1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Scheduler internal types and methods:
4 */
5 #ifndef _KERNEL_SCHED_SCHED_H
6 #define _KERNEL_SCHED_SCHED_H
7
8 #include <linux/sched/affinity.h>
9 #include <linux/sched/autogroup.h>
10 #include <linux/sched/cpufreq.h>
11 #include <linux/sched/deadline.h>
12 #include <linux/sched.h>
13 #include <linux/sched/loadavg.h>
14 #include <linux/sched/mm.h>
15 #include <linux/sched/rseq_api.h>
16 #include <linux/sched/signal.h>
17 #include <linux/sched/smt.h>
18 #include <linux/sched/stat.h>
19 #include <linux/sched/sysctl.h>
20 #include <linux/sched/task_flags.h>
21 #include <linux/sched/task.h>
22 #include <linux/sched/topology.h>
23
24 #include <linux/atomic.h>
25 #include <linux/bitmap.h>
26 #include <linux/bug.h>
27 #include <linux/capability.h>
28 #include <linux/cgroup_api.h>
29 #include <linux/cgroup.h>
30 #include <linux/context_tracking.h>
31 #include <linux/cpufreq.h>
32 #include <linux/cpumask_api.h>
33 #include <linux/ctype.h>
34 #include <linux/file.h>
35 #include <linux/fs_api.h>
36 #include <linux/hrtimer_api.h>
37 #include <linux/interrupt.h>
38 #include <linux/irq_work.h>
39 #include <linux/jiffies.h>
40 #include <linux/kref_api.h>
41 #include <linux/kthread.h>
42 #include <linux/ktime_api.h>
43 #include <linux/lockdep_api.h>
44 #include <linux/lockdep.h>
45 #include <linux/minmax.h>
46 #include <linux/mm.h>
47 #include <linux/module.h>
48 #include <linux/mutex_api.h>
49 #include <linux/plist.h>
50 #include <linux/poll.h>
51 #include <linux/proc_fs.h>
52 #include <linux/profile.h>
53 #include <linux/psi.h>
54 #include <linux/rcupdate.h>
55 #include <linux/seq_file.h>
56 #include <linux/seqlock.h>
57 #include <linux/softirq.h>
58 #include <linux/spinlock_api.h>
59 #include <linux/static_key.h>
60 #include <linux/stop_machine.h>
61 #include <linux/syscalls_api.h>
62 #include <linux/syscalls.h>
63 #include <linux/tick.h>
64 #include <linux/topology.h>
65 #include <linux/types.h>
66 #include <linux/u64_stats_sync_api.h>
67 #include <linux/uaccess.h>
68 #include <linux/wait_api.h>
69 #include <linux/wait_bit.h>
70 #include <linux/workqueue_api.h>
71 #include <linux/delayacct.h>
72 #include <linux/mmu_context.h>
73
74 #include <trace/events/power.h>
75 #include <trace/events/sched.h>
76
77 #include "../workqueue_internal.h"
78
79 struct rq;
80 struct cfs_rq;
81 struct rt_rq;
82 struct sched_group;
83 struct cpuidle_state;
84
85 #ifdef CONFIG_PARAVIRT
86 # include <asm/paravirt.h>
87 # include <asm/paravirt_api_clock.h>
88 #endif
89
90 #include <asm/barrier.h>
91
92 #include "cpupri.h"
93 #include "cpudeadline.h"
94
95 /* task_struct::on_rq states: */
96 #define TASK_ON_RQ_QUEUED 1
97 #define TASK_ON_RQ_MIGRATING 2
98
99 extern __read_mostly int scheduler_running;
100
101 extern unsigned long calc_load_update;
102 extern atomic_long_t calc_load_tasks;
103
104 extern void calc_global_load_tick(struct rq *this_rq);
105 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
106
107 extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
108
109 extern int sysctl_sched_rt_period;
110 extern int sysctl_sched_rt_runtime;
111 extern int sched_rr_timeslice;
112
113 /*
114 * Asymmetric CPU capacity bits
115 */
116 struct asym_cap_data {
117 struct list_head link;
118 struct rcu_head rcu;
119 unsigned long capacity;
120 unsigned long cpus[];
121 };
122
123 extern struct list_head asym_cap_list;
124
125 #define cpu_capacity_span(asym_data) to_cpumask((asym_data)->cpus)
126
127 /*
128 * Helpers for converting nanosecond timing to jiffy resolution
129 */
130 #define NS_TO_JIFFIES(time) ((unsigned long)(time) / (NSEC_PER_SEC/HZ))
131
132 /*
133 * Increase resolution of nice-level calculations for 64-bit architectures.
134 * The extra resolution improves shares distribution and load balancing of
135 * low-weight task groups (eg. nice +19 on an autogroup), deeper task-group
136 * hierarchies, especially on larger systems. This is not a user-visible change
137 * and does not change the user-interface for setting shares/weights.
138 *
139 * We increase resolution only if we have enough bits to allow this increased
140 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
141 * are pretty high and the returns do not justify the increased costs.
142 *
143 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
144 * increase coverage and consistency always enable it on 64-bit platforms.
145 */
146 #ifdef CONFIG_64BIT
147 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
148 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
149 # define scale_load_down(w) \
150 ({ \
151 unsigned long __w = (w); \
152 \
153 if (__w) \
154 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
155 __w; \
156 })
157 #else
158 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
159 # define scale_load(w) (w)
160 # define scale_load_down(w) (w)
161 #endif
162
163 /*
164 * Task weight (visible to users) and its load (invisible to users) have
165 * independent resolution, but they should be well calibrated. We use
166 * scale_load() and scale_load_down(w) to convert between them. The
167 * following must be true:
168 *
169 * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
170 *
171 */
172 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
173
174 /*
175 * Single value that decides SCHED_DEADLINE internal math precision.
176 * 10 -> just above 1us
177 * 9 -> just above 0.5us
178 */
179 #define DL_SCALE 10
180
181 /*
182 * Single value that denotes runtime == period, ie unlimited time.
183 */
184 #define RUNTIME_INF ((u64)~0ULL)
185
idle_policy(int policy)186 static inline int idle_policy(int policy)
187 {
188 return policy == SCHED_IDLE;
189 }
190
normal_policy(int policy)191 static inline int normal_policy(int policy)
192 {
193 #ifdef CONFIG_SCHED_CLASS_EXT
194 if (policy == SCHED_EXT)
195 return true;
196 #endif
197 return policy == SCHED_NORMAL;
198 }
199
fair_policy(int policy)200 static inline int fair_policy(int policy)
201 {
202 return normal_policy(policy) || policy == SCHED_BATCH;
203 }
204
rt_policy(int policy)205 static inline int rt_policy(int policy)
206 {
207 return policy == SCHED_FIFO || policy == SCHED_RR;
208 }
209
dl_policy(int policy)210 static inline int dl_policy(int policy)
211 {
212 return policy == SCHED_DEADLINE;
213 }
214
valid_policy(int policy)215 static inline bool valid_policy(int policy)
216 {
217 return idle_policy(policy) || fair_policy(policy) ||
218 rt_policy(policy) || dl_policy(policy);
219 }
220
task_has_idle_policy(struct task_struct * p)221 static inline int task_has_idle_policy(struct task_struct *p)
222 {
223 return idle_policy(p->policy);
224 }
225
task_has_rt_policy(struct task_struct * p)226 static inline int task_has_rt_policy(struct task_struct *p)
227 {
228 return rt_policy(p->policy);
229 }
230
task_has_dl_policy(struct task_struct * p)231 static inline int task_has_dl_policy(struct task_struct *p)
232 {
233 return dl_policy(p->policy);
234 }
235
236 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
237
update_avg(u64 * avg,u64 sample)238 static inline void update_avg(u64 *avg, u64 sample)
239 {
240 s64 diff = sample - *avg;
241
242 *avg += diff / 8;
243 }
244
245 /*
246 * Shifting a value by an exponent greater *or equal* to the size of said value
247 * is UB; cap at size-1.
248 */
249 #define shr_bound(val, shift) \
250 (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1))
251
252 /*
253 * cgroup weight knobs should use the common MIN, DFL and MAX values which are
254 * 1, 100 and 10000 respectively. While it loses a bit of range on both ends, it
255 * maps pretty well onto the shares value used by scheduler and the round-trip
256 * conversions preserve the original value over the entire range.
257 */
sched_weight_from_cgroup(unsigned long cgrp_weight)258 static inline unsigned long sched_weight_from_cgroup(unsigned long cgrp_weight)
259 {
260 return DIV_ROUND_CLOSEST_ULL(cgrp_weight * 1024, CGROUP_WEIGHT_DFL);
261 }
262
sched_weight_to_cgroup(unsigned long weight)263 static inline unsigned long sched_weight_to_cgroup(unsigned long weight)
264 {
265 return clamp_t(unsigned long,
266 DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024),
267 CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX);
268 }
269
270 /*
271 * !! For sched_setattr_nocheck() (kernel) only !!
272 *
273 * This is actually gross. :(
274 *
275 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
276 * tasks, but still be able to sleep. We need this on platforms that cannot
277 * atomically change clock frequency. Remove once fast switching will be
278 * available on such platforms.
279 *
280 * SUGOV stands for SchedUtil GOVernor.
281 */
282 #define SCHED_FLAG_SUGOV 0x10000000
283
284 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
285
dl_entity_is_special(const struct sched_dl_entity * dl_se)286 static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se)
287 {
288 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
289 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV);
290 #else
291 return false;
292 #endif
293 }
294
295 /*
296 * Tells if entity @a should preempt entity @b.
297 */
dl_entity_preempt(const struct sched_dl_entity * a,const struct sched_dl_entity * b)298 static inline bool dl_entity_preempt(const struct sched_dl_entity *a,
299 const struct sched_dl_entity *b)
300 {
301 return dl_entity_is_special(a) ||
302 dl_time_before(a->deadline, b->deadline);
303 }
304
305 /*
306 * This is the priority-queue data structure of the RT scheduling class:
307 */
308 struct rt_prio_array {
309 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
310 struct list_head queue[MAX_RT_PRIO];
311 };
312
313 struct rt_bandwidth {
314 /* nests inside the rq lock: */
315 raw_spinlock_t rt_runtime_lock;
316 ktime_t rt_period;
317 u64 rt_runtime;
318 struct hrtimer rt_period_timer;
319 unsigned int rt_period_active;
320 };
321
dl_bandwidth_enabled(void)322 static inline int dl_bandwidth_enabled(void)
323 {
324 return sysctl_sched_rt_runtime >= 0;
325 }
326
327 /*
328 * To keep the bandwidth of -deadline tasks under control
329 * we need some place where:
330 * - store the maximum -deadline bandwidth of each cpu;
331 * - cache the fraction of bandwidth that is currently allocated in
332 * each root domain;
333 *
334 * This is all done in the data structure below. It is similar to the
335 * one used for RT-throttling (rt_bandwidth), with the main difference
336 * that, since here we are only interested in admission control, we
337 * do not decrease any runtime while the group "executes", neither we
338 * need a timer to replenish it.
339 *
340 * With respect to SMP, bandwidth is given on a per root domain basis,
341 * meaning that:
342 * - bw (< 100%) is the deadline bandwidth of each CPU;
343 * - total_bw is the currently allocated bandwidth in each root domain;
344 */
345 struct dl_bw {
346 raw_spinlock_t lock;
347 u64 bw;
348 u64 total_bw;
349 };
350
351 extern void init_dl_bw(struct dl_bw *dl_b);
352 extern int sched_dl_global_validate(void);
353 extern void sched_dl_do_global(void);
354 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr);
355 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
356 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
357 extern bool __checkparam_dl(const struct sched_attr *attr);
358 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
359 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
360 extern int dl_bw_deactivate(int cpu);
361 extern s64 dl_scaled_delta_exec(struct rq *rq, struct sched_dl_entity *dl_se, s64 delta_exec);
362 /*
363 * SCHED_DEADLINE supports servers (nested scheduling) with the following
364 * interface:
365 *
366 * dl_se::rq -- runqueue we belong to.
367 *
368 * dl_se::server_pick() -- nested pick_next_task(); we yield the period if this
369 * returns NULL.
370 *
371 * dl_server_update() -- called from update_curr_common(), propagates runtime
372 * to the server.
373 *
374 * dl_server_start() -- start the server when it has tasks; it will stop
375 * automatically when there are no more tasks, per
376 * dl_se::server_pick() returning NULL.
377 *
378 * dl_server_stop() -- (force) stop the server; use when updating
379 * parameters.
380 *
381 * dl_server_init() -- initializes the server.
382 *
383 * When started the dl_server will (per dl_defer) schedule a timer for its
384 * zero-laxity point -- that is, unlike regular EDF tasks which run ASAP, a
385 * server will run at the very end of its period.
386 *
387 * This is done such that any runtime from the target class can be accounted
388 * against the server -- through dl_server_update() above -- such that when it
389 * becomes time to run, it might already be out of runtime and get deferred
390 * until the next period. In this case dl_server_timer() will alternate
391 * between defer and replenish but never actually enqueue the server.
392 *
393 * Only when the target class does not manage to exhaust the server's runtime
394 * (there's actualy starvation in the given period), will the dl_server get on
395 * the runqueue. Once queued it will pick tasks from the target class and run
396 * them until either its runtime is exhaused, at which point its back to
397 * dl_server_timer, or until there are no more tasks to run, at which point
398 * the dl_server stops itself.
399 *
400 * By stopping at this point the dl_server retains bandwidth, which, if a new
401 * task wakes up imminently (starting the server again), can be used --
402 * subject to CBS wakeup rules -- without having to wait for the next period.
403 *
404 * Additionally, because of the dl_defer behaviour the start/stop behaviour is
405 * naturally thottled to once per period, avoiding high context switch
406 * workloads from spamming the hrtimer program/cancel paths.
407 */
408 extern void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec);
409 extern void dl_server_start(struct sched_dl_entity *dl_se);
410 extern void dl_server_stop(struct sched_dl_entity *dl_se);
411 extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq,
412 dl_server_pick_f pick_task);
413 extern void sched_init_dl_servers(void);
414
415 extern void dl_server_update_idle_time(struct rq *rq,
416 struct task_struct *p);
417 extern void fair_server_init(struct rq *rq);
418 extern void __dl_server_attach_root(struct sched_dl_entity *dl_se, struct rq *rq);
419 extern int dl_server_apply_params(struct sched_dl_entity *dl_se,
420 u64 runtime, u64 period, bool init);
421
dl_server_active(struct sched_dl_entity * dl_se)422 static inline bool dl_server_active(struct sched_dl_entity *dl_se)
423 {
424 return dl_se->dl_server_active;
425 }
426
427 #ifdef CONFIG_CGROUP_SCHED
428
429 extern struct list_head task_groups;
430
431 #ifdef CONFIG_GROUP_SCHED_BANDWIDTH
432 extern const u64 max_bw_quota_period_us;
433
434 /*
435 * default period for group bandwidth.
436 * default: 0.1s, units: microseconds
437 */
default_bw_period_us(void)438 static inline u64 default_bw_period_us(void)
439 {
440 return 100000ULL;
441 }
442 #endif /* CONFIG_GROUP_SCHED_BANDWIDTH */
443
444 struct cfs_bandwidth {
445 #ifdef CONFIG_CFS_BANDWIDTH
446 raw_spinlock_t lock;
447 ktime_t period;
448 u64 quota;
449 u64 runtime;
450 u64 burst;
451 u64 runtime_snap;
452 s64 hierarchical_quota;
453
454 u8 idle;
455 u8 period_active;
456 u8 slack_started;
457 struct hrtimer period_timer;
458 struct hrtimer slack_timer;
459 struct list_head throttled_cfs_rq;
460
461 /* Statistics: */
462 int nr_periods;
463 int nr_throttled;
464 int nr_burst;
465 u64 throttled_time;
466 u64 burst_time;
467 #endif /* CONFIG_CFS_BANDWIDTH */
468 };
469
470 /* Task group related information */
471 struct task_group {
472 struct cgroup_subsys_state css;
473
474 #ifdef CONFIG_GROUP_SCHED_WEIGHT
475 /* A positive value indicates that this is a SCHED_IDLE group. */
476 int idle;
477 #endif
478
479 #ifdef CONFIG_FAIR_GROUP_SCHED
480 /* schedulable entities of this group on each CPU */
481 struct sched_entity **se;
482 /* runqueue "owned" by this group on each CPU */
483 struct cfs_rq **cfs_rq;
484 unsigned long shares;
485 /*
486 * load_avg can be heavily contended at clock tick time, so put
487 * it in its own cache-line separated from the fields above which
488 * will also be accessed at each tick.
489 */
490 atomic_long_t load_avg ____cacheline_aligned;
491 #endif /* CONFIG_FAIR_GROUP_SCHED */
492
493 #ifdef CONFIG_RT_GROUP_SCHED
494 struct sched_rt_entity **rt_se;
495 struct rt_rq **rt_rq;
496
497 struct rt_bandwidth rt_bandwidth;
498 #endif
499
500 struct scx_task_group scx;
501
502 struct rcu_head rcu;
503 struct list_head list;
504
505 struct task_group *parent;
506 struct list_head siblings;
507 struct list_head children;
508
509 #ifdef CONFIG_SCHED_AUTOGROUP
510 struct autogroup *autogroup;
511 #endif
512
513 struct cfs_bandwidth cfs_bandwidth;
514
515 #ifdef CONFIG_UCLAMP_TASK_GROUP
516 /* The two decimal precision [%] value requested from user-space */
517 unsigned int uclamp_pct[UCLAMP_CNT];
518 /* Clamp values requested for a task group */
519 struct uclamp_se uclamp_req[UCLAMP_CNT];
520 /* Effective clamp values used for a task group */
521 struct uclamp_se uclamp[UCLAMP_CNT];
522 #endif
523
524 };
525
526 #ifdef CONFIG_GROUP_SCHED_WEIGHT
527 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
528
529 /*
530 * A weight of 0 or 1 can cause arithmetics problems.
531 * A weight of a cfs_rq is the sum of weights of which entities
532 * are queued on this cfs_rq, so a weight of a entity should not be
533 * too large, so as the shares value of a task group.
534 * (The default weight is 1024 - so there's no practical
535 * limitation from this.)
536 */
537 #define MIN_SHARES (1UL << 1)
538 #define MAX_SHARES (1UL << 18)
539 #endif
540
541 typedef int (*tg_visitor)(struct task_group *, void *);
542
543 extern int walk_tg_tree_from(struct task_group *from,
544 tg_visitor down, tg_visitor up, void *data);
545
546 /*
547 * Iterate the full tree, calling @down when first entering a node and @up when
548 * leaving it for the final time.
549 *
550 * Caller must hold rcu_lock or sufficient equivalent.
551 */
walk_tg_tree(tg_visitor down,tg_visitor up,void * data)552 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
553 {
554 return walk_tg_tree_from(&root_task_group, down, up, data);
555 }
556
css_tg(struct cgroup_subsys_state * css)557 static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
558 {
559 return css ? container_of(css, struct task_group, css) : NULL;
560 }
561
562 extern int tg_nop(struct task_group *tg, void *data);
563
564 #ifdef CONFIG_FAIR_GROUP_SCHED
565 extern void free_fair_sched_group(struct task_group *tg);
566 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
567 extern void online_fair_sched_group(struct task_group *tg);
568 extern void unregister_fair_sched_group(struct task_group *tg);
569 #else /* !CONFIG_FAIR_GROUP_SCHED: */
free_fair_sched_group(struct task_group * tg)570 static inline void free_fair_sched_group(struct task_group *tg) { }
alloc_fair_sched_group(struct task_group * tg,struct task_group * parent)571 static inline int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
572 {
573 return 1;
574 }
online_fair_sched_group(struct task_group * tg)575 static inline void online_fair_sched_group(struct task_group *tg) { }
unregister_fair_sched_group(struct task_group * tg)576 static inline void unregister_fair_sched_group(struct task_group *tg) { }
577 #endif /* !CONFIG_FAIR_GROUP_SCHED */
578
579 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
580 struct sched_entity *se, int cpu,
581 struct sched_entity *parent);
582 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *parent);
583
584 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
585 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
586 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
587 extern bool cfs_task_bw_constrained(struct task_struct *p);
588
589 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
590 struct sched_rt_entity *rt_se, int cpu,
591 struct sched_rt_entity *parent);
592 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
593 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
594 extern long sched_group_rt_runtime(struct task_group *tg);
595 extern long sched_group_rt_period(struct task_group *tg);
596 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
597
598 extern struct task_group *sched_create_group(struct task_group *parent);
599 extern void sched_online_group(struct task_group *tg,
600 struct task_group *parent);
601 extern void sched_destroy_group(struct task_group *tg);
602 extern void sched_release_group(struct task_group *tg);
603
604 extern void sched_move_task(struct task_struct *tsk, bool for_autogroup);
605
606 #ifdef CONFIG_FAIR_GROUP_SCHED
607 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
608
609 extern int sched_group_set_idle(struct task_group *tg, long idle);
610
611 extern void set_task_rq_fair(struct sched_entity *se,
612 struct cfs_rq *prev, struct cfs_rq *next);
613 #else /* !CONFIG_FAIR_GROUP_SCHED: */
sched_group_set_shares(struct task_group * tg,unsigned long shares)614 static inline int sched_group_set_shares(struct task_group *tg, unsigned long shares) { return 0; }
sched_group_set_idle(struct task_group * tg,long idle)615 static inline int sched_group_set_idle(struct task_group *tg, long idle) { return 0; }
616 #endif /* !CONFIG_FAIR_GROUP_SCHED */
617
618 #else /* !CONFIG_CGROUP_SCHED: */
619
620 struct cfs_bandwidth { };
621
cfs_task_bw_constrained(struct task_struct * p)622 static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; }
623
624 #endif /* !CONFIG_CGROUP_SCHED */
625
626 extern void unregister_rt_sched_group(struct task_group *tg);
627 extern void free_rt_sched_group(struct task_group *tg);
628 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
629
630 /*
631 * u64_u32_load/u64_u32_store
632 *
633 * Use a copy of a u64 value to protect against data race. This is only
634 * applicable for 32-bits architectures.
635 */
636 #ifdef CONFIG_64BIT
637 # define u64_u32_load_copy(var, copy) var
638 # define u64_u32_store_copy(var, copy, val) (var = val)
639 #else
640 # define u64_u32_load_copy(var, copy) \
641 ({ \
642 u64 __val, __val_copy; \
643 do { \
644 __val_copy = copy; \
645 /* \
646 * paired with u64_u32_store_copy(), ordering access \
647 * to var and copy. \
648 */ \
649 smp_rmb(); \
650 __val = var; \
651 } while (__val != __val_copy); \
652 __val; \
653 })
654 # define u64_u32_store_copy(var, copy, val) \
655 do { \
656 typeof(val) __val = (val); \
657 var = __val; \
658 /* \
659 * paired with u64_u32_load_copy(), ordering access to var and \
660 * copy. \
661 */ \
662 smp_wmb(); \
663 copy = __val; \
664 } while (0)
665 #endif
666 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy)
667 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val)
668
669 struct balance_callback {
670 struct balance_callback *next;
671 void (*func)(struct rq *rq);
672 };
673
674 /* CFS-related fields in a runqueue */
675 struct cfs_rq {
676 struct load_weight load;
677 unsigned int nr_queued;
678 unsigned int h_nr_queued; /* SCHED_{NORMAL,BATCH,IDLE} */
679 unsigned int h_nr_runnable; /* SCHED_{NORMAL,BATCH,IDLE} */
680 unsigned int h_nr_idle; /* SCHED_IDLE */
681
682 s64 avg_vruntime;
683 u64 avg_load;
684
685 u64 min_vruntime;
686 #ifdef CONFIG_SCHED_CORE
687 unsigned int forceidle_seq;
688 u64 min_vruntime_fi;
689 #endif
690
691 struct rb_root_cached tasks_timeline;
692
693 /*
694 * 'curr' points to currently running entity on this cfs_rq.
695 * It is set to NULL otherwise (i.e when none are currently running).
696 */
697 struct sched_entity *curr;
698 struct sched_entity *next;
699
700 /*
701 * CFS load tracking
702 */
703 struct sched_avg avg;
704 #ifndef CONFIG_64BIT
705 u64 last_update_time_copy;
706 #endif
707 struct {
708 raw_spinlock_t lock ____cacheline_aligned;
709 int nr;
710 unsigned long load_avg;
711 unsigned long util_avg;
712 unsigned long runnable_avg;
713 } removed;
714
715 #ifdef CONFIG_FAIR_GROUP_SCHED
716 u64 last_update_tg_load_avg;
717 unsigned long tg_load_avg_contrib;
718 long propagate;
719 long prop_runnable_sum;
720
721 /*
722 * h_load = weight * f(tg)
723 *
724 * Where f(tg) is the recursive weight fraction assigned to
725 * this group.
726 */
727 unsigned long h_load;
728 u64 last_h_load_update;
729 struct sched_entity *h_load_next;
730 #endif /* CONFIG_FAIR_GROUP_SCHED */
731
732 #ifdef CONFIG_FAIR_GROUP_SCHED
733 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */
734
735 /*
736 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
737 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
738 * (like users, containers etc.)
739 *
740 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU.
741 * This list is used during load balance.
742 */
743 int on_list;
744 struct list_head leaf_cfs_rq_list;
745 struct task_group *tg; /* group that "owns" this runqueue */
746
747 /* Locally cached copy of our task_group's idle value */
748 int idle;
749
750 #ifdef CONFIG_CFS_BANDWIDTH
751 int runtime_enabled;
752 s64 runtime_remaining;
753
754 u64 throttled_pelt_idle;
755 #ifndef CONFIG_64BIT
756 u64 throttled_pelt_idle_copy;
757 #endif
758 u64 throttled_clock;
759 u64 throttled_clock_pelt;
760 u64 throttled_clock_pelt_time;
761 u64 throttled_clock_self;
762 u64 throttled_clock_self_time;
763 bool throttled:1;
764 bool pelt_clock_throttled:1;
765 int throttle_count;
766 struct list_head throttled_list;
767 struct list_head throttled_csd_list;
768 struct list_head throttled_limbo_list;
769 #endif /* CONFIG_CFS_BANDWIDTH */
770 #endif /* CONFIG_FAIR_GROUP_SCHED */
771 };
772
773 #ifdef CONFIG_SCHED_CLASS_EXT
774 /* scx_rq->flags, protected by the rq lock */
775 enum scx_rq_flags {
776 /*
777 * A hotplugged CPU starts scheduling before rq_online_scx(). Track
778 * ops.cpu_on/offline() state so that ops.enqueue/dispatch() are called
779 * only while the BPF scheduler considers the CPU to be online.
780 */
781 SCX_RQ_ONLINE = 1 << 0,
782 SCX_RQ_CAN_STOP_TICK = 1 << 1,
783 SCX_RQ_BAL_PENDING = 1 << 2, /* balance hasn't run yet */
784 SCX_RQ_BAL_KEEP = 1 << 3, /* balance decided to keep current */
785 SCX_RQ_BYPASSING = 1 << 4,
786 SCX_RQ_CLK_VALID = 1 << 5, /* RQ clock is fresh and valid */
787 SCX_RQ_BAL_CB_PENDING = 1 << 6, /* must queue a cb after dispatching */
788
789 SCX_RQ_IN_WAKEUP = 1 << 16,
790 SCX_RQ_IN_BALANCE = 1 << 17,
791 };
792
793 struct scx_rq {
794 struct scx_dispatch_q local_dsq;
795 struct list_head runnable_list; /* runnable tasks on this rq */
796 struct list_head ddsp_deferred_locals; /* deferred ddsps from enq */
797 unsigned long ops_qseq;
798 u64 extra_enq_flags; /* see move_task_to_local_dsq() */
799 u32 nr_running;
800 u32 cpuperf_target; /* [0, SCHED_CAPACITY_SCALE] */
801 bool cpu_released;
802 u32 flags;
803 u64 clock; /* current per-rq clock -- see scx_bpf_now() */
804 cpumask_var_t cpus_to_kick;
805 cpumask_var_t cpus_to_kick_if_idle;
806 cpumask_var_t cpus_to_preempt;
807 cpumask_var_t cpus_to_wait;
808 unsigned long pnt_seq;
809 struct balance_callback deferred_bal_cb;
810 struct irq_work deferred_irq_work;
811 struct irq_work kick_cpus_irq_work;
812 };
813 #endif /* CONFIG_SCHED_CLASS_EXT */
814
rt_bandwidth_enabled(void)815 static inline int rt_bandwidth_enabled(void)
816 {
817 return sysctl_sched_rt_runtime >= 0;
818 }
819
820 /* RT IPI pull logic requires IRQ_WORK */
821 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP)
822 # define HAVE_RT_PUSH_IPI
823 #endif
824
825 /* Real-Time classes' related field in a runqueue: */
826 struct rt_rq {
827 struct rt_prio_array active;
828 unsigned int rt_nr_running;
829 unsigned int rr_nr_running;
830 struct {
831 int curr; /* highest queued rt task prio */
832 int next; /* next highest */
833 } highest_prio;
834 bool overloaded;
835 struct plist_head pushable_tasks;
836
837 int rt_queued;
838
839 #ifdef CONFIG_RT_GROUP_SCHED
840 int rt_throttled;
841 u64 rt_time; /* consumed RT time, goes up in update_curr_rt */
842 u64 rt_runtime; /* allotted RT time, "slice" from rt_bandwidth, RT sharing/balancing */
843 /* Nests inside the rq lock: */
844 raw_spinlock_t rt_runtime_lock;
845
846 unsigned int rt_nr_boosted;
847
848 struct rq *rq; /* this is always top-level rq, cache? */
849 #endif
850 #ifdef CONFIG_CGROUP_SCHED
851 struct task_group *tg; /* this tg has "this" rt_rq on given CPU for runnable entities */
852 #endif
853 };
854
rt_rq_is_runnable(struct rt_rq * rt_rq)855 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
856 {
857 return rt_rq->rt_queued && rt_rq->rt_nr_running;
858 }
859
860 /* Deadline class' related fields in a runqueue */
861 struct dl_rq {
862 /* runqueue is an rbtree, ordered by deadline */
863 struct rb_root_cached root;
864
865 unsigned int dl_nr_running;
866
867 /*
868 * Deadline values of the currently executing and the
869 * earliest ready task on this rq. Caching these facilitates
870 * the decision whether or not a ready but not running task
871 * should migrate somewhere else.
872 */
873 struct {
874 u64 curr;
875 u64 next;
876 } earliest_dl;
877
878 bool overloaded;
879
880 /*
881 * Tasks on this rq that can be pushed away. They are kept in
882 * an rb-tree, ordered by tasks' deadlines, with caching
883 * of the leftmost (earliest deadline) element.
884 */
885 struct rb_root_cached pushable_dl_tasks_root;
886
887 /*
888 * "Active utilization" for this runqueue: increased when a
889 * task wakes up (becomes TASK_RUNNING) and decreased when a
890 * task blocks
891 */
892 u64 running_bw;
893
894 /*
895 * Utilization of the tasks "assigned" to this runqueue (including
896 * the tasks that are in runqueue and the tasks that executed on this
897 * CPU and blocked). Increased when a task moves to this runqueue, and
898 * decreased when the task moves away (migrates, changes scheduling
899 * policy, or terminates).
900 * This is needed to compute the "inactive utilization" for the
901 * runqueue (inactive utilization = this_bw - running_bw).
902 */
903 u64 this_bw;
904 u64 extra_bw;
905
906 /*
907 * Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM
908 * tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB).
909 */
910 u64 max_bw;
911
912 /*
913 * Inverse of the fraction of CPU utilization that can be reclaimed
914 * by the GRUB algorithm.
915 */
916 u64 bw_ratio;
917 };
918
919 #ifdef CONFIG_FAIR_GROUP_SCHED
920
921 /* An entity is a task if it doesn't "own" a runqueue */
922 #define entity_is_task(se) (!se->my_q)
923
se_update_runnable(struct sched_entity * se)924 static inline void se_update_runnable(struct sched_entity *se)
925 {
926 if (!entity_is_task(se))
927 se->runnable_weight = se->my_q->h_nr_runnable;
928 }
929
se_runnable(struct sched_entity * se)930 static inline long se_runnable(struct sched_entity *se)
931 {
932 if (se->sched_delayed)
933 return false;
934
935 if (entity_is_task(se))
936 return !!se->on_rq;
937 else
938 return se->runnable_weight;
939 }
940
941 #else /* !CONFIG_FAIR_GROUP_SCHED: */
942
943 #define entity_is_task(se) 1
944
se_update_runnable(struct sched_entity * se)945 static inline void se_update_runnable(struct sched_entity *se) { }
946
se_runnable(struct sched_entity * se)947 static inline long se_runnable(struct sched_entity *se)
948 {
949 if (se->sched_delayed)
950 return false;
951
952 return !!se->on_rq;
953 }
954
955 #endif /* !CONFIG_FAIR_GROUP_SCHED */
956
957 /*
958 * XXX we want to get rid of these helpers and use the full load resolution.
959 */
se_weight(struct sched_entity * se)960 static inline long se_weight(struct sched_entity *se)
961 {
962 return scale_load_down(se->load.weight);
963 }
964
965
sched_asym_prefer(int a,int b)966 static inline bool sched_asym_prefer(int a, int b)
967 {
968 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
969 }
970
971 struct perf_domain {
972 struct em_perf_domain *em_pd;
973 struct perf_domain *next;
974 struct rcu_head rcu;
975 };
976
977 /*
978 * We add the notion of a root-domain which will be used to define per-domain
979 * variables. Each exclusive cpuset essentially defines an island domain by
980 * fully partitioning the member CPUs from any other cpuset. Whenever a new
981 * exclusive cpuset is created, we also create and attach a new root-domain
982 * object.
983 *
984 */
985 struct root_domain {
986 atomic_t refcount;
987 atomic_t rto_count;
988 struct rcu_head rcu;
989 cpumask_var_t span;
990 cpumask_var_t online;
991
992 /*
993 * Indicate pullable load on at least one CPU, e.g:
994 * - More than one runnable task
995 * - Running task is misfit
996 */
997 bool overloaded;
998
999 /* Indicate one or more CPUs over-utilized (tipping point) */
1000 bool overutilized;
1001
1002 /*
1003 * The bit corresponding to a CPU gets set here if such CPU has more
1004 * than one runnable -deadline task (as it is below for RT tasks).
1005 */
1006 cpumask_var_t dlo_mask;
1007 atomic_t dlo_count;
1008 struct dl_bw dl_bw;
1009 struct cpudl cpudl;
1010
1011 /*
1012 * Indicate whether a root_domain's dl_bw has been checked or
1013 * updated. It's monotonously increasing value.
1014 *
1015 * Also, some corner cases, like 'wrap around' is dangerous, but given
1016 * that u64 is 'big enough'. So that shouldn't be a concern.
1017 */
1018 u64 visit_cookie;
1019
1020 #ifdef HAVE_RT_PUSH_IPI
1021 /*
1022 * For IPI pull requests, loop across the rto_mask.
1023 */
1024 struct irq_work rto_push_work;
1025 raw_spinlock_t rto_lock;
1026 /* These are only updated and read within rto_lock */
1027 int rto_loop;
1028 int rto_cpu;
1029 /* These atomics are updated outside of a lock */
1030 atomic_t rto_loop_next;
1031 atomic_t rto_loop_start;
1032 #endif /* HAVE_RT_PUSH_IPI */
1033 /*
1034 * The "RT overload" flag: it gets set if a CPU has more than
1035 * one runnable RT task.
1036 */
1037 cpumask_var_t rto_mask;
1038 struct cpupri cpupri;
1039
1040 /*
1041 * NULL-terminated list of performance domains intersecting with the
1042 * CPUs of the rd. Protected by RCU.
1043 */
1044 struct perf_domain __rcu *pd;
1045 };
1046
1047 extern void init_defrootdomain(void);
1048 extern int sched_init_domains(const struct cpumask *cpu_map);
1049 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
1050 extern void sched_get_rd(struct root_domain *rd);
1051 extern void sched_put_rd(struct root_domain *rd);
1052
get_rd_overloaded(struct root_domain * rd)1053 static inline int get_rd_overloaded(struct root_domain *rd)
1054 {
1055 return READ_ONCE(rd->overloaded);
1056 }
1057
set_rd_overloaded(struct root_domain * rd,int status)1058 static inline void set_rd_overloaded(struct root_domain *rd, int status)
1059 {
1060 if (get_rd_overloaded(rd) != status)
1061 WRITE_ONCE(rd->overloaded, status);
1062 }
1063
1064 #ifdef HAVE_RT_PUSH_IPI
1065 extern void rto_push_irq_work_func(struct irq_work *work);
1066 #endif
1067
1068 #ifdef CONFIG_UCLAMP_TASK
1069 /*
1070 * struct uclamp_bucket - Utilization clamp bucket
1071 * @value: utilization clamp value for tasks on this clamp bucket
1072 * @tasks: number of RUNNABLE tasks on this clamp bucket
1073 *
1074 * Keep track of how many tasks are RUNNABLE for a given utilization
1075 * clamp value.
1076 */
1077 struct uclamp_bucket {
1078 unsigned long value : bits_per(SCHED_CAPACITY_SCALE);
1079 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE);
1080 };
1081
1082 /*
1083 * struct uclamp_rq - rq's utilization clamp
1084 * @value: currently active clamp values for a rq
1085 * @bucket: utilization clamp buckets affecting a rq
1086 *
1087 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values.
1088 * A clamp value is affecting a rq when there is at least one task RUNNABLE
1089 * (or actually running) with that value.
1090 *
1091 * There are up to UCLAMP_CNT possible different clamp values, currently there
1092 * are only two: minimum utilization and maximum utilization.
1093 *
1094 * All utilization clamping values are MAX aggregated, since:
1095 * - for util_min: we want to run the CPU at least at the max of the minimum
1096 * utilization required by its currently RUNNABLE tasks.
1097 * - for util_max: we want to allow the CPU to run up to the max of the
1098 * maximum utilization allowed by its currently RUNNABLE tasks.
1099 *
1100 * Since on each system we expect only a limited number of different
1101 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track
1102 * the metrics required to compute all the per-rq utilization clamp values.
1103 */
1104 struct uclamp_rq {
1105 unsigned int value;
1106 struct uclamp_bucket bucket[UCLAMP_BUCKETS];
1107 };
1108
1109 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used);
1110 #endif /* CONFIG_UCLAMP_TASK */
1111
1112 /*
1113 * This is the main, per-CPU runqueue data structure.
1114 *
1115 * Locking rule: those places that want to lock multiple runqueues
1116 * (such as the load balancing or the thread migration code), lock
1117 * acquire operations must be ordered by ascending &runqueue.
1118 */
1119 struct rq {
1120 /* runqueue lock: */
1121 raw_spinlock_t __lock;
1122
1123 unsigned int nr_running;
1124 #ifdef CONFIG_NUMA_BALANCING
1125 unsigned int nr_numa_running;
1126 unsigned int nr_preferred_running;
1127 unsigned int numa_migrate_on;
1128 #endif
1129 #ifdef CONFIG_NO_HZ_COMMON
1130 unsigned long last_blocked_load_update_tick;
1131 unsigned int has_blocked_load;
1132 call_single_data_t nohz_csd;
1133 unsigned int nohz_tick_stopped;
1134 atomic_t nohz_flags;
1135 #endif /* CONFIG_NO_HZ_COMMON */
1136
1137 unsigned int ttwu_pending;
1138 u64 nr_switches;
1139
1140 #ifdef CONFIG_UCLAMP_TASK
1141 /* Utilization clamp values based on CPU's RUNNABLE tasks */
1142 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned;
1143 unsigned int uclamp_flags;
1144 #define UCLAMP_FLAG_IDLE 0x01
1145 #endif
1146
1147 struct cfs_rq cfs;
1148 struct rt_rq rt;
1149 struct dl_rq dl;
1150 #ifdef CONFIG_SCHED_CLASS_EXT
1151 struct scx_rq scx;
1152 #endif
1153
1154 struct sched_dl_entity fair_server;
1155
1156 #ifdef CONFIG_FAIR_GROUP_SCHED
1157 /* list of leaf cfs_rq on this CPU: */
1158 struct list_head leaf_cfs_rq_list;
1159 struct list_head *tmp_alone_branch;
1160 #endif /* CONFIG_FAIR_GROUP_SCHED */
1161
1162 /*
1163 * This is part of a global counter where only the total sum
1164 * over all CPUs matters. A task can increase this counter on
1165 * one CPU and if it got migrated afterwards it may decrease
1166 * it on another CPU. Always updated under the runqueue lock:
1167 */
1168 unsigned long nr_uninterruptible;
1169
1170 #ifdef CONFIG_SCHED_PROXY_EXEC
1171 struct task_struct __rcu *donor; /* Scheduling context */
1172 struct task_struct __rcu *curr; /* Execution context */
1173 #else
1174 union {
1175 struct task_struct __rcu *donor; /* Scheduler context */
1176 struct task_struct __rcu *curr; /* Execution context */
1177 };
1178 #endif
1179 struct sched_dl_entity *dl_server;
1180 struct task_struct *idle;
1181 struct task_struct *stop;
1182 unsigned long next_balance;
1183 struct mm_struct *prev_mm;
1184
1185 unsigned int clock_update_flags;
1186 u64 clock;
1187 /* Ensure that all clocks are in the same cache line */
1188 u64 clock_task ____cacheline_aligned;
1189 u64 clock_pelt;
1190 unsigned long lost_idle_time;
1191 u64 clock_pelt_idle;
1192 u64 clock_idle;
1193 #ifndef CONFIG_64BIT
1194 u64 clock_pelt_idle_copy;
1195 u64 clock_idle_copy;
1196 #endif
1197
1198 atomic_t nr_iowait;
1199
1200 u64 last_seen_need_resched_ns;
1201 int ticks_without_resched;
1202
1203 #ifdef CONFIG_MEMBARRIER
1204 int membarrier_state;
1205 #endif
1206
1207 struct root_domain *rd;
1208 struct sched_domain __rcu *sd;
1209
1210 unsigned long cpu_capacity;
1211
1212 struct balance_callback *balance_callback;
1213
1214 unsigned char nohz_idle_balance;
1215 unsigned char idle_balance;
1216
1217 unsigned long misfit_task_load;
1218
1219 /* For active balancing */
1220 int active_balance;
1221 int push_cpu;
1222 struct cpu_stop_work active_balance_work;
1223
1224 /* CPU of this runqueue: */
1225 int cpu;
1226 int online;
1227
1228 struct list_head cfs_tasks;
1229
1230 struct sched_avg avg_rt;
1231 struct sched_avg avg_dl;
1232 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
1233 struct sched_avg avg_irq;
1234 #endif
1235 #ifdef CONFIG_SCHED_HW_PRESSURE
1236 struct sched_avg avg_hw;
1237 #endif
1238 u64 idle_stamp;
1239 u64 avg_idle;
1240
1241 /* This is used to determine avg_idle's max value */
1242 u64 max_idle_balance_cost;
1243
1244 #ifdef CONFIG_HOTPLUG_CPU
1245 struct rcuwait hotplug_wait;
1246 #endif
1247
1248 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1249 u64 prev_irq_time;
1250 u64 psi_irq_time;
1251 #endif
1252 #ifdef CONFIG_PARAVIRT
1253 u64 prev_steal_time;
1254 #endif
1255 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
1256 u64 prev_steal_time_rq;
1257 #endif
1258
1259 /* calc_load related fields */
1260 unsigned long calc_load_update;
1261 long calc_load_active;
1262
1263 #ifdef CONFIG_SCHED_HRTICK
1264 call_single_data_t hrtick_csd;
1265 struct hrtimer hrtick_timer;
1266 ktime_t hrtick_time;
1267 #endif
1268
1269 #ifdef CONFIG_SCHEDSTATS
1270 /* latency stats */
1271 struct sched_info rq_sched_info;
1272 unsigned long long rq_cpu_time;
1273
1274 /* sys_sched_yield() stats */
1275 unsigned int yld_count;
1276
1277 /* schedule() stats */
1278 unsigned int sched_count;
1279 unsigned int sched_goidle;
1280
1281 /* try_to_wake_up() stats */
1282 unsigned int ttwu_count;
1283 unsigned int ttwu_local;
1284 #endif
1285
1286 #ifdef CONFIG_CPU_IDLE
1287 /* Must be inspected within a RCU lock section */
1288 struct cpuidle_state *idle_state;
1289 #endif
1290
1291 unsigned int nr_pinned;
1292 unsigned int push_busy;
1293 struct cpu_stop_work push_work;
1294
1295 #ifdef CONFIG_SCHED_CORE
1296 /* per rq */
1297 struct rq *core;
1298 struct task_struct *core_pick;
1299 struct sched_dl_entity *core_dl_server;
1300 unsigned int core_enabled;
1301 unsigned int core_sched_seq;
1302 struct rb_root core_tree;
1303
1304 /* shared state -- careful with sched_core_cpu_deactivate() */
1305 unsigned int core_task_seq;
1306 unsigned int core_pick_seq;
1307 unsigned long core_cookie;
1308 unsigned int core_forceidle_count;
1309 unsigned int core_forceidle_seq;
1310 unsigned int core_forceidle_occupation;
1311 u64 core_forceidle_start;
1312 #endif /* CONFIG_SCHED_CORE */
1313
1314 /* Scratch cpumask to be temporarily used under rq_lock */
1315 cpumask_var_t scratch_mask;
1316
1317 #ifdef CONFIG_CFS_BANDWIDTH
1318 call_single_data_t cfsb_csd;
1319 struct list_head cfsb_csd_list;
1320 #endif
1321 };
1322
1323 #ifdef CONFIG_FAIR_GROUP_SCHED
1324
1325 /* CPU runqueue to which this cfs_rq is attached */
rq_of(struct cfs_rq * cfs_rq)1326 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1327 {
1328 return cfs_rq->rq;
1329 }
1330
1331 #else /* !CONFIG_FAIR_GROUP_SCHED: */
1332
rq_of(struct cfs_rq * cfs_rq)1333 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1334 {
1335 return container_of(cfs_rq, struct rq, cfs);
1336 }
1337 #endif /* !CONFIG_FAIR_GROUP_SCHED */
1338
cpu_of(struct rq * rq)1339 static inline int cpu_of(struct rq *rq)
1340 {
1341 return rq->cpu;
1342 }
1343
1344 #define MDF_PUSH 0x01
1345
is_migration_disabled(struct task_struct * p)1346 static inline bool is_migration_disabled(struct task_struct *p)
1347 {
1348 return p->migration_disabled;
1349 }
1350
1351 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
1352
1353 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
1354 #define this_rq() this_cpu_ptr(&runqueues)
1355 #define task_rq(p) cpu_rq(task_cpu(p))
1356 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
1357 #define raw_rq() raw_cpu_ptr(&runqueues)
1358
1359 #ifdef CONFIG_SCHED_PROXY_EXEC
rq_set_donor(struct rq * rq,struct task_struct * t)1360 static inline void rq_set_donor(struct rq *rq, struct task_struct *t)
1361 {
1362 rcu_assign_pointer(rq->donor, t);
1363 }
1364 #else
rq_set_donor(struct rq * rq,struct task_struct * t)1365 static inline void rq_set_donor(struct rq *rq, struct task_struct *t)
1366 {
1367 /* Do nothing */
1368 }
1369 #endif
1370
1371 #ifdef CONFIG_SCHED_CORE
1372 static inline struct cpumask *sched_group_span(struct sched_group *sg);
1373
1374 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled);
1375
sched_core_enabled(struct rq * rq)1376 static inline bool sched_core_enabled(struct rq *rq)
1377 {
1378 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled;
1379 }
1380
sched_core_disabled(void)1381 static inline bool sched_core_disabled(void)
1382 {
1383 return !static_branch_unlikely(&__sched_core_enabled);
1384 }
1385
1386 /*
1387 * Be careful with this function; not for general use. The return value isn't
1388 * stable unless you actually hold a relevant rq->__lock.
1389 */
rq_lockp(struct rq * rq)1390 static inline raw_spinlock_t *rq_lockp(struct rq *rq)
1391 {
1392 if (sched_core_enabled(rq))
1393 return &rq->core->__lock;
1394
1395 return &rq->__lock;
1396 }
1397
__rq_lockp(struct rq * rq)1398 static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
1399 {
1400 if (rq->core_enabled)
1401 return &rq->core->__lock;
1402
1403 return &rq->__lock;
1404 }
1405
1406 extern bool
1407 cfs_prio_less(const struct task_struct *a, const struct task_struct *b, bool fi);
1408
1409 extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi);
1410
1411 /*
1412 * Helpers to check if the CPU's core cookie matches with the task's cookie
1413 * when core scheduling is enabled.
1414 * A special case is that the task's cookie always matches with CPU's core
1415 * cookie if the CPU is in an idle core.
1416 */
sched_cpu_cookie_match(struct rq * rq,struct task_struct * p)1417 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
1418 {
1419 /* Ignore cookie match if core scheduler is not enabled on the CPU. */
1420 if (!sched_core_enabled(rq))
1421 return true;
1422
1423 return rq->core->core_cookie == p->core_cookie;
1424 }
1425
sched_core_cookie_match(struct rq * rq,struct task_struct * p)1426 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
1427 {
1428 bool idle_core = true;
1429 int cpu;
1430
1431 /* Ignore cookie match if core scheduler is not enabled on the CPU. */
1432 if (!sched_core_enabled(rq))
1433 return true;
1434
1435 for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) {
1436 if (!available_idle_cpu(cpu)) {
1437 idle_core = false;
1438 break;
1439 }
1440 }
1441
1442 /*
1443 * A CPU in an idle core is always the best choice for tasks with
1444 * cookies.
1445 */
1446 return idle_core || rq->core->core_cookie == p->core_cookie;
1447 }
1448
sched_group_cookie_match(struct rq * rq,struct task_struct * p,struct sched_group * group)1449 static inline bool sched_group_cookie_match(struct rq *rq,
1450 struct task_struct *p,
1451 struct sched_group *group)
1452 {
1453 int cpu;
1454
1455 /* Ignore cookie match if core scheduler is not enabled on the CPU. */
1456 if (!sched_core_enabled(rq))
1457 return true;
1458
1459 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) {
1460 if (sched_core_cookie_match(cpu_rq(cpu), p))
1461 return true;
1462 }
1463 return false;
1464 }
1465
sched_core_enqueued(struct task_struct * p)1466 static inline bool sched_core_enqueued(struct task_struct *p)
1467 {
1468 return !RB_EMPTY_NODE(&p->core_node);
1469 }
1470
1471 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p);
1472 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags);
1473
1474 extern void sched_core_get(void);
1475 extern void sched_core_put(void);
1476
1477 #else /* !CONFIG_SCHED_CORE: */
1478
sched_core_enabled(struct rq * rq)1479 static inline bool sched_core_enabled(struct rq *rq)
1480 {
1481 return false;
1482 }
1483
sched_core_disabled(void)1484 static inline bool sched_core_disabled(void)
1485 {
1486 return true;
1487 }
1488
rq_lockp(struct rq * rq)1489 static inline raw_spinlock_t *rq_lockp(struct rq *rq)
1490 {
1491 return &rq->__lock;
1492 }
1493
__rq_lockp(struct rq * rq)1494 static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
1495 {
1496 return &rq->__lock;
1497 }
1498
sched_cpu_cookie_match(struct rq * rq,struct task_struct * p)1499 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
1500 {
1501 return true;
1502 }
1503
sched_core_cookie_match(struct rq * rq,struct task_struct * p)1504 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
1505 {
1506 return true;
1507 }
1508
sched_group_cookie_match(struct rq * rq,struct task_struct * p,struct sched_group * group)1509 static inline bool sched_group_cookie_match(struct rq *rq,
1510 struct task_struct *p,
1511 struct sched_group *group)
1512 {
1513 return true;
1514 }
1515
1516 #endif /* !CONFIG_SCHED_CORE */
1517
1518 #ifdef CONFIG_RT_GROUP_SCHED
1519 # ifdef CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED
1520 DECLARE_STATIC_KEY_FALSE(rt_group_sched);
rt_group_sched_enabled(void)1521 static inline bool rt_group_sched_enabled(void)
1522 {
1523 return static_branch_unlikely(&rt_group_sched);
1524 }
1525 # else /* !CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED: */
1526 DECLARE_STATIC_KEY_TRUE(rt_group_sched);
rt_group_sched_enabled(void)1527 static inline bool rt_group_sched_enabled(void)
1528 {
1529 return static_branch_likely(&rt_group_sched);
1530 }
1531 # endif /* !CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED */
1532 #else /* !CONFIG_RT_GROUP_SCHED: */
1533 # define rt_group_sched_enabled() false
1534 #endif /* !CONFIG_RT_GROUP_SCHED */
1535
lockdep_assert_rq_held(struct rq * rq)1536 static inline void lockdep_assert_rq_held(struct rq *rq)
1537 {
1538 lockdep_assert_held(__rq_lockp(rq));
1539 }
1540
1541 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass);
1542 extern bool raw_spin_rq_trylock(struct rq *rq);
1543 extern void raw_spin_rq_unlock(struct rq *rq);
1544
raw_spin_rq_lock(struct rq * rq)1545 static inline void raw_spin_rq_lock(struct rq *rq)
1546 {
1547 raw_spin_rq_lock_nested(rq, 0);
1548 }
1549
raw_spin_rq_lock_irq(struct rq * rq)1550 static inline void raw_spin_rq_lock_irq(struct rq *rq)
1551 {
1552 local_irq_disable();
1553 raw_spin_rq_lock(rq);
1554 }
1555
raw_spin_rq_unlock_irq(struct rq * rq)1556 static inline void raw_spin_rq_unlock_irq(struct rq *rq)
1557 {
1558 raw_spin_rq_unlock(rq);
1559 local_irq_enable();
1560 }
1561
_raw_spin_rq_lock_irqsave(struct rq * rq)1562 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq)
1563 {
1564 unsigned long flags;
1565
1566 local_irq_save(flags);
1567 raw_spin_rq_lock(rq);
1568
1569 return flags;
1570 }
1571
raw_spin_rq_unlock_irqrestore(struct rq * rq,unsigned long flags)1572 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags)
1573 {
1574 raw_spin_rq_unlock(rq);
1575 local_irq_restore(flags);
1576 }
1577
1578 #define raw_spin_rq_lock_irqsave(rq, flags) \
1579 do { \
1580 flags = _raw_spin_rq_lock_irqsave(rq); \
1581 } while (0)
1582
1583 #ifdef CONFIG_SCHED_SMT
1584 extern void __update_idle_core(struct rq *rq);
1585
update_idle_core(struct rq * rq)1586 static inline void update_idle_core(struct rq *rq)
1587 {
1588 if (static_branch_unlikely(&sched_smt_present))
1589 __update_idle_core(rq);
1590 }
1591
1592 #else /* !CONFIG_SCHED_SMT: */
update_idle_core(struct rq * rq)1593 static inline void update_idle_core(struct rq *rq) { }
1594 #endif /* !CONFIG_SCHED_SMT */
1595
1596 #ifdef CONFIG_FAIR_GROUP_SCHED
1597
task_of(struct sched_entity * se)1598 static inline struct task_struct *task_of(struct sched_entity *se)
1599 {
1600 WARN_ON_ONCE(!entity_is_task(se));
1601 return container_of(se, struct task_struct, se);
1602 }
1603
task_cfs_rq(struct task_struct * p)1604 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
1605 {
1606 return p->se.cfs_rq;
1607 }
1608
1609 /* runqueue on which this entity is (to be) queued */
cfs_rq_of(const struct sched_entity * se)1610 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se)
1611 {
1612 return se->cfs_rq;
1613 }
1614
1615 /* runqueue "owned" by this group */
group_cfs_rq(struct sched_entity * grp)1616 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
1617 {
1618 return grp->my_q;
1619 }
1620
1621 #else /* !CONFIG_FAIR_GROUP_SCHED: */
1622
1623 #define task_of(_se) container_of(_se, struct task_struct, se)
1624
task_cfs_rq(const struct task_struct * p)1625 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p)
1626 {
1627 return &task_rq(p)->cfs;
1628 }
1629
cfs_rq_of(const struct sched_entity * se)1630 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se)
1631 {
1632 const struct task_struct *p = task_of(se);
1633 struct rq *rq = task_rq(p);
1634
1635 return &rq->cfs;
1636 }
1637
1638 /* runqueue "owned" by this group */
group_cfs_rq(struct sched_entity * grp)1639 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
1640 {
1641 return NULL;
1642 }
1643
1644 #endif /* !CONFIG_FAIR_GROUP_SCHED */
1645
1646 extern void update_rq_clock(struct rq *rq);
1647
1648 /*
1649 * rq::clock_update_flags bits
1650 *
1651 * %RQCF_REQ_SKIP - will request skipping of clock update on the next
1652 * call to __schedule(). This is an optimisation to avoid
1653 * neighbouring rq clock updates.
1654 *
1655 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is
1656 * in effect and calls to update_rq_clock() are being ignored.
1657 *
1658 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been
1659 * made to update_rq_clock() since the last time rq::lock was pinned.
1660 *
1661 * If inside of __schedule(), clock_update_flags will have been
1662 * shifted left (a left shift is a cheap operation for the fast path
1663 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use,
1664 *
1665 * if (rq-clock_update_flags >= RQCF_UPDATED)
1666 *
1667 * to check if %RQCF_UPDATED is set. It'll never be shifted more than
1668 * one position though, because the next rq_unpin_lock() will shift it
1669 * back.
1670 */
1671 #define RQCF_REQ_SKIP 0x01
1672 #define RQCF_ACT_SKIP 0x02
1673 #define RQCF_UPDATED 0x04
1674
assert_clock_updated(struct rq * rq)1675 static inline void assert_clock_updated(struct rq *rq)
1676 {
1677 /*
1678 * The only reason for not seeing a clock update since the
1679 * last rq_pin_lock() is if we're currently skipping updates.
1680 */
1681 WARN_ON_ONCE(rq->clock_update_flags < RQCF_ACT_SKIP);
1682 }
1683
rq_clock(struct rq * rq)1684 static inline u64 rq_clock(struct rq *rq)
1685 {
1686 lockdep_assert_rq_held(rq);
1687 assert_clock_updated(rq);
1688
1689 return rq->clock;
1690 }
1691
rq_clock_task(struct rq * rq)1692 static inline u64 rq_clock_task(struct rq *rq)
1693 {
1694 lockdep_assert_rq_held(rq);
1695 assert_clock_updated(rq);
1696
1697 return rq->clock_task;
1698 }
1699
rq_clock_skip_update(struct rq * rq)1700 static inline void rq_clock_skip_update(struct rq *rq)
1701 {
1702 lockdep_assert_rq_held(rq);
1703 rq->clock_update_flags |= RQCF_REQ_SKIP;
1704 }
1705
1706 /*
1707 * See rt task throttling, which is the only time a skip
1708 * request is canceled.
1709 */
rq_clock_cancel_skipupdate(struct rq * rq)1710 static inline void rq_clock_cancel_skipupdate(struct rq *rq)
1711 {
1712 lockdep_assert_rq_held(rq);
1713 rq->clock_update_flags &= ~RQCF_REQ_SKIP;
1714 }
1715
1716 /*
1717 * During cpu offlining and rq wide unthrottling, we can trigger
1718 * an update_rq_clock() for several cfs and rt runqueues (Typically
1719 * when using list_for_each_entry_*)
1720 * rq_clock_start_loop_update() can be called after updating the clock
1721 * once and before iterating over the list to prevent multiple update.
1722 * After the iterative traversal, we need to call rq_clock_stop_loop_update()
1723 * to clear RQCF_ACT_SKIP of rq->clock_update_flags.
1724 */
rq_clock_start_loop_update(struct rq * rq)1725 static inline void rq_clock_start_loop_update(struct rq *rq)
1726 {
1727 lockdep_assert_rq_held(rq);
1728 WARN_ON_ONCE(rq->clock_update_flags & RQCF_ACT_SKIP);
1729 rq->clock_update_flags |= RQCF_ACT_SKIP;
1730 }
1731
rq_clock_stop_loop_update(struct rq * rq)1732 static inline void rq_clock_stop_loop_update(struct rq *rq)
1733 {
1734 lockdep_assert_rq_held(rq);
1735 rq->clock_update_flags &= ~RQCF_ACT_SKIP;
1736 }
1737
1738 struct rq_flags {
1739 unsigned long flags;
1740 struct pin_cookie cookie;
1741 /*
1742 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
1743 * current pin context is stashed here in case it needs to be
1744 * restored in rq_repin_lock().
1745 */
1746 unsigned int clock_update_flags;
1747 };
1748
1749 extern struct balance_callback balance_push_callback;
1750
1751 #ifdef CONFIG_SCHED_CLASS_EXT
1752 extern const struct sched_class ext_sched_class;
1753
1754 DECLARE_STATIC_KEY_FALSE(__scx_enabled); /* SCX BPF scheduler loaded */
1755 DECLARE_STATIC_KEY_FALSE(__scx_switched_all); /* all fair class tasks on SCX */
1756
1757 #define scx_enabled() static_branch_unlikely(&__scx_enabled)
1758 #define scx_switched_all() static_branch_unlikely(&__scx_switched_all)
1759
scx_rq_clock_update(struct rq * rq,u64 clock)1760 static inline void scx_rq_clock_update(struct rq *rq, u64 clock)
1761 {
1762 if (!scx_enabled())
1763 return;
1764 WRITE_ONCE(rq->scx.clock, clock);
1765 smp_store_release(&rq->scx.flags, rq->scx.flags | SCX_RQ_CLK_VALID);
1766 }
1767
scx_rq_clock_invalidate(struct rq * rq)1768 static inline void scx_rq_clock_invalidate(struct rq *rq)
1769 {
1770 if (!scx_enabled())
1771 return;
1772 WRITE_ONCE(rq->scx.flags, rq->scx.flags & ~SCX_RQ_CLK_VALID);
1773 }
1774
1775 #else /* !CONFIG_SCHED_CLASS_EXT: */
1776 #define scx_enabled() false
1777 #define scx_switched_all() false
1778
scx_rq_clock_update(struct rq * rq,u64 clock)1779 static inline void scx_rq_clock_update(struct rq *rq, u64 clock) {}
scx_rq_clock_invalidate(struct rq * rq)1780 static inline void scx_rq_clock_invalidate(struct rq *rq) {}
1781 #endif /* !CONFIG_SCHED_CLASS_EXT */
1782
1783 /*
1784 * Lockdep annotation that avoids accidental unlocks; it's like a
1785 * sticky/continuous lockdep_assert_held().
1786 *
1787 * This avoids code that has access to 'struct rq *rq' (basically everything in
1788 * the scheduler) from accidentally unlocking the rq if they do not also have a
1789 * copy of the (on-stack) 'struct rq_flags rf'.
1790 *
1791 * Also see Documentation/locking/lockdep-design.rst.
1792 */
rq_pin_lock(struct rq * rq,struct rq_flags * rf)1793 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
1794 {
1795 rf->cookie = lockdep_pin_lock(__rq_lockp(rq));
1796
1797 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
1798 rf->clock_update_flags = 0;
1799 WARN_ON_ONCE(rq->balance_callback && rq->balance_callback != &balance_push_callback);
1800 }
1801
rq_unpin_lock(struct rq * rq,struct rq_flags * rf)1802 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
1803 {
1804 if (rq->clock_update_flags > RQCF_ACT_SKIP)
1805 rf->clock_update_flags = RQCF_UPDATED;
1806
1807 scx_rq_clock_invalidate(rq);
1808 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie);
1809 }
1810
rq_repin_lock(struct rq * rq,struct rq_flags * rf)1811 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
1812 {
1813 lockdep_repin_lock(__rq_lockp(rq), rf->cookie);
1814
1815 /*
1816 * Restore the value we stashed in @rf for this pin context.
1817 */
1818 rq->clock_update_flags |= rf->clock_update_flags;
1819 }
1820
1821 extern
1822 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1823 __acquires(rq->lock);
1824
1825 extern
1826 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1827 __acquires(p->pi_lock)
1828 __acquires(rq->lock);
1829
__task_rq_unlock(struct rq * rq,struct rq_flags * rf)1830 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
1831 __releases(rq->lock)
1832 {
1833 rq_unpin_lock(rq, rf);
1834 raw_spin_rq_unlock(rq);
1835 }
1836
1837 static inline void
task_rq_unlock(struct rq * rq,struct task_struct * p,struct rq_flags * rf)1838 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
1839 __releases(rq->lock)
1840 __releases(p->pi_lock)
1841 {
1842 rq_unpin_lock(rq, rf);
1843 raw_spin_rq_unlock(rq);
1844 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1845 }
1846
1847 DEFINE_LOCK_GUARD_1(task_rq_lock, struct task_struct,
1848 _T->rq = task_rq_lock(_T->lock, &_T->rf),
1849 task_rq_unlock(_T->rq, _T->lock, &_T->rf),
1850 struct rq *rq; struct rq_flags rf)
1851
rq_lock_irqsave(struct rq * rq,struct rq_flags * rf)1852 static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
1853 __acquires(rq->lock)
1854 {
1855 raw_spin_rq_lock_irqsave(rq, rf->flags);
1856 rq_pin_lock(rq, rf);
1857 }
1858
rq_lock_irq(struct rq * rq,struct rq_flags * rf)1859 static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf)
1860 __acquires(rq->lock)
1861 {
1862 raw_spin_rq_lock_irq(rq);
1863 rq_pin_lock(rq, rf);
1864 }
1865
rq_lock(struct rq * rq,struct rq_flags * rf)1866 static inline void rq_lock(struct rq *rq, struct rq_flags *rf)
1867 __acquires(rq->lock)
1868 {
1869 raw_spin_rq_lock(rq);
1870 rq_pin_lock(rq, rf);
1871 }
1872
rq_unlock_irqrestore(struct rq * rq,struct rq_flags * rf)1873 static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
1874 __releases(rq->lock)
1875 {
1876 rq_unpin_lock(rq, rf);
1877 raw_spin_rq_unlock_irqrestore(rq, rf->flags);
1878 }
1879
rq_unlock_irq(struct rq * rq,struct rq_flags * rf)1880 static inline void rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
1881 __releases(rq->lock)
1882 {
1883 rq_unpin_lock(rq, rf);
1884 raw_spin_rq_unlock_irq(rq);
1885 }
1886
rq_unlock(struct rq * rq,struct rq_flags * rf)1887 static inline void rq_unlock(struct rq *rq, struct rq_flags *rf)
1888 __releases(rq->lock)
1889 {
1890 rq_unpin_lock(rq, rf);
1891 raw_spin_rq_unlock(rq);
1892 }
1893
1894 DEFINE_LOCK_GUARD_1(rq_lock, struct rq,
1895 rq_lock(_T->lock, &_T->rf),
1896 rq_unlock(_T->lock, &_T->rf),
1897 struct rq_flags rf)
1898
1899 DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq,
1900 rq_lock_irq(_T->lock, &_T->rf),
1901 rq_unlock_irq(_T->lock, &_T->rf),
1902 struct rq_flags rf)
1903
1904 DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq,
1905 rq_lock_irqsave(_T->lock, &_T->rf),
1906 rq_unlock_irqrestore(_T->lock, &_T->rf),
1907 struct rq_flags rf)
1908
this_rq_lock_irq(struct rq_flags * rf)1909 static inline struct rq *this_rq_lock_irq(struct rq_flags *rf)
1910 __acquires(rq->lock)
1911 {
1912 struct rq *rq;
1913
1914 local_irq_disable();
1915 rq = this_rq();
1916 rq_lock(rq, rf);
1917
1918 return rq;
1919 }
1920
1921 #ifdef CONFIG_NUMA
1922
1923 enum numa_topology_type {
1924 NUMA_DIRECT,
1925 NUMA_GLUELESS_MESH,
1926 NUMA_BACKPLANE,
1927 };
1928
1929 extern enum numa_topology_type sched_numa_topology_type;
1930 extern int sched_max_numa_distance;
1931 extern bool find_numa_distance(int distance);
1932 extern void sched_init_numa(int offline_node);
1933 extern void sched_update_numa(int cpu, bool online);
1934 extern void sched_domains_numa_masks_set(unsigned int cpu);
1935 extern void sched_domains_numa_masks_clear(unsigned int cpu);
1936 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
1937
1938 #else /* !CONFIG_NUMA: */
1939
sched_init_numa(int offline_node)1940 static inline void sched_init_numa(int offline_node) { }
sched_update_numa(int cpu,bool online)1941 static inline void sched_update_numa(int cpu, bool online) { }
sched_domains_numa_masks_set(unsigned int cpu)1942 static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
sched_domains_numa_masks_clear(unsigned int cpu)1943 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
1944
sched_numa_find_closest(const struct cpumask * cpus,int cpu)1945 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
1946 {
1947 return nr_cpu_ids;
1948 }
1949
1950 #endif /* !CONFIG_NUMA */
1951
1952 #ifdef CONFIG_NUMA_BALANCING
1953
1954 /* The regions in numa_faults array from task_struct */
1955 enum numa_faults_stats {
1956 NUMA_MEM = 0,
1957 NUMA_CPU,
1958 NUMA_MEMBUF,
1959 NUMA_CPUBUF
1960 };
1961
1962 extern void sched_setnuma(struct task_struct *p, int node);
1963 extern int migrate_task_to(struct task_struct *p, int cpu);
1964 extern int migrate_swap(struct task_struct *p, struct task_struct *t,
1965 int cpu, int scpu);
1966 extern void init_numa_balancing(u64 clone_flags, struct task_struct *p);
1967
1968 #else /* !CONFIG_NUMA_BALANCING: */
1969
1970 static inline void
init_numa_balancing(u64 clone_flags,struct task_struct * p)1971 init_numa_balancing(u64 clone_flags, struct task_struct *p)
1972 {
1973 }
1974
1975 #endif /* !CONFIG_NUMA_BALANCING */
1976
1977 static inline void
queue_balance_callback(struct rq * rq,struct balance_callback * head,void (* func)(struct rq * rq))1978 queue_balance_callback(struct rq *rq,
1979 struct balance_callback *head,
1980 void (*func)(struct rq *rq))
1981 {
1982 lockdep_assert_rq_held(rq);
1983
1984 /*
1985 * Don't (re)queue an already queued item; nor queue anything when
1986 * balance_push() is active, see the comment with
1987 * balance_push_callback.
1988 */
1989 if (unlikely(head->next || rq->balance_callback == &balance_push_callback))
1990 return;
1991
1992 head->func = func;
1993 head->next = rq->balance_callback;
1994 rq->balance_callback = head;
1995 }
1996
1997 #define rcu_dereference_check_sched_domain(p) \
1998 rcu_dereference_check((p), lockdep_is_held(&sched_domains_mutex))
1999
2000 /*
2001 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
2002 * See destroy_sched_domains: call_rcu for details.
2003 *
2004 * The domain tree of any CPU may only be accessed from within
2005 * preempt-disabled sections.
2006 */
2007 #define for_each_domain(cpu, __sd) \
2008 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
2009 __sd; __sd = __sd->parent)
2010
2011 /* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */
2012 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) |
2013 static const unsigned int SD_SHARED_CHILD_MASK =
2014 #include <linux/sched/sd_flags.h>
2015 0;
2016 #undef SD_FLAG
2017
2018 /**
2019 * highest_flag_domain - Return highest sched_domain containing flag.
2020 * @cpu: The CPU whose highest level of sched domain is to
2021 * be returned.
2022 * @flag: The flag to check for the highest sched_domain
2023 * for the given CPU.
2024 *
2025 * Returns the highest sched_domain of a CPU which contains @flag. If @flag has
2026 * the SDF_SHARED_CHILD metaflag, all the children domains also have @flag.
2027 */
highest_flag_domain(int cpu,int flag)2028 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
2029 {
2030 struct sched_domain *sd, *hsd = NULL;
2031
2032 for_each_domain(cpu, sd) {
2033 if (sd->flags & flag) {
2034 hsd = sd;
2035 continue;
2036 }
2037
2038 /*
2039 * Stop the search if @flag is known to be shared at lower
2040 * levels. It will not be found further up.
2041 */
2042 if (flag & SD_SHARED_CHILD_MASK)
2043 break;
2044 }
2045
2046 return hsd;
2047 }
2048
lowest_flag_domain(int cpu,int flag)2049 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
2050 {
2051 struct sched_domain *sd;
2052
2053 for_each_domain(cpu, sd) {
2054 if (sd->flags & flag)
2055 break;
2056 }
2057
2058 return sd;
2059 }
2060
2061 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);
2062 DECLARE_PER_CPU(int, sd_llc_size);
2063 DECLARE_PER_CPU(int, sd_llc_id);
2064 DECLARE_PER_CPU(int, sd_share_id);
2065 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
2066 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);
2067 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
2068 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
2069
2070 extern struct static_key_false sched_asym_cpucapacity;
2071 extern struct static_key_false sched_cluster_active;
2072
sched_asym_cpucap_active(void)2073 static __always_inline bool sched_asym_cpucap_active(void)
2074 {
2075 return static_branch_unlikely(&sched_asym_cpucapacity);
2076 }
2077
2078 struct sched_group_capacity {
2079 atomic_t ref;
2080 /*
2081 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
2082 * for a single CPU.
2083 */
2084 unsigned long capacity;
2085 unsigned long min_capacity; /* Min per-CPU capacity in group */
2086 unsigned long max_capacity; /* Max per-CPU capacity in group */
2087 unsigned long next_update;
2088 int imbalance; /* XXX unrelated to capacity but shared group state */
2089
2090 int id;
2091
2092 unsigned long cpumask[]; /* Balance mask */
2093 };
2094
2095 struct sched_group {
2096 struct sched_group *next; /* Must be a circular list */
2097 atomic_t ref;
2098
2099 unsigned int group_weight;
2100 unsigned int cores;
2101 struct sched_group_capacity *sgc;
2102 int asym_prefer_cpu; /* CPU of highest priority in group */
2103 int flags;
2104
2105 /*
2106 * The CPUs this group covers.
2107 *
2108 * NOTE: this field is variable length. (Allocated dynamically
2109 * by attaching extra space to the end of the structure,
2110 * depending on how many CPUs the kernel has booted up with)
2111 */
2112 unsigned long cpumask[];
2113 };
2114
sched_group_span(struct sched_group * sg)2115 static inline struct cpumask *sched_group_span(struct sched_group *sg)
2116 {
2117 return to_cpumask(sg->cpumask);
2118 }
2119
2120 /*
2121 * See build_balance_mask().
2122 */
group_balance_mask(struct sched_group * sg)2123 static inline struct cpumask *group_balance_mask(struct sched_group *sg)
2124 {
2125 return to_cpumask(sg->sgc->cpumask);
2126 }
2127
2128 extern int group_balance_cpu(struct sched_group *sg);
2129
2130 extern void update_sched_domain_debugfs(void);
2131 extern void dirty_sched_domain_sysctl(int cpu);
2132
2133 extern int sched_update_scaling(void);
2134
task_user_cpus(struct task_struct * p)2135 static inline const struct cpumask *task_user_cpus(struct task_struct *p)
2136 {
2137 if (!p->user_cpus_ptr)
2138 return cpu_possible_mask; /* &init_task.cpus_mask */
2139 return p->user_cpus_ptr;
2140 }
2141
2142 #ifdef CONFIG_CGROUP_SCHED
2143
2144 /*
2145 * Return the group to which this tasks belongs.
2146 *
2147 * We cannot use task_css() and friends because the cgroup subsystem
2148 * changes that value before the cgroup_subsys::attach() method is called,
2149 * therefore we cannot pin it and might observe the wrong value.
2150 *
2151 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
2152 * core changes this before calling sched_move_task().
2153 *
2154 * Instead we use a 'copy' which is updated from sched_move_task() while
2155 * holding both task_struct::pi_lock and rq::lock.
2156 */
task_group(struct task_struct * p)2157 static inline struct task_group *task_group(struct task_struct *p)
2158 {
2159 return p->sched_task_group;
2160 }
2161
2162 /* 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)2163 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
2164 {
2165 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
2166 struct task_group *tg = task_group(p);
2167 #endif
2168
2169 #ifdef CONFIG_FAIR_GROUP_SCHED
2170 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
2171 p->se.cfs_rq = tg->cfs_rq[cpu];
2172 p->se.parent = tg->se[cpu];
2173 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0;
2174 #endif
2175
2176 #ifdef CONFIG_RT_GROUP_SCHED
2177 /*
2178 * p->rt.rt_rq is NULL initially and it is easier to assign
2179 * root_task_group's rt_rq than switching in rt_rq_of_se()
2180 * Clobbers tg(!)
2181 */
2182 if (!rt_group_sched_enabled())
2183 tg = &root_task_group;
2184 p->rt.rt_rq = tg->rt_rq[cpu];
2185 p->rt.parent = tg->rt_se[cpu];
2186 #endif /* CONFIG_RT_GROUP_SCHED */
2187 }
2188
2189 #else /* !CONFIG_CGROUP_SCHED: */
2190
set_task_rq(struct task_struct * p,unsigned int cpu)2191 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
2192
task_group(struct task_struct * p)2193 static inline struct task_group *task_group(struct task_struct *p)
2194 {
2195 return NULL;
2196 }
2197
2198 #endif /* !CONFIG_CGROUP_SCHED */
2199
__set_task_cpu(struct task_struct * p,unsigned int cpu)2200 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
2201 {
2202 set_task_rq(p, cpu);
2203 #ifdef CONFIG_SMP
2204 /*
2205 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
2206 * successfully executed on another CPU. We must ensure that updates of
2207 * per-task data have been completed by this moment.
2208 */
2209 smp_wmb();
2210 WRITE_ONCE(task_thread_info(p)->cpu, cpu);
2211 p->wake_cpu = cpu;
2212 #endif /* CONFIG_SMP */
2213 }
2214
2215 /*
2216 * Tunables:
2217 */
2218
2219 #define SCHED_FEAT(name, enabled) \
2220 __SCHED_FEAT_##name ,
2221
2222 enum {
2223 #include "features.h"
2224 __SCHED_FEAT_NR,
2225 };
2226
2227 #undef SCHED_FEAT
2228
2229 /*
2230 * To support run-time toggling of sched features, all the translation units
2231 * (but core.c) reference the sysctl_sched_features defined in core.c.
2232 */
2233 extern __read_mostly unsigned int sysctl_sched_features;
2234
2235 #ifdef CONFIG_JUMP_LABEL
2236
2237 #define SCHED_FEAT(name, enabled) \
2238 static __always_inline bool static_branch_##name(struct static_key *key) \
2239 { \
2240 return static_key_##enabled(key); \
2241 }
2242
2243 #include "features.h"
2244 #undef SCHED_FEAT
2245
2246 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
2247 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
2248
2249 #else /* !CONFIG_JUMP_LABEL: */
2250
2251 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
2252
2253 #endif /* !CONFIG_JUMP_LABEL */
2254
2255 extern struct static_key_false sched_numa_balancing;
2256 extern struct static_key_false sched_schedstats;
2257
global_rt_period(void)2258 static inline u64 global_rt_period(void)
2259 {
2260 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
2261 }
2262
global_rt_runtime(void)2263 static inline u64 global_rt_runtime(void)
2264 {
2265 if (sysctl_sched_rt_runtime < 0)
2266 return RUNTIME_INF;
2267
2268 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
2269 }
2270
2271 /*
2272 * Is p the current execution context?
2273 */
task_current(struct rq * rq,struct task_struct * p)2274 static inline int task_current(struct rq *rq, struct task_struct *p)
2275 {
2276 return rq->curr == p;
2277 }
2278
2279 /*
2280 * Is p the current scheduling context?
2281 *
2282 * Note that it might be the current execution context at the same time if
2283 * rq->curr == rq->donor == p.
2284 */
task_current_donor(struct rq * rq,struct task_struct * p)2285 static inline int task_current_donor(struct rq *rq, struct task_struct *p)
2286 {
2287 return rq->donor == p;
2288 }
2289
task_is_blocked(struct task_struct * p)2290 static inline bool task_is_blocked(struct task_struct *p)
2291 {
2292 if (!sched_proxy_exec())
2293 return false;
2294
2295 return !!p->blocked_on;
2296 }
2297
task_on_cpu(struct rq * rq,struct task_struct * p)2298 static inline int task_on_cpu(struct rq *rq, struct task_struct *p)
2299 {
2300 return p->on_cpu;
2301 }
2302
task_on_rq_queued(struct task_struct * p)2303 static inline int task_on_rq_queued(struct task_struct *p)
2304 {
2305 return READ_ONCE(p->on_rq) == TASK_ON_RQ_QUEUED;
2306 }
2307
task_on_rq_migrating(struct task_struct * p)2308 static inline int task_on_rq_migrating(struct task_struct *p)
2309 {
2310 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
2311 }
2312
2313 /* Wake flags. The first three directly map to some SD flag value */
2314 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */
2315 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */
2316 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */
2317
2318 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */
2319 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */
2320 #define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */
2321 #define WF_RQ_SELECTED 0x80 /* ->select_task_rq() was called */
2322
2323 static_assert(WF_EXEC == SD_BALANCE_EXEC);
2324 static_assert(WF_FORK == SD_BALANCE_FORK);
2325 static_assert(WF_TTWU == SD_BALANCE_WAKE);
2326
2327 /*
2328 * To aid in avoiding the subversion of "niceness" due to uneven distribution
2329 * of tasks with abnormal "nice" values across CPUs the contribution that
2330 * each task makes to its run queue's load is weighted according to its
2331 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
2332 * scaled version of the new time slice allocation that they receive on time
2333 * slice expiry etc.
2334 */
2335
2336 #define WEIGHT_IDLEPRIO 3
2337 #define WMULT_IDLEPRIO 1431655765
2338
2339 extern const int sched_prio_to_weight[40];
2340 extern const u32 sched_prio_to_wmult[40];
2341
2342 /*
2343 * {de,en}queue flags:
2344 *
2345 * DEQUEUE_SLEEP - task is no longer runnable
2346 * ENQUEUE_WAKEUP - task just became runnable
2347 *
2348 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
2349 * are in a known state which allows modification. Such pairs
2350 * should preserve as much state as possible.
2351 *
2352 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
2353 * in the runqueue.
2354 *
2355 * NOCLOCK - skip the update_rq_clock() (avoids double updates)
2356 *
2357 * MIGRATION - p->on_rq == TASK_ON_RQ_MIGRATING (used for DEADLINE)
2358 *
2359 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
2360 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
2361 * ENQUEUE_MIGRATED - the task was migrated during wakeup
2362 * ENQUEUE_RQ_SELECTED - ->select_task_rq() was called
2363 *
2364 */
2365
2366 #define DEQUEUE_SLEEP 0x01 /* Matches ENQUEUE_WAKEUP */
2367 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */
2368 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */
2369 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */
2370 #define DEQUEUE_SPECIAL 0x10
2371 #define DEQUEUE_MIGRATING 0x100 /* Matches ENQUEUE_MIGRATING */
2372 #define DEQUEUE_DELAYED 0x200 /* Matches ENQUEUE_DELAYED */
2373 #define DEQUEUE_THROTTLE 0x800
2374
2375 #define ENQUEUE_WAKEUP 0x01
2376 #define ENQUEUE_RESTORE 0x02
2377 #define ENQUEUE_MOVE 0x04
2378 #define ENQUEUE_NOCLOCK 0x08
2379
2380 #define ENQUEUE_HEAD 0x10
2381 #define ENQUEUE_REPLENISH 0x20
2382 #define ENQUEUE_MIGRATED 0x40
2383 #define ENQUEUE_INITIAL 0x80
2384 #define ENQUEUE_MIGRATING 0x100
2385 #define ENQUEUE_DELAYED 0x200
2386 #define ENQUEUE_RQ_SELECTED 0x400
2387
2388 #define RETRY_TASK ((void *)-1UL)
2389
2390 struct affinity_context {
2391 const struct cpumask *new_mask;
2392 struct cpumask *user_mask;
2393 unsigned int flags;
2394 };
2395
2396 extern s64 update_curr_common(struct rq *rq);
2397
2398 struct sched_class {
2399
2400 #ifdef CONFIG_UCLAMP_TASK
2401 int uclamp_enabled;
2402 #endif
2403
2404 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
2405 bool (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
2406 void (*yield_task) (struct rq *rq);
2407 bool (*yield_to_task)(struct rq *rq, struct task_struct *p);
2408
2409 void (*wakeup_preempt)(struct rq *rq, struct task_struct *p, int flags);
2410
2411 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
2412 struct task_struct *(*pick_task)(struct rq *rq);
2413 /*
2414 * Optional! When implemented pick_next_task() should be equivalent to:
2415 *
2416 * next = pick_task();
2417 * if (next) {
2418 * put_prev_task(prev);
2419 * set_next_task_first(next);
2420 * }
2421 */
2422 struct task_struct *(*pick_next_task)(struct rq *rq, struct task_struct *prev);
2423
2424 void (*put_prev_task)(struct rq *rq, struct task_struct *p, struct task_struct *next);
2425 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
2426
2427 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags);
2428
2429 void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
2430
2431 void (*task_woken)(struct rq *this_rq, struct task_struct *task);
2432
2433 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx);
2434
2435 void (*rq_online)(struct rq *rq);
2436 void (*rq_offline)(struct rq *rq);
2437
2438 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq);
2439
2440 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued);
2441 void (*task_fork)(struct task_struct *p);
2442 void (*task_dead)(struct task_struct *p);
2443
2444 /*
2445 * The switched_from() call is allowed to drop rq->lock, therefore we
2446 * cannot assume the switched_from/switched_to pair is serialized by
2447 * rq->lock. They are however serialized by p->pi_lock.
2448 */
2449 void (*switching_to) (struct rq *this_rq, struct task_struct *task);
2450 void (*switched_from)(struct rq *this_rq, struct task_struct *task);
2451 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
2452 void (*reweight_task)(struct rq *this_rq, struct task_struct *task,
2453 const struct load_weight *lw);
2454 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
2455 int oldprio);
2456
2457 unsigned int (*get_rr_interval)(struct rq *rq,
2458 struct task_struct *task);
2459
2460 void (*update_curr)(struct rq *rq);
2461
2462 #ifdef CONFIG_FAIR_GROUP_SCHED
2463 void (*task_change_group)(struct task_struct *p);
2464 #endif
2465
2466 #ifdef CONFIG_SCHED_CORE
2467 int (*task_is_throttled)(struct task_struct *p, int cpu);
2468 #endif
2469 };
2470
put_prev_task(struct rq * rq,struct task_struct * prev)2471 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
2472 {
2473 WARN_ON_ONCE(rq->donor != prev);
2474 prev->sched_class->put_prev_task(rq, prev, NULL);
2475 }
2476
set_next_task(struct rq * rq,struct task_struct * next)2477 static inline void set_next_task(struct rq *rq, struct task_struct *next)
2478 {
2479 next->sched_class->set_next_task(rq, next, false);
2480 }
2481
2482 static inline void
__put_prev_set_next_dl_server(struct rq * rq,struct task_struct * prev,struct task_struct * next)2483 __put_prev_set_next_dl_server(struct rq *rq,
2484 struct task_struct *prev,
2485 struct task_struct *next)
2486 {
2487 prev->dl_server = NULL;
2488 next->dl_server = rq->dl_server;
2489 rq->dl_server = NULL;
2490 }
2491
put_prev_set_next_task(struct rq * rq,struct task_struct * prev,struct task_struct * next)2492 static inline void put_prev_set_next_task(struct rq *rq,
2493 struct task_struct *prev,
2494 struct task_struct *next)
2495 {
2496 WARN_ON_ONCE(rq->donor != prev);
2497
2498 __put_prev_set_next_dl_server(rq, prev, next);
2499
2500 if (next == prev)
2501 return;
2502
2503 prev->sched_class->put_prev_task(rq, prev, next);
2504 next->sched_class->set_next_task(rq, next, true);
2505 }
2506
2507 /*
2508 * Helper to define a sched_class instance; each one is placed in a separate
2509 * section which is ordered by the linker script:
2510 *
2511 * include/asm-generic/vmlinux.lds.h
2512 *
2513 * *CAREFUL* they are laid out in *REVERSE* order!!!
2514 *
2515 * Also enforce alignment on the instance, not the type, to guarantee layout.
2516 */
2517 #define DEFINE_SCHED_CLASS(name) \
2518 const struct sched_class name##_sched_class \
2519 __aligned(__alignof__(struct sched_class)) \
2520 __section("__" #name "_sched_class")
2521
2522 /* Defined in include/asm-generic/vmlinux.lds.h */
2523 extern struct sched_class __sched_class_highest[];
2524 extern struct sched_class __sched_class_lowest[];
2525
2526 extern const struct sched_class stop_sched_class;
2527 extern const struct sched_class dl_sched_class;
2528 extern const struct sched_class rt_sched_class;
2529 extern const struct sched_class fair_sched_class;
2530 extern const struct sched_class idle_sched_class;
2531
2532 /*
2533 * Iterate only active classes. SCX can take over all fair tasks or be
2534 * completely disabled. If the former, skip fair. If the latter, skip SCX.
2535 */
next_active_class(const struct sched_class * class)2536 static inline const struct sched_class *next_active_class(const struct sched_class *class)
2537 {
2538 class++;
2539 #ifdef CONFIG_SCHED_CLASS_EXT
2540 if (scx_switched_all() && class == &fair_sched_class)
2541 class++;
2542 if (!scx_enabled() && class == &ext_sched_class)
2543 class++;
2544 #endif
2545 return class;
2546 }
2547
2548 #define for_class_range(class, _from, _to) \
2549 for (class = (_from); class < (_to); class++)
2550
2551 #define for_each_class(class) \
2552 for_class_range(class, __sched_class_highest, __sched_class_lowest)
2553
2554 #define for_active_class_range(class, _from, _to) \
2555 for (class = (_from); class != (_to); class = next_active_class(class))
2556
2557 #define for_each_active_class(class) \
2558 for_active_class_range(class, __sched_class_highest, __sched_class_lowest)
2559
2560 #define sched_class_above(_a, _b) ((_a) < (_b))
2561
sched_stop_runnable(struct rq * rq)2562 static inline bool sched_stop_runnable(struct rq *rq)
2563 {
2564 return rq->stop && task_on_rq_queued(rq->stop);
2565 }
2566
sched_dl_runnable(struct rq * rq)2567 static inline bool sched_dl_runnable(struct rq *rq)
2568 {
2569 return rq->dl.dl_nr_running > 0;
2570 }
2571
sched_rt_runnable(struct rq * rq)2572 static inline bool sched_rt_runnable(struct rq *rq)
2573 {
2574 return rq->rt.rt_queued > 0;
2575 }
2576
sched_fair_runnable(struct rq * rq)2577 static inline bool sched_fair_runnable(struct rq *rq)
2578 {
2579 return rq->cfs.nr_queued > 0;
2580 }
2581
2582 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
2583 extern struct task_struct *pick_task_idle(struct rq *rq);
2584
2585 #define SCA_CHECK 0x01
2586 #define SCA_MIGRATE_DISABLE 0x02
2587 #define SCA_MIGRATE_ENABLE 0x04
2588 #define SCA_USER 0x08
2589
2590 extern void update_group_capacity(struct sched_domain *sd, int cpu);
2591
2592 extern void sched_balance_trigger(struct rq *rq);
2593
2594 extern int __set_cpus_allowed_ptr(struct task_struct *p, struct affinity_context *ctx);
2595 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx);
2596
task_allowed_on_cpu(struct task_struct * p,int cpu)2597 static inline bool task_allowed_on_cpu(struct task_struct *p, int cpu)
2598 {
2599 /* When not in the task's cpumask, no point in looking further. */
2600 if (!cpumask_test_cpu(cpu, p->cpus_ptr))
2601 return false;
2602
2603 /* Can @cpu run a user thread? */
2604 if (!(p->flags & PF_KTHREAD) && !task_cpu_possible(cpu, p))
2605 return false;
2606
2607 return true;
2608 }
2609
alloc_user_cpus_ptr(int node)2610 static inline cpumask_t *alloc_user_cpus_ptr(int node)
2611 {
2612 /*
2613 * See do_set_cpus_allowed() above for the rcu_head usage.
2614 */
2615 int size = max_t(int, cpumask_size(), sizeof(struct rcu_head));
2616
2617 return kmalloc_node(size, GFP_KERNEL, node);
2618 }
2619
get_push_task(struct rq * rq)2620 static inline struct task_struct *get_push_task(struct rq *rq)
2621 {
2622 struct task_struct *p = rq->donor;
2623
2624 lockdep_assert_rq_held(rq);
2625
2626 if (rq->push_busy)
2627 return NULL;
2628
2629 if (p->nr_cpus_allowed == 1)
2630 return NULL;
2631
2632 if (p->migration_disabled)
2633 return NULL;
2634
2635 rq->push_busy = true;
2636 return get_task_struct(p);
2637 }
2638
2639 extern int push_cpu_stop(void *arg);
2640
2641 #ifdef CONFIG_CPU_IDLE
2642
idle_set_state(struct rq * rq,struct cpuidle_state * idle_state)2643 static inline void idle_set_state(struct rq *rq,
2644 struct cpuidle_state *idle_state)
2645 {
2646 rq->idle_state = idle_state;
2647 }
2648
idle_get_state(struct rq * rq)2649 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
2650 {
2651 WARN_ON_ONCE(!rcu_read_lock_held());
2652
2653 return rq->idle_state;
2654 }
2655
2656 #else /* !CONFIG_CPU_IDLE: */
2657
idle_set_state(struct rq * rq,struct cpuidle_state * idle_state)2658 static inline void idle_set_state(struct rq *rq,
2659 struct cpuidle_state *idle_state)
2660 {
2661 }
2662
idle_get_state(struct rq * rq)2663 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
2664 {
2665 return NULL;
2666 }
2667
2668 #endif /* !CONFIG_CPU_IDLE */
2669
2670 extern void schedule_idle(void);
2671 asmlinkage void schedule_user(void);
2672
2673 extern void sysrq_sched_debug_show(void);
2674 extern void sched_init_granularity(void);
2675 extern void update_max_interval(void);
2676
2677 extern void init_sched_dl_class(void);
2678 extern void init_sched_rt_class(void);
2679 extern void init_sched_fair_class(void);
2680
2681 extern void resched_curr(struct rq *rq);
2682 extern void resched_curr_lazy(struct rq *rq);
2683 extern void resched_cpu(int cpu);
2684
2685 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
2686 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
2687
2688 extern void init_dl_entity(struct sched_dl_entity *dl_se);
2689
2690 extern void init_cfs_throttle_work(struct task_struct *p);
2691
2692 #define BW_SHIFT 20
2693 #define BW_UNIT (1 << BW_SHIFT)
2694 #define RATIO_SHIFT 8
2695 #define MAX_BW_BITS (64 - BW_SHIFT)
2696 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1)
2697
2698 extern unsigned long to_ratio(u64 period, u64 runtime);
2699
2700 extern void init_entity_runnable_average(struct sched_entity *se);
2701 extern void post_init_entity_util_avg(struct task_struct *p);
2702
2703 #ifdef CONFIG_NO_HZ_FULL
2704 extern bool sched_can_stop_tick(struct rq *rq);
2705 extern int __init sched_tick_offload_init(void);
2706
2707 /*
2708 * Tick may be needed by tasks in the runqueue depending on their policy and
2709 * requirements. If tick is needed, lets send the target an IPI to kick it out of
2710 * nohz mode if necessary.
2711 */
sched_update_tick_dependency(struct rq * rq)2712 static inline void sched_update_tick_dependency(struct rq *rq)
2713 {
2714 int cpu = cpu_of(rq);
2715
2716 if (!tick_nohz_full_cpu(cpu))
2717 return;
2718
2719 if (sched_can_stop_tick(rq))
2720 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
2721 else
2722 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
2723 }
2724 #else /* !CONFIG_NO_HZ_FULL: */
sched_tick_offload_init(void)2725 static inline int sched_tick_offload_init(void) { return 0; }
sched_update_tick_dependency(struct rq * rq)2726 static inline void sched_update_tick_dependency(struct rq *rq) { }
2727 #endif /* !CONFIG_NO_HZ_FULL */
2728
add_nr_running(struct rq * rq,unsigned count)2729 static inline void add_nr_running(struct rq *rq, unsigned count)
2730 {
2731 unsigned prev_nr = rq->nr_running;
2732
2733 rq->nr_running = prev_nr + count;
2734 if (trace_sched_update_nr_running_tp_enabled()) {
2735 call_trace_sched_update_nr_running(rq, count);
2736 }
2737
2738 if (prev_nr < 2 && rq->nr_running >= 2)
2739 set_rd_overloaded(rq->rd, 1);
2740
2741 sched_update_tick_dependency(rq);
2742 }
2743
sub_nr_running(struct rq * rq,unsigned count)2744 static inline void sub_nr_running(struct rq *rq, unsigned count)
2745 {
2746 rq->nr_running -= count;
2747 if (trace_sched_update_nr_running_tp_enabled()) {
2748 call_trace_sched_update_nr_running(rq, -count);
2749 }
2750
2751 /* Check if we still need preemption */
2752 sched_update_tick_dependency(rq);
2753 }
2754
__block_task(struct rq * rq,struct task_struct * p)2755 static inline void __block_task(struct rq *rq, struct task_struct *p)
2756 {
2757 if (p->sched_contributes_to_load)
2758 rq->nr_uninterruptible++;
2759
2760 if (p->in_iowait) {
2761 atomic_inc(&rq->nr_iowait);
2762 delayacct_blkio_start();
2763 }
2764
2765 ASSERT_EXCLUSIVE_WRITER(p->on_rq);
2766
2767 /*
2768 * The moment this write goes through, ttwu() can swoop in and migrate
2769 * this task, rendering our rq->__lock ineffective.
2770 *
2771 * __schedule() try_to_wake_up()
2772 * LOCK rq->__lock LOCK p->pi_lock
2773 * pick_next_task()
2774 * pick_next_task_fair()
2775 * pick_next_entity()
2776 * dequeue_entities()
2777 * __block_task()
2778 * RELEASE p->on_rq = 0 if (p->on_rq && ...)
2779 * break;
2780 *
2781 * ACQUIRE (after ctrl-dep)
2782 *
2783 * cpu = select_task_rq();
2784 * set_task_cpu(p, cpu);
2785 * ttwu_queue()
2786 * ttwu_do_activate()
2787 * LOCK rq->__lock
2788 * activate_task()
2789 * STORE p->on_rq = 1
2790 * UNLOCK rq->__lock
2791 *
2792 * Callers must ensure to not reference @p after this -- we no longer
2793 * own it.
2794 */
2795 smp_store_release(&p->on_rq, 0);
2796 }
2797
2798 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
2799 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
2800
2801 extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags);
2802
2803 #ifdef CONFIG_PREEMPT_RT
2804 # define SCHED_NR_MIGRATE_BREAK 8
2805 #else
2806 # define SCHED_NR_MIGRATE_BREAK 32
2807 #endif
2808
2809 extern __read_mostly unsigned int sysctl_sched_nr_migrate;
2810 extern __read_mostly unsigned int sysctl_sched_migration_cost;
2811
2812 extern unsigned int sysctl_sched_base_slice;
2813
2814 extern int sysctl_resched_latency_warn_ms;
2815 extern int sysctl_resched_latency_warn_once;
2816
2817 extern unsigned int sysctl_sched_tunable_scaling;
2818
2819 extern unsigned int sysctl_numa_balancing_scan_delay;
2820 extern unsigned int sysctl_numa_balancing_scan_period_min;
2821 extern unsigned int sysctl_numa_balancing_scan_period_max;
2822 extern unsigned int sysctl_numa_balancing_scan_size;
2823 extern unsigned int sysctl_numa_balancing_hot_threshold;
2824
2825 #ifdef CONFIG_SCHED_HRTICK
2826
2827 /*
2828 * Use hrtick when:
2829 * - enabled by features
2830 * - hrtimer is actually high res
2831 */
hrtick_enabled(struct rq * rq)2832 static inline int hrtick_enabled(struct rq *rq)
2833 {
2834 if (!cpu_active(cpu_of(rq)))
2835 return 0;
2836 return hrtimer_is_hres_active(&rq->hrtick_timer);
2837 }
2838
hrtick_enabled_fair(struct rq * rq)2839 static inline int hrtick_enabled_fair(struct rq *rq)
2840 {
2841 if (!sched_feat(HRTICK))
2842 return 0;
2843 return hrtick_enabled(rq);
2844 }
2845
hrtick_enabled_dl(struct rq * rq)2846 static inline int hrtick_enabled_dl(struct rq *rq)
2847 {
2848 if (!sched_feat(HRTICK_DL))
2849 return 0;
2850 return hrtick_enabled(rq);
2851 }
2852
2853 extern void hrtick_start(struct rq *rq, u64 delay);
2854
2855 #else /* !CONFIG_SCHED_HRTICK: */
2856
hrtick_enabled_fair(struct rq * rq)2857 static inline int hrtick_enabled_fair(struct rq *rq)
2858 {
2859 return 0;
2860 }
2861
hrtick_enabled_dl(struct rq * rq)2862 static inline int hrtick_enabled_dl(struct rq *rq)
2863 {
2864 return 0;
2865 }
2866
hrtick_enabled(struct rq * rq)2867 static inline int hrtick_enabled(struct rq *rq)
2868 {
2869 return 0;
2870 }
2871
2872 #endif /* !CONFIG_SCHED_HRTICK */
2873
2874 #ifndef arch_scale_freq_tick
arch_scale_freq_tick(void)2875 static __always_inline void arch_scale_freq_tick(void) { }
2876 #endif
2877
2878 #ifndef arch_scale_freq_capacity
2879 /**
2880 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
2881 * @cpu: the CPU in question.
2882 *
2883 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e.
2884 *
2885 * f_curr
2886 * ------ * SCHED_CAPACITY_SCALE
2887 * f_max
2888 */
2889 static __always_inline
arch_scale_freq_capacity(int cpu)2890 unsigned long arch_scale_freq_capacity(int cpu)
2891 {
2892 return SCHED_CAPACITY_SCALE;
2893 }
2894 #endif
2895
2896 /*
2897 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to
2898 * acquire rq lock instead of rq_lock(). So at the end of these two functions
2899 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of
2900 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning.
2901 */
double_rq_clock_clear_update(struct rq * rq1,struct rq * rq2)2902 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2)
2903 {
2904 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
2905 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
2906 }
2907
2908 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \
2909 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \
2910 static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \
2911 { class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \
2912 _lock; return _t; }
2913
rq_order_less(struct rq * rq1,struct rq * rq2)2914 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2)
2915 {
2916 #ifdef CONFIG_SCHED_CORE
2917 /*
2918 * In order to not have {0,2},{1,3} turn into into an AB-BA,
2919 * order by core-id first and cpu-id second.
2920 *
2921 * Notably:
2922 *
2923 * double_rq_lock(0,3); will take core-0, core-1 lock
2924 * double_rq_lock(1,2); will take core-1, core-0 lock
2925 *
2926 * when only cpu-id is considered.
2927 */
2928 if (rq1->core->cpu < rq2->core->cpu)
2929 return true;
2930 if (rq1->core->cpu > rq2->core->cpu)
2931 return false;
2932
2933 /*
2934 * __sched_core_flip() relies on SMT having cpu-id lock order.
2935 */
2936 #endif /* CONFIG_SCHED_CORE */
2937 return rq1->cpu < rq2->cpu;
2938 }
2939
2940 extern void double_rq_lock(struct rq *rq1, struct rq *rq2);
2941
2942 #ifdef CONFIG_PREEMPTION
2943
2944 /*
2945 * fair double_lock_balance: Safely acquires both rq->locks in a fair
2946 * way at the expense of forcing extra atomic operations in all
2947 * invocations. This assures that the double_lock is acquired using the
2948 * same underlying policy as the spinlock_t on this architecture, which
2949 * reduces latency compared to the unfair variant below. However, it
2950 * also adds more overhead and therefore may reduce throughput.
2951 */
_double_lock_balance(struct rq * this_rq,struct rq * busiest)2952 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
2953 __releases(this_rq->lock)
2954 __acquires(busiest->lock)
2955 __acquires(this_rq->lock)
2956 {
2957 raw_spin_rq_unlock(this_rq);
2958 double_rq_lock(this_rq, busiest);
2959
2960 return 1;
2961 }
2962
2963 #else /* !CONFIG_PREEMPTION: */
2964 /*
2965 * Unfair double_lock_balance: Optimizes throughput at the expense of
2966 * latency by eliminating extra atomic operations when the locks are
2967 * already in proper order on entry. This favors lower CPU-ids and will
2968 * grant the double lock to lower CPUs over higher ids under contention,
2969 * regardless of entry order into the function.
2970 */
_double_lock_balance(struct rq * this_rq,struct rq * busiest)2971 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
2972 __releases(this_rq->lock)
2973 __acquires(busiest->lock)
2974 __acquires(this_rq->lock)
2975 {
2976 if (__rq_lockp(this_rq) == __rq_lockp(busiest) ||
2977 likely(raw_spin_rq_trylock(busiest))) {
2978 double_rq_clock_clear_update(this_rq, busiest);
2979 return 0;
2980 }
2981
2982 if (rq_order_less(this_rq, busiest)) {
2983 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING);
2984 double_rq_clock_clear_update(this_rq, busiest);
2985 return 0;
2986 }
2987
2988 raw_spin_rq_unlock(this_rq);
2989 double_rq_lock(this_rq, busiest);
2990
2991 return 1;
2992 }
2993
2994 #endif /* !CONFIG_PREEMPTION */
2995
2996 /*
2997 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
2998 */
double_lock_balance(struct rq * this_rq,struct rq * busiest)2999 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
3000 {
3001 lockdep_assert_irqs_disabled();
3002
3003 return _double_lock_balance(this_rq, busiest);
3004 }
3005
double_unlock_balance(struct rq * this_rq,struct rq * busiest)3006 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
3007 __releases(busiest->lock)
3008 {
3009 if (__rq_lockp(this_rq) != __rq_lockp(busiest))
3010 raw_spin_rq_unlock(busiest);
3011 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_);
3012 }
3013
double_lock(spinlock_t * l1,spinlock_t * l2)3014 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
3015 {
3016 if (l1 > l2)
3017 swap(l1, l2);
3018
3019 spin_lock(l1);
3020 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
3021 }
3022
double_lock_irq(spinlock_t * l1,spinlock_t * l2)3023 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
3024 {
3025 if (l1 > l2)
3026 swap(l1, l2);
3027
3028 spin_lock_irq(l1);
3029 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
3030 }
3031
double_raw_lock(raw_spinlock_t * l1,raw_spinlock_t * l2)3032 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
3033 {
3034 if (l1 > l2)
3035 swap(l1, l2);
3036
3037 raw_spin_lock(l1);
3038 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
3039 }
3040
double_raw_unlock(raw_spinlock_t * l1,raw_spinlock_t * l2)3041 static inline void double_raw_unlock(raw_spinlock_t *l1, raw_spinlock_t *l2)
3042 {
3043 raw_spin_unlock(l1);
3044 raw_spin_unlock(l2);
3045 }
3046
3047 DEFINE_LOCK_GUARD_2(double_raw_spinlock, raw_spinlock_t,
3048 double_raw_lock(_T->lock, _T->lock2),
3049 double_raw_unlock(_T->lock, _T->lock2))
3050
3051 /*
3052 * double_rq_unlock - safely unlock two runqueues
3053 *
3054 * Note this does not restore interrupts like task_rq_unlock,
3055 * you need to do so manually after calling.
3056 */
double_rq_unlock(struct rq * rq1,struct rq * rq2)3057 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
3058 __releases(rq1->lock)
3059 __releases(rq2->lock)
3060 {
3061 if (__rq_lockp(rq1) != __rq_lockp(rq2))
3062 raw_spin_rq_unlock(rq2);
3063 else
3064 __release(rq2->lock);
3065 raw_spin_rq_unlock(rq1);
3066 }
3067
3068 extern void set_rq_online (struct rq *rq);
3069 extern void set_rq_offline(struct rq *rq);
3070
3071 extern bool sched_smp_initialized;
3072
3073 DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq,
3074 double_rq_lock(_T->lock, _T->lock2),
3075 double_rq_unlock(_T->lock, _T->lock2))
3076
3077 extern struct sched_entity *__pick_root_entity(struct cfs_rq *cfs_rq);
3078 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
3079 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
3080
3081 extern bool sched_debug_verbose;
3082
3083 extern void print_cfs_stats(struct seq_file *m, int cpu);
3084 extern void print_rt_stats(struct seq_file *m, int cpu);
3085 extern void print_dl_stats(struct seq_file *m, int cpu);
3086 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
3087 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
3088 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
3089
3090 extern void resched_latency_warn(int cpu, u64 latency);
3091
3092 #ifdef CONFIG_NUMA_BALANCING
3093 extern void show_numa_stats(struct task_struct *p, struct seq_file *m);
3094 extern void
3095 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
3096 unsigned long tpf, unsigned long gsf, unsigned long gpf);
3097 #endif /* CONFIG_NUMA_BALANCING */
3098
3099 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
3100 extern void init_rt_rq(struct rt_rq *rt_rq);
3101 extern void init_dl_rq(struct dl_rq *dl_rq);
3102
3103 extern void cfs_bandwidth_usage_inc(void);
3104 extern void cfs_bandwidth_usage_dec(void);
3105
3106 #ifdef CONFIG_NO_HZ_COMMON
3107
3108 #define NOHZ_BALANCE_KICK_BIT 0
3109 #define NOHZ_STATS_KICK_BIT 1
3110 #define NOHZ_NEWILB_KICK_BIT 2
3111 #define NOHZ_NEXT_KICK_BIT 3
3112
3113 /* Run sched_balance_domains() */
3114 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT)
3115 /* Update blocked load */
3116 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT)
3117 /* Update blocked load when entering idle */
3118 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT)
3119 /* Update nohz.next_balance */
3120 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT)
3121
3122 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK)
3123
3124 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
3125
3126 extern void nohz_balance_exit_idle(struct rq *rq);
3127 #else /* !CONFIG_NO_HZ_COMMON: */
nohz_balance_exit_idle(struct rq * rq)3128 static inline void nohz_balance_exit_idle(struct rq *rq) { }
3129 #endif /* !CONFIG_NO_HZ_COMMON */
3130
3131 #ifdef CONFIG_NO_HZ_COMMON
3132 extern void nohz_run_idle_balance(int cpu);
3133 #else
nohz_run_idle_balance(int cpu)3134 static inline void nohz_run_idle_balance(int cpu) { }
3135 #endif
3136
3137 #include "stats.h"
3138
3139 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS)
3140
3141 extern void __sched_core_account_forceidle(struct rq *rq);
3142
sched_core_account_forceidle(struct rq * rq)3143 static inline void sched_core_account_forceidle(struct rq *rq)
3144 {
3145 if (schedstat_enabled())
3146 __sched_core_account_forceidle(rq);
3147 }
3148
3149 extern void __sched_core_tick(struct rq *rq);
3150
sched_core_tick(struct rq * rq)3151 static inline void sched_core_tick(struct rq *rq)
3152 {
3153 if (sched_core_enabled(rq) && schedstat_enabled())
3154 __sched_core_tick(rq);
3155 }
3156
3157 #else /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS): */
3158
sched_core_account_forceidle(struct rq * rq)3159 static inline void sched_core_account_forceidle(struct rq *rq) { }
3160
sched_core_tick(struct rq * rq)3161 static inline void sched_core_tick(struct rq *rq) { }
3162
3163 #endif /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS) */
3164
3165 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
3166
3167 struct irqtime {
3168 u64 total;
3169 u64 tick_delta;
3170 u64 irq_start_time;
3171 struct u64_stats_sync sync;
3172 };
3173
3174 DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
3175 extern int sched_clock_irqtime;
3176
irqtime_enabled(void)3177 static inline int irqtime_enabled(void)
3178 {
3179 return sched_clock_irqtime;
3180 }
3181
3182 /*
3183 * Returns the irqtime minus the softirq time computed by ksoftirqd.
3184 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime
3185 * and never move forward.
3186 */
irq_time_read(int cpu)3187 static inline u64 irq_time_read(int cpu)
3188 {
3189 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
3190 unsigned int seq;
3191 u64 total;
3192
3193 do {
3194 seq = __u64_stats_fetch_begin(&irqtime->sync);
3195 total = irqtime->total;
3196 } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
3197
3198 return total;
3199 }
3200
3201 #else /* !CONFIG_IRQ_TIME_ACCOUNTING: */
3202
irqtime_enabled(void)3203 static inline int irqtime_enabled(void)
3204 {
3205 return 0;
3206 }
3207
3208 #endif /* !CONFIG_IRQ_TIME_ACCOUNTING */
3209
3210 #ifdef CONFIG_CPU_FREQ
3211
3212 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
3213
3214 /**
3215 * cpufreq_update_util - Take a note about CPU utilization changes.
3216 * @rq: Runqueue to carry out the update for.
3217 * @flags: Update reason flags.
3218 *
3219 * This function is called by the scheduler on the CPU whose utilization is
3220 * being updated.
3221 *
3222 * It can only be called from RCU-sched read-side critical sections.
3223 *
3224 * The way cpufreq is currently arranged requires it to evaluate the CPU
3225 * performance state (frequency/voltage) on a regular basis to prevent it from
3226 * being stuck in a completely inadequate performance level for too long.
3227 * That is not guaranteed to happen if the updates are only triggered from CFS
3228 * and DL, though, because they may not be coming in if only RT tasks are
3229 * active all the time (or there are RT tasks only).
3230 *
3231 * As a workaround for that issue, this function is called periodically by the
3232 * RT sched class to trigger extra cpufreq updates to prevent it from stalling,
3233 * but that really is a band-aid. Going forward it should be replaced with
3234 * solutions targeted more specifically at RT tasks.
3235 */
cpufreq_update_util(struct rq * rq,unsigned int flags)3236 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
3237 {
3238 struct update_util_data *data;
3239
3240 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
3241 cpu_of(rq)));
3242 if (data)
3243 data->func(data, rq_clock(rq), flags);
3244 }
3245 #else /* !CONFIG_CPU_FREQ: */
cpufreq_update_util(struct rq * rq,unsigned int flags)3246 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) { }
3247 #endif /* !CONFIG_CPU_FREQ */
3248
3249 #ifdef arch_scale_freq_capacity
3250 # ifndef arch_scale_freq_invariant
3251 # define arch_scale_freq_invariant() true
3252 # endif
3253 #else
3254 # define arch_scale_freq_invariant() false
3255 #endif
3256
3257 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
3258 unsigned long *min,
3259 unsigned long *max);
3260
3261 unsigned long sugov_effective_cpu_perf(int cpu, unsigned long actual,
3262 unsigned long min,
3263 unsigned long max);
3264
3265
3266 /*
3267 * Verify the fitness of task @p to run on @cpu taking into account the
3268 * CPU original capacity and the runtime/deadline ratio of the task.
3269 *
3270 * The function will return true if the original capacity of @cpu is
3271 * greater than or equal to task's deadline density right shifted by
3272 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise.
3273 */
dl_task_fits_capacity(struct task_struct * p,int cpu)3274 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu)
3275 {
3276 unsigned long cap = arch_scale_cpu_capacity(cpu);
3277
3278 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT);
3279 }
3280
cpu_bw_dl(struct rq * rq)3281 static inline unsigned long cpu_bw_dl(struct rq *rq)
3282 {
3283 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
3284 }
3285
cpu_util_dl(struct rq * rq)3286 static inline unsigned long cpu_util_dl(struct rq *rq)
3287 {
3288 return READ_ONCE(rq->avg_dl.util_avg);
3289 }
3290
3291
3292 extern unsigned long cpu_util_cfs(int cpu);
3293 extern unsigned long cpu_util_cfs_boost(int cpu);
3294
cpu_util_rt(struct rq * rq)3295 static inline unsigned long cpu_util_rt(struct rq *rq)
3296 {
3297 return READ_ONCE(rq->avg_rt.util_avg);
3298 }
3299
3300 #ifdef CONFIG_UCLAMP_TASK
3301
3302 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
3303
3304 /*
3305 * When uclamp is compiled in, the aggregation at rq level is 'turned off'
3306 * by default in the fast path and only gets turned on once userspace performs
3307 * an operation that requires it.
3308 *
3309 * Returns true if userspace opted-in to use uclamp and aggregation at rq level
3310 * hence is active.
3311 */
uclamp_is_used(void)3312 static inline bool uclamp_is_used(void)
3313 {
3314 return static_branch_likely(&sched_uclamp_used);
3315 }
3316
3317 /*
3318 * Enabling static branches would get the cpus_read_lock(),
3319 * check whether uclamp_is_used before enable it to avoid always
3320 * calling cpus_read_lock(). Because we never disable this
3321 * static key once enable it.
3322 */
sched_uclamp_enable(void)3323 static inline void sched_uclamp_enable(void)
3324 {
3325 if (!uclamp_is_used())
3326 static_branch_enable(&sched_uclamp_used);
3327 }
3328
uclamp_rq_get(struct rq * rq,enum uclamp_id clamp_id)3329 static inline unsigned long uclamp_rq_get(struct rq *rq,
3330 enum uclamp_id clamp_id)
3331 {
3332 return READ_ONCE(rq->uclamp[clamp_id].value);
3333 }
3334
uclamp_rq_set(struct rq * rq,enum uclamp_id clamp_id,unsigned int value)3335 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id,
3336 unsigned int value)
3337 {
3338 WRITE_ONCE(rq->uclamp[clamp_id].value, value);
3339 }
3340
uclamp_rq_is_idle(struct rq * rq)3341 static inline bool uclamp_rq_is_idle(struct rq *rq)
3342 {
3343 return rq->uclamp_flags & UCLAMP_FLAG_IDLE;
3344 }
3345
3346 /* Is the rq being capped/throttled by uclamp_max? */
uclamp_rq_is_capped(struct rq * rq)3347 static inline bool uclamp_rq_is_capped(struct rq *rq)
3348 {
3349 unsigned long rq_util;
3350 unsigned long max_util;
3351
3352 if (!uclamp_is_used())
3353 return false;
3354
3355 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq);
3356 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
3357
3358 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util;
3359 }
3360
3361 #define for_each_clamp_id(clamp_id) \
3362 for ((clamp_id) = 0; (clamp_id) < UCLAMP_CNT; (clamp_id)++)
3363
3364 extern unsigned int sysctl_sched_uclamp_util_min_rt_default;
3365
3366
uclamp_none(enum uclamp_id clamp_id)3367 static inline unsigned int uclamp_none(enum uclamp_id clamp_id)
3368 {
3369 if (clamp_id == UCLAMP_MIN)
3370 return 0;
3371 return SCHED_CAPACITY_SCALE;
3372 }
3373
3374 /* Integer rounded range for each bucket */
3375 #define UCLAMP_BUCKET_DELTA DIV_ROUND_CLOSEST(SCHED_CAPACITY_SCALE, UCLAMP_BUCKETS)
3376
uclamp_bucket_id(unsigned int clamp_value)3377 static inline unsigned int uclamp_bucket_id(unsigned int clamp_value)
3378 {
3379 return min_t(unsigned int, clamp_value / UCLAMP_BUCKET_DELTA, UCLAMP_BUCKETS - 1);
3380 }
3381
3382 static inline void
uclamp_se_set(struct uclamp_se * uc_se,unsigned int value,bool user_defined)3383 uclamp_se_set(struct uclamp_se *uc_se, unsigned int value, bool user_defined)
3384 {
3385 uc_se->value = value;
3386 uc_se->bucket_id = uclamp_bucket_id(value);
3387 uc_se->user_defined = user_defined;
3388 }
3389
3390 #else /* !CONFIG_UCLAMP_TASK: */
3391
3392 static inline unsigned long
uclamp_eff_value(struct task_struct * p,enum uclamp_id clamp_id)3393 uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id)
3394 {
3395 if (clamp_id == UCLAMP_MIN)
3396 return 0;
3397
3398 return SCHED_CAPACITY_SCALE;
3399 }
3400
uclamp_rq_is_capped(struct rq * rq)3401 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; }
3402
uclamp_is_used(void)3403 static inline bool uclamp_is_used(void)
3404 {
3405 return false;
3406 }
3407
sched_uclamp_enable(void)3408 static inline void sched_uclamp_enable(void) {}
3409
3410 static inline unsigned long
uclamp_rq_get(struct rq * rq,enum uclamp_id clamp_id)3411 uclamp_rq_get(struct rq *rq, enum uclamp_id clamp_id)
3412 {
3413 if (clamp_id == UCLAMP_MIN)
3414 return 0;
3415
3416 return SCHED_CAPACITY_SCALE;
3417 }
3418
3419 static inline void
uclamp_rq_set(struct rq * rq,enum uclamp_id clamp_id,unsigned int value)3420 uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, unsigned int value)
3421 {
3422 }
3423
uclamp_rq_is_idle(struct rq * rq)3424 static inline bool uclamp_rq_is_idle(struct rq *rq)
3425 {
3426 return false;
3427 }
3428
3429 #endif /* !CONFIG_UCLAMP_TASK */
3430
3431 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
3432
cpu_util_irq(struct rq * rq)3433 static inline unsigned long cpu_util_irq(struct rq *rq)
3434 {
3435 return READ_ONCE(rq->avg_irq.util_avg);
3436 }
3437
3438 static inline
scale_irq_capacity(unsigned long util,unsigned long irq,unsigned long max)3439 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
3440 {
3441 util *= (max - irq);
3442 util /= max;
3443
3444 return util;
3445
3446 }
3447
3448 #else /* !CONFIG_HAVE_SCHED_AVG_IRQ: */
3449
cpu_util_irq(struct rq * rq)3450 static inline unsigned long cpu_util_irq(struct rq *rq)
3451 {
3452 return 0;
3453 }
3454
3455 static inline
scale_irq_capacity(unsigned long util,unsigned long irq,unsigned long max)3456 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
3457 {
3458 return util;
3459 }
3460
3461 #endif /* !CONFIG_HAVE_SCHED_AVG_IRQ */
3462
3463 extern void __setparam_fair(struct task_struct *p, const struct sched_attr *attr);
3464
3465 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
3466
3467 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
3468
3469 DECLARE_STATIC_KEY_FALSE(sched_energy_present);
3470
sched_energy_enabled(void)3471 static inline bool sched_energy_enabled(void)
3472 {
3473 return static_branch_unlikely(&sched_energy_present);
3474 }
3475
3476 #else /* !(CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL): */
3477
3478 #define perf_domain_span(pd) NULL
3479
sched_energy_enabled(void)3480 static inline bool sched_energy_enabled(void) { return false; }
3481
3482 #endif /* !(CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */
3483
3484 #ifdef CONFIG_MEMBARRIER
3485
3486 /*
3487 * The scheduler provides memory barriers required by membarrier between:
3488 * - prior user-space memory accesses and store to rq->membarrier_state,
3489 * - store to rq->membarrier_state and following user-space memory accesses.
3490 * In the same way it provides those guarantees around store to rq->curr.
3491 */
membarrier_switch_mm(struct rq * rq,struct mm_struct * prev_mm,struct mm_struct * next_mm)3492 static inline void membarrier_switch_mm(struct rq *rq,
3493 struct mm_struct *prev_mm,
3494 struct mm_struct *next_mm)
3495 {
3496 int membarrier_state;
3497
3498 if (prev_mm == next_mm)
3499 return;
3500
3501 membarrier_state = atomic_read(&next_mm->membarrier_state);
3502 if (READ_ONCE(rq->membarrier_state) == membarrier_state)
3503 return;
3504
3505 WRITE_ONCE(rq->membarrier_state, membarrier_state);
3506 }
3507
3508 #else /* !CONFIG_MEMBARRIER: */
3509
membarrier_switch_mm(struct rq * rq,struct mm_struct * prev_mm,struct mm_struct * next_mm)3510 static inline void membarrier_switch_mm(struct rq *rq,
3511 struct mm_struct *prev_mm,
3512 struct mm_struct *next_mm)
3513 {
3514 }
3515
3516 #endif /* !CONFIG_MEMBARRIER */
3517
is_per_cpu_kthread(struct task_struct * p)3518 static inline bool is_per_cpu_kthread(struct task_struct *p)
3519 {
3520 if (!(p->flags & PF_KTHREAD))
3521 return false;
3522
3523 if (p->nr_cpus_allowed != 1)
3524 return false;
3525
3526 return true;
3527 }
3528
3529 extern void swake_up_all_locked(struct swait_queue_head *q);
3530 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
3531
3532 extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags);
3533
3534 #ifdef CONFIG_PREEMPT_DYNAMIC
3535 extern int preempt_dynamic_mode;
3536 extern int sched_dynamic_mode(const char *str);
3537 extern void sched_dynamic_update(int mode);
3538 #endif
3539 extern const char *preempt_modes[];
3540
3541 #ifdef CONFIG_SCHED_MM_CID
3542
3543 #define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */
3544 #define MM_CID_SCAN_DELAY 100 /* 100ms */
3545
3546 extern raw_spinlock_t cid_lock;
3547 extern int use_cid_lock;
3548
3549 extern void sched_mm_cid_migrate_from(struct task_struct *t);
3550 extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t);
3551 extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr);
3552 extern void init_sched_mm_cid(struct task_struct *t);
3553
__mm_cid_put(struct mm_struct * mm,int cid)3554 static inline void __mm_cid_put(struct mm_struct *mm, int cid)
3555 {
3556 if (cid < 0)
3557 return;
3558 cpumask_clear_cpu(cid, mm_cidmask(mm));
3559 }
3560
3561 /*
3562 * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to
3563 * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to
3564 * be held to transition to other states.
3565 *
3566 * State transitions synchronized with cmpxchg or try_cmpxchg need to be
3567 * consistent across CPUs, which prevents use of this_cpu_cmpxchg.
3568 */
mm_cid_put_lazy(struct task_struct * t)3569 static inline void mm_cid_put_lazy(struct task_struct *t)
3570 {
3571 struct mm_struct *mm = t->mm;
3572 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
3573 int cid;
3574
3575 lockdep_assert_irqs_disabled();
3576 cid = __this_cpu_read(pcpu_cid->cid);
3577 if (!mm_cid_is_lazy_put(cid) ||
3578 !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET))
3579 return;
3580 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
3581 }
3582
mm_cid_pcpu_unset(struct mm_struct * mm)3583 static inline int mm_cid_pcpu_unset(struct mm_struct *mm)
3584 {
3585 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
3586 int cid, res;
3587
3588 lockdep_assert_irqs_disabled();
3589 cid = __this_cpu_read(pcpu_cid->cid);
3590 for (;;) {
3591 if (mm_cid_is_unset(cid))
3592 return MM_CID_UNSET;
3593 /*
3594 * Attempt transition from valid or lazy-put to unset.
3595 */
3596 res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET);
3597 if (res == cid)
3598 break;
3599 cid = res;
3600 }
3601 return cid;
3602 }
3603
mm_cid_put(struct mm_struct * mm)3604 static inline void mm_cid_put(struct mm_struct *mm)
3605 {
3606 int cid;
3607
3608 lockdep_assert_irqs_disabled();
3609 cid = mm_cid_pcpu_unset(mm);
3610 if (cid == MM_CID_UNSET)
3611 return;
3612 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
3613 }
3614
__mm_cid_try_get(struct task_struct * t,struct mm_struct * mm)3615 static inline int __mm_cid_try_get(struct task_struct *t, struct mm_struct *mm)
3616 {
3617 struct cpumask *cidmask = mm_cidmask(mm);
3618 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
3619 int cid, max_nr_cid, allowed_max_nr_cid;
3620
3621 /*
3622 * After shrinking the number of threads or reducing the number
3623 * of allowed cpus, reduce the value of max_nr_cid so expansion
3624 * of cid allocation will preserve cache locality if the number
3625 * of threads or allowed cpus increase again.
3626 */
3627 max_nr_cid = atomic_read(&mm->max_nr_cid);
3628 while ((allowed_max_nr_cid = min_t(int, READ_ONCE(mm->nr_cpus_allowed),
3629 atomic_read(&mm->mm_users))),
3630 max_nr_cid > allowed_max_nr_cid) {
3631 /* atomic_try_cmpxchg loads previous mm->max_nr_cid into max_nr_cid. */
3632 if (atomic_try_cmpxchg(&mm->max_nr_cid, &max_nr_cid, allowed_max_nr_cid)) {
3633 max_nr_cid = allowed_max_nr_cid;
3634 break;
3635 }
3636 }
3637 /* Try to re-use recent cid. This improves cache locality. */
3638 cid = __this_cpu_read(pcpu_cid->recent_cid);
3639 if (!mm_cid_is_unset(cid) && cid < max_nr_cid &&
3640 !cpumask_test_and_set_cpu(cid, cidmask))
3641 return cid;
3642 /*
3643 * Expand cid allocation if the maximum number of concurrency
3644 * IDs allocated (max_nr_cid) is below the number cpus allowed
3645 * and number of threads. Expanding cid allocation as much as
3646 * possible improves cache locality.
3647 */
3648 cid = max_nr_cid;
3649 while (cid < READ_ONCE(mm->nr_cpus_allowed) && cid < atomic_read(&mm->mm_users)) {
3650 /* atomic_try_cmpxchg loads previous mm->max_nr_cid into cid. */
3651 if (!atomic_try_cmpxchg(&mm->max_nr_cid, &cid, cid + 1))
3652 continue;
3653 if (!cpumask_test_and_set_cpu(cid, cidmask))
3654 return cid;
3655 }
3656 /*
3657 * Find the first available concurrency id.
3658 * Retry finding first zero bit if the mask is temporarily
3659 * filled. This only happens during concurrent remote-clear
3660 * which owns a cid without holding a rq lock.
3661 */
3662 for (;;) {
3663 cid = cpumask_first_zero(cidmask);
3664 if (cid < READ_ONCE(mm->nr_cpus_allowed))
3665 break;
3666 cpu_relax();
3667 }
3668 if (cpumask_test_and_set_cpu(cid, cidmask))
3669 return -1;
3670
3671 return cid;
3672 }
3673
3674 /*
3675 * Save a snapshot of the current runqueue time of this cpu
3676 * with the per-cpu cid value, allowing to estimate how recently it was used.
3677 */
mm_cid_snapshot_time(struct rq * rq,struct mm_struct * mm)3678 static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm)
3679 {
3680 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq));
3681
3682 lockdep_assert_rq_held(rq);
3683 WRITE_ONCE(pcpu_cid->time, rq->clock);
3684 }
3685
__mm_cid_get(struct rq * rq,struct task_struct * t,struct mm_struct * mm)3686 static inline int __mm_cid_get(struct rq *rq, struct task_struct *t,
3687 struct mm_struct *mm)
3688 {
3689 int cid;
3690
3691 /*
3692 * All allocations (even those using the cid_lock) are lock-free. If
3693 * use_cid_lock is set, hold the cid_lock to perform cid allocation to
3694 * guarantee forward progress.
3695 */
3696 if (!READ_ONCE(use_cid_lock)) {
3697 cid = __mm_cid_try_get(t, mm);
3698 if (cid >= 0)
3699 goto end;
3700 raw_spin_lock(&cid_lock);
3701 } else {
3702 raw_spin_lock(&cid_lock);
3703 cid = __mm_cid_try_get(t, mm);
3704 if (cid >= 0)
3705 goto unlock;
3706 }
3707
3708 /*
3709 * cid concurrently allocated. Retry while forcing following
3710 * allocations to use the cid_lock to ensure forward progress.
3711 */
3712 WRITE_ONCE(use_cid_lock, 1);
3713 /*
3714 * Set use_cid_lock before allocation. Only care about program order
3715 * because this is only required for forward progress.
3716 */
3717 barrier();
3718 /*
3719 * Retry until it succeeds. It is guaranteed to eventually succeed once
3720 * all newcoming allocations observe the use_cid_lock flag set.
3721 */
3722 do {
3723 cid = __mm_cid_try_get(t, mm);
3724 cpu_relax();
3725 } while (cid < 0);
3726 /*
3727 * Allocate before clearing use_cid_lock. Only care about
3728 * program order because this is for forward progress.
3729 */
3730 barrier();
3731 WRITE_ONCE(use_cid_lock, 0);
3732 unlock:
3733 raw_spin_unlock(&cid_lock);
3734 end:
3735 mm_cid_snapshot_time(rq, mm);
3736
3737 return cid;
3738 }
3739
mm_cid_get(struct rq * rq,struct task_struct * t,struct mm_struct * mm)3740 static inline int mm_cid_get(struct rq *rq, struct task_struct *t,
3741 struct mm_struct *mm)
3742 {
3743 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
3744 int cid;
3745
3746 lockdep_assert_rq_held(rq);
3747 cid = __this_cpu_read(pcpu_cid->cid);
3748 if (mm_cid_is_valid(cid)) {
3749 mm_cid_snapshot_time(rq, mm);
3750 return cid;
3751 }
3752 if (mm_cid_is_lazy_put(cid)) {
3753 if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET))
3754 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
3755 }
3756 cid = __mm_cid_get(rq, t, mm);
3757 __this_cpu_write(pcpu_cid->cid, cid);
3758 __this_cpu_write(pcpu_cid->recent_cid, cid);
3759
3760 return cid;
3761 }
3762
switch_mm_cid(struct rq * rq,struct task_struct * prev,struct task_struct * next)3763 static inline void switch_mm_cid(struct rq *rq,
3764 struct task_struct *prev,
3765 struct task_struct *next)
3766 {
3767 /*
3768 * Provide a memory barrier between rq->curr store and load of
3769 * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition.
3770 *
3771 * Should be adapted if context_switch() is modified.
3772 */
3773 if (!next->mm) { // to kernel
3774 /*
3775 * user -> kernel transition does not guarantee a barrier, but
3776 * we can use the fact that it performs an atomic operation in
3777 * mmgrab().
3778 */
3779 if (prev->mm) // from user
3780 smp_mb__after_mmgrab();
3781 /*
3782 * kernel -> kernel transition does not change rq->curr->mm
3783 * state. It stays NULL.
3784 */
3785 } else { // to user
3786 /*
3787 * kernel -> user transition does not provide a barrier
3788 * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu].
3789 * Provide it here.
3790 */
3791 if (!prev->mm) { // from kernel
3792 smp_mb();
3793 } else { // from user
3794 /*
3795 * user->user transition relies on an implicit
3796 * memory barrier in switch_mm() when
3797 * current->mm changes. If the architecture
3798 * switch_mm() does not have an implicit memory
3799 * barrier, it is emitted here. If current->mm
3800 * is unchanged, no barrier is needed.
3801 */
3802 smp_mb__after_switch_mm();
3803 }
3804 }
3805 if (prev->mm_cid_active) {
3806 mm_cid_snapshot_time(rq, prev->mm);
3807 mm_cid_put_lazy(prev);
3808 prev->mm_cid = -1;
3809 }
3810 if (next->mm_cid_active)
3811 next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next, next->mm);
3812 }
3813
3814 #else /* !CONFIG_SCHED_MM_CID: */
switch_mm_cid(struct rq * rq,struct task_struct * prev,struct task_struct * next)3815 static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { }
sched_mm_cid_migrate_from(struct task_struct * t)3816 static inline void sched_mm_cid_migrate_from(struct task_struct *t) { }
sched_mm_cid_migrate_to(struct rq * dst_rq,struct task_struct * t)3817 static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { }
task_tick_mm_cid(struct rq * rq,struct task_struct * curr)3818 static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { }
init_sched_mm_cid(struct task_struct * t)3819 static inline void init_sched_mm_cid(struct task_struct *t) { }
3820 #endif /* !CONFIG_SCHED_MM_CID */
3821
3822 extern u64 avg_vruntime(struct cfs_rq *cfs_rq);
3823 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se);
3824 static inline
move_queued_task_locked(struct rq * src_rq,struct rq * dst_rq,struct task_struct * task)3825 void move_queued_task_locked(struct rq *src_rq, struct rq *dst_rq, struct task_struct *task)
3826 {
3827 lockdep_assert_rq_held(src_rq);
3828 lockdep_assert_rq_held(dst_rq);
3829
3830 deactivate_task(src_rq, task, 0);
3831 set_task_cpu(task, dst_rq->cpu);
3832 activate_task(dst_rq, task, 0);
3833 }
3834
3835 static inline
task_is_pushable(struct rq * rq,struct task_struct * p,int cpu)3836 bool task_is_pushable(struct rq *rq, struct task_struct *p, int cpu)
3837 {
3838 if (!task_on_cpu(rq, p) &&
3839 cpumask_test_cpu(cpu, &p->cpus_mask))
3840 return true;
3841
3842 return false;
3843 }
3844
3845 #ifdef CONFIG_RT_MUTEXES
3846
__rt_effective_prio(struct task_struct * pi_task,int prio)3847 static inline int __rt_effective_prio(struct task_struct *pi_task, int prio)
3848 {
3849 if (pi_task)
3850 prio = min(prio, pi_task->prio);
3851
3852 return prio;
3853 }
3854
rt_effective_prio(struct task_struct * p,int prio)3855 static inline int rt_effective_prio(struct task_struct *p, int prio)
3856 {
3857 struct task_struct *pi_task = rt_mutex_get_top_task(p);
3858
3859 return __rt_effective_prio(pi_task, prio);
3860 }
3861
3862 #else /* !CONFIG_RT_MUTEXES: */
3863
rt_effective_prio(struct task_struct * p,int prio)3864 static inline int rt_effective_prio(struct task_struct *p, int prio)
3865 {
3866 return prio;
3867 }
3868
3869 #endif /* !CONFIG_RT_MUTEXES */
3870
3871 extern int __sched_setscheduler(struct task_struct *p, const struct sched_attr *attr, bool user, bool pi);
3872 extern int __sched_setaffinity(struct task_struct *p, struct affinity_context *ctx);
3873 extern const struct sched_class *__setscheduler_class(int policy, int prio);
3874 extern void set_load_weight(struct task_struct *p, bool update_load);
3875 extern void enqueue_task(struct rq *rq, struct task_struct *p, int flags);
3876 extern bool dequeue_task(struct rq *rq, struct task_struct *p, int flags);
3877
3878 extern void check_class_changing(struct rq *rq, struct task_struct *p,
3879 const struct sched_class *prev_class);
3880 extern void check_class_changed(struct rq *rq, struct task_struct *p,
3881 const struct sched_class *prev_class,
3882 int oldprio);
3883
3884 extern struct balance_callback *splice_balance_callbacks(struct rq *rq);
3885 extern void balance_callbacks(struct rq *rq, struct balance_callback *head);
3886
3887 #ifdef CONFIG_SCHED_CLASS_EXT
3888 /*
3889 * Used by SCX in the enable/disable paths to move tasks between sched_classes
3890 * and establish invariants.
3891 */
3892 struct sched_enq_and_set_ctx {
3893 struct task_struct *p;
3894 int queue_flags;
3895 bool queued;
3896 bool running;
3897 };
3898
3899 void sched_deq_and_put_task(struct task_struct *p, int queue_flags,
3900 struct sched_enq_and_set_ctx *ctx);
3901 void sched_enq_and_set_task(struct sched_enq_and_set_ctx *ctx);
3902
3903 #endif /* CONFIG_SCHED_CLASS_EXT */
3904
3905 #include "ext.h"
3906
3907 #endif /* _KERNEL_SCHED_SCHED_H */
3908