1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4
5 /*
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
8 */
9
10 #include <uapi/linux/sched.h>
11
12 #include <asm/current.h>
13 #include <asm/processor.h>
14 #include <linux/thread_info.h>
15 #include <linux/preempt.h>
16 #include <linux/cpumask_types.h>
17
18 #include <linux/cache.h>
19 #include <linux/futex_types.h>
20 #include <linux/irqflags_types.h>
21 #include <linux/smp_types.h>
22 #include <linux/pid_types.h>
23 #include <linux/sem_types.h>
24 #include <linux/shm.h>
25 #include <linux/kmsan_types.h>
26 #include <linux/mutex_types.h>
27 #include <linux/plist_types.h>
28 #include <linux/hrtimer_types.h>
29 #include <linux/timer_types.h>
30 #include <linux/seccomp_types.h>
31 #include <linux/nodemask_types.h>
32 #include <linux/refcount_types.h>
33 #include <linux/resource.h>
34 #include <linux/latencytop.h>
35 #include <linux/sched/prio.h>
36 #include <linux/sched/types.h>
37 #include <linux/signal_types.h>
38 #include <linux/spinlock.h>
39 #include <linux/syscall_user_dispatch_types.h>
40 #include <linux/mm_types_task.h>
41 #include <linux/netdevice_xmit.h>
42 #include <linux/task_io_accounting.h>
43 #include <linux/posix-timers_types.h>
44 #include <linux/restart_block.h>
45 #include <linux/rseq_types.h>
46 #include <linux/seqlock_types.h>
47 #include <linux/kcsan.h>
48 #include <linux/rv.h>
49 #include <linux/uidgid_types.h>
50 #include <linux/tracepoint-defs.h>
51 #include <linux/unwind_deferred_types.h>
52 #include <asm/kmap_size.h>
53 #include <linux/time64.h>
54 #ifndef COMPILE_OFFSETS
55 #include <generated/rq-offsets.h>
56 #endif
57
58 /* task_struct member predeclarations (sorted alphabetically): */
59 struct audit_context;
60 struct bio_list;
61 struct blk_plug;
62 struct bpf_local_storage;
63 struct bpf_run_ctx;
64 struct bpf_net_context;
65 struct capture_control;
66 struct cfs_rq;
67 struct fs_struct;
68 struct io_context;
69 struct io_uring_task;
70 struct mempolicy;
71 struct nameidata;
72 struct nsproxy;
73 struct perf_event_context;
74 struct perf_ctx_data;
75 struct pid_namespace;
76 struct pipe_inode_info;
77 struct rcu_node;
78 struct reclaim_state;
79 struct root_domain;
80 struct rq;
81 struct sched_attr;
82 struct sched_dl_entity;
83 struct seq_file;
84 struct sighand_struct;
85 struct signal_struct;
86 struct task_delay_info;
87 struct task_exec_state;
88 struct task_group;
89 struct task_struct;
90 struct timespec64;
91 struct user_event_mm;
92
93 #include <linux/sched/ext.h>
94
95 /*
96 * Task state bitmask. NOTE! These bits are also
97 * encoded in fs/proc/array.c: get_task_state().
98 *
99 * We have two separate sets of flags: task->__state
100 * is about runnability, while task->exit_state are
101 * about the task exiting. Confusing, but this way
102 * modifying one set can't modify the other one by
103 * mistake.
104 */
105
106 /* Used in tsk->__state: */
107 #define TASK_RUNNING 0x00000000
108 #define TASK_INTERRUPTIBLE 0x00000001
109 #define TASK_UNINTERRUPTIBLE 0x00000002
110 #define __TASK_STOPPED 0x00000004
111 #define __TASK_TRACED 0x00000008
112 /* Used in tsk->exit_state: */
113 #define EXIT_DEAD 0x00000010
114 #define EXIT_ZOMBIE 0x00000020
115 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
116 /* Used in tsk->__state again: */
117 #define TASK_PARKED 0x00000040
118 #define TASK_DEAD 0x00000080
119 #define TASK_WAKEKILL 0x00000100
120 #define TASK_WAKING 0x00000200
121 #define TASK_NOLOAD 0x00000400
122 #define TASK_NEW 0x00000800
123 #define TASK_RTLOCK_WAIT 0x00001000
124 #define TASK_FREEZABLE 0x00002000
125 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
126 #define TASK_FROZEN 0x00008000
127 #define TASK_STATE_MAX 0x00010000
128
129 #define TASK_ANY (TASK_STATE_MAX-1)
130
131 /*
132 * DO NOT ADD ANY NEW USERS !
133 */
134 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
135
136 /* Convenience macros for the sake of set_current_state: */
137 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
138 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
139 #define TASK_TRACED __TASK_TRACED
140
141 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
142
143 /* Convenience macros for the sake of wake_up(): */
144 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
145
146 /* get_task_state(): */
147 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
148 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
149 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
150 TASK_PARKED)
151
152 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
153
154 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
155 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
156 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
157
158 /*
159 * Special states are those that do not use the normal wait-loop pattern. See
160 * the comment with set_special_state().
161 */
162 #define is_special_task_state(state) \
163 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | \
164 TASK_DEAD | TASK_WAKING | TASK_FROZEN))
165
166 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
167 # define debug_normal_state_change(state_value) \
168 do { \
169 WARN_ON_ONCE(is_special_task_state(state_value)); \
170 current->task_state_change = _THIS_IP_; \
171 } while (0)
172
173 # define debug_special_state_change(state_value) \
174 do { \
175 WARN_ON_ONCE(!is_special_task_state(state_value)); \
176 current->task_state_change = _THIS_IP_; \
177 } while (0)
178
179 # define debug_rtlock_wait_set_state() \
180 do { \
181 current->saved_state_change = current->task_state_change;\
182 current->task_state_change = _THIS_IP_; \
183 } while (0)
184
185 # define debug_rtlock_wait_restore_state() \
186 do { \
187 current->task_state_change = current->saved_state_change;\
188 } while (0)
189
190 #else
191 # define debug_normal_state_change(cond) do { } while (0)
192 # define debug_special_state_change(cond) do { } while (0)
193 # define debug_rtlock_wait_set_state() do { } while (0)
194 # define debug_rtlock_wait_restore_state() do { } while (0)
195 #endif
196
197 #define trace_set_current_state(state_value) \
198 do { \
199 if (tracepoint_enabled(sched_set_state_tp)) \
200 __trace_set_current_state(state_value); \
201 } while (0)
202
203 /*
204 * set_current_state() includes a barrier so that the write of current->__state
205 * is correctly serialised wrt the caller's subsequent test of whether to
206 * actually sleep:
207 *
208 * for (;;) {
209 * set_current_state(TASK_UNINTERRUPTIBLE);
210 * if (CONDITION)
211 * break;
212 *
213 * schedule();
214 * }
215 * __set_current_state(TASK_RUNNING);
216 *
217 * If the caller does not need such serialisation (because, for instance, the
218 * CONDITION test and condition change and wakeup are under the same lock) then
219 * use __set_current_state().
220 *
221 * The above is typically ordered against the wakeup, which does:
222 *
223 * CONDITION = 1;
224 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
225 *
226 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
227 * accessing p->__state.
228 *
229 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
230 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
231 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
232 *
233 * However, with slightly different timing the wakeup TASK_RUNNING store can
234 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
235 * a problem either because that will result in one extra go around the loop
236 * and our @cond test will save the day.
237 *
238 * Also see the comments of try_to_wake_up().
239 */
240 #define __set_current_state(state_value) \
241 do { \
242 debug_normal_state_change((state_value)); \
243 trace_set_current_state(state_value); \
244 WRITE_ONCE(current->__state, (state_value)); \
245 } while (0)
246
247 #define set_current_state(state_value) \
248 do { \
249 debug_normal_state_change((state_value)); \
250 trace_set_current_state(state_value); \
251 smp_store_mb(current->__state, (state_value)); \
252 } while (0)
253
254 /*
255 * set_special_state() should be used for those states when the blocking task
256 * can not use the regular condition based wait-loop. In that case we must
257 * serialize against wakeups such that any possible in-flight TASK_RUNNING
258 * stores will not collide with our state change.
259 */
260 #define set_special_state(state_value) \
261 do { \
262 unsigned long flags; /* may shadow */ \
263 \
264 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
265 debug_special_state_change((state_value)); \
266 trace_set_current_state(state_value); \
267 WRITE_ONCE(current->__state, (state_value)); \
268 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
269 } while (0)
270
271 /*
272 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
273 *
274 * RT's spin/rwlock substitutions are state preserving. The state of the
275 * task when blocking on the lock is saved in task_struct::saved_state and
276 * restored after the lock has been acquired. These operations are
277 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
278 * lock related wakeups while the task is blocked on the lock are
279 * redirected to operate on task_struct::saved_state to ensure that these
280 * are not dropped. On restore task_struct::saved_state is set to
281 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
282 *
283 * The lock operation looks like this:
284 *
285 * current_save_and_set_rtlock_wait_state();
286 * for (;;) {
287 * if (try_lock())
288 * break;
289 * raw_spin_unlock_irq(&lock->wait_lock);
290 * schedule_rtlock();
291 * raw_spin_lock_irq(&lock->wait_lock);
292 * set_current_state(TASK_RTLOCK_WAIT);
293 * }
294 * current_restore_rtlock_saved_state();
295 */
296 #define current_save_and_set_rtlock_wait_state() \
297 do { \
298 lockdep_assert_irqs_disabled(); \
299 raw_spin_lock(¤t->pi_lock); \
300 current->saved_state = current->__state; \
301 debug_rtlock_wait_set_state(); \
302 trace_set_current_state(TASK_RTLOCK_WAIT); \
303 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
304 raw_spin_unlock(¤t->pi_lock); \
305 } while (0);
306
307 #define current_restore_rtlock_saved_state() \
308 do { \
309 lockdep_assert_irqs_disabled(); \
310 raw_spin_lock(¤t->pi_lock); \
311 debug_rtlock_wait_restore_state(); \
312 trace_set_current_state(current->saved_state); \
313 WRITE_ONCE(current->__state, current->saved_state); \
314 current->saved_state = TASK_RUNNING; \
315 raw_spin_unlock(¤t->pi_lock); \
316 } while (0);
317
318 #define get_current_state() READ_ONCE(current->__state)
319
320 /*
321 * Define the task command name length as enum, then it can be visible to
322 * BPF programs.
323 */
324 enum {
325 TASK_COMM_LEN = 16,
326 };
327
328 extern void sched_tick(void);
329
330 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
331
332 extern long schedule_timeout(long timeout);
333 extern long schedule_timeout_interruptible(long timeout);
334 extern long schedule_timeout_killable(long timeout);
335 extern long schedule_timeout_uninterruptible(long timeout);
336 extern long schedule_timeout_idle(long timeout);
337 asmlinkage void schedule(void);
338 extern void schedule_preempt_disabled(void);
339 asmlinkage void preempt_schedule_irq(void);
340 #ifdef CONFIG_PREEMPT_RT
341 extern void schedule_rtlock(void);
342 #endif
343
344 extern int __must_check io_schedule_prepare(void);
345 extern void io_schedule_finish(int token);
346 extern long io_schedule_timeout(long timeout);
347 extern void io_schedule(void);
348
349 /* wrapper functions to trace from this header file */
350 DECLARE_TRACEPOINT(sched_set_state_tp);
351 extern void __trace_set_current_state(int state_value);
352 DECLARE_TRACEPOINT(sched_set_need_resched_tp);
353 extern void __trace_set_need_resched(struct task_struct *curr, int tif);
354
355 /**
356 * struct prev_cputime - snapshot of system and user cputime
357 * @utime: time spent in user mode
358 * @stime: time spent in system mode
359 * @lock: protects the above two fields
360 *
361 * Stores previous user/system time values such that we can guarantee
362 * monotonicity.
363 */
364 struct prev_cputime {
365 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
366 u64 utime;
367 u64 stime;
368 raw_spinlock_t lock;
369 #endif
370 };
371
372 enum vtime_state {
373 /* Task is sleeping or running in a CPU with VTIME inactive: */
374 VTIME_INACTIVE = 0,
375 /* Task is idle */
376 VTIME_IDLE,
377 /* Task runs in kernelspace in a CPU with VTIME active: */
378 VTIME_SYS,
379 /* Task runs in userspace in a CPU with VTIME active: */
380 VTIME_USER,
381 /* Task runs as guests in a CPU with VTIME active: */
382 VTIME_GUEST,
383 };
384
385 struct vtime {
386 seqcount_t seqcount;
387 unsigned long long starttime;
388 enum vtime_state state;
389 unsigned int cpu;
390 u64 utime;
391 u64 stime;
392 u64 gtime;
393 };
394
395 /*
396 * Utilization clamp constraints.
397 * @UCLAMP_MIN: Minimum utilization
398 * @UCLAMP_MAX: Maximum utilization
399 * @UCLAMP_CNT: Utilization clamp constraints count
400 */
401 enum uclamp_id {
402 UCLAMP_MIN = 0,
403 UCLAMP_MAX,
404 UCLAMP_CNT
405 };
406
407 extern struct root_domain def_root_domain;
408 extern struct mutex sched_domains_mutex;
409 extern void sched_domains_mutex_lock(void);
410 extern void sched_domains_mutex_unlock(void);
411
412 struct sched_param {
413 int sched_priority;
414 };
415
416 struct sched_info {
417 #ifdef CONFIG_SCHED_INFO
418 /* Cumulative counters: */
419
420 /* # of times we have run on this CPU: */
421 unsigned long pcount;
422
423 /* Time spent waiting on a runqueue: */
424 unsigned long long run_delay;
425
426 /* Max time spent waiting on a runqueue: */
427 unsigned long long max_run_delay;
428
429 /* Min time spent waiting on a runqueue: */
430 unsigned long long min_run_delay;
431
432 /* Timestamps: */
433
434 /* When did we last run on a CPU? */
435 unsigned long long last_arrival;
436
437 /* When were we last queued to run? */
438 unsigned long long last_queued;
439
440 /* Timestamp of max time spent waiting on a runqueue: */
441 struct timespec64 max_run_delay_ts;
442
443 #endif /* CONFIG_SCHED_INFO */
444 };
445
446 /*
447 * Integer metrics need fixed point arithmetic, e.g., sched/fair
448 * has a few: load, load_avg, util_avg, freq, and capacity.
449 *
450 * We define a basic fixed point arithmetic range, and then formalize
451 * all these metrics based on that basic range.
452 */
453 # define SCHED_FIXEDPOINT_SHIFT 10
454 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
455
456 /* Increase resolution of cpu_capacity calculations */
457 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
458 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
459
460 struct load_weight {
461 unsigned long weight;
462 u32 inv_weight;
463 };
464
465 /*
466 * The load/runnable/util_avg accumulates an infinite geometric series
467 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
468 *
469 * [load_avg definition]
470 *
471 * load_avg = runnable% * scale_load_down(load)
472 *
473 * [runnable_avg definition]
474 *
475 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
476 *
477 * [util_avg definition]
478 *
479 * util_avg = running% * SCHED_CAPACITY_SCALE
480 *
481 * where runnable% is the time ratio that a sched_entity is runnable and
482 * running% the time ratio that a sched_entity is running.
483 *
484 * For cfs_rq, they are the aggregated values of all runnable and blocked
485 * sched_entities.
486 *
487 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
488 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
489 * for computing those signals (see update_rq_clock_pelt())
490 *
491 * N.B., the above ratios (runnable% and running%) themselves are in the
492 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
493 * to as large a range as necessary. This is for example reflected by
494 * util_avg's SCHED_CAPACITY_SCALE.
495 *
496 * [Overflow issue]
497 *
498 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
499 * with the highest load (=88761), always runnable on a single cfs_rq,
500 * and should not overflow as the number already hits PID_MAX_LIMIT.
501 *
502 * For all other cases (including 32-bit kernels), struct load_weight's
503 * weight will overflow first before we do, because:
504 *
505 * Max(load_avg) <= Max(load.weight)
506 *
507 * Then it is the load_weight's responsibility to consider overflow
508 * issues.
509 */
510 struct sched_avg {
511 u64 last_update_time;
512 u64 load_sum;
513 u64 runnable_sum;
514 u32 util_sum;
515 u32 period_contrib;
516 unsigned long load_avg;
517 unsigned long runnable_avg;
518 unsigned long util_avg;
519 unsigned int util_est;
520 } ____cacheline_aligned;
521
522 /*
523 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
524 * updates. When a task is dequeued, its util_est should not be updated if its
525 * util_avg has not been updated in the meantime.
526 * This information is mapped into the MSB bit of util_est at dequeue time.
527 * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
528 * it is safe to use MSB.
529 */
530 #define UTIL_EST_WEIGHT_SHIFT 2
531 #define UTIL_AVG_UNCHANGED 0x80000000
532
533 struct sched_statistics {
534 #ifdef CONFIG_SCHEDSTATS
535 u64 wait_start;
536 u64 wait_max;
537 u64 wait_count;
538 u64 wait_sum;
539 u64 iowait_count;
540 u64 iowait_sum;
541
542 u64 sleep_start;
543 u64 sleep_max;
544 s64 sum_sleep_runtime;
545
546 u64 block_start;
547 u64 block_max;
548 s64 sum_block_runtime;
549
550 s64 exec_max;
551 u64 slice_max;
552
553 u64 nr_failed_migrations_affine;
554 u64 nr_failed_migrations_running;
555 u64 nr_failed_migrations_hot;
556 u64 nr_forced_migrations;
557
558 u64 nr_wakeups;
559 u64 nr_wakeups_sync;
560 u64 nr_wakeups_migrate;
561 u64 nr_wakeups_local;
562 u64 nr_wakeups_remote;
563 u64 nr_wakeups_affine;
564 u64 nr_wakeups_affine_attempts;
565
566 #ifdef CONFIG_SCHED_CORE
567 u64 core_forceidle_sum;
568 #endif
569 #endif /* CONFIG_SCHEDSTATS */
570 } ____cacheline_aligned;
571
572 struct sched_entity {
573 /* For load-balancing: */
574 struct load_weight load;
575 struct load_weight h_load;
576 struct rb_node run_node;
577 u64 deadline;
578 u64 min_vruntime;
579 u64 min_slice;
580 u64 max_slice;
581
582 struct list_head group_node;
583 unsigned char on_rq;
584 unsigned char sched_delayed;
585 unsigned char rel_deadline;
586 unsigned char custom_slice;
587 /* hole */
588
589 u64 exec_start;
590 u64 sum_exec_runtime;
591 u64 prev_sum_exec_runtime;
592 u64 vruntime;
593 /* Approximated virtual lag: */
594 s64 vlag;
595 /* 'Protected' deadline, to give out minimum quantums: */
596 u64 vprot;
597 u64 slice;
598
599 u64 nr_migrations;
600
601 #ifdef CONFIG_FAIR_GROUP_SCHED
602 int depth;
603 struct sched_entity *parent;
604 /* rq on which this entity is (to be) queued: */
605 struct cfs_rq *cfs_rq;
606 /* rq "owned" by this entity/group: */
607 struct cfs_rq *my_q;
608 /* cached value of my_q->h_nr_running */
609 unsigned long runnable_weight;
610 #endif
611
612 /*
613 * Per entity load average tracking.
614 *
615 * Put into separate cache line so it does not
616 * collide with read-mostly values above.
617 */
618 struct sched_avg avg;
619 };
620
621 struct sched_rt_entity {
622 struct list_head run_list;
623 unsigned long timeout;
624 unsigned long watchdog_stamp;
625 unsigned int time_slice;
626 unsigned short on_rq;
627 unsigned short on_list;
628
629 struct sched_rt_entity *back;
630 #ifdef CONFIG_RT_GROUP_SCHED
631 struct sched_rt_entity *parent;
632 /* rq on which this entity is (to be) queued: */
633 struct rt_rq *rt_rq;
634 /* rq "owned" by this entity/group: */
635 struct rt_rq *my_q;
636 #endif
637 } __randomize_layout;
638
639 struct rq_flags;
640 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *, struct rq_flags *rf);
641
642 struct sched_dl_entity {
643 struct rb_node rb_node;
644
645 /*
646 * Original scheduling parameters. Copied here from sched_attr
647 * during sched_setattr(), they will remain the same until
648 * the next sched_setattr().
649 */
650 u64 dl_runtime; /* Maximum runtime for each instance */
651 u64 dl_deadline; /* Relative deadline of each instance */
652 u64 dl_period; /* Separation of two instances (period) */
653 u64 dl_bw; /* dl_runtime / dl_period */
654 u64 dl_density; /* dl_runtime / dl_deadline */
655
656 /*
657 * Actual scheduling parameters. Initialized with the values above,
658 * they are continuously updated during task execution. Note that
659 * the remaining runtime could be < 0 in case we are in overrun.
660 */
661 s64 runtime; /* Remaining runtime for this instance */
662 u64 deadline; /* Absolute deadline for this instance */
663 unsigned int flags; /* Specifying the scheduler behaviour */
664
665 /*
666 * Some bool flags:
667 *
668 * @dl_throttled tells if we exhausted the runtime. If so, the
669 * task has to wait for a replenishment to be performed at the
670 * next firing of dl_timer.
671 *
672 * @dl_yielded tells if task gave up the CPU before consuming
673 * all its available runtime during the last job.
674 *
675 * @dl_non_contending tells if the task is inactive while still
676 * contributing to the active utilization. In other words, it
677 * indicates if the inactive timer has been armed and its handler
678 * has not been executed yet. This flag is useful to avoid race
679 * conditions between the inactive timer handler and the wakeup
680 * code.
681 *
682 * @dl_overrun tells if the task asked to be informed about runtime
683 * overruns.
684 *
685 * @dl_server tells if this is a server entity.
686 *
687 * @dl_server_active tells if the dlserver is active(started).
688 * dlserver is started on first cfs enqueue on an idle runqueue
689 * and is stopped when a dequeue results in 0 cfs tasks on the
690 * runqueue. In other words, dlserver is active only when cpu's
691 * runqueue has atleast one cfs task.
692 *
693 * @dl_defer tells if this is a deferred or regular server. For
694 * now only defer server exists.
695 *
696 * @dl_defer_armed tells if the deferrable server is waiting
697 * for the replenishment timer to activate it.
698 *
699 * @dl_defer_running tells if the deferrable server is actually
700 * running, skipping the defer phase.
701 *
702 * @dl_defer_idle tracks idle state
703 *
704 * @dl_bw_attached tells if this server's bandwidth currently
705 * contributes to the root domain's total_bw. Only meaningful for server
706 * entities (@dl_server == 1). Allows toggling the reservation on/off
707 * without losing the configured @dl_runtime/@dl_period.
708 */
709 unsigned int dl_throttled : 1;
710 unsigned int dl_yielded : 1;
711 unsigned int dl_non_contending : 1;
712 unsigned int dl_overrun : 1;
713 unsigned int dl_server : 1;
714 unsigned int dl_server_active : 1;
715 unsigned int dl_defer : 1;
716 unsigned int dl_defer_armed : 1;
717 unsigned int dl_defer_running : 1;
718 unsigned int dl_defer_idle : 1;
719 unsigned int dl_bw_attached : 1;
720
721 /*
722 * Bandwidth enforcement timer. Each -deadline task has its
723 * own bandwidth to be enforced, thus we need one timer per task.
724 */
725 struct hrtimer dl_timer;
726
727 /*
728 * Inactive timer, responsible for decreasing the active utilization
729 * at the "0-lag time". When a -deadline task blocks, it contributes
730 * to GRUB's active utilization until the "0-lag time", hence a
731 * timer is needed to decrease the active utilization at the correct
732 * time.
733 */
734 struct hrtimer inactive_timer;
735
736 /*
737 * Bits for DL-server functionality. Also see the comment near
738 * dl_server_update().
739 *
740 * @rq the runqueue this server is for
741 */
742 struct rq *rq;
743 dl_server_pick_f server_pick_task;
744
745 #ifdef CONFIG_RT_MUTEXES
746 /*
747 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
748 * pi_se points to the donor, otherwise points to the dl_se it belongs
749 * to (the original one/itself).
750 */
751 struct sched_dl_entity *pi_se;
752 #endif
753 };
754
755 #ifdef CONFIG_UCLAMP_TASK
756 /* Number of utilization clamp buckets (shorter alias) */
757 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
758
759 /*
760 * Utilization clamp for a scheduling entity
761 * @value: clamp value "assigned" to a se
762 * @bucket_id: bucket index corresponding to the "assigned" value
763 * @active: the se is currently refcounted in a rq's bucket
764 * @user_defined: the requested clamp value comes from user-space
765 *
766 * The bucket_id is the index of the clamp bucket matching the clamp value
767 * which is pre-computed and stored to avoid expensive integer divisions from
768 * the fast path.
769 *
770 * The active bit is set whenever a task has got an "effective" value assigned,
771 * which can be different from the clamp value "requested" from user-space.
772 * This allows to know a task is refcounted in the rq's bucket corresponding
773 * to the "effective" bucket_id.
774 *
775 * The user_defined bit is set whenever a task has got a task-specific clamp
776 * value requested from userspace, i.e. the system defaults apply to this task
777 * just as a restriction. This allows to relax default clamps when a less
778 * restrictive task-specific value has been requested, thus allowing to
779 * implement a "nice" semantic. For example, a task running with a 20%
780 * default boost can still drop its own boosting to 0%.
781 */
782 struct uclamp_se {
783 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
784 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
785 unsigned int active : 1;
786 unsigned int user_defined : 1;
787 };
788 #endif /* CONFIG_UCLAMP_TASK */
789
790 union rcu_special {
791 struct {
792 u8 blocked;
793 u8 need_qs;
794 u8 exp_hint; /* Hint for performance. */
795 u8 need_mb; /* Readers need smp_mb(). */
796 } b; /* Bits. */
797 u32 s; /* Set of bits. */
798 };
799
800 enum perf_event_task_context {
801 perf_invalid_context = -1,
802 perf_hw_context = 0,
803 perf_sw_context,
804 perf_nr_task_contexts,
805 };
806
807 /*
808 * Number of contexts where an event can trigger:
809 * task, softirq, hardirq, nmi.
810 */
811 #define PERF_NR_CONTEXTS 4
812
813 struct wake_q_node {
814 struct wake_q_node *next;
815 };
816
817 struct kmap_ctrl {
818 #ifdef CONFIG_KMAP_LOCAL
819 int idx;
820 pte_t pteval[KM_MAX_IDX];
821 #endif
822 };
823
824 #if defined(CONFIG_SMP) && defined(CONFIG_PREEMPTION)
825 struct task_ipi_mask {
826 union {
827 cpumask_t *ipi_mask_ptr;
828 unsigned long ipi_mask_val;
829 };
830 };
831 #else
832 struct task_ipi_mask { };
833 #endif
834
835 struct task_struct {
836 #ifdef CONFIG_THREAD_INFO_IN_TASK
837 /*
838 * For reasons of header soup (see current_thread_info()), this
839 * must be the first element of task_struct.
840 */
841 struct thread_info thread_info;
842 #endif
843 unsigned int __state;
844
845 /* saved state for "spinlock sleepers" */
846 unsigned int saved_state;
847
848 /*
849 * This begins the randomizable portion of task_struct. Only
850 * scheduling-critical items should be added above here.
851 */
852 randomized_struct_fields_start
853
854 void *stack;
855 refcount_t usage;
856 /* Per task flags (PF_*), defined further below: */
857 unsigned int flags;
858 unsigned int ptrace;
859
860 #ifdef CONFIG_MEM_ALLOC_PROFILING
861 struct alloc_tag *alloc_tag;
862 #endif
863
864 u8 on_cpu;
865 u8 on_rq;
866 u8 is_blocked;
867 u8 __pad;
868
869 struct __call_single_node wake_entry;
870 unsigned int wakee_flips;
871 unsigned long wakee_flip_decay_ts;
872 struct task_struct *last_wakee;
873
874 /*
875 * recent_used_cpu is initially set as the last CPU used by a task
876 * that wakes affine another task. Waker/wakee relationships can
877 * push tasks around a CPU where each wakeup moves to the next one.
878 * Tracking a recently used CPU allows a quick search for a recently
879 * used CPU that may be idle.
880 */
881 int recent_used_cpu;
882 int wake_cpu;
883
884 int prio;
885 int static_prio;
886 int normal_prio;
887 unsigned int rt_priority;
888
889 struct sched_entity se;
890 struct sched_rt_entity rt;
891 struct sched_dl_entity dl;
892 struct sched_dl_entity *dl_server;
893 #ifdef CONFIG_SCHED_CLASS_EXT
894 struct sched_ext_entity scx;
895 #endif
896 const struct sched_class *sched_class;
897
898 #ifdef CONFIG_SCHED_CORE
899 struct rb_node core_node;
900 unsigned long core_cookie;
901 unsigned int core_occupation;
902 #endif
903
904 #ifdef CONFIG_CGROUP_SCHED
905 struct task_group *sched_task_group;
906 #ifdef CONFIG_CFS_BANDWIDTH
907 struct callback_head sched_throttle_work;
908 struct list_head throttle_node;
909 bool throttled;
910 #endif
911 #endif
912
913
914 #ifdef CONFIG_UCLAMP_TASK
915 /*
916 * Clamp values requested for a scheduling entity.
917 * Must be updated with task_rq_lock() held.
918 */
919 struct uclamp_se uclamp_req[UCLAMP_CNT];
920 /*
921 * Effective clamp values used for a scheduling entity.
922 * Must be updated with task_rq_lock() held.
923 */
924 struct uclamp_se uclamp[UCLAMP_CNT];
925 #endif
926
927 struct sched_statistics stats;
928
929 #ifdef CONFIG_PREEMPT_NOTIFIERS
930 /* List of struct preempt_notifier: */
931 struct hlist_head preempt_notifiers;
932 #endif
933
934 #ifdef CONFIG_BLK_DEV_IO_TRACE
935 unsigned int btrace_seq;
936 #endif
937
938 unsigned int policy;
939 unsigned long max_allowed_capacity;
940 int nr_cpus_allowed;
941 const cpumask_t *cpus_ptr;
942 cpumask_t *user_cpus_ptr;
943 cpumask_t cpus_mask;
944 void *migration_pending;
945 unsigned short migration_disabled;
946 unsigned short migration_flags;
947
948 #ifdef CONFIG_PREEMPT_RCU
949 int rcu_read_lock_nesting;
950 union rcu_special rcu_read_unlock_special;
951 struct list_head rcu_node_entry;
952 struct rcu_node *rcu_blocked_node;
953 #endif /* #ifdef CONFIG_PREEMPT_RCU */
954
955 #ifdef CONFIG_TASKS_RCU
956 unsigned long rcu_tasks_nvcsw;
957 u8 rcu_tasks_holdout;
958 u8 rcu_tasks_idx;
959 int rcu_tasks_idle_cpu;
960 struct list_head rcu_tasks_holdout_list;
961 int rcu_tasks_exit_cpu;
962 struct list_head rcu_tasks_exit_list;
963 #endif /* #ifdef CONFIG_TASKS_RCU */
964
965 #ifdef CONFIG_TASKS_TRACE_RCU
966 int trc_reader_nesting;
967 struct srcu_ctr __percpu *trc_reader_scp;
968 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
969
970 #ifdef CONFIG_TRIVIAL_PREEMPT_RCU
971 int rcu_trivial_preempt_nesting;
972 #endif /* #ifdef CONFIG_TRIVIAL_PREEMPT_RCU */
973
974 struct sched_info sched_info;
975
976 struct list_head tasks;
977 struct plist_node pushable_tasks;
978 struct rb_node pushable_dl_tasks;
979
980 struct mm_struct *mm;
981 struct mm_struct *active_mm;
982
983 struct task_exec_state __rcu *exec_state;
984
985 int exit_state;
986 int exit_code;
987 int exit_signal;
988 /* The signal sent when the parent dies: */
989 int pdeath_signal;
990 /* JOBCTL_*, siglock protected: */
991 unsigned long jobctl;
992
993 /* Used for emulating ABI behavior of previous Linux versions: */
994 unsigned int personality;
995
996 /* Scheduler bits, serialized by scheduler locks: */
997 unsigned sched_reset_on_fork:1;
998 unsigned sched_contributes_to_load:1;
999 unsigned sched_migrated:1;
1000 unsigned sched_task_hot:1;
1001
1002 /* Force alignment to the next boundary: */
1003 unsigned :0;
1004
1005 /* Unserialized, strictly 'current' */
1006
1007 /*
1008 * This field must not be in the scheduler word above due to wakelist
1009 * queueing no longer being serialized by p->on_cpu. However:
1010 *
1011 * p->XXX = X; ttwu()
1012 * schedule() if (p->on_rq && ..) // false
1013 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
1014 * deactivate_task() ttwu_queue_wakelist())
1015 * p->on_rq = 0; p->sched_remote_wakeup = Y;
1016 *
1017 * guarantees all stores of 'current' are visible before
1018 * ->sched_remote_wakeup gets used, so it can be in this word.
1019 */
1020 unsigned sched_remote_wakeup:1;
1021 #ifdef CONFIG_RT_MUTEXES
1022 unsigned sched_rt_mutex:1;
1023 #endif
1024
1025 /* Bit to tell TOMOYO we're in execve(): */
1026 unsigned in_execve:1;
1027 unsigned in_iowait:1;
1028 #ifndef TIF_RESTORE_SIGMASK
1029 unsigned restore_sigmask:1;
1030 #endif
1031 #ifdef CONFIG_MEMCG_V1
1032 unsigned in_user_fault:1;
1033 #endif
1034 #ifdef CONFIG_LRU_GEN
1035 /* whether the LRU algorithm may apply to this access */
1036 unsigned in_lru_fault:1;
1037 #endif
1038 #ifdef CONFIG_COMPAT_BRK
1039 unsigned brk_randomized:1;
1040 #endif
1041 #ifdef CONFIG_CGROUPS
1042 /* disallow userland-initiated cgroup migration */
1043 unsigned no_cgroup_migration:1;
1044 /* task is frozen/stopped (used by the cgroup freezer) */
1045 unsigned frozen:1;
1046 #endif
1047 #ifdef CONFIG_BLK_CGROUP
1048 unsigned use_memdelay:1;
1049 #endif
1050 #ifdef CONFIG_PSI
1051 /* Stalled due to lack of memory */
1052 unsigned in_memstall:1;
1053 #endif
1054 #ifdef CONFIG_PAGE_OWNER
1055 /* Used by page_owner=on to detect recursion in page tracking. */
1056 unsigned in_page_owner:1;
1057 #endif
1058 #ifdef CONFIG_EVENTFD
1059 /* Recursion prevention for eventfd_signal() */
1060 unsigned in_eventfd:1;
1061 #endif
1062 #ifdef CONFIG_ARCH_HAS_CPU_PASID
1063 unsigned pasid_activated:1;
1064 #endif
1065 #ifdef CONFIG_X86_BUS_LOCK_DETECT
1066 unsigned reported_split_lock:1;
1067 #endif
1068 #ifdef CONFIG_TASK_DELAY_ACCT
1069 /* delay due to memory thrashing */
1070 unsigned in_thrashing:1;
1071 #endif
1072 unsigned in_nf_duplicate:1;
1073 #ifdef CONFIG_PREEMPT_RT
1074 struct netdev_xmit net_xmit;
1075 #endif
1076 unsigned long atomic_flags; /* Flags requiring atomic access. */
1077
1078 struct restart_block restart_block;
1079
1080 pid_t pid;
1081 pid_t tgid;
1082
1083 #ifdef CONFIG_STACKPROTECTOR
1084 /* Canary value for the -fstack-protector GCC feature: */
1085 unsigned long stack_canary;
1086 #endif
1087 /*
1088 * Pointers to the (original) parent process, youngest child, younger sibling,
1089 * older sibling, respectively. (p->father can be replaced with
1090 * p->real_parent->pid)
1091 */
1092
1093 /* Real parent process: */
1094 struct task_struct __rcu *real_parent;
1095
1096 /* Recipient of SIGCHLD, wait4() reports: */
1097 struct task_struct __rcu *parent;
1098
1099 /*
1100 * Children/sibling form the list of natural children:
1101 */
1102 struct list_head children;
1103 struct list_head sibling;
1104 struct task_struct *group_leader;
1105
1106 /*
1107 * 'ptraced' is the list of tasks this task is using ptrace() on.
1108 *
1109 * This includes both natural children and PTRACE_ATTACH targets.
1110 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1111 */
1112 struct list_head ptraced;
1113 struct list_head ptrace_entry;
1114
1115 /* PID/PID hash table linkage. */
1116 struct pid *thread_pid;
1117 struct hlist_node pid_links[PIDTYPE_MAX];
1118 struct list_head thread_node;
1119
1120 struct completion *vfork_done;
1121
1122 /* CLONE_CHILD_SETTID: */
1123 int __user *set_child_tid;
1124
1125 /* CLONE_CHILD_CLEARTID: */
1126 int __user *clear_child_tid;
1127
1128 /* PF_KTHREAD | PF_IO_WORKER */
1129 void *worker_private;
1130
1131 u64 utime;
1132 u64 stime;
1133 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1134 u64 utimescaled;
1135 u64 stimescaled;
1136 #endif
1137 u64 gtime;
1138 struct prev_cputime prev_cputime;
1139 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1140 struct vtime vtime;
1141 #endif
1142
1143 #ifdef CONFIG_NO_HZ_FULL
1144 atomic_t tick_dep_mask;
1145 #endif
1146 /* Context switch counts: */
1147 unsigned long nvcsw;
1148 unsigned long nivcsw;
1149
1150 /* Monotonic time in nsecs: */
1151 u64 start_time;
1152
1153 /* Boot based time in nsecs: */
1154 u64 start_boottime;
1155
1156 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1157 unsigned long min_flt;
1158 unsigned long maj_flt;
1159
1160 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1161 struct posix_cputimers posix_cputimers;
1162
1163 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1164 struct posix_cputimers_work posix_cputimers_work;
1165 #endif
1166
1167 /* Process credentials: */
1168
1169 /* Tracer's credentials at attach: */
1170 const struct cred __rcu *ptracer_cred;
1171
1172 /* Objective and real subjective task credentials (COW): */
1173 const struct cred __rcu *real_cred;
1174
1175 /* Effective (overridable) subjective task credentials (COW): */
1176 const struct cred __rcu *cred;
1177
1178 #ifdef CONFIG_KEYS
1179 /* Cached requested key. */
1180 struct key *cached_requested_key;
1181 #endif
1182
1183 /*
1184 * executable name, excluding path.
1185 *
1186 * - normally initialized by begin_new_exec()
1187 * - set it with set_task_comm() to ensure it is always
1188 * NUL-terminated and zero-padded
1189 */
1190 char comm[TASK_COMM_LEN];
1191
1192 struct nameidata *nameidata;
1193
1194 #ifdef CONFIG_SYSVIPC
1195 struct sysv_sem sysvsem;
1196 struct sysv_shm sysvshm;
1197 #endif
1198 #ifdef CONFIG_DETECT_HUNG_TASK
1199 unsigned long last_switch_count;
1200 unsigned long last_switch_time;
1201 #endif
1202 /* Filesystem information: */
1203 struct fs_struct *real_fs;
1204 struct fs_struct *fs;
1205
1206 /* Open file information: */
1207 struct files_struct *files;
1208
1209 #ifdef CONFIG_IO_URING
1210 struct io_uring_task *io_uring;
1211 struct io_restriction *io_uring_restrict;
1212 #endif
1213
1214 /* Namespaces: */
1215 struct nsproxy *nsproxy;
1216
1217 /* Signal handlers: */
1218 struct signal_struct *signal;
1219 struct sighand_struct __rcu *sighand;
1220 sigset_t blocked;
1221 sigset_t real_blocked;
1222 /* Restored if set_restore_sigmask() was used: */
1223 sigset_t saved_sigmask;
1224 struct sigpending pending;
1225 unsigned long sas_ss_sp;
1226 size_t sas_ss_size;
1227 unsigned int sas_ss_flags;
1228
1229 struct callback_head *task_works;
1230
1231 #ifdef CONFIG_AUDIT
1232 #ifdef CONFIG_AUDITSYSCALL
1233 struct audit_context *audit_context;
1234 #endif
1235 kuid_t loginuid;
1236 unsigned int sessionid;
1237 #endif
1238 struct seccomp seccomp;
1239 struct syscall_user_dispatch syscall_dispatch;
1240
1241 /* Thread group tracking: */
1242 u64 parent_exec_id;
1243 u64 self_exec_id;
1244
1245 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1246 spinlock_t alloc_lock;
1247
1248 /* Protection of the PI data structures: */
1249 raw_spinlock_t pi_lock;
1250
1251 struct wake_q_node wake_q;
1252
1253 #ifdef CONFIG_RT_MUTEXES
1254 /* PI waiters blocked on a rt_mutex held by this task: */
1255 struct rb_root_cached pi_waiters;
1256 /* Updated under owner's pi_lock and rq lock */
1257 struct task_struct *pi_top_task;
1258 /* Deadlock detection and priority inheritance handling: */
1259 struct rt_mutex_waiter *pi_blocked_on;
1260 #endif
1261
1262 struct mutex *blocked_on; /* lock we're blocked on */
1263 raw_spinlock_t blocked_lock;
1264
1265 /*
1266 * The task that is boosting this task; a back link for the current
1267 * donor stack. Set in schedule() -> find_proxy_task() and only stable
1268 * under preempt_disable().
1269 */
1270 struct task_struct *blocked_donor;
1271
1272 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
1273 /*
1274 * Encoded lock address causing task block (lower 2 bits = type from
1275 * <linux/hung_task.h>). Accessed via hung_task_*() helpers.
1276 */
1277 unsigned long blocker;
1278 #endif
1279
1280 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1281 int non_block_count;
1282 #endif
1283
1284 #ifdef CONFIG_TRACE_IRQFLAGS
1285 struct irqtrace_events irqtrace;
1286 unsigned int hardirq_threaded;
1287 u64 hardirq_chain_key;
1288 int softirqs_enabled;
1289 int softirq_context;
1290 int irq_config;
1291 #endif
1292 #ifdef CONFIG_PREEMPT_RT
1293 int softirq_disable_cnt;
1294 #endif
1295
1296 #ifdef CONFIG_LOCKDEP
1297 # define MAX_LOCK_DEPTH 48UL
1298 u64 curr_chain_key;
1299 int lockdep_depth;
1300 unsigned int lockdep_recursion;
1301 unsigned int lockdep_seq;
1302 struct held_lock held_locks[MAX_LOCK_DEPTH];
1303 #endif
1304
1305 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1306 unsigned int in_ubsan;
1307 #endif
1308
1309 /* Journalling filesystem info: */
1310 void *journal_info;
1311
1312 /* Stacked block device info: */
1313 struct bio_list *bio_list;
1314
1315 /* Stack plugging: */
1316 struct blk_plug *plug;
1317
1318 /* VM state: */
1319 struct reclaim_state *reclaim_state;
1320
1321 struct io_context *io_context;
1322
1323 #ifdef CONFIG_COMPACTION
1324 struct capture_control *capture_control;
1325 #endif
1326 /* Ptrace state: */
1327 unsigned long ptrace_message;
1328 kernel_siginfo_t *last_siginfo;
1329
1330 struct task_io_accounting ioac;
1331 #ifdef CONFIG_PSI
1332 /* Pressure stall state */
1333 unsigned int psi_flags;
1334 #endif
1335 #ifdef CONFIG_TASK_XACCT
1336 /* Accumulated RSS usage: */
1337 u64 acct_rss_mem1;
1338 /* Accumulated virtual memory usage: */
1339 u64 acct_vm_mem1;
1340 /* stime + utime since last update: */
1341 u64 acct_timexpd;
1342 #endif
1343 #ifdef CONFIG_CPUSETS
1344 /* Protected by ->alloc_lock: */
1345 nodemask_t mems_allowed;
1346 /* Sequence number to catch updates: */
1347 seqcount_spinlock_t mems_allowed_seq;
1348 int cpuset_mem_spread_rotor;
1349 #endif
1350 #ifdef CONFIG_CGROUPS
1351 /* Control Group info protected by css_set_lock: */
1352 struct css_set __rcu *cgroups;
1353 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1354 struct list_head cg_list;
1355 #ifdef CONFIG_PREEMPT_RT
1356 struct llist_node cg_dead_lnode;
1357 #endif /* CONFIG_PREEMPT_RT */
1358 #endif /* CONFIG_CGROUPS */
1359 #ifdef CONFIG_X86_CPU_RESCTRL
1360 u32 closid;
1361 u32 rmid;
1362 #endif
1363
1364 struct futex_sched_data futex;
1365
1366 #ifdef CONFIG_PERF_EVENTS
1367 u8 perf_recursion[PERF_NR_CONTEXTS];
1368 struct perf_event_context *perf_event_ctxp;
1369 struct mutex perf_event_mutex;
1370 struct list_head perf_event_list;
1371 struct perf_ctx_data __rcu *perf_ctx_data;
1372 #endif
1373 struct task_ipi_mask __private ipi_mask;
1374 #ifdef CONFIG_DEBUG_PREEMPT
1375 unsigned long preempt_disable_ip;
1376 #endif
1377 #ifdef CONFIG_NUMA
1378 /* Protected by alloc_lock: */
1379 struct mempolicy *mempolicy;
1380 short il_prev;
1381 u8 il_weight;
1382 short pref_node_fork;
1383 #endif
1384 #ifdef CONFIG_NUMA_BALANCING
1385 int numa_scan_seq;
1386 unsigned int numa_scan_period;
1387 unsigned int numa_scan_period_max;
1388 int numa_preferred_nid;
1389 unsigned long numa_migrate_retry;
1390 /* Migration stamp: */
1391 u64 node_stamp;
1392 u64 last_task_numa_placement;
1393 u64 last_sum_exec_runtime;
1394 struct callback_head numa_work;
1395
1396 /*
1397 * This pointer is only modified for current in syscall and
1398 * pagefault context (and for tasks being destroyed), so it can be read
1399 * from any of the following contexts:
1400 * - RCU read-side critical section
1401 * - current->numa_group from everywhere
1402 * - task's runqueue locked, task not running
1403 */
1404 struct numa_group __rcu *numa_group;
1405
1406 /*
1407 * numa_faults is an array split into four regions:
1408 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1409 * in this precise order.
1410 *
1411 * faults_memory: Exponential decaying average of faults on a per-node
1412 * basis. Scheduling placement decisions are made based on these
1413 * counts. The values remain static for the duration of a PTE scan.
1414 * faults_cpu: Track the nodes the process was running on when a NUMA
1415 * hinting fault was incurred.
1416 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1417 * during the current scan window. When the scan completes, the counts
1418 * in faults_memory and faults_cpu decay and these values are copied.
1419 */
1420 unsigned long *numa_faults;
1421 unsigned long total_numa_faults;
1422
1423 /*
1424 * numa_faults_locality tracks if faults recorded during the last
1425 * scan window were remote/local or failed to migrate. The task scan
1426 * period is adapted based on the locality of the faults with different
1427 * weights depending on whether they were shared or private faults
1428 */
1429 unsigned long numa_faults_locality[3];
1430
1431 unsigned long numa_pages_migrated;
1432 #endif /* CONFIG_NUMA_BALANCING */
1433
1434 #ifdef CONFIG_SCHED_CACHE
1435 struct callback_head cache_work;
1436 int preferred_llc;
1437 /* 1: task was enqueued to its preferred LLC, 0 otherwise */
1438 int pref_llc_queued;
1439 #endif
1440
1441 struct rseq_data rseq;
1442 struct sched_mm_cid mm_cid;
1443
1444 struct tlbflush_unmap_batch tlb_ubc;
1445
1446 /* Cache last used pipe for splice(): */
1447 struct pipe_inode_info *splice_pipe;
1448
1449 struct page_frag task_frag;
1450
1451 #ifdef CONFIG_ARCH_HAS_LAZY_MMU_MODE
1452 struct lazy_mmu_state lazy_mmu_state;
1453 #endif
1454
1455 #ifdef CONFIG_TASK_DELAY_ACCT
1456 struct task_delay_info *delays;
1457 #endif
1458
1459 #ifdef CONFIG_FAULT_INJECTION
1460 int make_it_fail;
1461 unsigned int fail_nth;
1462 #endif
1463 /*
1464 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1465 * balance_dirty_pages() for a dirty throttling pause:
1466 */
1467 int nr_dirtied;
1468 int nr_dirtied_pause;
1469 /* Start of a write-and-pause period: */
1470 unsigned long dirty_paused_when;
1471
1472 #ifdef CONFIG_LATENCYTOP
1473 int latency_record_count;
1474 struct latency_record latency_record[LT_SAVECOUNT];
1475 #endif
1476 /*
1477 * Time slack values; these are used to round up poll() and
1478 * select() etc timeout values. These are in nanoseconds.
1479 */
1480 u64 timer_slack_ns;
1481 u64 default_timer_slack_ns;
1482
1483 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1484 unsigned int kasan_depth;
1485 #endif
1486
1487 #ifdef CONFIG_KCSAN
1488 struct kcsan_ctx kcsan_ctx;
1489 #ifdef CONFIG_TRACE_IRQFLAGS
1490 struct irqtrace_events kcsan_save_irqtrace;
1491 #endif
1492 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1493 int kcsan_stack_depth;
1494 #endif
1495 #endif
1496
1497 #ifdef CONFIG_KMSAN
1498 struct kmsan_ctx kmsan_ctx;
1499 #endif
1500
1501 #if IS_ENABLED(CONFIG_KUNIT)
1502 struct kunit *kunit_test;
1503 #endif
1504
1505 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1506 /* Index of current stored address in ret_stack: */
1507 int curr_ret_stack;
1508 int curr_ret_depth;
1509
1510 /* Stack of return addresses for return function tracing: */
1511 unsigned long *ret_stack;
1512
1513 /* Timestamp for last schedule: */
1514 unsigned long long ftrace_timestamp;
1515 unsigned long long ftrace_sleeptime;
1516
1517 /*
1518 * Number of functions that haven't been traced
1519 * because of depth overrun:
1520 */
1521 atomic_t trace_overrun;
1522
1523 /* Pause tracing: */
1524 atomic_t tracing_graph_pause;
1525 #endif
1526
1527 #ifdef CONFIG_TRACING
1528 /* Bitmask and counter of trace recursion: */
1529 unsigned long trace_recursion;
1530 #endif /* CONFIG_TRACING */
1531
1532 #ifdef CONFIG_KCOV
1533 /* See kernel/kcov.c for more details. */
1534
1535 /* Coverage collection mode enabled for this task (0 if disabled): */
1536 unsigned int kcov_mode;
1537
1538 /* Size of the kcov_area: */
1539 unsigned int kcov_size;
1540
1541 /* Buffer for coverage collection: */
1542 void *kcov_area;
1543
1544 /* KCOV descriptor wired with this task or NULL: */
1545 struct kcov *kcov;
1546
1547 /* KCOV descriptor for remote coverage collection from other tasks: */
1548 struct kcov *kcov_remote;
1549
1550 /* KCOV common handle for remote coverage collection: */
1551 u64 kcov_handle;
1552
1553 /* KCOV sequence number: */
1554 int kcov_sequence;
1555
1556 /* Collect coverage from softirq context: */
1557 unsigned int kcov_softirq;
1558
1559 /* Temporary storage for preempting remote coverage collection: */
1560 unsigned int kcov_saved_mode;
1561 unsigned int kcov_saved_size;
1562 void *kcov_saved_area;
1563 struct kcov *kcov_saved_kcov;
1564 int kcov_saved_sequence;
1565
1566 #endif
1567
1568 #ifdef CONFIG_MEMCG_V1
1569 struct mem_cgroup *memcg_in_oom;
1570 #endif
1571
1572 #ifdef CONFIG_MEMCG
1573 /* Number of pages to reclaim on returning to userland: */
1574 unsigned int memcg_nr_pages_over_high;
1575
1576 /* Used by memcontrol for targeted memcg charge: */
1577 struct mem_cgroup *active_memcg;
1578
1579 /* Cache for current->cgroups->memcg->nodeinfo[nid]->objcg lookups: */
1580 struct obj_cgroup *objcg;
1581 #endif
1582
1583 #ifdef CONFIG_BLK_CGROUP
1584 struct gendisk *throttle_disk;
1585 #endif
1586
1587 #ifdef CONFIG_UPROBES
1588 struct uprobe_task *utask;
1589 #endif
1590 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1591 unsigned int sequential_io;
1592 unsigned int sequential_io_avg;
1593 #endif
1594 struct kmap_ctrl kmap_ctrl;
1595 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1596 unsigned long task_state_change;
1597 # ifdef CONFIG_PREEMPT_RT
1598 unsigned long saved_state_change;
1599 # endif
1600 #endif
1601 struct rcu_head rcu;
1602 refcount_t rcu_users;
1603 int pagefault_disabled;
1604 #ifdef CONFIG_MMU
1605 struct task_struct *oom_reaper_list;
1606 struct timer_list oom_reaper_timer;
1607 #endif
1608 #ifdef CONFIG_VMAP_STACK
1609 struct vm_struct *stack_vm_area;
1610 #endif
1611 #ifdef CONFIG_THREAD_INFO_IN_TASK
1612 /* A live task holds one reference: */
1613 refcount_t stack_refcount;
1614 #endif
1615 #ifdef CONFIG_LIVEPATCH
1616 int patch_state;
1617 #endif
1618 #ifdef CONFIG_SECURITY
1619 /* Used by LSM modules for access restriction: */
1620 void *security;
1621 #endif
1622 #ifdef CONFIG_BPF_SYSCALL
1623 /* Used by BPF task local storage */
1624 struct bpf_local_storage __rcu *bpf_storage;
1625 /* Used for BPF run context */
1626 struct bpf_run_ctx *bpf_ctx;
1627 #endif
1628 /* Used by BPF for per-TASK xdp storage */
1629 struct bpf_net_context *bpf_net_context;
1630
1631 #ifdef CONFIG_KSTACK_ERASE
1632 unsigned long lowest_stack;
1633 #endif
1634 #ifdef CONFIG_KSTACK_ERASE_METRICS
1635 unsigned long prev_lowest_stack;
1636 #endif
1637
1638 #ifdef CONFIG_X86_MCE
1639 void __user *mce_vaddr;
1640 __u64 mce_kflags;
1641 u64 mce_addr;
1642 __u64 mce_ripv : 1,
1643 mce_whole_page : 1,
1644 __mce_reserved : 62;
1645 struct callback_head mce_kill_me;
1646 int mce_count;
1647 #endif
1648
1649 #ifdef CONFIG_KRETPROBES
1650 struct llist_head kretprobe_instances;
1651 #endif
1652 #ifdef CONFIG_RETHOOK
1653 struct llist_head rethooks;
1654 #endif
1655
1656 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1657 /*
1658 * If L1D flush is supported on mm context switch
1659 * then we use this callback head to queue kill work
1660 * to kill tasks that are not running on SMT disabled
1661 * cores
1662 */
1663 struct callback_head l1d_flush_kill;
1664 #endif
1665
1666 #ifdef CONFIG_RV
1667 /*
1668 * Per-task RV monitor, fixed in CONFIG_RV_PER_TASK_MONITORS.
1669 * If memory becomes a concern, we can think about a dynamic method.
1670 */
1671 union rv_task_monitor rv[CONFIG_RV_PER_TASK_MONITORS];
1672 #endif
1673
1674 #ifdef CONFIG_USER_EVENTS
1675 struct user_event_mm *user_event_mm;
1676 #endif
1677
1678 #ifdef CONFIG_UNWIND_USER
1679 struct unwind_task_info unwind_info;
1680 #endif
1681
1682 /* CPU-specific state of this task: */
1683 struct thread_struct thread;
1684
1685 /*
1686 * New fields for task_struct should be added above here, so that
1687 * they are included in the randomized portion of task_struct.
1688 */
1689 randomized_struct_fields_end
1690 } __attribute__ ((aligned (64)));
1691
1692 #ifdef CONFIG_SCHED_PROXY_EXEC
1693 DECLARE_STATIC_KEY_TRUE(__sched_proxy_exec);
sched_proxy_exec(void)1694 static inline bool sched_proxy_exec(void)
1695 {
1696 return static_branch_likely(&__sched_proxy_exec);
1697 }
1698 #else
sched_proxy_exec(void)1699 static inline bool sched_proxy_exec(void)
1700 {
1701 return false;
1702 }
1703 #endif
1704
1705 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1706 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1707
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1708 static inline unsigned int __task_state_index(unsigned int tsk_state,
1709 unsigned int tsk_exit_state)
1710 {
1711 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1712
1713 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1714
1715 if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1716 state = TASK_REPORT_IDLE;
1717
1718 /*
1719 * We're lying here, but rather than expose a completely new task state
1720 * to userspace, we can make this appear as if the task has gone through
1721 * a regular rt_mutex_lock() call.
1722 * Report frozen tasks as uninterruptible.
1723 */
1724 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN))
1725 state = TASK_UNINTERRUPTIBLE;
1726
1727 return fls(state);
1728 }
1729
task_state_index(struct task_struct * tsk)1730 static inline unsigned int task_state_index(struct task_struct *tsk)
1731 {
1732 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1733 }
1734
task_index_to_char(unsigned int state)1735 static inline char task_index_to_char(unsigned int state)
1736 {
1737 static const char state_char[] = "RSDTtXZPI";
1738
1739 BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1));
1740
1741 return state_char[state];
1742 }
1743
task_state_to_char(struct task_struct * tsk)1744 static inline char task_state_to_char(struct task_struct *tsk)
1745 {
1746 return task_index_to_char(task_state_index(tsk));
1747 }
1748
1749 #ifdef CONFIG_ARCH_HAS_LAZY_MMU_MODE
1750 /**
1751 * __task_lazy_mmu_mode_active() - Test the lazy MMU mode state for a task.
1752 * @tsk: The task to check.
1753 *
1754 * Test whether @tsk has its lazy MMU mode state set to active (i.e. enabled
1755 * and not paused).
1756 *
1757 * This function only considers the state saved in task_struct; to test whether
1758 * current actually is in lazy MMU mode, is_lazy_mmu_mode_active() should be
1759 * used instead.
1760 *
1761 * This function is intended for architectures that implement the lazy MMU
1762 * mode; it must not be called from generic code.
1763 */
__task_lazy_mmu_mode_active(struct task_struct * tsk)1764 static inline bool __task_lazy_mmu_mode_active(struct task_struct *tsk)
1765 {
1766 struct lazy_mmu_state *state = &tsk->lazy_mmu_state;
1767
1768 return state->enable_count > 0 && state->pause_count == 0;
1769 }
1770
1771 /**
1772 * is_lazy_mmu_mode_active() - Test whether we are currently in lazy MMU mode.
1773 *
1774 * Test whether the current context is in lazy MMU mode. This is true if both:
1775 * 1. We are not in interrupt context
1776 * 2. Lazy MMU mode is active for the current task
1777 *
1778 * This function is intended for architectures that implement the lazy MMU
1779 * mode; it must not be called from generic code.
1780 */
is_lazy_mmu_mode_active(void)1781 static inline bool is_lazy_mmu_mode_active(void)
1782 {
1783 if (in_interrupt())
1784 return false;
1785
1786 return __task_lazy_mmu_mode_active(current);
1787 }
1788 #endif
1789
1790 extern struct pid __rcu *cad_pid;
1791
1792 /*
1793 * Per process flags
1794 */
1795 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1796 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1797 #define PF_EXITING 0x00000004 /* Getting shut down */
1798 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1799 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1800 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1801 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1802 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1803 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1804 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1805 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1806 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */
1807 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1808 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1809 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */
1810 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1811 #define PF_KCOMPACTD 0x00010000 /* I am kcompactd */
1812 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1813 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */
1814 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */
1815 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1816 * I am cleaning dirty pages from some other bdi. */
1817 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1818 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1819 #define PF__HOLE__00800000 0x00800000
1820 #define PF__HOLE__01000000 0x01000000
1821 #define PF__HOLE__02000000 0x02000000
1822 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1823 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1824 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning.
1825 * See memalloc_pin_save() */
1826 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */
1827 #define PF__HOLE__40000000 0x40000000
1828 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1829
1830 /*
1831 * Only the _current_ task can read/write to tsk->flags, but other
1832 * tasks can access tsk->flags in readonly mode for example
1833 * with tsk_used_math (like during threaded core dumping).
1834 * There is however an exception to this rule during ptrace
1835 * or during fork: the ptracer task is allowed to write to the
1836 * child->flags of its traced child (same goes for fork, the parent
1837 * can write to the child->flags), because we're guaranteed the
1838 * child is not running and in turn not changing child->flags
1839 * at the same time the parent does it.
1840 */
1841 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1842 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1843 #define clear_used_math() clear_stopped_child_used_math(current)
1844 #define set_used_math() set_stopped_child_used_math(current)
1845
1846 #define conditional_stopped_child_used_math(condition, child) \
1847 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1848
1849 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1850
1851 #define copy_to_stopped_child_used_math(child) \
1852 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1853
1854 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1855 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1856 #define used_math() tsk_used_math(current)
1857
is_percpu_thread(void)1858 static __always_inline bool is_percpu_thread(void)
1859 {
1860 return (current->flags & PF_NO_SETAFFINITY) &&
1861 (current->nr_cpus_allowed == 1);
1862 }
1863
is_user_task(struct task_struct * task)1864 static __always_inline bool is_user_task(struct task_struct *task)
1865 {
1866 return task->mm && !(task->flags & (PF_KTHREAD | PF_USER_WORKER));
1867 }
1868
1869 /* Per-process atomic flags. */
1870 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1871 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1872 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1873 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1874 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1875 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1876 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1877
1878 #define TASK_PFA_TEST(name, func) \
1879 static inline bool task_##func(struct task_struct *p) \
1880 { return test_bit(PFA_##name, &p->atomic_flags); }
1881
1882 #define TASK_PFA_SET(name, func) \
1883 static inline void task_set_##func(struct task_struct *p) \
1884 { set_bit(PFA_##name, &p->atomic_flags); }
1885
1886 #define TASK_PFA_CLEAR(name, func) \
1887 static inline void task_clear_##func(struct task_struct *p) \
1888 { clear_bit(PFA_##name, &p->atomic_flags); }
1889
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1890 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1891 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1892
1893 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1894 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1895 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1896
1897 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1898 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1899 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1900
1901 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1902 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1903 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1904
1905 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1906 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1907
1908 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1909 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1910 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1911
1912 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1913 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1914
1915 static inline void
1916 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1917 {
1918 current->flags &= ~flags;
1919 current->flags |= orig_flags & flags;
1920 }
1921
1922 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1923 extern int task_can_attach(struct task_struct *p);
1924 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1925 extern void dl_bw_free(int cpu, u64 dl_bw);
1926
1927 /* set_cpus_allowed_force() - consider using set_cpus_allowed_ptr() instead */
1928 extern void set_cpus_allowed_force(struct task_struct *p, const struct cpumask *new_mask);
1929
1930 /**
1931 * set_cpus_allowed_ptr - set CPU affinity mask of a task
1932 * @p: the task
1933 * @new_mask: CPU affinity mask
1934 *
1935 * Return: zero if successful, or a negative error code
1936 */
1937 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1938 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1939 extern void release_user_cpus_ptr(struct task_struct *p);
1940 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1941 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1942 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1943
1944 extern int yield_to(struct task_struct *p, bool preempt);
1945 extern void set_user_nice(struct task_struct *p, long nice);
1946 extern int task_prio(const struct task_struct *p);
1947
1948 /**
1949 * task_nice - return the nice value of a given task.
1950 * @p: the task in question.
1951 *
1952 * Return: The nice value [ -20 ... 0 ... 19 ].
1953 */
task_nice(const struct task_struct * p)1954 static inline int task_nice(const struct task_struct *p)
1955 {
1956 return PRIO_TO_NICE((p)->static_prio);
1957 }
1958
1959 extern int can_nice(const struct task_struct *p, const int nice);
1960 extern int task_curr(const struct task_struct *p);
1961 extern int idle_cpu(int cpu);
1962 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1963 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1964 extern void sched_set_fifo(struct task_struct *p);
1965 extern void sched_set_fifo_low(struct task_struct *p);
1966 extern void sched_set_fifo_secondary(struct task_struct *p);
1967 extern void sched_set_normal(struct task_struct *p, int nice);
1968 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1969 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1970 extern struct task_struct *idle_task(int cpu);
1971
1972 /**
1973 * is_idle_task - is the specified task an idle task?
1974 * @p: the task in question.
1975 *
1976 * Return: 1 if @p is an idle task. 0 otherwise.
1977 */
is_idle_task(const struct task_struct * p)1978 static __always_inline bool is_idle_task(const struct task_struct *p)
1979 {
1980 return !!(p->flags & PF_IDLE);
1981 }
1982
1983 extern struct task_struct *curr_task(int cpu);
1984 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1985
1986 void yield(void);
1987
1988 union thread_union {
1989 struct task_struct task;
1990 #ifndef CONFIG_THREAD_INFO_IN_TASK
1991 struct thread_info thread_info;
1992 #endif
1993 unsigned long stack[THREAD_SIZE/sizeof(long)];
1994 };
1995
1996 #ifndef CONFIG_THREAD_INFO_IN_TASK
1997 extern struct thread_info init_thread_info;
1998 #endif
1999
2000 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
2001
2002 #ifdef CONFIG_THREAD_INFO_IN_TASK
2003 # define task_thread_info(task) (&(task)->thread_info)
2004 #else
2005 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
2006 #endif
2007
2008 /*
2009 * find a task by one of its numerical ids
2010 *
2011 * find_task_by_pid_ns():
2012 * finds a task by its pid in the specified namespace
2013 * find_task_by_vpid():
2014 * finds a task by its virtual pid
2015 *
2016 * see also find_vpid() etc in include/linux/pid.h
2017 */
2018
2019 extern struct task_struct *find_task_by_vpid(pid_t nr);
2020 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
2021
2022 /*
2023 * find a task by its virtual pid and get the task struct
2024 */
2025 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
2026
2027 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2028 extern int wake_up_process(struct task_struct *tsk);
2029 extern void wake_up_new_task(struct task_struct *tsk);
2030
2031 extern void kick_process(struct task_struct *tsk);
2032
2033 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2034 #define set_task_comm(tsk, from) ({ \
2035 BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \
2036 __set_task_comm(tsk, from, false); \
2037 })
2038
2039 /*
2040 * - Why not use task_lock()?
2041 * User space can randomly change their names anyway, so locking for readers
2042 * doesn't make sense. For writers, locking is probably necessary, as a race
2043 * condition could lead to long-term mixed results.
2044 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is
2045 * always NUL-terminated and zero-padded. Therefore the race condition between
2046 * reader and writer is not an issue.
2047 *
2048 * - BUILD_BUG_ON() can help prevent the buf from being truncated.
2049 * Since the callers don't perform any return value checks, this safeguard is
2050 * necessary.
2051 */
2052 #define get_task_comm(buf, tsk) ({ \
2053 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \
2054 strscpy_pad(buf, (tsk)->comm); \
2055 buf; \
2056 })
2057
scheduler_ipi(void)2058 static __always_inline void scheduler_ipi(void)
2059 {
2060 /*
2061 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2062 * TIF_NEED_RESCHED remotely (for the first time) will also send
2063 * this IPI.
2064 */
2065 preempt_fold_need_resched();
2066 }
2067
2068 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2069
2070 /*
2071 * Set thread flags in other task's structures.
2072 * See asm/thread_info.h for TIF_xxxx flags available:
2073 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2074 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2075 {
2076 set_ti_thread_flag(task_thread_info(tsk), flag);
2077 }
2078
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2079 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2080 {
2081 clear_ti_thread_flag(task_thread_info(tsk), flag);
2082 }
2083
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2084 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2085 bool value)
2086 {
2087 update_ti_thread_flag(task_thread_info(tsk), flag, value);
2088 }
2089
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2090 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2091 {
2092 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2093 }
2094
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2095 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2096 {
2097 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2098 }
2099
test_tsk_thread_flag(struct task_struct * tsk,int flag)2100 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2101 {
2102 return test_ti_thread_flag(task_thread_info(tsk), flag);
2103 }
2104
set_tsk_need_resched(struct task_struct * tsk)2105 static inline void set_tsk_need_resched(struct task_struct *tsk)
2106 {
2107 if (tracepoint_enabled(sched_set_need_resched_tp) &&
2108 !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED))
2109 __trace_set_need_resched(tsk, TIF_NEED_RESCHED);
2110 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2111 }
2112
clear_tsk_need_resched(struct task_struct * tsk)2113 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2114 {
2115 atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY,
2116 (atomic_long_t *)&task_thread_info(tsk)->flags);
2117 }
2118
test_tsk_need_resched(struct task_struct * tsk)2119 static inline int test_tsk_need_resched(struct task_struct *tsk)
2120 {
2121 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2122 }
2123
set_need_resched_current(void)2124 static inline void set_need_resched_current(void)
2125 {
2126 lockdep_assert_irqs_disabled();
2127 set_tsk_need_resched(current);
2128 set_preempt_need_resched();
2129 }
2130
2131 /*
2132 * cond_resched() and cond_resched_lock(): latency reduction via
2133 * explicit rescheduling in places that are safe. The return
2134 * value indicates whether a reschedule was done in fact.
2135 * cond_resched_lock() will drop the spinlock before scheduling,
2136 */
2137 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2138 extern int __cond_resched(void);
2139
2140 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2141
2142 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2143
_cond_resched(void)2144 static __always_inline int _cond_resched(void)
2145 {
2146 return static_call_mod(cond_resched)();
2147 }
2148
2149 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2150
2151 extern int dynamic_cond_resched(void);
2152
_cond_resched(void)2153 static __always_inline int _cond_resched(void)
2154 {
2155 return dynamic_cond_resched();
2156 }
2157
2158 #else /* !CONFIG_PREEMPTION */
2159
_cond_resched(void)2160 static inline int _cond_resched(void)
2161 {
2162 return __cond_resched();
2163 }
2164
2165 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2166
2167 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2168
_cond_resched(void)2169 static inline int _cond_resched(void)
2170 {
2171 return 0;
2172 }
2173
2174 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2175
2176 #define cond_resched() ({ \
2177 __might_resched(__FILE__, __LINE__, 0); \
2178 _cond_resched(); \
2179 })
2180
2181 extern int __cond_resched_lock(spinlock_t *lock) __must_hold(lock);
2182 extern int __cond_resched_rwlock_read(rwlock_t *lock) __must_hold_shared(lock);
2183 extern int __cond_resched_rwlock_write(rwlock_t *lock) __must_hold(lock);
2184
2185 #define MIGHT_RESCHED_RCU_SHIFT 8
2186 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2187
2188 #ifndef CONFIG_PREEMPT_RT
2189 /*
2190 * Non RT kernels have an elevated preempt count due to the held lock,
2191 * but are not allowed to be inside a RCU read side critical section
2192 */
2193 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2194 #else
2195 /*
2196 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2197 * cond_resched*lock() has to take that into account because it checks for
2198 * preempt_count() and rcu_preempt_depth().
2199 */
2200 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2201 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2202 #endif
2203
2204 #define cond_resched_lock(lock) ({ \
2205 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2206 __cond_resched_lock(lock); \
2207 })
2208
2209 #define cond_resched_rwlock_read(lock) ({ \
2210 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2211 __cond_resched_rwlock_read(lock); \
2212 })
2213
2214 #define cond_resched_rwlock_write(lock) ({ \
2215 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2216 __cond_resched_rwlock_write(lock); \
2217 })
2218
2219 #ifndef CONFIG_PREEMPT_RT
2220
__get_task_blocked_on(struct task_struct * p)2221 static inline struct mutex *__get_task_blocked_on(struct task_struct *p)
2222 {
2223 lockdep_assert_held_once(&p->blocked_lock);
2224 return p->blocked_on;
2225 }
2226
__set_task_blocked_on(struct task_struct * p,struct mutex * m)2227 static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m)
2228 {
2229 WARN_ON_ONCE(!m);
2230 /* The task should only be setting itself as blocked */
2231 WARN_ON_ONCE(p != current);
2232 /* Currently we serialize blocked_on under the task::blocked_lock */
2233 lockdep_assert_held_once(&p->blocked_lock);
2234 /*
2235 * Check ensure we don't overwrite existing mutex value
2236 * with a different mutex. Note, setting it to the same
2237 * lock repeatedly is ok.
2238 */
2239 WARN_ON_ONCE(p->blocked_on && p->blocked_on != m);
2240 p->blocked_on = m;
2241 }
2242
__clear_task_blocked_on(struct task_struct * p,struct mutex * m)2243 static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2244 {
2245 /* Currently we serialize blocked_on under the task::blocked_lock */
2246 lockdep_assert_held_once(&p->blocked_lock);
2247 /*
2248 * There may be cases where we re-clear already cleared
2249 * blocked_on relationships, but make sure we are not
2250 * clearing the relationship with a different lock.
2251 */
2252 WARN_ON_ONCE(m && p->blocked_on && p->blocked_on != m);
2253 p->blocked_on = NULL;
2254 }
2255
clear_task_blocked_on(struct task_struct * p,struct mutex * m)2256 static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2257 {
2258 guard(raw_spinlock_irqsave)(&p->blocked_lock);
2259 __clear_task_blocked_on(p, m);
2260 }
2261 #else
__clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2262 static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2263 {
2264 }
2265
clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2266 static inline void clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2267 {
2268 }
2269 #endif /* !CONFIG_PREEMPT_RT */
2270
need_resched(void)2271 static __always_inline bool need_resched(void)
2272 {
2273 return unlikely(tif_need_resched());
2274 }
2275
2276 /*
2277 * Wrappers for p->thread_info->cpu access. No-op on UP.
2278 */
2279 #ifdef CONFIG_SMP
2280
task_cpu(const struct task_struct * p)2281 static inline unsigned int task_cpu(const struct task_struct *p)
2282 {
2283 return READ_ONCE(task_thread_info(p)->cpu);
2284 }
2285
2286 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2287
2288 #else
2289
task_cpu(const struct task_struct * p)2290 static inline unsigned int task_cpu(const struct task_struct *p)
2291 {
2292 return 0;
2293 }
2294
set_task_cpu(struct task_struct * p,unsigned int cpu)2295 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2296 {
2297 }
2298
2299 #endif /* CONFIG_SMP */
2300
task_is_runnable(struct task_struct * p)2301 static inline bool task_is_runnable(struct task_struct *p)
2302 {
2303 return p->on_rq && !p->se.sched_delayed;
2304 }
2305
2306 extern bool sched_task_on_rq(struct task_struct *p);
2307 extern unsigned long get_wchan(struct task_struct *p);
2308 extern struct task_struct *cpu_curr_snapshot(int cpu);
2309
2310 /*
2311 * In order to reduce various lock holder preemption latencies provide an
2312 * interface to see if a vCPU is currently running or not.
2313 *
2314 * This allows us to terminate optimistic spin loops and block, analogous to
2315 * the native optimistic spin heuristic of testing if the lock owner task is
2316 * running or not.
2317 */
2318 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2319 static inline bool vcpu_is_preempted(int cpu)
2320 {
2321 return false;
2322 }
2323 #endif
2324
2325 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2326 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2327
2328 #ifndef TASK_SIZE_OF
2329 #define TASK_SIZE_OF(tsk) TASK_SIZE
2330 #endif
2331
owner_on_cpu(struct task_struct * owner)2332 static inline bool owner_on_cpu(struct task_struct *owner)
2333 {
2334 /*
2335 * As lock holder preemption issue, we both skip spinning if
2336 * task is not on cpu or its cpu is preempted
2337 */
2338 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2339 }
2340
2341 /* Returns effective CPU energy utilization, as seen by the scheduler */
2342 unsigned long sched_cpu_util(int cpu);
2343
2344 #ifdef CONFIG_SCHED_CORE
2345 extern void sched_core_free(struct task_struct *tsk);
2346 extern void sched_core_fork(struct task_struct *p);
2347 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2348 unsigned long uaddr);
2349 extern int sched_core_idle_cpu(int cpu);
2350 #else
sched_core_free(struct task_struct * tsk)2351 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2352 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2353 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2354 #endif
2355
2356 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2357
2358 #ifdef CONFIG_MEM_ALLOC_PROFILING
alloc_tag_save(struct alloc_tag * tag)2359 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag)
2360 {
2361 swap(current->alloc_tag, tag);
2362 return tag;
2363 }
2364
alloc_tag_restore(struct alloc_tag * tag,struct alloc_tag * old)2365 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old)
2366 {
2367 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
2368 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n");
2369 #endif
2370 current->alloc_tag = old;
2371 }
2372 #else
2373 #define alloc_tag_save(_tag) NULL
2374 #define alloc_tag_restore(_tag, _old) do {} while (0)
2375 #endif
2376
2377 /* Avoids recursive inclusion hell */
2378 #ifdef CONFIG_SCHED_MM_CID
2379 void sched_mm_cid_before_execve(struct task_struct *t);
2380 void sched_mm_cid_after_execve(struct task_struct *t);
2381 void sched_mm_cid_exit(struct task_struct *t);
task_mm_cid(struct task_struct * t)2382 static __always_inline int task_mm_cid(struct task_struct *t)
2383 {
2384 return t->mm_cid.cid & ~(MM_CID_ONCPU | MM_CID_TRANSIT);
2385 }
2386 #else
sched_mm_cid_before_execve(struct task_struct * t)2387 static inline void sched_mm_cid_before_execve(struct task_struct *t) { }
sched_mm_cid_after_execve(struct task_struct * t)2388 static inline void sched_mm_cid_after_execve(struct task_struct *t) { }
sched_mm_cid_exit(struct task_struct * t)2389 static inline void sched_mm_cid_exit(struct task_struct *t) { }
task_mm_cid(struct task_struct * t)2390 static __always_inline int task_mm_cid(struct task_struct *t)
2391 {
2392 /*
2393 * Use the processor id as a fall-back when the mm cid feature is
2394 * disabled. This provides functional per-cpu data structure accesses
2395 * in user-space, althrough it won't provide the memory usage benefits.
2396 */
2397 return task_cpu(t);
2398 }
2399 #endif
2400
2401 #ifdef CONFIG_SCHED_CACHE
2402
2403 struct sched_cache_time {
2404 u64 runtime;
2405 unsigned long epoch;
2406 };
2407
2408 struct sched_cache_stat {
2409 struct sched_cache_time __percpu *pcpu_sched;
2410 raw_spinlock_t lock;
2411 unsigned long epoch;
2412 u64 nr_running_avg;
2413 unsigned long next_scan;
2414 unsigned long footprint;
2415 int cpu;
2416 } ____cacheline_aligned_in_smp;
2417
2418 #else
2419
2420 struct sched_cache_stat { };
2421
2422 #endif
2423
2424 #ifndef MODULE
2425 #ifndef COMPILE_OFFSETS
2426
2427 extern void ___migrate_enable(void);
2428
2429 struct rq;
2430 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
2431
2432 /*
2433 * The "struct rq" is not available here, so we can't access the
2434 * "runqueues" with this_cpu_ptr(), as the compilation will fail in
2435 * this_cpu_ptr() -> raw_cpu_ptr() -> __verify_pcpu_ptr():
2436 * typeof((ptr) + 0)
2437 *
2438 * So use arch_raw_cpu_ptr()/PERCPU_PTR() directly here.
2439 */
2440 #ifdef CONFIG_SMP
2441 #define this_rq_raw() arch_raw_cpu_ptr(&runqueues)
2442 #else
2443 #define this_rq_raw() PERCPU_PTR(&runqueues)
2444 #endif
2445 #define this_rq_pinned() (*(unsigned int *)((void *)this_rq_raw() + RQ_nr_pinned))
2446
__migrate_enable(void)2447 static inline void __migrate_enable(void)
2448 {
2449 struct task_struct *p = current;
2450
2451 #ifdef CONFIG_DEBUG_PREEMPT
2452 /*
2453 * Check both overflow from migrate_disable() and superfluous
2454 * migrate_enable().
2455 */
2456 if (WARN_ON_ONCE((s16)p->migration_disabled <= 0))
2457 return;
2458 #endif
2459
2460 if (p->migration_disabled > 1) {
2461 p->migration_disabled--;
2462 return;
2463 }
2464
2465 /*
2466 * Ensure stop_task runs either before or after this, and that
2467 * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule().
2468 */
2469 guard(preempt)();
2470 if (unlikely(p->cpus_ptr != &p->cpus_mask))
2471 ___migrate_enable();
2472 /*
2473 * Mustn't clear migration_disabled() until cpus_ptr points back at the
2474 * regular cpus_mask, otherwise things that race (eg.
2475 * select_fallback_rq) get confused.
2476 */
2477 barrier();
2478 p->migration_disabled = 0;
2479 this_rq_pinned()--;
2480 }
2481
__migrate_disable(void)2482 static inline void __migrate_disable(void)
2483 {
2484 struct task_struct *p = current;
2485
2486 if (p->migration_disabled) {
2487 #ifdef CONFIG_DEBUG_PREEMPT
2488 /*
2489 *Warn about overflow half-way through the range.
2490 */
2491 WARN_ON_ONCE((s16)p->migration_disabled < 0);
2492 #endif
2493 p->migration_disabled++;
2494 return;
2495 }
2496
2497 guard(preempt)();
2498 this_rq_pinned()++;
2499 p->migration_disabled = 1;
2500 }
2501 #else /* !COMPILE_OFFSETS */
__migrate_disable(void)2502 static inline void __migrate_disable(void) { }
__migrate_enable(void)2503 static inline void __migrate_enable(void) { }
2504 #endif /* !COMPILE_OFFSETS */
2505
2506 /*
2507 * So that it is possible to not export the runqueues variable, define and
2508 * export migrate_enable/migrate_disable in kernel/sched/core.c too, and use
2509 * them for the modules. The macro "INSTANTIATE_EXPORTED_MIGRATE_DISABLE" will
2510 * be defined in kernel/sched/core.c.
2511 */
2512 #ifndef INSTANTIATE_EXPORTED_MIGRATE_DISABLE
migrate_disable(void)2513 static __always_inline void migrate_disable(void)
2514 {
2515 __migrate_disable();
2516 }
2517
migrate_enable(void)2518 static __always_inline void migrate_enable(void)
2519 {
2520 __migrate_enable();
2521 }
2522 #else /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */
2523 extern void migrate_disable(void);
2524 extern void migrate_enable(void);
2525 #endif /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */
2526
2527 #else /* MODULE */
2528 extern void migrate_disable(void);
2529 extern void migrate_enable(void);
2530 #endif /* MODULE */
2531
2532 DEFINE_LOCK_GUARD_0(migrate, migrate_disable(), migrate_enable())
2533
2534 #endif
2535