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