched_get_nr_running_avg(struct sched_avg_stats *stats);
3038 #else
sched_get_nr_running_avg(struct sched_avg_stats * stats)3039 static inline void sched_get_nr_running_avg(struct sched_avg_stats *stats)
3040 {
3041 }
3042 #endif
3043
3044 #ifdef CONFIG_CPU_ISOLATION_OPT
3045 extern int group_balance_cpu_not_isolated(struct sched_group *sg);
3046 #else
group_balance_cpu_not_isolated(struct sched_group * sg)3047 static inline int group_balance_cpu_not_isolated(struct sched_group *sg)
3048 {
3049 return group_balance_cpu(sg);
3050 }
3051 #endif /* CONFIG_CPU_ISOLATION_OPT */
3052
3053 #ifdef CONFIG_HOTPLUG_CPU
3054 extern void migrate_tasks(struct rq *dead_rq, struct rq_flags *rf, bool migrate_pinned_tasks);
3055 #endif
3056 #endif