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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): */
31 struct audit_context;
32 struct backing_dev_info;
33 struct bio_list;
34 struct blk_plug;
35 struct cfs_rq;
36 struct fs_struct;
37 struct futex_pi_state;
38 struct io_context;
39 struct mempolicy;
40 struct nameidata;
41 struct nsproxy;
42 struct perf_event_context;
43 struct pid_namespace;
44 struct pipe_inode_info;
45 struct rcu_node;
46 struct reclaim_state;
47 struct robust_list_head;
48 struct sched_attr;
49 struct sched_param;
50 struct seq_file;
51 struct sighand_struct;
52 struct signal_struct;
53 struct task_delay_info;
54 struct 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
169 extern cpumask_var_t cpu_isolated_map;
170
171 extern void scheduler_tick(void);
172
173 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
174
175 extern long schedule_timeout(long timeout);
176 extern long schedule_timeout_interruptible(long timeout);
177 extern long schedule_timeout_killable(long timeout);
178 extern long schedule_timeout_uninterruptible(long timeout);
179 extern long schedule_timeout_idle(long timeout);
180 asmlinkage void schedule(void);
181 extern void schedule_preempt_disabled(void);
182
183 extern int __must_check io_schedule_prepare(void);
184 extern void io_schedule_finish(int token);
185 extern long io_schedule_timeout(long timeout);
186 extern 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 */
197 struct 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 */
215 struct 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
226 enum vtime_state {
227 /* Task is sleeping or running in a CPU with VTIME inactive: */
228 VTIME_INACTIVE = 0,
229 /* Task runs in userspace in a CPU with VTIME active: */
230 VTIME_USER,
231 /* Task runs in kernelspace in a CPU with VTIME active: */
232 VTIME_SYS,
233 };
234
235 struct vtime {
236 seqcount_t seqcount;
237 unsigned long long starttime;
238 enum vtime_state state;
239 u64 utime;
240 u64 stime;
241 u64 gtime;
242 };
243
244 struct sched_info {
245 #ifdef CONFIG_SCHED_INFO
246 /* Cumulative counters: */
247
248 /* # of times we have run on this CPU: */
249 unsigned long pcount;
250
251 /* Time spent waiting on a runqueue: */
252 unsigned long long run_delay;
253
254 /* Timestamps: */
255
256 /* When did we last run on a CPU? */
257 unsigned long long last_arrival;
258
259 /* When were we last queued to run? */
260 unsigned long long last_queued;
261
262 #endif /* CONFIG_SCHED_INFO */
263 };
264
265 /*
266 * Integer metrics need fixed point arithmetic, e.g., sched/fair
267 * has a few: load, load_avg, util_avg, freq, and capacity.
268 *
269 * We define a basic fixed point arithmetic range, and then formalize
270 * all these metrics based on that basic range.
271 */
272 # define SCHED_FIXEDPOINT_SHIFT 10
273 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
274
275 struct load_weight {
276 unsigned long weight;
277 u32 inv_weight;
278 };
279
280 /*
281 * The load_avg/util_avg accumulates an infinite geometric series
282 * (see __update_load_avg() in kernel/sched/fair.c).
283 *
284 * [load_avg definition]
285 *
286 * load_avg = runnable% * scale_load_down(load)
287 *
288 * where runnable% is the time ratio that a sched_entity is runnable.
289 * For cfs_rq, it is the aggregated load_avg of all runnable and
290 * blocked sched_entities.
291 *
292 * load_avg may also take frequency scaling into account:
293 *
294 * load_avg = runnable% * scale_load_down(load) * freq%
295 *
296 * where freq% is the CPU frequency normalized to the highest frequency.
297 *
298 * [util_avg definition]
299 *
300 * util_avg = running% * SCHED_CAPACITY_SCALE
301 *
302 * where running% is the time ratio that a sched_entity is running on
303 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
304 * and blocked sched_entities.
305 *
306 * util_avg may also factor frequency scaling and CPU capacity scaling:
307 *
308 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
309 *
310 * where freq% is the same as above, and capacity% is the CPU capacity
311 * normalized to the greatest capacity (due to uarch differences, etc).
312 *
313 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
314 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
315 * we therefore scale them to as large a range as necessary. This is for
316 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
317 *
318 * [Overflow issue]
319 *
320 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
321 * with the highest load (=88761), always runnable on a single cfs_rq,
322 * and should not overflow as the number already hits PID_MAX_LIMIT.
323 *
324 * For all other cases (including 32-bit kernels), struct load_weight's
325 * weight will overflow first before we do, because:
326 *
327 * Max(load_avg) <= Max(load.weight)
328 *
329 * Then it is the load_weight's responsibility to consider overflow
330 * issues.
331 */
332 struct sched_avg {
333 u64 last_update_time;
334 u64 load_sum;
335 u32 util_sum;
336 u32 period_contrib;
337 unsigned long load_avg;
338 unsigned long util_avg;
339 };
340
341 struct sched_statistics {
342 #ifdef CONFIG_SCHEDSTATS
343 u64 wait_start;
344 u64 wait_max;
345 u64 wait_count;
346 u64 wait_sum;
347 u64 iowait_count;
348 u64 iowait_sum;
349
350 u64 sleep_start;
351 u64 sleep_max;
352 s64 sum_sleep_runtime;
353
354 u64 block_start;
355 u64 block_max;
356 u64 exec_max;
357 u64 slice_max;
358
359 u64 nr_migrations_cold;
360 u64 nr_failed_migrations_affine;
361 u64 nr_failed_migrations_running;
362 u64 nr_failed_migrations_hot;
363 u64 nr_forced_migrations;
364
365 u64 nr_wakeups;
366 u64 nr_wakeups_sync;
367 u64 nr_wakeups_migrate;
368 u64 nr_wakeups_local;
369 u64 nr_wakeups_remote;
370 u64 nr_wakeups_affine;
371 u64 nr_wakeups_affine_attempts;
372 u64 nr_wakeups_passive;
373 u64 nr_wakeups_idle;
374 #endif
375 };
376
377 struct sched_entity {
378 /* For load-balancing: */
379 struct load_weight load;
380 struct rb_node run_node;
381 struct list_head group_node;
382 unsigned int on_rq;
383
384 u64 exec_start;
385 u64 sum_exec_runtime;
386 u64 vruntime;
387 u64 prev_sum_exec_runtime;
388
389 u64 nr_migrations;
390
391 struct sched_statistics statistics;
392
393 #ifdef CONFIG_FAIR_GROUP_SCHED
394 int depth;
395 struct sched_entity *parent;
396 /* rq on which this entity is (to be) queued: */
397 struct cfs_rq *cfs_rq;
398 /* rq "owned" by this entity/group: */
399 struct cfs_rq *my_q;
400 #endif
401
402 #ifdef CONFIG_SMP
403 /*
404 * Per entity load average tracking.
405 *
406 * Put into separate cache line so it does not
407 * collide with read-mostly values above.
408 */
409 struct sched_avg avg ____cacheline_aligned_in_smp;
410 #endif
411 };
412
413 struct sched_rt_entity {
414 struct list_head run_list;
415 unsigned long timeout;
416 unsigned long watchdog_stamp;
417 unsigned int time_slice;
418 unsigned short on_rq;
419 unsigned short on_list;
420
421 struct sched_rt_entity *back;
422 #ifdef CONFIG_RT_GROUP_SCHED
423 struct sched_rt_entity *parent;
424 /* rq on which this entity is (to be) queued: */
425 struct rt_rq *rt_rq;
426 /* rq "owned" by this entity/group: */
427 struct rt_rq *my_q;
428 #endif
429 };
430
431 struct sched_dl_entity {
432 struct rb_node rb_node;
433
434 /*
435 * Original scheduling parameters. Copied here from sched_attr
436 * during sched_setattr(), they will remain the same until
437 * the next sched_setattr().
438 */
439 u64 dl_runtime; /* Maximum runtime for each instance */
440 u64 dl_deadline; /* Relative deadline of each instance */
441 u64 dl_period; /* Separation of two instances (period) */
442 u64 dl_bw; /* dl_runtime / dl_period */
443 u64 dl_density; /* dl_runtime / dl_deadline */
444
445 /*
446 * Actual scheduling parameters. Initialized with the values above,
447 * they are continously updated during task execution. Note that
448 * the remaining runtime could be < 0 in case we are in overrun.
449 */
450 s64 runtime; /* Remaining runtime for this instance */
451 u64 deadline; /* Absolute deadline for this instance */
452 unsigned int flags; /* Specifying the scheduler behaviour */
453
454 /*
455 * Some bool flags:
456 *
457 * @dl_throttled tells if we exhausted the runtime. If so, the
458 * task has to wait for a replenishment to be performed at the
459 * next firing of dl_timer.
460 *
461 * @dl_boosted tells if we are boosted due to DI. If so we are
462 * outside bandwidth enforcement mechanism (but only until we
463 * exit the critical section);
464 *
465 * @dl_yielded tells if task gave up the CPU before consuming
466 * all its available runtime during the last job.
467 *
468 * @dl_non_contending tells if the task is inactive while still
469 * contributing to the active utilization. In other words, it
470 * indicates if the inactive timer has been armed and its handler
471 * has not been executed yet. This flag is useful to avoid race
472 * conditions between the inactive timer handler and the wakeup
473 * code.
474 */
475 int dl_throttled;
476 int dl_boosted;
477 int dl_yielded;
478 int dl_non_contending;
479
480 /*
481 * Bandwidth enforcement timer. Each -deadline task has its
482 * own bandwidth to be enforced, thus we need one timer per task.
483 */
484 struct hrtimer dl_timer;
485
486 /*
487 * Inactive timer, responsible for decreasing the active utilization
488 * at the "0-lag time". When a -deadline task blocks, it contributes
489 * to GRUB's active utilization until the "0-lag time", hence a
490 * timer is needed to decrease the active utilization at the correct
491 * time.
492 */
493 struct hrtimer inactive_timer;
494 };
495
496 union rcu_special {
497 struct {
498 u8 blocked;
499 u8 need_qs;
500 u8 exp_need_qs;
501
502 /* Otherwise the compiler can store garbage here: */
503 u8 pad;
504 } b; /* Bits. */
505 u32 s; /* Set of bits. */
506 };
507
508 enum perf_event_task_context {
509 perf_invalid_context = -1,
510 perf_hw_context = 0,
511 perf_sw_context,
512 perf_nr_task_contexts,
513 };
514
515 struct wake_q_node {
516 struct wake_q_node *next;
517 };
518
519 struct task_struct {
520 #ifdef CONFIG_THREAD_INFO_IN_TASK
521 /*
522 * For reasons of header soup (see current_thread_info()), this
523 * must be the first element of task_struct.
524 */
525 struct thread_info thread_info;
526 #endif
527 /* -1 unrunnable, 0 runnable, >0 stopped: */
528 volatile long state;
529 void *stack;
530 atomic_t usage;
531 /* Per task flags (PF_*), defined further below: */
532 unsigned int flags;
533 unsigned int ptrace;
534
535 #ifdef CONFIG_SMP
536 struct llist_node wake_entry;
537 int on_cpu;
538 #ifdef CONFIG_THREAD_INFO_IN_TASK
539 /* Current CPU: */
540 unsigned int cpu;
541 #endif
542 unsigned int wakee_flips;
543 unsigned long wakee_flip_decay_ts;
544 struct task_struct *last_wakee;
545
546 int wake_cpu;
547 #endif
548 int on_rq;
549
550 int prio;
551 int static_prio;
552 int normal_prio;
553 unsigned int rt_priority;
554
555 const struct sched_class *sched_class;
556 struct sched_entity se;
557 struct sched_rt_entity rt;
558 #ifdef CONFIG_CGROUP_SCHED
559 struct task_group *sched_task_group;
560 #endif
561 struct sched_dl_entity dl;
562
563 #ifdef CONFIG_PREEMPT_NOTIFIERS
564 /* List of struct preempt_notifier: */
565 struct hlist_head preempt_notifiers;
566 #endif
567
568 #ifdef CONFIG_BLK_DEV_IO_TRACE
569 unsigned int btrace_seq;
570 #endif
571
572 unsigned int policy;
573 int nr_cpus_allowed;
574 cpumask_t cpus_allowed;
575
576 #ifdef CONFIG_PREEMPT_RCU
577 int rcu_read_lock_nesting;
578 union rcu_special rcu_read_unlock_special;
579 struct list_head rcu_node_entry;
580 struct rcu_node *rcu_blocked_node;
581 #endif /* #ifdef CONFIG_PREEMPT_RCU */
582
583 #ifdef CONFIG_TASKS_RCU
584 unsigned long rcu_tasks_nvcsw;
585 bool rcu_tasks_holdout;
586 struct list_head rcu_tasks_holdout_list;
587 int rcu_tasks_idle_cpu;
588 #endif /* #ifdef CONFIG_TASKS_RCU */
589
590 struct sched_info sched_info;
591
592 struct list_head tasks;
593 #ifdef CONFIG_SMP
594 struct plist_node pushable_tasks;
595 struct rb_node pushable_dl_tasks;
596 #endif
597
598 struct mm_struct *mm;
599 struct mm_struct *active_mm;
600
601 /* Per-thread vma caching: */
602 struct vmacache vmacache;
603
604 #ifdef SPLIT_RSS_COUNTING
605 struct task_rss_stat rss_stat;
606 #endif
607 int exit_state;
608 int exit_code;
609 int exit_signal;
610 /* The signal sent when the parent dies: */
611 int pdeath_signal;
612 /* JOBCTL_*, siglock protected: */
613 unsigned long jobctl;
614
615 /* Used for emulating ABI behavior of previous Linux versions: */
616 unsigned int personality;
617
618 /* Scheduler bits, serialized by scheduler locks: */
619 unsigned sched_reset_on_fork:1;
620 unsigned sched_contributes_to_load:1;
621 unsigned sched_migrated:1;
622 unsigned sched_remote_wakeup:1;
623 /* Force alignment to the next boundary: */
624 unsigned :0;
625
626 /* Unserialized, strictly 'current' */
627
628 /* Bit to tell LSMs we're in execve(): */
629 unsigned in_execve:1;
630 unsigned in_iowait:1;
631 #ifndef TIF_RESTORE_SIGMASK
632 unsigned restore_sigmask:1;
633 #endif
634 #ifdef CONFIG_MEMCG
635 unsigned memcg_may_oom:1;
636 #ifndef CONFIG_SLOB
637 unsigned memcg_kmem_skip_account:1;
638 #endif
639 #endif
640 #ifdef CONFIG_COMPAT_BRK
641 unsigned brk_randomized:1;
642 #endif
643 #ifdef CONFIG_CGROUPS
644 /* disallow userland-initiated cgroup migration */
645 unsigned no_cgroup_migration:1;
646 #endif
647
648 unsigned long atomic_flags; /* Flags requiring atomic access. */
649
650 struct restart_block restart_block;
651
652 pid_t pid;
653 pid_t tgid;
654
655 #ifdef CONFIG_CC_STACKPROTECTOR
656 /* Canary value for the -fstack-protector GCC feature: */
657 unsigned long stack_canary;
658 #endif
659 /*
660 * Pointers to the (original) parent process, youngest child, younger sibling,
661 * older sibling, respectively. (p->father can be replaced with
662 * p->real_parent->pid)
663 */
664
665 /* Real parent process: */
666 struct task_struct __rcu *real_parent;
667
668 /* Recipient of SIGCHLD, wait4() reports: */
669 struct task_struct __rcu *parent;
670
671 /*
672 * Children/sibling form the list of natural children:
673 */
674 struct list_head children;
675 struct list_head sibling;
676 struct task_struct *group_leader;
677
678 /*
679 * 'ptraced' is the list of tasks this task is using ptrace() on.
680 *
681 * This includes both natural children and PTRACE_ATTACH targets.
682 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
683 */
684 struct list_head ptraced;
685 struct list_head ptrace_entry;
686
687 /* PID/PID hash table linkage. */
688 struct pid_link pids[PIDTYPE_MAX];
689 struct list_head thread_group;
690 struct list_head thread_node;
691
692 struct completion *vfork_done;
693
694 /* CLONE_CHILD_SETTID: */
695 int __user *set_child_tid;
696
697 /* CLONE_CHILD_CLEARTID: */
698 int __user *clear_child_tid;
699
700 u64 utime;
701 u64 stime;
702 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
703 u64 utimescaled;
704 u64 stimescaled;
705 #endif
706 u64 gtime;
707 struct prev_cputime prev_cputime;
708 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
709 struct vtime vtime;
710 #endif
711
712 #ifdef CONFIG_NO_HZ_FULL
713 atomic_t tick_dep_mask;
714 #endif
715 /* Context switch counts: */
716 unsigned long nvcsw;
717 unsigned long nivcsw;
718
719 /* Monotonic time in nsecs: */
720 u64 start_time;
721
722 /* Boot based time in nsecs: */
723 u64 real_start_time;
724
725 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
726 unsigned long min_flt;
727 unsigned long maj_flt;
728
729 #ifdef CONFIG_POSIX_TIMERS
730 struct task_cputime cputime_expires;
731 struct list_head cpu_timers[3];
732 #endif
733
734 /* Process credentials: */
735
736 /* Tracer's credentials at attach: */
737 const struct cred __rcu *ptracer_cred;
738
739 /* Objective and real subjective task credentials (COW): */
740 const struct cred __rcu *real_cred;
741
742 /* Effective (overridable) subjective task credentials (COW): */
743 const struct cred __rcu *cred;
744
745 /*
746 * executable name, excluding path.
747 *
748 * - normally initialized setup_new_exec()
749 * - access it with [gs]et_task_comm()
750 * - lock it with task_lock()
751 */
752 char comm[TASK_COMM_LEN];
753
754 struct nameidata *nameidata;
755
756 #ifdef CONFIG_SYSVIPC
757 struct sysv_sem sysvsem;
758 struct sysv_shm sysvshm;
759 #endif
760 #ifdef CONFIG_DETECT_HUNG_TASK
761 unsigned long last_switch_count;
762 #endif
763 /* Filesystem information: */
764 struct fs_struct *fs;
765
766 /* Open file information: */
767 struct files_struct *files;
768
769 /* Namespaces: */
770 struct nsproxy *nsproxy;
771
772 /* Signal handlers: */
773 struct signal_struct *signal;
774 struct sighand_struct *sighand;
775 sigset_t blocked;
776 sigset_t real_blocked;
777 /* Restored if set_restore_sigmask() was used: */
778 sigset_t saved_sigmask;
779 struct sigpending pending;
780 unsigned long sas_ss_sp;
781 size_t sas_ss_size;
782 unsigned int sas_ss_flags;
783
784 struct callback_head *task_works;
785
786 struct audit_context *audit_context;
787 #ifdef CONFIG_AUDITSYSCALL
788 kuid_t loginuid;
789 unsigned int sessionid;
790 #endif
791 struct seccomp seccomp;
792
793 /* Thread group tracking: */
794 u32 parent_exec_id;
795 u32 self_exec_id;
796
797 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
798 spinlock_t alloc_lock;
799
800 /* Protection of the PI data structures: */
801 raw_spinlock_t pi_lock;
802
803 struct wake_q_node wake_q;
804
805 #ifdef CONFIG_RT_MUTEXES
806 /* PI waiters blocked on a rt_mutex held by this task: */
807 struct rb_root pi_waiters;
808 struct rb_node *pi_waiters_leftmost;
809 /* Updated under owner's pi_lock and rq lock */
810 struct task_struct *pi_top_task;
811 /* Deadlock detection and priority inheritance handling: */
812 struct rt_mutex_waiter *pi_blocked_on;
813 #endif
814
815 #ifdef CONFIG_DEBUG_MUTEXES
816 /* Mutex deadlock detection: */
817 struct mutex_waiter *blocked_on;
818 #endif
819
820 #ifdef CONFIG_TRACE_IRQFLAGS
821 unsigned int irq_events;
822 unsigned long hardirq_enable_ip;
823 unsigned long hardirq_disable_ip;
824 unsigned int hardirq_enable_event;
825 unsigned int hardirq_disable_event;
826 int hardirqs_enabled;
827 int hardirq_context;
828 unsigned long softirq_disable_ip;
829 unsigned long softirq_enable_ip;
830 unsigned int softirq_disable_event;
831 unsigned int softirq_enable_event;
832 int softirqs_enabled;
833 int softirq_context;
834 #endif
835
836 #ifdef CONFIG_LOCKDEP
837 # define MAX_LOCK_DEPTH 48UL
838 u64 curr_chain_key;
839 int lockdep_depth;
840 unsigned int lockdep_recursion;
841 struct held_lock held_locks[MAX_LOCK_DEPTH];
842 gfp_t lockdep_reclaim_gfp;
843 #endif
844
845 #ifdef CONFIG_UBSAN
846 unsigned int in_ubsan;
847 #endif
848
849 /* Journalling filesystem info: */
850 void *journal_info;
851
852 /* Stacked block device info: */
853 struct bio_list *bio_list;
854
855 #ifdef CONFIG_BLOCK
856 /* Stack plugging: */
857 struct blk_plug *plug;
858 #endif
859
860 /* VM state: */
861 struct reclaim_state *reclaim_state;
862
863 struct backing_dev_info *backing_dev_info;
864
865 struct io_context *io_context;
866
867 /* Ptrace state: */
868 unsigned long ptrace_message;
869 siginfo_t *last_siginfo;
870
871 struct task_io_accounting ioac;
872 #ifdef CONFIG_TASK_XACCT
873 /* Accumulated RSS usage: */
874 u64 acct_rss_mem1;
875 /* Accumulated virtual memory usage: */
876 u64 acct_vm_mem1;
877 /* stime + utime since last update: */
878 u64 acct_timexpd;
879 #endif
880 #ifdef CONFIG_CPUSETS
881 /* Protected by ->alloc_lock: */
882 nodemask_t mems_allowed;
883 /* Seqence number to catch updates: */
884 seqcount_t mems_allowed_seq;
885 int cpuset_mem_spread_rotor;
886 int cpuset_slab_spread_rotor;
887 #endif
888 #ifdef CONFIG_CGROUPS
889 /* Control Group info protected by css_set_lock: */
890 struct css_set __rcu *cgroups;
891 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
892 struct list_head cg_list;
893 #endif
894 #ifdef CONFIG_INTEL_RDT_A
895 int closid;
896 #endif
897 #ifdef CONFIG_FUTEX
898 struct robust_list_head __user *robust_list;
899 #ifdef CONFIG_COMPAT
900 struct compat_robust_list_head __user *compat_robust_list;
901 #endif
902 struct list_head pi_state_list;
903 struct futex_pi_state *pi_state_cache;
904 #endif
905 #ifdef CONFIG_PERF_EVENTS
906 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
907 struct mutex perf_event_mutex;
908 struct list_head perf_event_list;
909 #endif
910 #ifdef CONFIG_DEBUG_PREEMPT
911 unsigned long preempt_disable_ip;
912 #endif
913 #ifdef CONFIG_NUMA
914 /* Protected by alloc_lock: */
915 struct mempolicy *mempolicy;
916 short il_prev;
917 short pref_node_fork;
918 #endif
919 #ifdef CONFIG_NUMA_BALANCING
920 int numa_scan_seq;
921 unsigned int numa_scan_period;
922 unsigned int numa_scan_period_max;
923 int numa_preferred_nid;
924 unsigned long numa_migrate_retry;
925 /* Migration stamp: */
926 u64 node_stamp;
927 u64 last_task_numa_placement;
928 u64 last_sum_exec_runtime;
929 struct callback_head numa_work;
930
931 struct list_head numa_entry;
932 struct numa_group *numa_group;
933
934 /*
935 * numa_faults is an array split into four regions:
936 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
937 * in this precise order.
938 *
939 * faults_memory: Exponential decaying average of faults on a per-node
940 * basis. Scheduling placement decisions are made based on these
941 * counts. The values remain static for the duration of a PTE scan.
942 * faults_cpu: Track the nodes the process was running on when a NUMA
943 * hinting fault was incurred.
944 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
945 * during the current scan window. When the scan completes, the counts
946 * in faults_memory and faults_cpu decay and these values are copied.
947 */
948 unsigned long *numa_faults;
949 unsigned long total_numa_faults;
950
951 /*
952 * numa_faults_locality tracks if faults recorded during the last
953 * scan window were remote/local or failed to migrate. The task scan
954 * period is adapted based on the locality of the faults with different
955 * weights depending on whether they were shared or private faults
956 */
957 unsigned long numa_faults_locality[3];
958
959 unsigned long numa_pages_migrated;
960 #endif /* CONFIG_NUMA_BALANCING */
961
962 struct tlbflush_unmap_batch tlb_ubc;
963
964 struct rcu_head rcu;
965
966 /* Cache last used pipe for splice(): */
967 struct pipe_inode_info *splice_pipe;
968
969 struct page_frag task_frag;
970
971 #ifdef CONFIG_TASK_DELAY_ACCT
972 struct task_delay_info *delays;
973 #endif
974
975 #ifdef CONFIG_FAULT_INJECTION
976 int make_it_fail;
977 unsigned int fail_nth;
978 #endif
979 /*
980 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
981 * balance_dirty_pages() for a dirty throttling pause:
982 */
983 int nr_dirtied;
984 int nr_dirtied_pause;
985 /* Start of a write-and-pause period: */
986 unsigned long dirty_paused_when;
987
988 #ifdef CONFIG_LATENCYTOP
989 int latency_record_count;
990 struct latency_record latency_record[LT_SAVECOUNT];
991 #endif
992 /*
993 * Time slack values; these are used to round up poll() and
994 * select() etc timeout values. These are in nanoseconds.
995 */
996 u64 timer_slack_ns;
997 u64 default_timer_slack_ns;
998
999 #ifdef CONFIG_KASAN
1000 unsigned int kasan_depth;
1001 #endif
1002
1003 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1004 /* Index of current stored address in ret_stack: */
1005 int curr_ret_stack;
1006
1007 /* Stack of return addresses for return function tracing: */
1008 struct ftrace_ret_stack *ret_stack;
1009
1010 /* Timestamp for last schedule: */
1011 unsigned long long ftrace_timestamp;
1012
1013 /*
1014 * Number of functions that haven't been traced
1015 * because of depth overrun:
1016 */
1017 atomic_t trace_overrun;
1018
1019 /* Pause tracing: */
1020 atomic_t tracing_graph_pause;
1021 #endif
1022
1023 #ifdef CONFIG_TRACING
1024 /* State flags for use by tracers: */
1025 unsigned long trace;
1026
1027 /* Bitmask and counter of trace recursion: */
1028 unsigned long trace_recursion;
1029 #endif /* CONFIG_TRACING */
1030
1031 #ifdef CONFIG_KCOV
1032 /* Coverage collection mode enabled for this task (0 if disabled): */
1033 enum kcov_mode kcov_mode;
1034
1035 /* Size of the kcov_area: */
1036 unsigned int kcov_size;
1037
1038 /* Buffer for coverage collection: */
1039 void *kcov_area;
1040
1041 /* KCOV descriptor wired with this task or NULL: */
1042 struct kcov *kcov;
1043 #endif
1044
1045 #ifdef CONFIG_MEMCG
1046 struct mem_cgroup *memcg_in_oom;
1047 gfp_t memcg_oom_gfp_mask;
1048 int memcg_oom_order;
1049
1050 /* Number of pages to reclaim on returning to userland: */
1051 unsigned int memcg_nr_pages_over_high;
1052 #endif
1053
1054 #ifdef CONFIG_UPROBES
1055 struct uprobe_task *utask;
1056 #endif
1057 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1058 unsigned int sequential_io;
1059 unsigned int sequential_io_avg;
1060 #endif
1061 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1062 unsigned long task_state_change;
1063 #endif
1064 int pagefault_disabled;
1065 #ifdef CONFIG_MMU
1066 struct task_struct *oom_reaper_list;
1067 #endif
1068 #ifdef CONFIG_VMAP_STACK
1069 struct vm_struct *stack_vm_area;
1070 #endif
1071 #ifdef CONFIG_THREAD_INFO_IN_TASK
1072 /* A live task holds one reference: */
1073 atomic_t stack_refcount;
1074 #endif
1075 #ifdef CONFIG_LIVEPATCH
1076 int patch_state;
1077 #endif
1078 #ifdef CONFIG_SECURITY
1079 /* Used by LSM modules for access restriction: */
1080 void *security;
1081 #endif
1082 /* CPU-specific state of this task: */
1083 struct thread_struct thread;
1084
1085 /*
1086 * WARNING: on x86, 'thread_struct' contains a variable-sized
1087 * structure. It *MUST* be at the end of 'task_struct'.
1088 *
1089 * Do not put anything below here!
1090 */
1091 };
1092
1093 static inline struct pid *task_pid(struct task_struct *task)
1094 {
1095 return task->pids[PIDTYPE_PID].pid;
1096 }
1097
1098 static inline struct pid *task_tgid(struct task_struct *task)
1099 {
1100 return task->group_leader->pids[PIDTYPE_PID].pid;
1101 }
1102
1103 /*
1104 * Without tasklist or RCU lock it is not safe to dereference
1105 * the result of task_pgrp/task_session even if task == current,
1106 * we can race with another thread doing sys_setsid/sys_setpgid.
1107 */
1108 static inline struct pid *task_pgrp(struct task_struct *task)
1109 {
1110 return task->group_leader->pids[PIDTYPE_PGID].pid;
1111 }
1112
1113 static inline struct pid *task_session(struct task_struct *task)
1114 {
1115 return task->group_leader->pids[PIDTYPE_SID].pid;
1116 }
1117
1118 /*
1119 * the helpers to get the task's different pids as they are seen
1120 * from various namespaces
1121 *
1122 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1123 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1124 * current.
1125 * task_xid_nr_ns() : id seen from the ns specified;
1126 *
1127 * see also pid_nr() etc in include/linux/pid.h
1128 */
1129 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1130
1131 static inline pid_t task_pid_nr(struct task_struct *tsk)
1132 {
1133 return tsk->pid;
1134 }
1135
1136 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1137 {
1138 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1139 }
1140
1141 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1142 {
1143 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1144 }
1145
1146
1147 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1148 {
1149 return tsk->tgid;
1150 }
1151
1152 extern pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1153
1154 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1155 {
1156 return pid_vnr(task_tgid(tsk));
1157 }
1158
1159 /**
1160 * pid_alive - check that a task structure is not stale
1161 * @p: Task structure to be checked.
1162 *
1163 * Test if a process is not yet dead (at most zombie state)
1164 * If pid_alive fails, then pointers within the task structure
1165 * can be stale and must not be dereferenced.
1166 *
1167 * Return: 1 if the process is alive. 0 otherwise.
1168 */
1169 static inline int pid_alive(const struct task_struct *p)
1170 {
1171 return p->pids[PIDTYPE_PID].pid != NULL;
1172 }
1173
1174 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1175 {
1176 pid_t pid = 0;
1177
1178 rcu_read_lock();
1179 if (pid_alive(tsk))
1180 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1181 rcu_read_unlock();
1182
1183 return pid;
1184 }
1185
1186 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1187 {
1188 return task_ppid_nr_ns(tsk, &init_pid_ns);
1189 }
1190
1191 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1192 {
1193 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1194 }
1195
1196 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1197 {
1198 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1199 }
1200
1201
1202 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1203 {
1204 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1205 }
1206
1207 static inline pid_t task_session_vnr(struct task_struct *tsk)
1208 {
1209 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1210 }
1211
1212 /* Obsolete, do not use: */
1213 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1214 {
1215 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1216 }
1217
1218 /**
1219 * is_global_init - check if a task structure is init. Since init
1220 * is free to have sub-threads we need to check tgid.
1221 * @tsk: Task structure to be checked.
1222 *
1223 * Check if a task structure is the first user space task the kernel created.
1224 *
1225 * Return: 1 if the task structure is init. 0 otherwise.
1226 */
1227 static inline int is_global_init(struct task_struct *tsk)
1228 {
1229 return task_tgid_nr(tsk) == 1;
1230 }
1231
1232 extern struct pid *cad_pid;
1233
1234 /*
1235 * Per process flags
1236 */
1237 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1238 #define PF_EXITING 0x00000004 /* Getting shut down */
1239 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1240 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1241 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1242 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1243 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1244 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1245 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1246 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1247 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1248 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1249 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1250 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1251 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1252 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1253 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1254 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1255 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1256 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1257 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1258 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1259 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1260 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1261 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1262 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1263 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1264 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1265
1266 /*
1267 * Only the _current_ task can read/write to tsk->flags, but other
1268 * tasks can access tsk->flags in readonly mode for example
1269 * with tsk_used_math (like during threaded core dumping).
1270 * There is however an exception to this rule during ptrace
1271 * or during fork: the ptracer task is allowed to write to the
1272 * child->flags of its traced child (same goes for fork, the parent
1273 * can write to the child->flags), because we're guaranteed the
1274 * child is not running and in turn not changing child->flags
1275 * at the same time the parent does it.
1276 */
1277 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1278 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1279 #define clear_used_math() clear_stopped_child_used_math(current)
1280 #define set_used_math() set_stopped_child_used_math(current)
1281
1282 #define conditional_stopped_child_used_math(condition, child) \
1283 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1284
1285 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1286
1287 #define copy_to_stopped_child_used_math(child) \
1288 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1289
1290 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1291 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1292 #define used_math() tsk_used_math(current)
1293
1294 static inline bool is_percpu_thread(void)
1295 {
1296 #ifdef CONFIG_SMP
1297 return (current->flags & PF_NO_SETAFFINITY) &&
1298 (current->nr_cpus_allowed == 1);
1299 #else
1300 return true;
1301 #endif
1302 }
1303
1304 /* Per-process atomic flags. */
1305 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1306 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1307 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1308
1309
1310 #define TASK_PFA_TEST(name, func) \
1311 static inline bool task_##func(struct task_struct *p) \
1312 { return test_bit(PFA_##name, &p->atomic_flags); }
1313
1314 #define TASK_PFA_SET(name, func) \
1315 static inline void task_set_##func(struct task_struct *p) \
1316 { set_bit(PFA_##name, &p->atomic_flags); }
1317
1318 #define TASK_PFA_CLEAR(name, func) \
1319 static inline void task_clear_##func(struct task_struct *p) \
1320 { clear_bit(PFA_##name, &p->atomic_flags); }
1321
1322 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1323 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1324
1325 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1326 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1327 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1328
1329 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1330 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1331 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1332
1333 static inline void
1334 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1335 {
1336 current->flags &= ~flags;
1337 current->flags |= orig_flags & flags;
1338 }
1339
1340 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1341 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1342 #ifdef CONFIG_SMP
1343 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1344 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1345 #else
1346 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1347 {
1348 }
1349 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1350 {
1351 if (!cpumask_test_cpu(0, new_mask))
1352 return -EINVAL;
1353 return 0;
1354 }
1355 #endif
1356
1357 #ifndef cpu_relax_yield
1358 #define cpu_relax_yield() cpu_relax()
1359 #endif
1360
1361 extern int yield_to(struct task_struct *p, bool preempt);
1362 extern void set_user_nice(struct task_struct *p, long nice);
1363 extern int task_prio(const struct task_struct *p);
1364
1365 /**
1366 * task_nice - return the nice value of a given task.
1367 * @p: the task in question.
1368 *
1369 * Return: The nice value [ -20 ... 0 ... 19 ].
1370 */
1371 static inline int task_nice(const struct task_struct *p)
1372 {
1373 return PRIO_TO_NICE((p)->static_prio);
1374 }
1375
1376 extern int can_nice(const struct task_struct *p, const int nice);
1377 extern int task_curr(const struct task_struct *p);
1378 extern int idle_cpu(int cpu);
1379 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1380 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1381 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1382 extern struct task_struct *idle_task(int cpu);
1383
1384 /**
1385 * is_idle_task - is the specified task an idle task?
1386 * @p: the task in question.
1387 *
1388 * Return: 1 if @p is an idle task. 0 otherwise.
1389 */
1390 static inline bool is_idle_task(const struct task_struct *p)
1391 {
1392 return !!(p->flags & PF_IDLE);
1393 }
1394
1395 extern struct task_struct *curr_task(int cpu);
1396 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1397
1398 void yield(void);
1399
1400 union thread_union {
1401 #ifndef CONFIG_THREAD_INFO_IN_TASK
1402 struct thread_info thread_info;
1403 #endif
1404 unsigned long stack[THREAD_SIZE/sizeof(long)];
1405 };
1406
1407 #ifdef CONFIG_THREAD_INFO_IN_TASK
1408 static inline struct thread_info *task_thread_info(struct task_struct *task)
1409 {
1410 return &task->thread_info;
1411 }
1412 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1413 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1414 #endif
1415
1416 /*
1417 * find a task by one of its numerical ids
1418 *
1419 * find_task_by_pid_ns():
1420 * finds a task by its pid in the specified namespace
1421 * find_task_by_vpid():
1422 * finds a task by its virtual pid
1423 *
1424 * see also find_vpid() etc in include/linux/pid.h
1425 */
1426
1427 extern struct task_struct *find_task_by_vpid(pid_t nr);
1428 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1429
1430 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1431 extern int wake_up_process(struct task_struct *tsk);
1432 extern void wake_up_new_task(struct task_struct *tsk);
1433
1434 #ifdef CONFIG_SMP
1435 extern void kick_process(struct task_struct *tsk);
1436 #else
1437 static inline void kick_process(struct task_struct *tsk) { }
1438 #endif
1439
1440 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1441
1442 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1443 {
1444 __set_task_comm(tsk, from, false);
1445 }
1446
1447 extern char *get_task_comm(char *to, struct task_struct *tsk);
1448
1449 #ifdef CONFIG_SMP
1450 void scheduler_ipi(void);
1451 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1452 #else
1453 static inline void scheduler_ipi(void) { }
1454 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1455 {
1456 return 1;
1457 }
1458 #endif
1459
1460 /*
1461 * Set thread flags in other task's structures.
1462 * See asm/thread_info.h for TIF_xxxx flags available:
1463 */
1464 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1465 {
1466 set_ti_thread_flag(task_thread_info(tsk), flag);
1467 }
1468
1469 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1470 {
1471 clear_ti_thread_flag(task_thread_info(tsk), flag);
1472 }
1473
1474 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1475 {
1476 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1477 }
1478
1479 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1480 {
1481 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1482 }
1483
1484 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1485 {
1486 return test_ti_thread_flag(task_thread_info(tsk), flag);
1487 }
1488
1489 static inline void set_tsk_need_resched(struct task_struct *tsk)
1490 {
1491 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1492 }
1493
1494 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1495 {
1496 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1497 }
1498
1499 static inline int test_tsk_need_resched(struct task_struct *tsk)
1500 {
1501 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1502 }
1503
1504 /*
1505 * cond_resched() and cond_resched_lock(): latency reduction via
1506 * explicit rescheduling in places that are safe. The return
1507 * value indicates whether a reschedule was done in fact.
1508 * cond_resched_lock() will drop the spinlock before scheduling,
1509 * cond_resched_softirq() will enable bhs before scheduling.
1510 */
1511 #ifndef CONFIG_PREEMPT
1512 extern int _cond_resched(void);
1513 #else
1514 static inline int _cond_resched(void) { return 0; }
1515 #endif
1516
1517 #define cond_resched() ({ \
1518 ___might_sleep(__FILE__, __LINE__, 0); \
1519 _cond_resched(); \
1520 })
1521
1522 extern int __cond_resched_lock(spinlock_t *lock);
1523
1524 #define cond_resched_lock(lock) ({ \
1525 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1526 __cond_resched_lock(lock); \
1527 })
1528
1529 extern int __cond_resched_softirq(void);
1530
1531 #define cond_resched_softirq() ({ \
1532 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
1533 __cond_resched_softirq(); \
1534 })
1535
1536 static inline void cond_resched_rcu(void)
1537 {
1538 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1539 rcu_read_unlock();
1540 cond_resched();
1541 rcu_read_lock();
1542 #endif
1543 }
1544
1545 /*
1546 * Does a critical section need to be broken due to another
1547 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1548 * but a general need for low latency)
1549 */
1550 static inline int spin_needbreak(spinlock_t *lock)
1551 {
1552 #ifdef CONFIG_PREEMPT
1553 return spin_is_contended(lock);
1554 #else
1555 return 0;
1556 #endif
1557 }
1558
1559 static __always_inline bool need_resched(void)
1560 {
1561 return unlikely(tif_need_resched());
1562 }
1563
1564 /*
1565 * Wrappers for p->thread_info->cpu access. No-op on UP.
1566 */
1567 #ifdef CONFIG_SMP
1568
1569 static inline unsigned int task_cpu(const struct task_struct *p)
1570 {
1571 #ifdef CONFIG_THREAD_INFO_IN_TASK
1572 return p->cpu;
1573 #else
1574 return task_thread_info(p)->cpu;
1575 #endif
1576 }
1577
1578 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1579
1580 #else
1581
1582 static inline unsigned int task_cpu(const struct task_struct *p)
1583 {
1584 return 0;
1585 }
1586
1587 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1588 {
1589 }
1590
1591 #endif /* CONFIG_SMP */
1592
1593 /*
1594 * In order to reduce various lock holder preemption latencies provide an
1595 * interface to see if a vCPU is currently running or not.
1596 *
1597 * This allows us to terminate optimistic spin loops and block, analogous to
1598 * the native optimistic spin heuristic of testing if the lock owner task is
1599 * running or not.
1600 */
1601 #ifndef vcpu_is_preempted
1602 # define vcpu_is_preempted(cpu) false
1603 #endif
1604
1605 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1606 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1607
1608 #ifndef TASK_SIZE_OF
1609 #define TASK_SIZE_OF(tsk) TASK_SIZE
1610 #endif
1611
1612 #endif