1#ifndef _LINUX_SCHED_H
2#define _LINUX_SCHED_H
3
4/*
5 * Define 'struct task_struct' and provide the main scheduler
6 * APIs (schedule(), wakeup variants, etc.)
7 */
8
9#include <uapi/linux/sched.h>
10
11#include <asm/current.h>
12
13#include <linux/pid.h>
14#include <linux/sem.h>
15#include <linux/shm.h>
16#include <linux/kcov.h>
17#include <linux/mutex.h>
18#include <linux/plist.h>
19#include <linux/hrtimer.h>
20#include <linux/seccomp.h>
21#include <linux/nodemask.h>
22#include <linux/rcupdate.h>
23#include <linux/resource.h>
24#include <linux/latencytop.h>
25#include <linux/sched/prio.h>
26#include <linux/signal_types.h>
27#include <linux/mm_types_task.h>
28#include <linux/task_io_accounting.h>
29
30/* task_struct member predeclarations (sorted alphabetically): */
31struct audit_context;
32struct backing_dev_info;
33struct bio_list;
34struct blk_plug;
35struct cfs_rq;
36struct fs_struct;
37struct futex_pi_state;
38struct io_context;
39struct mempolicy;
40struct nameidata;
41struct nsproxy;
42struct perf_event_context;
43struct pid_namespace;
44struct pipe_inode_info;
45struct rcu_node;
46struct reclaim_state;
47struct robust_list_head;
48struct sched_attr;
49struct sched_param;
50struct seq_file;
51struct sighand_struct;
52struct signal_struct;
53struct task_delay_info;
54struct task_group;
55
56/*
57 * Task state bitmask. NOTE! These bits are also
58 * encoded in fs/proc/array.c: get_task_state().
59 *
60 * We have two separate sets of flags: task->state
61 * is about runnability, while task->exit_state are
62 * about the task exiting. Confusing, but this way
63 * modifying one set can't modify the other one by
64 * mistake.
65 */
66
67/* Used in tsk->state: */
68#define TASK_RUNNING 0
69#define TASK_INTERRUPTIBLE 1
70#define TASK_UNINTERRUPTIBLE 2
71#define __TASK_STOPPED 4
72#define __TASK_TRACED 8
73/* Used in tsk->exit_state: */
74#define EXIT_DEAD 16
75#define EXIT_ZOMBIE 32
76#define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
77/* Used in tsk->state again: */
78#define TASK_DEAD 64
79#define TASK_WAKEKILL 128
80#define TASK_WAKING 256
81#define TASK_PARKED 512
82#define TASK_NOLOAD 1024
83#define TASK_NEW 2048
84#define TASK_STATE_MAX 4096
85
86#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
87
88/* Convenience macros for the sake of set_current_state: */
89#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
90#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
91#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
92
93#define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
94
95/* Convenience macros for the sake of wake_up(): */
96#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
97#define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
98
99/* get_task_state(): */
100#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
101 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
102 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
103
104#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
105
106#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
107
108#define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
109
110#define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
111 (task->flags & PF_FROZEN) == 0 && \
112 (task->state & TASK_NOLOAD) == 0)
113
114#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
115
116#define __set_current_state(state_value) \
117 do { \
118 current->task_state_change = _THIS_IP_; \
119 current->state = (state_value); \
120 } while (0)
121#define set_current_state(state_value) \
122 do { \
123 current->task_state_change = _THIS_IP_; \
124 smp_store_mb(current->state, (state_value)); \
125 } while (0)
126
127#else
128/*
129 * set_current_state() includes a barrier so that the write of current->state
130 * is correctly serialised wrt the caller's subsequent test of whether to
131 * actually sleep:
132 *
133 * for (;;) {
134 * set_current_state(TASK_UNINTERRUPTIBLE);
135 * if (!need_sleep)
136 * break;
137 *
138 * schedule();
139 * }
140 * __set_current_state(TASK_RUNNING);
141 *
142 * If the caller does not need such serialisation (because, for instance, the
143 * condition test and condition change and wakeup are under the same lock) then
144 * use __set_current_state().
145 *
146 * The above is typically ordered against the wakeup, which does:
147 *
148 * need_sleep = false;
149 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
150 *
151 * Where wake_up_state() (and all other wakeup primitives) imply enough
152 * barriers to order the store of the variable against wakeup.
153 *
154 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
155 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
156 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
157 *
158 * This is obviously fine, since they both store the exact same value.
159 *
160 * Also see the comments of try_to_wake_up().
161 */
162#define __set_current_state(state_value) do { current->state = (state_value); } while (0)
163#define set_current_state(state_value) smp_store_mb(current->state, (state_value))
164#endif
165
166/* Task command name length: */
167#define TASK_COMM_LEN 16
168
169extern cpumask_var_t cpu_isolated_map;
170
171extern void scheduler_tick(void);
172
173#define MAX_SCHEDULE_TIMEOUT LONG_MAX
174
175extern long schedule_timeout(long timeout);
176extern long schedule_timeout_interruptible(long timeout);
177extern long schedule_timeout_killable(long timeout);
178extern long schedule_timeout_uninterruptible(long timeout);
179extern long schedule_timeout_idle(long timeout);
180asmlinkage void schedule(void);
181extern void schedule_preempt_disabled(void);
182
183extern int __must_check io_schedule_prepare(void);
184extern void io_schedule_finish(int token);
185extern long io_schedule_timeout(long timeout);
186extern void io_schedule(void);
187
188/**
189 * struct prev_cputime - snapshot of system and user cputime
190 * @utime: time spent in user mode
191 * @stime: time spent in system mode
192 * @lock: protects the above two fields
193 *
194 * Stores previous user/system time values such that we can guarantee
195 * monotonicity.
196 */
197struct prev_cputime {
198#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
199 u64 utime;
200 u64 stime;
201 raw_spinlock_t lock;
202#endif
203};
204
205/**
206 * struct task_cputime - collected CPU time counts
207 * @utime: time spent in user mode, in nanoseconds
208 * @stime: time spent in kernel mode, in nanoseconds
209 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
210 *
211 * This structure groups together three kinds of CPU time that are tracked for
212 * threads and thread groups. Most things considering CPU time want to group
213 * these counts together and treat all three of them in parallel.
214 */
215struct task_cputime {
216 u64 utime;
217 u64 stime;
218 unsigned long long sum_exec_runtime;
219};
220
221/* Alternate field names when used on cache expirations: */
222#define virt_exp utime
223#define prof_exp stime
224#define sched_exp sum_exec_runtime
225
226struct sched_info {
227#ifdef CONFIG_SCHED_INFO
228 /* Cumulative counters: */
229
230 /* # of times we have run on this CPU: */
231 unsigned long pcount;
232
233 /* Time spent waiting on a runqueue: */
234 unsigned long long run_delay;
235
236 /* Timestamps: */
237
238 /* When did we last run on a CPU? */
239 unsigned long long last_arrival;
240
241 /* When were we last queued to run? */
242 unsigned long long last_queued;
243
244#endif /* CONFIG_SCHED_INFO */
245};
246
247/*
248 * Integer metrics need fixed point arithmetic, e.g., sched/fair
249 * has a few: load, load_avg, util_avg, freq, and capacity.
250 *
251 * We define a basic fixed point arithmetic range, and then formalize
252 * all these metrics based on that basic range.
253 */
254# define SCHED_FIXEDPOINT_SHIFT 10
255# define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
256
257struct load_weight {
258 unsigned long weight;
259 u32 inv_weight;
260};
261
262/*
263 * The load_avg/util_avg accumulates an infinite geometric series
264 * (see __update_load_avg() in kernel/sched/fair.c).
265 *
266 * [load_avg definition]
267 *
268 * load_avg = runnable% * scale_load_down(load)
269 *
270 * where runnable% is the time ratio that a sched_entity is runnable.
271 * For cfs_rq, it is the aggregated load_avg of all runnable and
272 * blocked sched_entities.
273 *
274 * load_avg may also take frequency scaling into account:
275 *
276 * load_avg = runnable% * scale_load_down(load) * freq%
277 *
278 * where freq% is the CPU frequency normalized to the highest frequency.
279 *
280 * [util_avg definition]
281 *
282 * util_avg = running% * SCHED_CAPACITY_SCALE
283 *
284 * where running% is the time ratio that a sched_entity is running on
285 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
286 * and blocked sched_entities.
287 *
288 * util_avg may also factor frequency scaling and CPU capacity scaling:
289 *
290 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
291 *
292 * where freq% is the same as above, and capacity% is the CPU capacity
293 * normalized to the greatest capacity (due to uarch differences, etc).
294 *
295 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
296 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
297 * we therefore scale them to as large a range as necessary. This is for
298 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
299 *
300 * [Overflow issue]
301 *
302 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
303 * with the highest load (=88761), always runnable on a single cfs_rq,
304 * and should not overflow as the number already hits PID_MAX_LIMIT.
305 *
306 * For all other cases (including 32-bit kernels), struct load_weight's
307 * weight will overflow first before we do, because:
308 *
309 * Max(load_avg) <= Max(load.weight)
310 *
311 * Then it is the load_weight's responsibility to consider overflow
312 * issues.
313 */
314struct sched_avg {
315 u64 last_update_time;
316 u64 load_sum;
317 u32 util_sum;
318 u32 period_contrib;
319 unsigned long load_avg;
320 unsigned long util_avg;
321};
322
323struct sched_statistics {
324#ifdef CONFIG_SCHEDSTATS
325 u64 wait_start;
326 u64 wait_max;
327 u64 wait_count;
328 u64 wait_sum;
329 u64 iowait_count;
330 u64 iowait_sum;
331
332 u64 sleep_start;
333 u64 sleep_max;
334 s64 sum_sleep_runtime;
335
336 u64 block_start;
337 u64 block_max;
338 u64 exec_max;
339 u64 slice_max;
340
341 u64 nr_migrations_cold;
342 u64 nr_failed_migrations_affine;
343 u64 nr_failed_migrations_running;
344 u64 nr_failed_migrations_hot;
345 u64 nr_forced_migrations;
346
347 u64 nr_wakeups;
348 u64 nr_wakeups_sync;
349 u64 nr_wakeups_migrate;
350 u64 nr_wakeups_local;
351 u64 nr_wakeups_remote;
352 u64 nr_wakeups_affine;
353 u64 nr_wakeups_affine_attempts;
354 u64 nr_wakeups_passive;
355 u64 nr_wakeups_idle;
356#endif
357};
358
359struct sched_entity {
360 /* For load-balancing: */
361 struct load_weight load;
362 struct rb_node run_node;
363 struct list_head group_node;
364 unsigned int on_rq;
365
366 u64 exec_start;
367 u64 sum_exec_runtime;
368 u64 vruntime;
369 u64 prev_sum_exec_runtime;
370
371 u64 nr_migrations;
372
373 struct sched_statistics statistics;
374
375#ifdef CONFIG_FAIR_GROUP_SCHED
376 int depth;
377 struct sched_entity *parent;
378 /* rq on which this entity is (to be) queued: */
379 struct cfs_rq *cfs_rq;
380 /* rq "owned" by this entity/group: */
381 struct cfs_rq *my_q;
382#endif
383
384#ifdef CONFIG_SMP
385 /*
386 * Per entity load average tracking.
387 *
388 * Put into separate cache line so it does not
389 * collide with read-mostly values above.
390 */
391 struct sched_avg avg ____cacheline_aligned_in_smp;
392#endif
393};
394
395struct sched_rt_entity {
396 struct list_head run_list;
397 unsigned long timeout;
398 unsigned long watchdog_stamp;
399 unsigned int time_slice;
400 unsigned short on_rq;
401 unsigned short on_list;
402
403 struct sched_rt_entity *back;
404#ifdef CONFIG_RT_GROUP_SCHED
405 struct sched_rt_entity *parent;
406 /* rq on which this entity is (to be) queued: */
407 struct rt_rq *rt_rq;
408 /* rq "owned" by this entity/group: */
409 struct rt_rq *my_q;
410#endif
411};
412
413struct sched_dl_entity {
414 struct rb_node rb_node;
415
416 /*
417 * Original scheduling parameters. Copied here from sched_attr
418 * during sched_setattr(), they will remain the same until
419 * the next sched_setattr().
420 */
421 u64 dl_runtime; /* Maximum runtime for each instance */
422 u64 dl_deadline; /* Relative deadline of each instance */
423 u64 dl_period; /* Separation of two instances (period) */
424 u64 dl_bw; /* dl_runtime / dl_deadline */
425
426 /*
427 * Actual scheduling parameters. Initialized with the values above,
428 * they are continously updated during task execution. Note that
429 * the remaining runtime could be < 0 in case we are in overrun.
430 */
431 s64 runtime; /* Remaining runtime for this instance */
432 u64 deadline; /* Absolute deadline for this instance */
433 unsigned int flags; /* Specifying the scheduler behaviour */
434
435 /*
436 * Some bool flags:
437 *
438 * @dl_throttled tells if we exhausted the runtime. If so, the
439 * task has to wait for a replenishment to be performed at the
440 * next firing of dl_timer.
441 *
442 * @dl_boosted tells if we are boosted due to DI. If so we are
443 * outside bandwidth enforcement mechanism (but only until we
444 * exit the critical section);
445 *
446 * @dl_yielded tells if task gave up the CPU before consuming
447 * all its available runtime during the last job.
448 */
449 int dl_throttled;
450 int dl_boosted;
451 int dl_yielded;
452
453 /*
454 * Bandwidth enforcement timer. Each -deadline task has its
455 * own bandwidth to be enforced, thus we need one timer per task.
456 */
457 struct hrtimer dl_timer;
458};
459
460union rcu_special {
461 struct {
462 u8 blocked;
463 u8 need_qs;
464 u8 exp_need_qs;
465
466 /* Otherwise the compiler can store garbage here: */
467 u8 pad;
468 } b; /* Bits. */
469 u32 s; /* Set of bits. */
470};
471
472enum perf_event_task_context {
473 perf_invalid_context = -1,
474 perf_hw_context = 0,
475 perf_sw_context,
476 perf_nr_task_contexts,
477};
478
479struct wake_q_node {
480 struct wake_q_node *next;
481};
482
483struct task_struct {
484#ifdef CONFIG_THREAD_INFO_IN_TASK
485 /*
486 * For reasons of header soup (see current_thread_info()), this
487 * must be the first element of task_struct.
488 */
489 struct thread_info thread_info;
490#endif
491 /* -1 unrunnable, 0 runnable, >0 stopped: */
492 volatile long state;
493 void *stack;
494 atomic_t usage;
495 /* Per task flags (PF_*), defined further below: */
496 unsigned int flags;
497 unsigned int ptrace;
498
499#ifdef CONFIG_SMP
500 struct llist_node wake_entry;
501 int on_cpu;
502#ifdef CONFIG_THREAD_INFO_IN_TASK
503 /* Current CPU: */
504 unsigned int cpu;
505#endif
506 unsigned int wakee_flips;
507 unsigned long wakee_flip_decay_ts;
508 struct task_struct *last_wakee;
509
510 int wake_cpu;
511#endif
512 int on_rq;
513
514 int prio;
515 int static_prio;
516 int normal_prio;
517 unsigned int rt_priority;
518
519 const struct sched_class *sched_class;
520 struct sched_entity se;
521 struct sched_rt_entity rt;
522#ifdef CONFIG_CGROUP_SCHED
523 struct task_group *sched_task_group;
524#endif
525 struct sched_dl_entity dl;
526
527#ifdef CONFIG_PREEMPT_NOTIFIERS
528 /* List of struct preempt_notifier: */
529 struct hlist_head preempt_notifiers;
530#endif
531
532#ifdef CONFIG_BLK_DEV_IO_TRACE
533 unsigned int btrace_seq;
534#endif
535
536 unsigned int policy;
537 int nr_cpus_allowed;
538 cpumask_t cpus_allowed;
539
540#ifdef CONFIG_PREEMPT_RCU
541 int rcu_read_lock_nesting;
542 union rcu_special rcu_read_unlock_special;
543 struct list_head rcu_node_entry;
544 struct rcu_node *rcu_blocked_node;
545#endif /* #ifdef CONFIG_PREEMPT_RCU */
546
547#ifdef CONFIG_TASKS_RCU
548 unsigned long rcu_tasks_nvcsw;
549 bool rcu_tasks_holdout;
550 struct list_head rcu_tasks_holdout_list;
551 int rcu_tasks_idle_cpu;
552#endif /* #ifdef CONFIG_TASKS_RCU */
553
554 struct sched_info sched_info;
555
556 struct list_head tasks;
557#ifdef CONFIG_SMP
558 struct plist_node pushable_tasks;
559 struct rb_node pushable_dl_tasks;
560#endif
561
562 struct mm_struct *mm;
563 struct mm_struct *active_mm;
564
565 /* Per-thread vma caching: */
566 struct vmacache vmacache;
567
568#ifdef SPLIT_RSS_COUNTING
569 struct task_rss_stat rss_stat;
570#endif
571 int exit_state;
572 int exit_code;
573 int exit_signal;
574 /* The signal sent when the parent dies: */
575 int pdeath_signal;
576 /* JOBCTL_*, siglock protected: */
577 unsigned long jobctl;
578
579 /* Used for emulating ABI behavior of previous Linux versions: */
580 unsigned int personality;
581
582 /* Scheduler bits, serialized by scheduler locks: */
583 unsigned sched_reset_on_fork:1;
584 unsigned sched_contributes_to_load:1;
585 unsigned sched_migrated:1;
586 unsigned sched_remote_wakeup:1;
587 /* Force alignment to the next boundary: */
588 unsigned :0;
589
590 /* Unserialized, strictly 'current' */
591
592 /* Bit to tell LSMs we're in execve(): */
593 unsigned in_execve:1;
594 unsigned in_iowait:1;
595#ifndef TIF_RESTORE_SIGMASK
596 unsigned restore_sigmask:1;
597#endif
598#ifdef CONFIG_MEMCG
599 unsigned memcg_may_oom:1;
600#ifndef CONFIG_SLOB
601 unsigned memcg_kmem_skip_account:1;
602#endif
603#endif
604#ifdef CONFIG_COMPAT_BRK
605 unsigned brk_randomized:1;
606#endif
607#ifdef CONFIG_CGROUPS
608 /* disallow userland-initiated cgroup migration */
609 unsigned no_cgroup_migration:1;
610#endif
611
612 unsigned long atomic_flags; /* Flags requiring atomic access. */
613
614 struct restart_block restart_block;
615
616 pid_t pid;
617 pid_t tgid;
618
619#ifdef CONFIG_CC_STACKPROTECTOR
620 /* Canary value for the -fstack-protector GCC feature: */
621 unsigned long stack_canary;
622#endif
623 /*
624 * Pointers to the (original) parent process, youngest child, younger sibling,
625 * older sibling, respectively. (p->father can be replaced with
626 * p->real_parent->pid)
627 */
628
629 /* Real parent process: */
630 struct task_struct __rcu *real_parent;
631
632 /* Recipient of SIGCHLD, wait4() reports: */
633 struct task_struct __rcu *parent;
634
635 /*
636 * Children/sibling form the list of natural children:
637 */
638 struct list_head children;
639 struct list_head sibling;
640 struct task_struct *group_leader;
641
642 /*
643 * 'ptraced' is the list of tasks this task is using ptrace() on.
644 *
645 * This includes both natural children and PTRACE_ATTACH targets.
646 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
647 */
648 struct list_head ptraced;
649 struct list_head ptrace_entry;
650
651 /* PID/PID hash table linkage. */
652 struct pid_link pids[PIDTYPE_MAX];
653 struct list_head thread_group;
654 struct list_head thread_node;
655
656 struct completion *vfork_done;
657
658 /* CLONE_CHILD_SETTID: */
659 int __user *set_child_tid;
660
661 /* CLONE_CHILD_CLEARTID: */
662 int __user *clear_child_tid;
663
664 u64 utime;
665 u64 stime;
666#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
667 u64 utimescaled;
668 u64 stimescaled;
669#endif
670 u64 gtime;
671 struct prev_cputime prev_cputime;
672#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
673 seqcount_t vtime_seqcount;
674 unsigned long long vtime_snap;
675 enum {
676 /* Task is sleeping or running in a CPU with VTIME inactive: */
677 VTIME_INACTIVE = 0,
678 /* Task runs in userspace in a CPU with VTIME active: */
679 VTIME_USER,
680 /* Task runs in kernelspace in a CPU with VTIME active: */
681 VTIME_SYS,
682 } vtime_snap_whence;
683#endif
684
685#ifdef CONFIG_NO_HZ_FULL
686 atomic_t tick_dep_mask;
687#endif
688 /* Context switch counts: */
689 unsigned long nvcsw;
690 unsigned long nivcsw;
691
692 /* Monotonic time in nsecs: */
693 u64 start_time;
694
695 /* Boot based time in nsecs: */
696 u64 real_start_time;
697
698 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
699 unsigned long min_flt;
700 unsigned long maj_flt;
701
702#ifdef CONFIG_POSIX_TIMERS
703 struct task_cputime cputime_expires;
704 struct list_head cpu_timers[3];
705#endif
706
707 /* Process credentials: */
708
709 /* Tracer's credentials at attach: */
710 const struct cred __rcu *ptracer_cred;
711
712 /* Objective and real subjective task credentials (COW): */
713 const struct cred __rcu *real_cred;
714
715 /* Effective (overridable) subjective task credentials (COW): */
716 const struct cred __rcu *cred;
717
718 /*
719 * executable name, excluding path.
720 *
721 * - normally initialized setup_new_exec()
722 * - access it with [gs]et_task_comm()
723 * - lock it with task_lock()
724 */
725 char comm[TASK_COMM_LEN];
726
727 struct nameidata *nameidata;
728
729#ifdef CONFIG_SYSVIPC
730 struct sysv_sem sysvsem;
731 struct sysv_shm sysvshm;
732#endif
733#ifdef CONFIG_DETECT_HUNG_TASK
734 unsigned long last_switch_count;
735#endif
736 /* Filesystem information: */
737 struct fs_struct *fs;
738
739 /* Open file information: */
740 struct files_struct *files;
741
742 /* Namespaces: */
743 struct nsproxy *nsproxy;
744
745 /* Signal handlers: */
746 struct signal_struct *signal;
747 struct sighand_struct *sighand;
748 sigset_t blocked;
749 sigset_t real_blocked;
750 /* Restored if set_restore_sigmask() was used: */
751 sigset_t saved_sigmask;
752 struct sigpending pending;
753 unsigned long sas_ss_sp;
754 size_t sas_ss_size;
755 unsigned int sas_ss_flags;
756
757 struct callback_head *task_works;
758
759 struct audit_context *audit_context;
760#ifdef CONFIG_AUDITSYSCALL
761 kuid_t loginuid;
762 unsigned int sessionid;
763#endif
764 struct seccomp seccomp;
765
766 /* Thread group tracking: */
767 u32 parent_exec_id;
768 u32 self_exec_id;
769
770 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
771 spinlock_t alloc_lock;
772
773 /* Protection of the PI data structures: */
774 raw_spinlock_t pi_lock;
775
776 struct wake_q_node wake_q;
777
778#ifdef CONFIG_RT_MUTEXES
779 /* PI waiters blocked on a rt_mutex held by this task: */
780 struct rb_root pi_waiters;
781 struct rb_node *pi_waiters_leftmost;
782 /* Updated under owner's pi_lock and rq lock */
783 struct task_struct *pi_top_task;
784 /* Deadlock detection and priority inheritance handling: */
785 struct rt_mutex_waiter *pi_blocked_on;
786#endif
787
788#ifdef CONFIG_DEBUG_MUTEXES
789 /* Mutex deadlock detection: */
790 struct mutex_waiter *blocked_on;
791#endif
792
793#ifdef CONFIG_TRACE_IRQFLAGS
794 unsigned int irq_events;
795 unsigned long hardirq_enable_ip;
796 unsigned long hardirq_disable_ip;
797 unsigned int hardirq_enable_event;
798 unsigned int hardirq_disable_event;
799 int hardirqs_enabled;
800 int hardirq_context;
801 unsigned long softirq_disable_ip;
802 unsigned long softirq_enable_ip;
803 unsigned int softirq_disable_event;
804 unsigned int softirq_enable_event;
805 int softirqs_enabled;
806 int softirq_context;
807#endif
808
809#ifdef CONFIG_LOCKDEP
810# define MAX_LOCK_DEPTH 48UL
811 u64 curr_chain_key;
812 int lockdep_depth;
813 unsigned int lockdep_recursion;
814 struct held_lock held_locks[MAX_LOCK_DEPTH];
815 gfp_t lockdep_reclaim_gfp;
816#endif
817
818#ifdef CONFIG_UBSAN
819 unsigned int in_ubsan;
820#endif
821
822 /* Journalling filesystem info: */
823 void *journal_info;
824
825 /* Stacked block device info: */
826 struct bio_list *bio_list;
827
828#ifdef CONFIG_BLOCK
829 /* Stack plugging: */
830 struct blk_plug *plug;
831#endif
832
833 /* VM state: */
834 struct reclaim_state *reclaim_state;
835
836 struct backing_dev_info *backing_dev_info;
837
838 struct io_context *io_context;
839
840 /* Ptrace state: */
841 unsigned long ptrace_message;
842 siginfo_t *last_siginfo;
843
844 struct task_io_accounting ioac;
845#ifdef CONFIG_TASK_XACCT
846 /* Accumulated RSS usage: */
847 u64 acct_rss_mem1;
848 /* Accumulated virtual memory usage: */
849 u64 acct_vm_mem1;
850 /* stime + utime since last update: */
851 u64 acct_timexpd;
852#endif
853#ifdef CONFIG_CPUSETS
854 /* Protected by ->alloc_lock: */
855 nodemask_t mems_allowed;
856 /* Seqence number to catch updates: */
857 seqcount_t mems_allowed_seq;
858 int cpuset_mem_spread_rotor;
859 int cpuset_slab_spread_rotor;
860#endif
861#ifdef CONFIG_CGROUPS
862 /* Control Group info protected by css_set_lock: */
863 struct css_set __rcu *cgroups;
864 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
865 struct list_head cg_list;
866#endif
867#ifdef CONFIG_INTEL_RDT_A
868 int closid;
869#endif
870#ifdef CONFIG_FUTEX
871 struct robust_list_head __user *robust_list;
872#ifdef CONFIG_COMPAT
873 struct compat_robust_list_head __user *compat_robust_list;
874#endif
875 struct list_head pi_state_list;
876 struct futex_pi_state *pi_state_cache;
877#endif
878#ifdef CONFIG_PERF_EVENTS
879 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
880 struct mutex perf_event_mutex;
881 struct list_head perf_event_list;
882#endif
883#ifdef CONFIG_DEBUG_PREEMPT
884 unsigned long preempt_disable_ip;
885#endif
886#ifdef CONFIG_NUMA
887 /* Protected by alloc_lock: */
888 struct mempolicy *mempolicy;
889 short il_next;
890 short pref_node_fork;
891#endif
892#ifdef CONFIG_NUMA_BALANCING
893 int numa_scan_seq;
894 unsigned int numa_scan_period;
895 unsigned int numa_scan_period_max;
896 int numa_preferred_nid;
897 unsigned long numa_migrate_retry;
898 /* Migration stamp: */
899 u64 node_stamp;
900 u64 last_task_numa_placement;
901 u64 last_sum_exec_runtime;
902 struct callback_head numa_work;
903
904 struct list_head numa_entry;
905 struct numa_group *numa_group;
906
907 /*
908 * numa_faults is an array split into four regions:
909 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
910 * in this precise order.
911 *
912 * faults_memory: Exponential decaying average of faults on a per-node
913 * basis. Scheduling placement decisions are made based on these
914 * counts. The values remain static for the duration of a PTE scan.
915 * faults_cpu: Track the nodes the process was running on when a NUMA
916 * hinting fault was incurred.
917 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
918 * during the current scan window. When the scan completes, the counts
919 * in faults_memory and faults_cpu decay and these values are copied.
920 */
921 unsigned long *numa_faults;
922 unsigned long total_numa_faults;
923
924 /*
925 * numa_faults_locality tracks if faults recorded during the last
926 * scan window were remote/local or failed to migrate. The task scan
927 * period is adapted based on the locality of the faults with different
928 * weights depending on whether they were shared or private faults
929 */
930 unsigned long numa_faults_locality[3];
931
932 unsigned long numa_pages_migrated;
933#endif /* CONFIG_NUMA_BALANCING */
934
935 struct tlbflush_unmap_batch tlb_ubc;
936
937 struct rcu_head rcu;
938
939 /* Cache last used pipe for splice(): */
940 struct pipe_inode_info *splice_pipe;
941
942 struct page_frag task_frag;
943
944#ifdef CONFIG_TASK_DELAY_ACCT
945 struct task_delay_info *delays;
946#endif
947
948#ifdef CONFIG_FAULT_INJECTION
949 int make_it_fail;
950#endif
951 /*
952 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
953 * balance_dirty_pages() for a dirty throttling pause:
954 */
955 int nr_dirtied;
956 int nr_dirtied_pause;
957 /* Start of a write-and-pause period: */
958 unsigned long dirty_paused_when;
959
960#ifdef CONFIG_LATENCYTOP
961 int latency_record_count;
962 struct latency_record latency_record[LT_SAVECOUNT];
963#endif
964 /*
965 * Time slack values; these are used to round up poll() and
966 * select() etc timeout values. These are in nanoseconds.
967 */
968 u64 timer_slack_ns;
969 u64 default_timer_slack_ns;
970
971#ifdef CONFIG_KASAN
972 unsigned int kasan_depth;
973#endif
974
975#ifdef CONFIG_FUNCTION_GRAPH_TRACER
976 /* Index of current stored address in ret_stack: */
977 int curr_ret_stack;
978
979 /* Stack of return addresses for return function tracing: */
980 struct ftrace_ret_stack *ret_stack;
981
982 /* Timestamp for last schedule: */
983 unsigned long long ftrace_timestamp;
984
985 /*
986 * Number of functions that haven't been traced
987 * because of depth overrun:
988 */
989 atomic_t trace_overrun;
990
991 /* Pause tracing: */
992 atomic_t tracing_graph_pause;
993#endif
994
995#ifdef CONFIG_TRACING
996 /* State flags for use by tracers: */
997 unsigned long trace;
998
999 /* Bitmask and counter of trace recursion: */
1000 unsigned long trace_recursion;
1001#endif /* CONFIG_TRACING */
1002
1003#ifdef CONFIG_KCOV
1004 /* Coverage collection mode enabled for this task (0 if disabled): */
1005 enum kcov_mode kcov_mode;
1006
1007 /* Size of the kcov_area: */
1008 unsigned int kcov_size;
1009
1010 /* Buffer for coverage collection: */
1011 void *kcov_area;
1012
1013 /* KCOV descriptor wired with this task or NULL: */
1014 struct kcov *kcov;
1015#endif
1016
1017#ifdef CONFIG_MEMCG
1018 struct mem_cgroup *memcg_in_oom;
1019 gfp_t memcg_oom_gfp_mask;
1020 int memcg_oom_order;
1021
1022 /* Number of pages to reclaim on returning to userland: */
1023 unsigned int memcg_nr_pages_over_high;
1024#endif
1025
1026#ifdef CONFIG_UPROBES
1027 struct uprobe_task *utask;
1028#endif
1029#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1030 unsigned int sequential_io;
1031 unsigned int sequential_io_avg;
1032#endif
1033#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1034 unsigned long task_state_change;
1035#endif
1036 int pagefault_disabled;
1037#ifdef CONFIG_MMU
1038 struct task_struct *oom_reaper_list;
1039#endif
1040#ifdef CONFIG_VMAP_STACK
1041 struct vm_struct *stack_vm_area;
1042#endif
1043#ifdef CONFIG_THREAD_INFO_IN_TASK
1044 /* A live task holds one reference: */
1045 atomic_t stack_refcount;
1046#endif
1047#ifdef CONFIG_LIVEPATCH
1048 int patch_state;
1049#endif
1050#ifdef CONFIG_SECURITY
1051 /* Used by LSM modules for access restriction: */
1052 void *security;
1053#endif
1054 /* CPU-specific state of this task: */
1055 struct thread_struct thread;
1056
1057 /*
1058 * WARNING: on x86, 'thread_struct' contains a variable-sized
1059 * structure. It *MUST* be at the end of 'task_struct'.
1060 *
1061 * Do not put anything below here!
1062 */
1063};
1064
1065static inline struct pid *task_pid(struct task_struct *task)
1066{
1067 return task->pids[PIDTYPE_PID].pid;
1068}
1069
1070static inline struct pid *task_tgid(struct task_struct *task)
1071{
1072 return task->group_leader->pids[PIDTYPE_PID].pid;
1073}
1074
1075/*
1076 * Without tasklist or RCU lock it is not safe to dereference
1077 * the result of task_pgrp/task_session even if task == current,
1078 * we can race with another thread doing sys_setsid/sys_setpgid.
1079 */
1080static inline struct pid *task_pgrp(struct task_struct *task)
1081{
1082 return task->group_leader->pids[PIDTYPE_PGID].pid;
1083}
1084
1085static inline struct pid *task_session(struct task_struct *task)
1086{
1087 return task->group_leader->pids[PIDTYPE_SID].pid;
1088}
1089
1090/*
1091 * the helpers to get the task's different pids as they are seen
1092 * from various namespaces
1093 *
1094 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1095 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1096 * current.
1097 * task_xid_nr_ns() : id seen from the ns specified;
1098 *
1099 * set_task_vxid() : assigns a virtual id to a task;
1100 *
1101 * see also pid_nr() etc in include/linux/pid.h
1102 */
1103pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1104
1105static inline pid_t task_pid_nr(struct task_struct *tsk)
1106{
1107 return tsk->pid;
1108}
1109
1110static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1111{
1112 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1113}
1114
1115static inline pid_t task_pid_vnr(struct task_struct *tsk)
1116{
1117 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1118}
1119
1120
1121static inline pid_t task_tgid_nr(struct task_struct *tsk)
1122{
1123 return tsk->tgid;
1124}
1125
1126extern pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1127
1128static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1129{
1130 return pid_vnr(task_tgid(tsk));
1131}
1132
1133/**
1134 * pid_alive - check that a task structure is not stale
1135 * @p: Task structure to be checked.
1136 *
1137 * Test if a process is not yet dead (at most zombie state)
1138 * If pid_alive fails, then pointers within the task structure
1139 * can be stale and must not be dereferenced.
1140 *
1141 * Return: 1 if the process is alive. 0 otherwise.
1142 */
1143static inline int pid_alive(const struct task_struct *p)
1144{
1145 return p->pids[PIDTYPE_PID].pid != NULL;
1146}
1147
1148static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1149{
1150 pid_t pid = 0;
1151
1152 rcu_read_lock();
1153 if (pid_alive(tsk))
1154 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1155 rcu_read_unlock();
1156
1157 return pid;
1158}
1159
1160static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1161{
1162 return task_ppid_nr_ns(tsk, &init_pid_ns);
1163}
1164
1165static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1166{
1167 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1168}
1169
1170static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1171{
1172 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1173}
1174
1175
1176static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1177{
1178 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1179}
1180
1181static inline pid_t task_session_vnr(struct task_struct *tsk)
1182{
1183 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1184}
1185
1186/* Obsolete, do not use: */
1187static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1188{
1189 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1190}
1191
1192/**
1193 * is_global_init - check if a task structure is init. Since init
1194 * is free to have sub-threads we need to check tgid.
1195 * @tsk: Task structure to be checked.
1196 *
1197 * Check if a task structure is the first user space task the kernel created.
1198 *
1199 * Return: 1 if the task structure is init. 0 otherwise.
1200 */
1201static inline int is_global_init(struct task_struct *tsk)
1202{
1203 return task_tgid_nr(tsk) == 1;
1204}
1205
1206extern struct pid *cad_pid;
1207
1208/*
1209 * Per process flags
1210 */
1211#define PF_IDLE 0x00000002 /* I am an IDLE thread */
1212#define PF_EXITING 0x00000004 /* Getting shut down */
1213#define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1214#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1215#define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1216#define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1217#define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1218#define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1219#define PF_DUMPCORE 0x00000200 /* Dumped core */
1220#define PF_SIGNALED 0x00000400 /* Killed by a signal */
1221#define PF_MEMALLOC 0x00000800 /* Allocating memory */
1222#define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1223#define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1224#define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1225#define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1226#define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1227#define PF_KSWAPD 0x00020000 /* I am kswapd */
1228#define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1229#define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1230#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1231#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1232#define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1233#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1234#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1235#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1236#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1237#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1238#define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1239
1240/*
1241 * Only the _current_ task can read/write to tsk->flags, but other
1242 * tasks can access tsk->flags in readonly mode for example
1243 * with tsk_used_math (like during threaded core dumping).
1244 * There is however an exception to this rule during ptrace
1245 * or during fork: the ptracer task is allowed to write to the
1246 * child->flags of its traced child (same goes for fork, the parent
1247 * can write to the child->flags), because we're guaranteed the
1248 * child is not running and in turn not changing child->flags
1249 * at the same time the parent does it.
1250 */
1251#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1252#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1253#define clear_used_math() clear_stopped_child_used_math(current)
1254#define set_used_math() set_stopped_child_used_math(current)
1255
1256#define conditional_stopped_child_used_math(condition, child) \
1257 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1258
1259#define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1260
1261#define copy_to_stopped_child_used_math(child) \
1262 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1263
1264/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1265#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1266#define used_math() tsk_used_math(current)
1267
1268/* Per-process atomic flags. */
1269#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1270#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1271#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1272
1273
1274#define TASK_PFA_TEST(name, func) \
1275 static inline bool task_##func(struct task_struct *p) \
1276 { return test_bit(PFA_##name, &p->atomic_flags); }
1277
1278#define TASK_PFA_SET(name, func) \
1279 static inline void task_set_##func(struct task_struct *p) \
1280 { set_bit(PFA_##name, &p->atomic_flags); }
1281
1282#define TASK_PFA_CLEAR(name, func) \
1283 static inline void task_clear_##func(struct task_struct *p) \
1284 { clear_bit(PFA_##name, &p->atomic_flags); }
1285
1286TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1287TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1288
1289TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1290TASK_PFA_SET(SPREAD_PAGE, spread_page)
1291TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1292
1293TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1294TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1295TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1296
1297static inline void
1298current_restore_flags(unsigned long orig_flags, unsigned long flags)
1299{
1300 current->flags &= ~flags;
1301 current->flags |= orig_flags & flags;
1302}
1303
1304extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1305extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1306#ifdef CONFIG_SMP
1307extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1308extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1309#else
1310static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1311{
1312}
1313static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1314{
1315 if (!cpumask_test_cpu(0, new_mask))
1316 return -EINVAL;
1317 return 0;
1318}
1319#endif
1320
1321#ifndef cpu_relax_yield
1322#define cpu_relax_yield() cpu_relax()
1323#endif
1324
1325extern int yield_to(struct task_struct *p, bool preempt);
1326extern void set_user_nice(struct task_struct *p, long nice);
1327extern int task_prio(const struct task_struct *p);
1328
1329/**
1330 * task_nice - return the nice value of a given task.
1331 * @p: the task in question.
1332 *
1333 * Return: The nice value [ -20 ... 0 ... 19 ].
1334 */
1335static inline int task_nice(const struct task_struct *p)
1336{
1337 return PRIO_TO_NICE((p)->static_prio);
1338}
1339
1340extern int can_nice(const struct task_struct *p, const int nice);
1341extern int task_curr(const struct task_struct *p);
1342extern int idle_cpu(int cpu);
1343extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1344extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1345extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1346extern struct task_struct *idle_task(int cpu);
1347
1348/**
1349 * is_idle_task - is the specified task an idle task?
1350 * @p: the task in question.
1351 *
1352 * Return: 1 if @p is an idle task. 0 otherwise.
1353 */
1354static inline bool is_idle_task(const struct task_struct *p)
1355{
1356 return !!(p->flags & PF_IDLE);
1357}
1358
1359extern struct task_struct *curr_task(int cpu);
1360extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1361
1362void yield(void);
1363
1364union thread_union {
1365#ifndef CONFIG_THREAD_INFO_IN_TASK
1366 struct thread_info thread_info;
1367#endif
1368 unsigned long stack[THREAD_SIZE/sizeof(long)];
1369};
1370
1371#ifdef CONFIG_THREAD_INFO_IN_TASK
1372static inline struct thread_info *task_thread_info(struct task_struct *task)
1373{
1374 return &task->thread_info;
1375}
1376#elif !defined(__HAVE_THREAD_FUNCTIONS)
1377# define task_thread_info(task) ((struct thread_info *)(task)->stack)
1378#endif
1379
1380/*
1381 * find a task by one of its numerical ids
1382 *
1383 * find_task_by_pid_ns():
1384 * finds a task by its pid in the specified namespace
1385 * find_task_by_vpid():
1386 * finds a task by its virtual pid
1387 *
1388 * see also find_vpid() etc in include/linux/pid.h
1389 */
1390
1391extern struct task_struct *find_task_by_vpid(pid_t nr);
1392extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1393
1394extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1395extern int wake_up_process(struct task_struct *tsk);
1396extern void wake_up_new_task(struct task_struct *tsk);
1397
1398#ifdef CONFIG_SMP
1399extern void kick_process(struct task_struct *tsk);
1400#else
1401static inline void kick_process(struct task_struct *tsk) { }
1402#endif
1403
1404extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1405
1406static inline void set_task_comm(struct task_struct *tsk, const char *from)
1407{
1408 __set_task_comm(tsk, from, false);
1409}
1410
1411extern char *get_task_comm(char *to, struct task_struct *tsk);
1412
1413#ifdef CONFIG_SMP
1414void scheduler_ipi(void);
1415extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1416#else
1417static inline void scheduler_ipi(void) { }
1418static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1419{
1420 return 1;
1421}
1422#endif
1423
1424/*
1425 * Set thread flags in other task's structures.
1426 * See asm/thread_info.h for TIF_xxxx flags available:
1427 */
1428static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1429{
1430 set_ti_thread_flag(task_thread_info(tsk), flag);
1431}
1432
1433static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1434{
1435 clear_ti_thread_flag(task_thread_info(tsk), flag);
1436}
1437
1438static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1439{
1440 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1441}
1442
1443static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1444{
1445 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1446}
1447
1448static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1449{
1450 return test_ti_thread_flag(task_thread_info(tsk), flag);
1451}
1452
1453static inline void set_tsk_need_resched(struct task_struct *tsk)
1454{
1455 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1456}
1457
1458static inline void clear_tsk_need_resched(struct task_struct *tsk)
1459{
1460 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1461}
1462
1463static inline int test_tsk_need_resched(struct task_struct *tsk)
1464{
1465 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1466}
1467
1468/*
1469 * cond_resched() and cond_resched_lock(): latency reduction via
1470 * explicit rescheduling in places that are safe. The return
1471 * value indicates whether a reschedule was done in fact.
1472 * cond_resched_lock() will drop the spinlock before scheduling,
1473 * cond_resched_softirq() will enable bhs before scheduling.
1474 */
1475#ifndef CONFIG_PREEMPT
1476extern int _cond_resched(void);
1477#else
1478static inline int _cond_resched(void) { return 0; }
1479#endif
1480
1481#define cond_resched() ({ \
1482 ___might_sleep(__FILE__, __LINE__, 0); \
1483 _cond_resched(); \
1484})
1485
1486extern int __cond_resched_lock(spinlock_t *lock);
1487
1488#define cond_resched_lock(lock) ({ \
1489 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1490 __cond_resched_lock(lock); \
1491})
1492
1493extern int __cond_resched_softirq(void);
1494
1495#define cond_resched_softirq() ({ \
1496 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
1497 __cond_resched_softirq(); \
1498})
1499
1500static inline void cond_resched_rcu(void)
1501{
1502#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1503 rcu_read_unlock();
1504 cond_resched();
1505 rcu_read_lock();
1506#endif
1507}
1508
1509/*
1510 * Does a critical section need to be broken due to another
1511 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1512 * but a general need for low latency)
1513 */
1514static inline int spin_needbreak(spinlock_t *lock)
1515{
1516#ifdef CONFIG_PREEMPT
1517 return spin_is_contended(lock);
1518#else
1519 return 0;
1520#endif
1521}
1522
1523static __always_inline bool need_resched(void)
1524{
1525 return unlikely(tif_need_resched());
1526}
1527
1528/*
1529 * Wrappers for p->thread_info->cpu access. No-op on UP.
1530 */
1531#ifdef CONFIG_SMP
1532
1533static inline unsigned int task_cpu(const struct task_struct *p)
1534{
1535#ifdef CONFIG_THREAD_INFO_IN_TASK
1536 return p->cpu;
1537#else
1538 return task_thread_info(p)->cpu;
1539#endif
1540}
1541
1542extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1543
1544#else
1545
1546static inline unsigned int task_cpu(const struct task_struct *p)
1547{
1548 return 0;
1549}
1550
1551static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1552{
1553}
1554
1555#endif /* CONFIG_SMP */
1556
1557/*
1558 * In order to reduce various lock holder preemption latencies provide an
1559 * interface to see if a vCPU is currently running or not.
1560 *
1561 * This allows us to terminate optimistic spin loops and block, analogous to
1562 * the native optimistic spin heuristic of testing if the lock owner task is
1563 * running or not.
1564 */
1565#ifndef vcpu_is_preempted
1566# define vcpu_is_preempted(cpu) false
1567#endif
1568
1569extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1570extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1571
1572#ifndef TASK_SIZE_OF
1573#define TASK_SIZE_OF(tsk) TASK_SIZE
1574#endif
1575
1576#endif
1577