1 /* SPDX-License-Identifier: GPL-2.0 */
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
10 #include <uapi/linux/sched.h>
12 #include <asm/current.h>
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kcov.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/seccomp.h>
22 #include <linux/nodemask.h>
23 #include <linux/rcupdate.h>
24 #include <linux/resource.h>
25 #include <linux/latencytop.h>
26 #include <linux/sched/prio.h>
27 #include <linux/signal_types.h>
28 #include <linux/psi_types.h>
29 #include <linux/mm_types_task.h>
30 #include <linux/task_io_accounting.h>
31 #include <linux/rseq.h>
33 /* task_struct member predeclarations (sorted alphabetically): */
35 struct backing_dev_info
;
40 struct futex_pi_state
;
45 struct perf_event_context
;
47 struct pipe_inode_info
;
50 struct robust_list_head
;
54 struct sighand_struct
;
56 struct task_delay_info
;
60 * Task state bitmask. NOTE! These bits are also
61 * encoded in fs/proc/array.c: get_task_state().
63 * We have two separate sets of flags: task->state
64 * is about runnability, while task->exit_state are
65 * about the task exiting. Confusing, but this way
66 * modifying one set can't modify the other one by
70 /* Used in tsk->state: */
71 #define TASK_RUNNING 0x0000
72 #define TASK_INTERRUPTIBLE 0x0001
73 #define TASK_UNINTERRUPTIBLE 0x0002
74 #define __TASK_STOPPED 0x0004
75 #define __TASK_TRACED 0x0008
76 /* Used in tsk->exit_state: */
77 #define EXIT_DEAD 0x0010
78 #define EXIT_ZOMBIE 0x0020
79 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
80 /* Used in tsk->state again: */
81 #define TASK_PARKED 0x0040
82 #define TASK_DEAD 0x0080
83 #define TASK_WAKEKILL 0x0100
84 #define TASK_WAKING 0x0200
85 #define TASK_NOLOAD 0x0400
86 #define TASK_NEW 0x0800
87 #define TASK_STATE_MAX 0x1000
89 /* Convenience macros for the sake of set_current_state: */
90 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
91 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
92 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
94 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
96 /* Convenience macros for the sake of wake_up(): */
97 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
99 /* get_task_state(): */
100 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
101 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
102 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
105 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
107 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
109 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
111 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
112 (task->flags & PF_FROZEN) == 0 && \
113 (task->state & TASK_NOLOAD) == 0)
115 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
118 * Special states are those that do not use the normal wait-loop pattern. See
119 * the comment with set_special_state().
121 #define is_special_task_state(state) \
122 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
124 #define __set_current_state(state_value) \
126 WARN_ON_ONCE(is_special_task_state(state_value));\
127 current->task_state_change = _THIS_IP_; \
128 current->state = (state_value); \
131 #define set_current_state(state_value) \
133 WARN_ON_ONCE(is_special_task_state(state_value));\
134 current->task_state_change = _THIS_IP_; \
135 smp_store_mb(current->state, (state_value)); \
138 #define set_special_state(state_value) \
140 unsigned long flags; /* may shadow */ \
141 WARN_ON_ONCE(!is_special_task_state(state_value)); \
142 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
143 current->task_state_change = _THIS_IP_; \
144 current->state = (state_value); \
145 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
149 * set_current_state() includes a barrier so that the write of current->state
150 * is correctly serialised wrt the caller's subsequent test of whether to
154 * set_current_state(TASK_UNINTERRUPTIBLE);
160 * __set_current_state(TASK_RUNNING);
162 * If the caller does not need such serialisation (because, for instance, the
163 * condition test and condition change and wakeup are under the same lock) then
164 * use __set_current_state().
166 * The above is typically ordered against the wakeup, which does:
168 * need_sleep = false;
169 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
171 * where wake_up_state() executes a full memory barrier before accessing the
174 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
175 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
176 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
178 * However, with slightly different timing the wakeup TASK_RUNNING store can
179 * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
180 * a problem either because that will result in one extra go around the loop
181 * and our @cond test will save the day.
183 * Also see the comments of try_to_wake_up().
185 #define __set_current_state(state_value) \
186 current->state = (state_value)
188 #define set_current_state(state_value) \
189 smp_store_mb(current->state, (state_value))
192 * set_special_state() should be used for those states when the blocking task
193 * can not use the regular condition based wait-loop. In that case we must
194 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
195 * will not collide with our state change.
197 #define set_special_state(state_value) \
199 unsigned long flags; /* may shadow */ \
200 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
201 current->state = (state_value); \
202 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
207 /* Task command name length: */
208 #define TASK_COMM_LEN 16
210 extern void scheduler_tick(void);
212 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
214 extern long schedule_timeout(long timeout
);
215 extern long schedule_timeout_interruptible(long timeout
);
216 extern long schedule_timeout_killable(long timeout
);
217 extern long schedule_timeout_uninterruptible(long timeout
);
218 extern long schedule_timeout_idle(long timeout
);
219 asmlinkage
void schedule(void);
220 extern void schedule_preempt_disabled(void);
222 extern int __must_check
io_schedule_prepare(void);
223 extern void io_schedule_finish(int token
);
224 extern long io_schedule_timeout(long timeout
);
225 extern void io_schedule(void);
228 * struct prev_cputime - snapshot of system and user cputime
229 * @utime: time spent in user mode
230 * @stime: time spent in system mode
231 * @lock: protects the above two fields
233 * Stores previous user/system time values such that we can guarantee
236 struct prev_cputime
{
237 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
245 * struct task_cputime - collected CPU time counts
246 * @utime: time spent in user mode, in nanoseconds
247 * @stime: time spent in kernel mode, in nanoseconds
248 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
250 * This structure groups together three kinds of CPU time that are tracked for
251 * threads and thread groups. Most things considering CPU time want to group
252 * these counts together and treat all three of them in parallel.
254 struct task_cputime
{
257 unsigned long long sum_exec_runtime
;
260 /* Alternate field names when used on cache expirations: */
261 #define virt_exp utime
262 #define prof_exp stime
263 #define sched_exp sum_exec_runtime
266 /* Task is sleeping or running in a CPU with VTIME inactive: */
268 /* Task runs in userspace in a CPU with VTIME active: */
270 /* Task runs in kernelspace in a CPU with VTIME active: */
276 unsigned long long starttime
;
277 enum vtime_state state
;
284 #ifdef CONFIG_SCHED_INFO
285 /* Cumulative counters: */
287 /* # of times we have run on this CPU: */
288 unsigned long pcount
;
290 /* Time spent waiting on a runqueue: */
291 unsigned long long run_delay
;
295 /* When did we last run on a CPU? */
296 unsigned long long last_arrival
;
298 /* When were we last queued to run? */
299 unsigned long long last_queued
;
301 #endif /* CONFIG_SCHED_INFO */
305 * Integer metrics need fixed point arithmetic, e.g., sched/fair
306 * has a few: load, load_avg, util_avg, freq, and capacity.
308 * We define a basic fixed point arithmetic range, and then formalize
309 * all these metrics based on that basic range.
311 # define SCHED_FIXEDPOINT_SHIFT 10
312 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
315 unsigned long weight
;
320 * struct util_est - Estimation utilization of FAIR tasks
321 * @enqueued: instantaneous estimated utilization of a task/cpu
322 * @ewma: the Exponential Weighted Moving Average (EWMA)
323 * utilization of a task
325 * Support data structure to track an Exponential Weighted Moving Average
326 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
327 * average each time a task completes an activation. Sample's weight is chosen
328 * so that the EWMA will be relatively insensitive to transient changes to the
331 * The enqueued attribute has a slightly different meaning for tasks and cpus:
332 * - task: the task's util_avg at last task dequeue time
333 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
334 * Thus, the util_est.enqueued of a task represents the contribution on the
335 * estimated utilization of the CPU where that task is currently enqueued.
337 * Only for tasks we track a moving average of the past instantaneous
338 * estimated utilization. This allows to absorb sporadic drops in utilization
339 * of an otherwise almost periodic task.
342 unsigned int enqueued
;
344 #define UTIL_EST_WEIGHT_SHIFT 2
345 } __attribute__((__aligned__(sizeof(u64
))));
348 * The load_avg/util_avg accumulates an infinite geometric series
349 * (see __update_load_avg() in kernel/sched/fair.c).
351 * [load_avg definition]
353 * load_avg = runnable% * scale_load_down(load)
355 * where runnable% is the time ratio that a sched_entity is runnable.
356 * For cfs_rq, it is the aggregated load_avg of all runnable and
357 * blocked sched_entities.
359 * load_avg may also take frequency scaling into account:
361 * load_avg = runnable% * scale_load_down(load) * freq%
363 * where freq% is the CPU frequency normalized to the highest frequency.
365 * [util_avg definition]
367 * util_avg = running% * SCHED_CAPACITY_SCALE
369 * where running% is the time ratio that a sched_entity is running on
370 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
371 * and blocked sched_entities.
373 * util_avg may also factor frequency scaling and CPU capacity scaling:
375 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
377 * where freq% is the same as above, and capacity% is the CPU capacity
378 * normalized to the greatest capacity (due to uarch differences, etc).
380 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
381 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
382 * we therefore scale them to as large a range as necessary. This is for
383 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
387 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
388 * with the highest load (=88761), always runnable on a single cfs_rq,
389 * and should not overflow as the number already hits PID_MAX_LIMIT.
391 * For all other cases (including 32-bit kernels), struct load_weight's
392 * weight will overflow first before we do, because:
394 * Max(load_avg) <= Max(load.weight)
396 * Then it is the load_weight's responsibility to consider overflow
400 u64 last_update_time
;
402 u64 runnable_load_sum
;
405 unsigned long load_avg
;
406 unsigned long runnable_load_avg
;
407 unsigned long util_avg
;
408 struct util_est util_est
;
409 } ____cacheline_aligned
;
411 struct sched_statistics
{
412 #ifdef CONFIG_SCHEDSTATS
422 s64 sum_sleep_runtime
;
429 u64 nr_migrations_cold
;
430 u64 nr_failed_migrations_affine
;
431 u64 nr_failed_migrations_running
;
432 u64 nr_failed_migrations_hot
;
433 u64 nr_forced_migrations
;
437 u64 nr_wakeups_migrate
;
438 u64 nr_wakeups_local
;
439 u64 nr_wakeups_remote
;
440 u64 nr_wakeups_affine
;
441 u64 nr_wakeups_affine_attempts
;
442 u64 nr_wakeups_passive
;
447 struct sched_entity
{
448 /* For load-balancing: */
449 struct load_weight load
;
450 unsigned long runnable_weight
;
451 struct rb_node run_node
;
452 struct list_head group_node
;
456 u64 sum_exec_runtime
;
458 u64 prev_sum_exec_runtime
;
462 struct sched_statistics statistics
;
464 #ifdef CONFIG_FAIR_GROUP_SCHED
466 struct sched_entity
*parent
;
467 /* rq on which this entity is (to be) queued: */
468 struct cfs_rq
*cfs_rq
;
469 /* rq "owned" by this entity/group: */
475 * Per entity load average tracking.
477 * Put into separate cache line so it does not
478 * collide with read-mostly values above.
480 struct sched_avg avg
;
484 struct sched_rt_entity
{
485 struct list_head run_list
;
486 unsigned long timeout
;
487 unsigned long watchdog_stamp
;
488 unsigned int time_slice
;
489 unsigned short on_rq
;
490 unsigned short on_list
;
492 struct sched_rt_entity
*back
;
493 #ifdef CONFIG_RT_GROUP_SCHED
494 struct sched_rt_entity
*parent
;
495 /* rq on which this entity is (to be) queued: */
497 /* rq "owned" by this entity/group: */
500 } __randomize_layout
;
502 struct sched_dl_entity
{
503 struct rb_node rb_node
;
506 * Original scheduling parameters. Copied here from sched_attr
507 * during sched_setattr(), they will remain the same until
508 * the next sched_setattr().
510 u64 dl_runtime
; /* Maximum runtime for each instance */
511 u64 dl_deadline
; /* Relative deadline of each instance */
512 u64 dl_period
; /* Separation of two instances (period) */
513 u64 dl_bw
; /* dl_runtime / dl_period */
514 u64 dl_density
; /* dl_runtime / dl_deadline */
517 * Actual scheduling parameters. Initialized with the values above,
518 * they are continously updated during task execution. Note that
519 * the remaining runtime could be < 0 in case we are in overrun.
521 s64 runtime
; /* Remaining runtime for this instance */
522 u64 deadline
; /* Absolute deadline for this instance */
523 unsigned int flags
; /* Specifying the scheduler behaviour */
528 * @dl_throttled tells if we exhausted the runtime. If so, the
529 * task has to wait for a replenishment to be performed at the
530 * next firing of dl_timer.
532 * @dl_boosted tells if we are boosted due to DI. If so we are
533 * outside bandwidth enforcement mechanism (but only until we
534 * exit the critical section);
536 * @dl_yielded tells if task gave up the CPU before consuming
537 * all its available runtime during the last job.
539 * @dl_non_contending tells if the task is inactive while still
540 * contributing to the active utilization. In other words, it
541 * indicates if the inactive timer has been armed and its handler
542 * has not been executed yet. This flag is useful to avoid race
543 * conditions between the inactive timer handler and the wakeup
546 * @dl_overrun tells if the task asked to be informed about runtime
549 unsigned int dl_throttled
: 1;
550 unsigned int dl_boosted
: 1;
551 unsigned int dl_yielded
: 1;
552 unsigned int dl_non_contending
: 1;
553 unsigned int dl_overrun
: 1;
556 * Bandwidth enforcement timer. Each -deadline task has its
557 * own bandwidth to be enforced, thus we need one timer per task.
559 struct hrtimer dl_timer
;
562 * Inactive timer, responsible for decreasing the active utilization
563 * at the "0-lag time". When a -deadline task blocks, it contributes
564 * to GRUB's active utilization until the "0-lag time", hence a
565 * timer is needed to decrease the active utilization at the correct
568 struct hrtimer inactive_timer
;
576 u16 s
; /* Set of bits. */
579 enum perf_event_task_context
{
580 perf_invalid_context
= -1,
583 perf_nr_task_contexts
,
587 struct wake_q_node
*next
;
591 #ifdef CONFIG_THREAD_INFO_IN_TASK
593 * For reasons of header soup (see current_thread_info()), this
594 * must be the first element of task_struct.
596 struct thread_info thread_info
;
598 /* -1 unrunnable, 0 runnable, >0 stopped: */
602 * This begins the randomizable portion of task_struct. Only
603 * scheduling-critical items should be added above here.
605 randomized_struct_fields_start
609 /* Per task flags (PF_*), defined further below: */
614 struct llist_node wake_entry
;
616 #ifdef CONFIG_THREAD_INFO_IN_TASK
620 unsigned int wakee_flips
;
621 unsigned long wakee_flip_decay_ts
;
622 struct task_struct
*last_wakee
;
625 * recent_used_cpu is initially set as the last CPU used by a task
626 * that wakes affine another task. Waker/wakee relationships can
627 * push tasks around a CPU where each wakeup moves to the next one.
628 * Tracking a recently used CPU allows a quick search for a recently
629 * used CPU that may be idle.
639 unsigned int rt_priority
;
641 const struct sched_class
*sched_class
;
642 struct sched_entity se
;
643 struct sched_rt_entity rt
;
644 #ifdef CONFIG_CGROUP_SCHED
645 struct task_group
*sched_task_group
;
647 struct sched_dl_entity dl
;
649 #ifdef CONFIG_PREEMPT_NOTIFIERS
650 /* List of struct preempt_notifier: */
651 struct hlist_head preempt_notifiers
;
654 #ifdef CONFIG_BLK_DEV_IO_TRACE
655 unsigned int btrace_seq
;
660 cpumask_t cpus_allowed
;
662 #ifdef CONFIG_PREEMPT_RCU
663 int rcu_read_lock_nesting
;
664 union rcu_special rcu_read_unlock_special
;
665 struct list_head rcu_node_entry
;
666 struct rcu_node
*rcu_blocked_node
;
667 #endif /* #ifdef CONFIG_PREEMPT_RCU */
669 #ifdef CONFIG_TASKS_RCU
670 unsigned long rcu_tasks_nvcsw
;
671 u8 rcu_tasks_holdout
;
673 int rcu_tasks_idle_cpu
;
674 struct list_head rcu_tasks_holdout_list
;
675 #endif /* #ifdef CONFIG_TASKS_RCU */
677 struct sched_info sched_info
;
679 struct list_head tasks
;
681 struct plist_node pushable_tasks
;
682 struct rb_node pushable_dl_tasks
;
685 struct mm_struct
*mm
;
686 struct mm_struct
*active_mm
;
688 /* Per-thread vma caching: */
689 struct vmacache vmacache
;
691 #ifdef SPLIT_RSS_COUNTING
692 struct task_rss_stat rss_stat
;
697 /* The signal sent when the parent dies: */
699 /* JOBCTL_*, siglock protected: */
700 unsigned long jobctl
;
702 /* Used for emulating ABI behavior of previous Linux versions: */
703 unsigned int personality
;
705 /* Scheduler bits, serialized by scheduler locks: */
706 unsigned sched_reset_on_fork
:1;
707 unsigned sched_contributes_to_load
:1;
708 unsigned sched_migrated
:1;
709 unsigned sched_remote_wakeup
:1;
711 unsigned sched_psi_wake_requeue
:1;
714 /* Force alignment to the next boundary: */
717 /* Unserialized, strictly 'current' */
719 /* Bit to tell LSMs we're in execve(): */
720 unsigned in_execve
:1;
721 unsigned in_iowait
:1;
722 #ifndef TIF_RESTORE_SIGMASK
723 unsigned restore_sigmask
:1;
726 unsigned in_user_fault
:1;
728 #ifdef CONFIG_COMPAT_BRK
729 unsigned brk_randomized
:1;
731 #ifdef CONFIG_CGROUPS
732 /* disallow userland-initiated cgroup migration */
733 unsigned no_cgroup_migration
:1;
735 #ifdef CONFIG_BLK_CGROUP
736 /* to be used once the psi infrastructure lands upstream. */
737 unsigned use_memdelay
:1;
741 * May usercopy functions fault on kernel addresses?
742 * This is not just a single bit because this can potentially nest.
744 unsigned int kernel_uaccess_faults_ok
;
746 unsigned long atomic_flags
; /* Flags requiring atomic access. */
748 struct restart_block restart_block
;
753 #ifdef CONFIG_STACKPROTECTOR
754 /* Canary value for the -fstack-protector GCC feature: */
755 unsigned long stack_canary
;
758 * Pointers to the (original) parent process, youngest child, younger sibling,
759 * older sibling, respectively. (p->father can be replaced with
760 * p->real_parent->pid)
763 /* Real parent process: */
764 struct task_struct __rcu
*real_parent
;
766 /* Recipient of SIGCHLD, wait4() reports: */
767 struct task_struct __rcu
*parent
;
770 * Children/sibling form the list of natural children:
772 struct list_head children
;
773 struct list_head sibling
;
774 struct task_struct
*group_leader
;
777 * 'ptraced' is the list of tasks this task is using ptrace() on.
779 * This includes both natural children and PTRACE_ATTACH targets.
780 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
782 struct list_head ptraced
;
783 struct list_head ptrace_entry
;
785 /* PID/PID hash table linkage. */
786 struct pid
*thread_pid
;
787 struct hlist_node pid_links
[PIDTYPE_MAX
];
788 struct list_head thread_group
;
789 struct list_head thread_node
;
791 struct completion
*vfork_done
;
793 /* CLONE_CHILD_SETTID: */
794 int __user
*set_child_tid
;
796 /* CLONE_CHILD_CLEARTID: */
797 int __user
*clear_child_tid
;
801 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
806 struct prev_cputime prev_cputime
;
807 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
811 #ifdef CONFIG_NO_HZ_FULL
812 atomic_t tick_dep_mask
;
814 /* Context switch counts: */
816 unsigned long nivcsw
;
818 /* Monotonic time in nsecs: */
821 /* Boot based time in nsecs: */
824 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
825 unsigned long min_flt
;
826 unsigned long maj_flt
;
828 #ifdef CONFIG_POSIX_TIMERS
829 struct task_cputime cputime_expires
;
830 struct list_head cpu_timers
[3];
833 /* Process credentials: */
835 /* Tracer's credentials at attach: */
836 const struct cred __rcu
*ptracer_cred
;
838 /* Objective and real subjective task credentials (COW): */
839 const struct cred __rcu
*real_cred
;
841 /* Effective (overridable) subjective task credentials (COW): */
842 const struct cred __rcu
*cred
;
845 * executable name, excluding path.
847 * - normally initialized setup_new_exec()
848 * - access it with [gs]et_task_comm()
849 * - lock it with task_lock()
851 char comm
[TASK_COMM_LEN
];
853 struct nameidata
*nameidata
;
855 #ifdef CONFIG_SYSVIPC
856 struct sysv_sem sysvsem
;
857 struct sysv_shm sysvshm
;
859 #ifdef CONFIG_DETECT_HUNG_TASK
860 unsigned long last_switch_count
;
861 unsigned long last_switch_time
;
863 /* Filesystem information: */
864 struct fs_struct
*fs
;
866 /* Open file information: */
867 struct files_struct
*files
;
870 struct nsproxy
*nsproxy
;
872 /* Signal handlers: */
873 struct signal_struct
*signal
;
874 struct sighand_struct
*sighand
;
876 sigset_t real_blocked
;
877 /* Restored if set_restore_sigmask() was used: */
878 sigset_t saved_sigmask
;
879 struct sigpending pending
;
880 unsigned long sas_ss_sp
;
882 unsigned int sas_ss_flags
;
884 struct callback_head
*task_works
;
886 struct audit_context
*audit_context
;
887 #ifdef CONFIG_AUDITSYSCALL
889 unsigned int sessionid
;
891 struct seccomp seccomp
;
893 /* Thread group tracking: */
897 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
898 spinlock_t alloc_lock
;
900 /* Protection of the PI data structures: */
901 raw_spinlock_t pi_lock
;
903 struct wake_q_node wake_q
;
905 #ifdef CONFIG_RT_MUTEXES
906 /* PI waiters blocked on a rt_mutex held by this task: */
907 struct rb_root_cached pi_waiters
;
908 /* Updated under owner's pi_lock and rq lock */
909 struct task_struct
*pi_top_task
;
910 /* Deadlock detection and priority inheritance handling: */
911 struct rt_mutex_waiter
*pi_blocked_on
;
914 #ifdef CONFIG_DEBUG_MUTEXES
915 /* Mutex deadlock detection: */
916 struct mutex_waiter
*blocked_on
;
919 #ifdef CONFIG_TRACE_IRQFLAGS
920 unsigned int irq_events
;
921 unsigned long hardirq_enable_ip
;
922 unsigned long hardirq_disable_ip
;
923 unsigned int hardirq_enable_event
;
924 unsigned int hardirq_disable_event
;
925 int hardirqs_enabled
;
927 unsigned long softirq_disable_ip
;
928 unsigned long softirq_enable_ip
;
929 unsigned int softirq_disable_event
;
930 unsigned int softirq_enable_event
;
931 int softirqs_enabled
;
935 #ifdef CONFIG_LOCKDEP
936 # define MAX_LOCK_DEPTH 48UL
939 unsigned int lockdep_recursion
;
940 struct held_lock held_locks
[MAX_LOCK_DEPTH
];
944 unsigned int in_ubsan
;
947 /* Journalling filesystem info: */
950 /* Stacked block device info: */
951 struct bio_list
*bio_list
;
954 /* Stack plugging: */
955 struct blk_plug
*plug
;
959 struct reclaim_state
*reclaim_state
;
961 struct backing_dev_info
*backing_dev_info
;
963 struct io_context
*io_context
;
966 unsigned long ptrace_message
;
967 kernel_siginfo_t
*last_siginfo
;
969 struct task_io_accounting ioac
;
971 /* Pressure stall state */
972 unsigned int psi_flags
;
974 #ifdef CONFIG_TASK_XACCT
975 /* Accumulated RSS usage: */
977 /* Accumulated virtual memory usage: */
979 /* stime + utime since last update: */
982 #ifdef CONFIG_CPUSETS
983 /* Protected by ->alloc_lock: */
984 nodemask_t mems_allowed
;
985 /* Seqence number to catch updates: */
986 seqcount_t mems_allowed_seq
;
987 int cpuset_mem_spread_rotor
;
988 int cpuset_slab_spread_rotor
;
990 #ifdef CONFIG_CGROUPS
991 /* Control Group info protected by css_set_lock: */
992 struct css_set __rcu
*cgroups
;
993 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
994 struct list_head cg_list
;
996 #ifdef CONFIG_INTEL_RDT
1001 struct robust_list_head __user
*robust_list
;
1002 #ifdef CONFIG_COMPAT
1003 struct compat_robust_list_head __user
*compat_robust_list
;
1005 struct list_head pi_state_list
;
1006 struct futex_pi_state
*pi_state_cache
;
1008 #ifdef CONFIG_PERF_EVENTS
1009 struct perf_event_context
*perf_event_ctxp
[perf_nr_task_contexts
];
1010 struct mutex perf_event_mutex
;
1011 struct list_head perf_event_list
;
1013 #ifdef CONFIG_DEBUG_PREEMPT
1014 unsigned long preempt_disable_ip
;
1017 /* Protected by alloc_lock: */
1018 struct mempolicy
*mempolicy
;
1020 short pref_node_fork
;
1022 #ifdef CONFIG_NUMA_BALANCING
1024 unsigned int numa_scan_period
;
1025 unsigned int numa_scan_period_max
;
1026 int numa_preferred_nid
;
1027 unsigned long numa_migrate_retry
;
1028 /* Migration stamp: */
1030 u64 last_task_numa_placement
;
1031 u64 last_sum_exec_runtime
;
1032 struct callback_head numa_work
;
1034 struct numa_group
*numa_group
;
1037 * numa_faults is an array split into four regions:
1038 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1039 * in this precise order.
1041 * faults_memory: Exponential decaying average of faults on a per-node
1042 * basis. Scheduling placement decisions are made based on these
1043 * counts. The values remain static for the duration of a PTE scan.
1044 * faults_cpu: Track the nodes the process was running on when a NUMA
1045 * hinting fault was incurred.
1046 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1047 * during the current scan window. When the scan completes, the counts
1048 * in faults_memory and faults_cpu decay and these values are copied.
1050 unsigned long *numa_faults
;
1051 unsigned long total_numa_faults
;
1054 * numa_faults_locality tracks if faults recorded during the last
1055 * scan window were remote/local or failed to migrate. The task scan
1056 * period is adapted based on the locality of the faults with different
1057 * weights depending on whether they were shared or private faults
1059 unsigned long numa_faults_locality
[3];
1061 unsigned long numa_pages_migrated
;
1062 #endif /* CONFIG_NUMA_BALANCING */
1065 struct rseq __user
*rseq
;
1069 * RmW on rseq_event_mask must be performed atomically
1070 * with respect to preemption.
1072 unsigned long rseq_event_mask
;
1075 struct tlbflush_unmap_batch tlb_ubc
;
1077 struct rcu_head rcu
;
1079 /* Cache last used pipe for splice(): */
1080 struct pipe_inode_info
*splice_pipe
;
1082 struct page_frag task_frag
;
1084 #ifdef CONFIG_TASK_DELAY_ACCT
1085 struct task_delay_info
*delays
;
1088 #ifdef CONFIG_FAULT_INJECTION
1090 unsigned int fail_nth
;
1093 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1094 * balance_dirty_pages() for a dirty throttling pause:
1097 int nr_dirtied_pause
;
1098 /* Start of a write-and-pause period: */
1099 unsigned long dirty_paused_when
;
1101 #ifdef CONFIG_LATENCYTOP
1102 int latency_record_count
;
1103 struct latency_record latency_record
[LT_SAVECOUNT
];
1106 * Time slack values; these are used to round up poll() and
1107 * select() etc timeout values. These are in nanoseconds.
1110 u64 default_timer_slack_ns
;
1113 unsigned int kasan_depth
;
1116 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1117 /* Index of current stored address in ret_stack: */
1121 /* Stack of return addresses for return function tracing: */
1122 struct ftrace_ret_stack
*ret_stack
;
1124 /* Timestamp for last schedule: */
1125 unsigned long long ftrace_timestamp
;
1128 * Number of functions that haven't been traced
1129 * because of depth overrun:
1131 atomic_t trace_overrun
;
1133 /* Pause tracing: */
1134 atomic_t tracing_graph_pause
;
1137 #ifdef CONFIG_TRACING
1138 /* State flags for use by tracers: */
1139 unsigned long trace
;
1141 /* Bitmask and counter of trace recursion: */
1142 unsigned long trace_recursion
;
1143 #endif /* CONFIG_TRACING */
1146 /* Coverage collection mode enabled for this task (0 if disabled): */
1147 unsigned int kcov_mode
;
1149 /* Size of the kcov_area: */
1150 unsigned int kcov_size
;
1152 /* Buffer for coverage collection: */
1155 /* KCOV descriptor wired with this task or NULL: */
1160 struct mem_cgroup
*memcg_in_oom
;
1161 gfp_t memcg_oom_gfp_mask
;
1162 int memcg_oom_order
;
1164 /* Number of pages to reclaim on returning to userland: */
1165 unsigned int memcg_nr_pages_over_high
;
1167 /* Used by memcontrol for targeted memcg charge: */
1168 struct mem_cgroup
*active_memcg
;
1171 #ifdef CONFIG_BLK_CGROUP
1172 struct request_queue
*throttle_queue
;
1175 #ifdef CONFIG_UPROBES
1176 struct uprobe_task
*utask
;
1178 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1179 unsigned int sequential_io
;
1180 unsigned int sequential_io_avg
;
1182 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1183 unsigned long task_state_change
;
1185 int pagefault_disabled
;
1187 struct task_struct
*oom_reaper_list
;
1189 #ifdef CONFIG_VMAP_STACK
1190 struct vm_struct
*stack_vm_area
;
1192 #ifdef CONFIG_THREAD_INFO_IN_TASK
1193 /* A live task holds one reference: */
1194 atomic_t stack_refcount
;
1196 #ifdef CONFIG_LIVEPATCH
1199 #ifdef CONFIG_SECURITY
1200 /* Used by LSM modules for access restriction: */
1204 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1205 unsigned long lowest_stack
;
1206 unsigned long prev_lowest_stack
;
1210 * New fields for task_struct should be added above here, so that
1211 * they are included in the randomized portion of task_struct.
1213 randomized_struct_fields_end
1215 /* CPU-specific state of this task: */
1216 struct thread_struct thread
;
1219 * WARNING: on x86, 'thread_struct' contains a variable-sized
1220 * structure. It *MUST* be at the end of 'task_struct'.
1222 * Do not put anything below here!
1226 static inline struct pid
*task_pid(struct task_struct
*task
)
1228 return task
->thread_pid
;
1232 * the helpers to get the task's different pids as they are seen
1233 * from various namespaces
1235 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1236 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1238 * task_xid_nr_ns() : id seen from the ns specified;
1240 * see also pid_nr() etc in include/linux/pid.h
1242 pid_t
__task_pid_nr_ns(struct task_struct
*task
, enum pid_type type
, struct pid_namespace
*ns
);
1244 static inline pid_t
task_pid_nr(struct task_struct
*tsk
)
1249 static inline pid_t
task_pid_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1251 return __task_pid_nr_ns(tsk
, PIDTYPE_PID
, ns
);
1254 static inline pid_t
task_pid_vnr(struct task_struct
*tsk
)
1256 return __task_pid_nr_ns(tsk
, PIDTYPE_PID
, NULL
);
1260 static inline pid_t
task_tgid_nr(struct task_struct
*tsk
)
1266 * pid_alive - check that a task structure is not stale
1267 * @p: Task structure to be checked.
1269 * Test if a process is not yet dead (at most zombie state)
1270 * If pid_alive fails, then pointers within the task structure
1271 * can be stale and must not be dereferenced.
1273 * Return: 1 if the process is alive. 0 otherwise.
1275 static inline int pid_alive(const struct task_struct
*p
)
1277 return p
->thread_pid
!= NULL
;
1280 static inline pid_t
task_pgrp_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1282 return __task_pid_nr_ns(tsk
, PIDTYPE_PGID
, ns
);
1285 static inline pid_t
task_pgrp_vnr(struct task_struct
*tsk
)
1287 return __task_pid_nr_ns(tsk
, PIDTYPE_PGID
, NULL
);
1291 static inline pid_t
task_session_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1293 return __task_pid_nr_ns(tsk
, PIDTYPE_SID
, ns
);
1296 static inline pid_t
task_session_vnr(struct task_struct
*tsk
)
1298 return __task_pid_nr_ns(tsk
, PIDTYPE_SID
, NULL
);
1301 static inline pid_t
task_tgid_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1303 return __task_pid_nr_ns(tsk
, PIDTYPE_TGID
, ns
);
1306 static inline pid_t
task_tgid_vnr(struct task_struct
*tsk
)
1308 return __task_pid_nr_ns(tsk
, PIDTYPE_TGID
, NULL
);
1311 static inline pid_t
task_ppid_nr_ns(const struct task_struct
*tsk
, struct pid_namespace
*ns
)
1317 pid
= task_tgid_nr_ns(rcu_dereference(tsk
->real_parent
), ns
);
1323 static inline pid_t
task_ppid_nr(const struct task_struct
*tsk
)
1325 return task_ppid_nr_ns(tsk
, &init_pid_ns
);
1328 /* Obsolete, do not use: */
1329 static inline pid_t
task_pgrp_nr(struct task_struct
*tsk
)
1331 return task_pgrp_nr_ns(tsk
, &init_pid_ns
);
1334 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1335 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1337 static inline unsigned int task_state_index(struct task_struct
*tsk
)
1339 unsigned int tsk_state
= READ_ONCE(tsk
->state
);
1340 unsigned int state
= (tsk_state
| tsk
->exit_state
) & TASK_REPORT
;
1342 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX
);
1344 if (tsk_state
== TASK_IDLE
)
1345 state
= TASK_REPORT_IDLE
;
1350 static inline char task_index_to_char(unsigned int state
)
1352 static const char state_char
[] = "RSDTtXZPI";
1354 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX
) != sizeof(state_char
) - 1);
1356 return state_char
[state
];
1359 static inline char task_state_to_char(struct task_struct
*tsk
)
1361 return task_index_to_char(task_state_index(tsk
));
1365 * is_global_init - check if a task structure is init. Since init
1366 * is free to have sub-threads we need to check tgid.
1367 * @tsk: Task structure to be checked.
1369 * Check if a task structure is the first user space task the kernel created.
1371 * Return: 1 if the task structure is init. 0 otherwise.
1373 static inline int is_global_init(struct task_struct
*tsk
)
1375 return task_tgid_nr(tsk
) == 1;
1378 extern struct pid
*cad_pid
;
1383 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1384 #define PF_EXITING 0x00000004 /* Getting shut down */
1385 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1386 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1387 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1388 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1389 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1390 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1391 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1392 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1393 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1394 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1395 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1396 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1397 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1398 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1399 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1400 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1401 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1402 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1403 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1404 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1405 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1406 #define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */
1407 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1408 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1409 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1410 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1411 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1414 * Only the _current_ task can read/write to tsk->flags, but other
1415 * tasks can access tsk->flags in readonly mode for example
1416 * with tsk_used_math (like during threaded core dumping).
1417 * There is however an exception to this rule during ptrace
1418 * or during fork: the ptracer task is allowed to write to the
1419 * child->flags of its traced child (same goes for fork, the parent
1420 * can write to the child->flags), because we're guaranteed the
1421 * child is not running and in turn not changing child->flags
1422 * at the same time the parent does it.
1424 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1425 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1426 #define clear_used_math() clear_stopped_child_used_math(current)
1427 #define set_used_math() set_stopped_child_used_math(current)
1429 #define conditional_stopped_child_used_math(condition, child) \
1430 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1432 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1434 #define copy_to_stopped_child_used_math(child) \
1435 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1437 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1438 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1439 #define used_math() tsk_used_math(current)
1441 static inline bool is_percpu_thread(void)
1444 return (current
->flags
& PF_NO_SETAFFINITY
) &&
1445 (current
->nr_cpus_allowed
== 1);
1451 /* Per-process atomic flags. */
1452 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1453 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1454 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1455 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1456 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1457 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1458 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1460 #define TASK_PFA_TEST(name, func) \
1461 static inline bool task_##func(struct task_struct *p) \
1462 { return test_bit(PFA_##name, &p->atomic_flags); }
1464 #define TASK_PFA_SET(name, func) \
1465 static inline void task_set_##func(struct task_struct *p) \
1466 { set_bit(PFA_##name, &p->atomic_flags); }
1468 #define TASK_PFA_CLEAR(name, func) \
1469 static inline void task_clear_##func(struct task_struct *p) \
1470 { clear_bit(PFA_##name, &p->atomic_flags); }
1472 TASK_PFA_TEST(NO_NEW_PRIVS
, no_new_privs
)
1473 TASK_PFA_SET(NO_NEW_PRIVS
, no_new_privs
)
1475 TASK_PFA_TEST(SPREAD_PAGE
, spread_page
)
1476 TASK_PFA_SET(SPREAD_PAGE
, spread_page
)
1477 TASK_PFA_CLEAR(SPREAD_PAGE
, spread_page
)
1479 TASK_PFA_TEST(SPREAD_SLAB
, spread_slab
)
1480 TASK_PFA_SET(SPREAD_SLAB
, spread_slab
)
1481 TASK_PFA_CLEAR(SPREAD_SLAB
, spread_slab
)
1483 TASK_PFA_TEST(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1484 TASK_PFA_SET(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1485 TASK_PFA_CLEAR(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1487 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1488 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1490 TASK_PFA_TEST(SPEC_IB_DISABLE
, spec_ib_disable
)
1491 TASK_PFA_SET(SPEC_IB_DISABLE
, spec_ib_disable
)
1492 TASK_PFA_CLEAR(SPEC_IB_DISABLE
, spec_ib_disable
)
1494 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE
, spec_ib_force_disable
)
1495 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE
, spec_ib_force_disable
)
1498 current_restore_flags(unsigned long orig_flags
, unsigned long flags
)
1500 current
->flags
&= ~flags
;
1501 current
->flags
|= orig_flags
& flags
;
1504 extern int cpuset_cpumask_can_shrink(const struct cpumask
*cur
, const struct cpumask
*trial
);
1505 extern int task_can_attach(struct task_struct
*p
, const struct cpumask
*cs_cpus_allowed
);
1507 extern void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
);
1508 extern int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
);
1510 static inline void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
)
1513 static inline int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
)
1515 if (!cpumask_test_cpu(0, new_mask
))
1521 #ifndef cpu_relax_yield
1522 #define cpu_relax_yield() cpu_relax()
1525 extern int yield_to(struct task_struct
*p
, bool preempt
);
1526 extern void set_user_nice(struct task_struct
*p
, long nice
);
1527 extern int task_prio(const struct task_struct
*p
);
1530 * task_nice - return the nice value of a given task.
1531 * @p: the task in question.
1533 * Return: The nice value [ -20 ... 0 ... 19 ].
1535 static inline int task_nice(const struct task_struct
*p
)
1537 return PRIO_TO_NICE((p
)->static_prio
);
1540 extern int can_nice(const struct task_struct
*p
, const int nice
);
1541 extern int task_curr(const struct task_struct
*p
);
1542 extern int idle_cpu(int cpu
);
1543 extern int available_idle_cpu(int cpu
);
1544 extern int sched_setscheduler(struct task_struct
*, int, const struct sched_param
*);
1545 extern int sched_setscheduler_nocheck(struct task_struct
*, int, const struct sched_param
*);
1546 extern int sched_setattr(struct task_struct
*, const struct sched_attr
*);
1547 extern int sched_setattr_nocheck(struct task_struct
*, const struct sched_attr
*);
1548 extern struct task_struct
*idle_task(int cpu
);
1551 * is_idle_task - is the specified task an idle task?
1552 * @p: the task in question.
1554 * Return: 1 if @p is an idle task. 0 otherwise.
1556 static inline bool is_idle_task(const struct task_struct
*p
)
1558 return !!(p
->flags
& PF_IDLE
);
1561 extern struct task_struct
*curr_task(int cpu
);
1562 extern void ia64_set_curr_task(int cpu
, struct task_struct
*p
);
1566 union thread_union
{
1567 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1568 struct task_struct task
;
1570 #ifndef CONFIG_THREAD_INFO_IN_TASK
1571 struct thread_info thread_info
;
1573 unsigned long stack
[THREAD_SIZE
/sizeof(long)];
1576 #ifndef CONFIG_THREAD_INFO_IN_TASK
1577 extern struct thread_info init_thread_info
;
1580 extern unsigned long init_stack
[THREAD_SIZE
/ sizeof(unsigned long)];
1582 #ifdef CONFIG_THREAD_INFO_IN_TASK
1583 static inline struct thread_info
*task_thread_info(struct task_struct
*task
)
1585 return &task
->thread_info
;
1587 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1588 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1592 * find a task by one of its numerical ids
1594 * find_task_by_pid_ns():
1595 * finds a task by its pid in the specified namespace
1596 * find_task_by_vpid():
1597 * finds a task by its virtual pid
1599 * see also find_vpid() etc in include/linux/pid.h
1602 extern struct task_struct
*find_task_by_vpid(pid_t nr
);
1603 extern struct task_struct
*find_task_by_pid_ns(pid_t nr
, struct pid_namespace
*ns
);
1606 * find a task by its virtual pid and get the task struct
1608 extern struct task_struct
*find_get_task_by_vpid(pid_t nr
);
1610 extern int wake_up_state(struct task_struct
*tsk
, unsigned int state
);
1611 extern int wake_up_process(struct task_struct
*tsk
);
1612 extern void wake_up_new_task(struct task_struct
*tsk
);
1615 extern void kick_process(struct task_struct
*tsk
);
1617 static inline void kick_process(struct task_struct
*tsk
) { }
1620 extern void __set_task_comm(struct task_struct
*tsk
, const char *from
, bool exec
);
1622 static inline void set_task_comm(struct task_struct
*tsk
, const char *from
)
1624 __set_task_comm(tsk
, from
, false);
1627 extern char *__get_task_comm(char *to
, size_t len
, struct task_struct
*tsk
);
1628 #define get_task_comm(buf, tsk) ({ \
1629 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1630 __get_task_comm(buf, sizeof(buf), tsk); \
1634 void scheduler_ipi(void);
1635 extern unsigned long wait_task_inactive(struct task_struct
*, long match_state
);
1637 static inline void scheduler_ipi(void) { }
1638 static inline unsigned long wait_task_inactive(struct task_struct
*p
, long match_state
)
1645 * Set thread flags in other task's structures.
1646 * See asm/thread_info.h for TIF_xxxx flags available:
1648 static inline void set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1650 set_ti_thread_flag(task_thread_info(tsk
), flag
);
1653 static inline void clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1655 clear_ti_thread_flag(task_thread_info(tsk
), flag
);
1658 static inline void update_tsk_thread_flag(struct task_struct
*tsk
, int flag
,
1661 update_ti_thread_flag(task_thread_info(tsk
), flag
, value
);
1664 static inline int test_and_set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1666 return test_and_set_ti_thread_flag(task_thread_info(tsk
), flag
);
1669 static inline int test_and_clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1671 return test_and_clear_ti_thread_flag(task_thread_info(tsk
), flag
);
1674 static inline int test_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1676 return test_ti_thread_flag(task_thread_info(tsk
), flag
);
1679 static inline void set_tsk_need_resched(struct task_struct
*tsk
)
1681 set_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
);
1684 static inline void clear_tsk_need_resched(struct task_struct
*tsk
)
1686 clear_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
);
1689 static inline int test_tsk_need_resched(struct task_struct
*tsk
)
1691 return unlikely(test_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
));
1695 * cond_resched() and cond_resched_lock(): latency reduction via
1696 * explicit rescheduling in places that are safe. The return
1697 * value indicates whether a reschedule was done in fact.
1698 * cond_resched_lock() will drop the spinlock before scheduling,
1700 #ifndef CONFIG_PREEMPT
1701 extern int _cond_resched(void);
1703 static inline int _cond_resched(void) { return 0; }
1706 #define cond_resched() ({ \
1707 ___might_sleep(__FILE__, __LINE__, 0); \
1711 extern int __cond_resched_lock(spinlock_t
*lock
);
1713 #define cond_resched_lock(lock) ({ \
1714 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1715 __cond_resched_lock(lock); \
1718 static inline void cond_resched_rcu(void)
1720 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1728 * Does a critical section need to be broken due to another
1729 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1730 * but a general need for low latency)
1732 static inline int spin_needbreak(spinlock_t
*lock
)
1734 #ifdef CONFIG_PREEMPT
1735 return spin_is_contended(lock
);
1741 static __always_inline
bool need_resched(void)
1743 return unlikely(tif_need_resched());
1747 * Wrappers for p->thread_info->cpu access. No-op on UP.
1751 static inline unsigned int task_cpu(const struct task_struct
*p
)
1753 #ifdef CONFIG_THREAD_INFO_IN_TASK
1756 return task_thread_info(p
)->cpu
;
1760 extern void set_task_cpu(struct task_struct
*p
, unsigned int cpu
);
1764 static inline unsigned int task_cpu(const struct task_struct
*p
)
1769 static inline void set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
1773 #endif /* CONFIG_SMP */
1776 * In order to reduce various lock holder preemption latencies provide an
1777 * interface to see if a vCPU is currently running or not.
1779 * This allows us to terminate optimistic spin loops and block, analogous to
1780 * the native optimistic spin heuristic of testing if the lock owner task is
1783 #ifndef vcpu_is_preempted
1784 # define vcpu_is_preempted(cpu) false
1787 extern long sched_setaffinity(pid_t pid
, const struct cpumask
*new_mask
);
1788 extern long sched_getaffinity(pid_t pid
, struct cpumask
*mask
);
1790 #ifndef TASK_SIZE_OF
1791 #define TASK_SIZE_OF(tsk) TASK_SIZE
1797 * Map the event mask on the user-space ABI enum rseq_cs_flags
1798 * for direct mask checks.
1800 enum rseq_event_mask_bits
{
1801 RSEQ_EVENT_PREEMPT_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT
,
1802 RSEQ_EVENT_SIGNAL_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT
,
1803 RSEQ_EVENT_MIGRATE_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT
,
1806 enum rseq_event_mask
{
1807 RSEQ_EVENT_PREEMPT
= (1U << RSEQ_EVENT_PREEMPT_BIT
),
1808 RSEQ_EVENT_SIGNAL
= (1U << RSEQ_EVENT_SIGNAL_BIT
),
1809 RSEQ_EVENT_MIGRATE
= (1U << RSEQ_EVENT_MIGRATE_BIT
),
1812 static inline void rseq_set_notify_resume(struct task_struct
*t
)
1815 set_tsk_thread_flag(t
, TIF_NOTIFY_RESUME
);
1818 void __rseq_handle_notify_resume(struct ksignal
*sig
, struct pt_regs
*regs
);
1820 static inline void rseq_handle_notify_resume(struct ksignal
*ksig
,
1821 struct pt_regs
*regs
)
1824 __rseq_handle_notify_resume(ksig
, regs
);
1827 static inline void rseq_signal_deliver(struct ksignal
*ksig
,
1828 struct pt_regs
*regs
)
1831 __set_bit(RSEQ_EVENT_SIGNAL_BIT
, ¤t
->rseq_event_mask
);
1833 rseq_handle_notify_resume(ksig
, regs
);
1836 /* rseq_preempt() requires preemption to be disabled. */
1837 static inline void rseq_preempt(struct task_struct
*t
)
1839 __set_bit(RSEQ_EVENT_PREEMPT_BIT
, &t
->rseq_event_mask
);
1840 rseq_set_notify_resume(t
);
1843 /* rseq_migrate() requires preemption to be disabled. */
1844 static inline void rseq_migrate(struct task_struct
*t
)
1846 __set_bit(RSEQ_EVENT_MIGRATE_BIT
, &t
->rseq_event_mask
);
1847 rseq_set_notify_resume(t
);
1851 * If parent process has a registered restartable sequences area, the
1852 * child inherits. Only applies when forking a process, not a thread.
1854 static inline void rseq_fork(struct task_struct
*t
, unsigned long clone_flags
)
1856 if (clone_flags
& CLONE_THREAD
) {
1860 t
->rseq_event_mask
= 0;
1862 t
->rseq
= current
->rseq
;
1863 t
->rseq_len
= current
->rseq_len
;
1864 t
->rseq_sig
= current
->rseq_sig
;
1865 t
->rseq_event_mask
= current
->rseq_event_mask
;
1869 static inline void rseq_execve(struct task_struct
*t
)
1874 t
->rseq_event_mask
= 0;
1879 static inline void rseq_set_notify_resume(struct task_struct
*t
)
1882 static inline void rseq_handle_notify_resume(struct ksignal
*ksig
,
1883 struct pt_regs
*regs
)
1886 static inline void rseq_signal_deliver(struct ksignal
*ksig
,
1887 struct pt_regs
*regs
)
1890 static inline void rseq_preempt(struct task_struct
*t
)
1893 static inline void rseq_migrate(struct task_struct
*t
)
1896 static inline void rseq_fork(struct task_struct
*t
, unsigned long clone_flags
)
1899 static inline void rseq_execve(struct task_struct
*t
)
1905 #ifdef CONFIG_DEBUG_RSEQ
1907 void rseq_syscall(struct pt_regs
*regs
);
1911 static inline void rseq_syscall(struct pt_regs
*regs
)