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/mm_types_task.h>
29 #include <linux/task_io_accounting.h>
30 #include <linux/rseq.h>
32 /* task_struct member predeclarations (sorted alphabetically): */
34 struct backing_dev_info
;
39 struct futex_pi_state
;
44 struct perf_event_context
;
46 struct pipe_inode_info
;
49 struct robust_list_head
;
53 struct sighand_struct
;
55 struct task_delay_info
;
59 * Task state bitmask. NOTE! These bits are also
60 * encoded in fs/proc/array.c: get_task_state().
62 * We have two separate sets of flags: task->state
63 * is about runnability, while task->exit_state are
64 * about the task exiting. Confusing, but this way
65 * modifying one set can't modify the other one by
69 /* Used in tsk->state: */
70 #define TASK_RUNNING 0x0000
71 #define TASK_INTERRUPTIBLE 0x0001
72 #define TASK_UNINTERRUPTIBLE 0x0002
73 #define __TASK_STOPPED 0x0004
74 #define __TASK_TRACED 0x0008
75 /* Used in tsk->exit_state: */
76 #define EXIT_DEAD 0x0010
77 #define EXIT_ZOMBIE 0x0020
78 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
79 /* Used in tsk->state again: */
80 #define TASK_PARKED 0x0040
81 #define TASK_DEAD 0x0080
82 #define TASK_WAKEKILL 0x0100
83 #define TASK_WAKING 0x0200
84 #define TASK_NOLOAD 0x0400
85 #define TASK_NEW 0x0800
86 #define TASK_STATE_MAX 0x1000
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)
93 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
95 /* Convenience macros for the sake of wake_up(): */
96 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
98 /* get_task_state(): */
99 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
100 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
101 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
104 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
106 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
108 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
110 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
111 (task->flags & PF_FROZEN) == 0 && \
112 (task->state & TASK_NOLOAD) == 0)
114 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
117 * Special states are those that do not use the normal wait-loop pattern. See
118 * the comment with set_special_state().
120 #define is_special_task_state(state) \
121 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
123 #define __set_current_state(state_value) \
125 WARN_ON_ONCE(is_special_task_state(state_value));\
126 current->task_state_change = _THIS_IP_; \
127 current->state = (state_value); \
130 #define set_current_state(state_value) \
132 WARN_ON_ONCE(is_special_task_state(state_value));\
133 current->task_state_change = _THIS_IP_; \
134 smp_store_mb(current->state, (state_value)); \
137 #define set_special_state(state_value) \
139 unsigned long flags; /* may shadow */ \
140 WARN_ON_ONCE(!is_special_task_state(state_value)); \
141 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
142 current->task_state_change = _THIS_IP_; \
143 current->state = (state_value); \
144 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
148 * set_current_state() includes a barrier so that the write of current->state
149 * is correctly serialised wrt the caller's subsequent test of whether to
153 * set_current_state(TASK_UNINTERRUPTIBLE);
159 * __set_current_state(TASK_RUNNING);
161 * If the caller does not need such serialisation (because, for instance, the
162 * condition test and condition change and wakeup are under the same lock) then
163 * use __set_current_state().
165 * The above is typically ordered against the wakeup, which does:
167 * need_sleep = false;
168 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
170 * Where wake_up_state() (and all other wakeup primitives) imply enough
171 * barriers to order the store of the variable against wakeup.
173 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
174 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
175 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
177 * However, with slightly different timing the wakeup TASK_RUNNING store can
178 * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
179 * a problem either because that will result in one extra go around the loop
180 * and our @cond test will save the day.
182 * Also see the comments of try_to_wake_up().
184 #define __set_current_state(state_value) \
185 current->state = (state_value)
187 #define set_current_state(state_value) \
188 smp_store_mb(current->state, (state_value))
191 * set_special_state() should be used for those states when the blocking task
192 * can not use the regular condition based wait-loop. In that case we must
193 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
194 * will not collide with our state change.
196 #define set_special_state(state_value) \
198 unsigned long flags; /* may shadow */ \
199 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
200 current->state = (state_value); \
201 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
206 /* Task command name length: */
207 #define TASK_COMM_LEN 16
209 extern void scheduler_tick(void);
211 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
213 extern long schedule_timeout(long timeout
);
214 extern long schedule_timeout_interruptible(long timeout
);
215 extern long schedule_timeout_killable(long timeout
);
216 extern long schedule_timeout_uninterruptible(long timeout
);
217 extern long schedule_timeout_idle(long timeout
);
218 asmlinkage
void schedule(void);
219 extern void schedule_preempt_disabled(void);
221 extern int __must_check
io_schedule_prepare(void);
222 extern void io_schedule_finish(int token
);
223 extern long io_schedule_timeout(long timeout
);
224 extern void io_schedule(void);
227 * struct prev_cputime - snapshot of system and user cputime
228 * @utime: time spent in user mode
229 * @stime: time spent in system mode
230 * @lock: protects the above two fields
232 * Stores previous user/system time values such that we can guarantee
235 struct prev_cputime
{
236 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
244 * struct task_cputime - collected CPU time counts
245 * @utime: time spent in user mode, in nanoseconds
246 * @stime: time spent in kernel mode, in nanoseconds
247 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
249 * This structure groups together three kinds of CPU time that are tracked for
250 * threads and thread groups. Most things considering CPU time want to group
251 * these counts together and treat all three of them in parallel.
253 struct task_cputime
{
256 unsigned long long sum_exec_runtime
;
259 /* Alternate field names when used on cache expirations: */
260 #define virt_exp utime
261 #define prof_exp stime
262 #define sched_exp sum_exec_runtime
265 /* Task is sleeping or running in a CPU with VTIME inactive: */
267 /* Task runs in userspace in a CPU with VTIME active: */
269 /* Task runs in kernelspace in a CPU with VTIME active: */
275 unsigned long long starttime
;
276 enum vtime_state state
;
283 #ifdef CONFIG_SCHED_INFO
284 /* Cumulative counters: */
286 /* # of times we have run on this CPU: */
287 unsigned long pcount
;
289 /* Time spent waiting on a runqueue: */
290 unsigned long long run_delay
;
294 /* When did we last run on a CPU? */
295 unsigned long long last_arrival
;
297 /* When were we last queued to run? */
298 unsigned long long last_queued
;
300 #endif /* CONFIG_SCHED_INFO */
304 * Integer metrics need fixed point arithmetic, e.g., sched/fair
305 * has a few: load, load_avg, util_avg, freq, and capacity.
307 * We define a basic fixed point arithmetic range, and then formalize
308 * all these metrics based on that basic range.
310 # define SCHED_FIXEDPOINT_SHIFT 10
311 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
314 unsigned long weight
;
319 * struct util_est - Estimation utilization of FAIR tasks
320 * @enqueued: instantaneous estimated utilization of a task/cpu
321 * @ewma: the Exponential Weighted Moving Average (EWMA)
322 * utilization of a task
324 * Support data structure to track an Exponential Weighted Moving Average
325 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
326 * average each time a task completes an activation. Sample's weight is chosen
327 * so that the EWMA will be relatively insensitive to transient changes to the
330 * The enqueued attribute has a slightly different meaning for tasks and cpus:
331 * - task: the task's util_avg at last task dequeue time
332 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
333 * Thus, the util_est.enqueued of a task represents the contribution on the
334 * estimated utilization of the CPU where that task is currently enqueued.
336 * Only for tasks we track a moving average of the past instantaneous
337 * estimated utilization. This allows to absorb sporadic drops in utilization
338 * of an otherwise almost periodic task.
341 unsigned int enqueued
;
343 #define UTIL_EST_WEIGHT_SHIFT 2
344 } __attribute__((__aligned__(sizeof(u64
))));
347 * The load_avg/util_avg accumulates an infinite geometric series
348 * (see __update_load_avg() in kernel/sched/fair.c).
350 * [load_avg definition]
352 * load_avg = runnable% * scale_load_down(load)
354 * where runnable% is the time ratio that a sched_entity is runnable.
355 * For cfs_rq, it is the aggregated load_avg of all runnable and
356 * blocked sched_entities.
358 * load_avg may also take frequency scaling into account:
360 * load_avg = runnable% * scale_load_down(load) * freq%
362 * where freq% is the CPU frequency normalized to the highest frequency.
364 * [util_avg definition]
366 * util_avg = running% * SCHED_CAPACITY_SCALE
368 * where running% is the time ratio that a sched_entity is running on
369 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
370 * and blocked sched_entities.
372 * util_avg may also factor frequency scaling and CPU capacity scaling:
374 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
376 * where freq% is the same as above, and capacity% is the CPU capacity
377 * normalized to the greatest capacity (due to uarch differences, etc).
379 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
380 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
381 * we therefore scale them to as large a range as necessary. This is for
382 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
386 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
387 * with the highest load (=88761), always runnable on a single cfs_rq,
388 * and should not overflow as the number already hits PID_MAX_LIMIT.
390 * For all other cases (including 32-bit kernels), struct load_weight's
391 * weight will overflow first before we do, because:
393 * Max(load_avg) <= Max(load.weight)
395 * Then it is the load_weight's responsibility to consider overflow
399 u64 last_update_time
;
401 u64 runnable_load_sum
;
404 unsigned long load_avg
;
405 unsigned long runnable_load_avg
;
406 unsigned long util_avg
;
407 struct util_est util_est
;
408 } ____cacheline_aligned
;
410 struct sched_statistics
{
411 #ifdef CONFIG_SCHEDSTATS
421 s64 sum_sleep_runtime
;
428 u64 nr_migrations_cold
;
429 u64 nr_failed_migrations_affine
;
430 u64 nr_failed_migrations_running
;
431 u64 nr_failed_migrations_hot
;
432 u64 nr_forced_migrations
;
436 u64 nr_wakeups_migrate
;
437 u64 nr_wakeups_local
;
438 u64 nr_wakeups_remote
;
439 u64 nr_wakeups_affine
;
440 u64 nr_wakeups_affine_attempts
;
441 u64 nr_wakeups_passive
;
446 struct sched_entity
{
447 /* For load-balancing: */
448 struct load_weight load
;
449 unsigned long runnable_weight
;
450 struct rb_node run_node
;
451 struct list_head group_node
;
455 u64 sum_exec_runtime
;
457 u64 prev_sum_exec_runtime
;
461 struct sched_statistics statistics
;
463 #ifdef CONFIG_FAIR_GROUP_SCHED
465 struct sched_entity
*parent
;
466 /* rq on which this entity is (to be) queued: */
467 struct cfs_rq
*cfs_rq
;
468 /* rq "owned" by this entity/group: */
474 * Per entity load average tracking.
476 * Put into separate cache line so it does not
477 * collide with read-mostly values above.
479 struct sched_avg avg
;
483 struct sched_rt_entity
{
484 struct list_head run_list
;
485 unsigned long timeout
;
486 unsigned long watchdog_stamp
;
487 unsigned int time_slice
;
488 unsigned short on_rq
;
489 unsigned short on_list
;
491 struct sched_rt_entity
*back
;
492 #ifdef CONFIG_RT_GROUP_SCHED
493 struct sched_rt_entity
*parent
;
494 /* rq on which this entity is (to be) queued: */
496 /* rq "owned" by this entity/group: */
499 } __randomize_layout
;
501 struct sched_dl_entity
{
502 struct rb_node rb_node
;
505 * Original scheduling parameters. Copied here from sched_attr
506 * during sched_setattr(), they will remain the same until
507 * the next sched_setattr().
509 u64 dl_runtime
; /* Maximum runtime for each instance */
510 u64 dl_deadline
; /* Relative deadline of each instance */
511 u64 dl_period
; /* Separation of two instances (period) */
512 u64 dl_bw
; /* dl_runtime / dl_period */
513 u64 dl_density
; /* dl_runtime / dl_deadline */
516 * Actual scheduling parameters. Initialized with the values above,
517 * they are continously updated during task execution. Note that
518 * the remaining runtime could be < 0 in case we are in overrun.
520 s64 runtime
; /* Remaining runtime for this instance */
521 u64 deadline
; /* Absolute deadline for this instance */
522 unsigned int flags
; /* Specifying the scheduler behaviour */
527 * @dl_throttled tells if we exhausted the runtime. If so, the
528 * task has to wait for a replenishment to be performed at the
529 * next firing of dl_timer.
531 * @dl_boosted tells if we are boosted due to DI. If so we are
532 * outside bandwidth enforcement mechanism (but only until we
533 * exit the critical section);
535 * @dl_yielded tells if task gave up the CPU before consuming
536 * all its available runtime during the last job.
538 * @dl_non_contending tells if the task is inactive while still
539 * contributing to the active utilization. In other words, it
540 * indicates if the inactive timer has been armed and its handler
541 * has not been executed yet. This flag is useful to avoid race
542 * conditions between the inactive timer handler and the wakeup
545 * @dl_overrun tells if the task asked to be informed about runtime
548 unsigned int dl_throttled
: 1;
549 unsigned int dl_boosted
: 1;
550 unsigned int dl_yielded
: 1;
551 unsigned int dl_non_contending
: 1;
552 unsigned int dl_overrun
: 1;
555 * Bandwidth enforcement timer. Each -deadline task has its
556 * own bandwidth to be enforced, thus we need one timer per task.
558 struct hrtimer dl_timer
;
561 * Inactive timer, responsible for decreasing the active utilization
562 * at the "0-lag time". When a -deadline task blocks, it contributes
563 * to GRUB's active utilization until the "0-lag time", hence a
564 * timer is needed to decrease the active utilization at the correct
567 struct hrtimer inactive_timer
;
576 /* Otherwise the compiler can store garbage here: */
579 u32 s
; /* Set of bits. */
582 enum perf_event_task_context
{
583 perf_invalid_context
= -1,
586 perf_nr_task_contexts
,
590 struct wake_q_node
*next
;
594 #ifdef CONFIG_THREAD_INFO_IN_TASK
596 * For reasons of header soup (see current_thread_info()), this
597 * must be the first element of task_struct.
599 struct thread_info thread_info
;
601 /* -1 unrunnable, 0 runnable, >0 stopped: */
605 * This begins the randomizable portion of task_struct. Only
606 * scheduling-critical items should be added above here.
608 randomized_struct_fields_start
612 /* Per task flags (PF_*), defined further below: */
617 struct llist_node wake_entry
;
619 #ifdef CONFIG_THREAD_INFO_IN_TASK
623 unsigned int wakee_flips
;
624 unsigned long wakee_flip_decay_ts
;
625 struct task_struct
*last_wakee
;
628 * recent_used_cpu is initially set as the last CPU used by a task
629 * that wakes affine another task. Waker/wakee relationships can
630 * push tasks around a CPU where each wakeup moves to the next one.
631 * Tracking a recently used CPU allows a quick search for a recently
632 * used CPU that may be idle.
642 unsigned int rt_priority
;
644 const struct sched_class
*sched_class
;
645 struct sched_entity se
;
646 struct sched_rt_entity rt
;
647 #ifdef CONFIG_CGROUP_SCHED
648 struct task_group
*sched_task_group
;
650 struct sched_dl_entity dl
;
652 #ifdef CONFIG_PREEMPT_NOTIFIERS
653 /* List of struct preempt_notifier: */
654 struct hlist_head preempt_notifiers
;
657 #ifdef CONFIG_BLK_DEV_IO_TRACE
658 unsigned int btrace_seq
;
663 cpumask_t cpus_allowed
;
665 #ifdef CONFIG_PREEMPT_RCU
666 int rcu_read_lock_nesting
;
667 union rcu_special rcu_read_unlock_special
;
668 struct list_head rcu_node_entry
;
669 struct rcu_node
*rcu_blocked_node
;
670 #endif /* #ifdef CONFIG_PREEMPT_RCU */
672 #ifdef CONFIG_TASKS_RCU
673 unsigned long rcu_tasks_nvcsw
;
674 u8 rcu_tasks_holdout
;
676 int rcu_tasks_idle_cpu
;
677 struct list_head rcu_tasks_holdout_list
;
678 #endif /* #ifdef CONFIG_TASKS_RCU */
680 struct sched_info sched_info
;
682 struct list_head tasks
;
684 struct plist_node pushable_tasks
;
685 struct rb_node pushable_dl_tasks
;
688 struct mm_struct
*mm
;
689 struct mm_struct
*active_mm
;
691 /* Per-thread vma caching: */
692 struct vmacache vmacache
;
694 #ifdef SPLIT_RSS_COUNTING
695 struct task_rss_stat rss_stat
;
700 /* The signal sent when the parent dies: */
702 /* JOBCTL_*, siglock protected: */
703 unsigned long jobctl
;
705 /* Used for emulating ABI behavior of previous Linux versions: */
706 unsigned int personality
;
708 /* Scheduler bits, serialized by scheduler locks: */
709 unsigned sched_reset_on_fork
:1;
710 unsigned sched_contributes_to_load
:1;
711 unsigned sched_migrated
:1;
712 unsigned sched_remote_wakeup
:1;
713 /* Force alignment to the next boundary: */
716 /* Unserialized, strictly 'current' */
718 /* Bit to tell LSMs we're in execve(): */
719 unsigned in_execve
:1;
720 unsigned in_iowait
:1;
721 #ifndef TIF_RESTORE_SIGMASK
722 unsigned restore_sigmask
:1;
725 unsigned memcg_may_oom
:1;
727 unsigned memcg_kmem_skip_account
:1;
730 #ifdef CONFIG_COMPAT_BRK
731 unsigned brk_randomized
:1;
733 #ifdef CONFIG_CGROUPS
734 /* disallow userland-initiated cgroup migration */
735 unsigned no_cgroup_migration
:1;
738 unsigned long atomic_flags
; /* Flags requiring atomic access. */
740 struct restart_block restart_block
;
745 #ifdef CONFIG_STACKPROTECTOR
746 /* Canary value for the -fstack-protector GCC feature: */
747 unsigned long stack_canary
;
750 * Pointers to the (original) parent process, youngest child, younger sibling,
751 * older sibling, respectively. (p->father can be replaced with
752 * p->real_parent->pid)
755 /* Real parent process: */
756 struct task_struct __rcu
*real_parent
;
758 /* Recipient of SIGCHLD, wait4() reports: */
759 struct task_struct __rcu
*parent
;
762 * Children/sibling form the list of natural children:
764 struct list_head children
;
765 struct list_head sibling
;
766 struct task_struct
*group_leader
;
769 * 'ptraced' is the list of tasks this task is using ptrace() on.
771 * This includes both natural children and PTRACE_ATTACH targets.
772 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
774 struct list_head ptraced
;
775 struct list_head ptrace_entry
;
777 /* PID/PID hash table linkage. */
778 struct pid_link pids
[PIDTYPE_MAX
];
779 struct list_head thread_group
;
780 struct list_head thread_node
;
782 struct completion
*vfork_done
;
784 /* CLONE_CHILD_SETTID: */
785 int __user
*set_child_tid
;
787 /* CLONE_CHILD_CLEARTID: */
788 int __user
*clear_child_tid
;
792 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
797 struct prev_cputime prev_cputime
;
798 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
802 #ifdef CONFIG_NO_HZ_FULL
803 atomic_t tick_dep_mask
;
805 /* Context switch counts: */
807 unsigned long nivcsw
;
809 /* Monotonic time in nsecs: */
812 /* Boot based time in nsecs: */
815 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
816 unsigned long min_flt
;
817 unsigned long maj_flt
;
819 #ifdef CONFIG_POSIX_TIMERS
820 struct task_cputime cputime_expires
;
821 struct list_head cpu_timers
[3];
824 /* Process credentials: */
826 /* Tracer's credentials at attach: */
827 const struct cred __rcu
*ptracer_cred
;
829 /* Objective and real subjective task credentials (COW): */
830 const struct cred __rcu
*real_cred
;
832 /* Effective (overridable) subjective task credentials (COW): */
833 const struct cred __rcu
*cred
;
836 * executable name, excluding path.
838 * - normally initialized setup_new_exec()
839 * - access it with [gs]et_task_comm()
840 * - lock it with task_lock()
842 char comm
[TASK_COMM_LEN
];
844 struct nameidata
*nameidata
;
846 #ifdef CONFIG_SYSVIPC
847 struct sysv_sem sysvsem
;
848 struct sysv_shm sysvshm
;
850 #ifdef CONFIG_DETECT_HUNG_TASK
851 unsigned long last_switch_count
;
853 /* Filesystem information: */
854 struct fs_struct
*fs
;
856 /* Open file information: */
857 struct files_struct
*files
;
860 struct nsproxy
*nsproxy
;
862 /* Signal handlers: */
863 struct signal_struct
*signal
;
864 struct sighand_struct
*sighand
;
866 sigset_t real_blocked
;
867 /* Restored if set_restore_sigmask() was used: */
868 sigset_t saved_sigmask
;
869 struct sigpending pending
;
870 unsigned long sas_ss_sp
;
872 unsigned int sas_ss_flags
;
874 struct callback_head
*task_works
;
876 struct audit_context
*audit_context
;
877 #ifdef CONFIG_AUDITSYSCALL
879 unsigned int sessionid
;
881 struct seccomp seccomp
;
883 /* Thread group tracking: */
887 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
888 spinlock_t alloc_lock
;
890 /* Protection of the PI data structures: */
891 raw_spinlock_t pi_lock
;
893 struct wake_q_node wake_q
;
895 #ifdef CONFIG_RT_MUTEXES
896 /* PI waiters blocked on a rt_mutex held by this task: */
897 struct rb_root_cached pi_waiters
;
898 /* Updated under owner's pi_lock and rq lock */
899 struct task_struct
*pi_top_task
;
900 /* Deadlock detection and priority inheritance handling: */
901 struct rt_mutex_waiter
*pi_blocked_on
;
904 #ifdef CONFIG_DEBUG_MUTEXES
905 /* Mutex deadlock detection: */
906 struct mutex_waiter
*blocked_on
;
909 #ifdef CONFIG_TRACE_IRQFLAGS
910 unsigned int irq_events
;
911 unsigned long hardirq_enable_ip
;
912 unsigned long hardirq_disable_ip
;
913 unsigned int hardirq_enable_event
;
914 unsigned int hardirq_disable_event
;
915 int hardirqs_enabled
;
917 unsigned long softirq_disable_ip
;
918 unsigned long softirq_enable_ip
;
919 unsigned int softirq_disable_event
;
920 unsigned int softirq_enable_event
;
921 int softirqs_enabled
;
925 #ifdef CONFIG_LOCKDEP
926 # define MAX_LOCK_DEPTH 48UL
929 unsigned int lockdep_recursion
;
930 struct held_lock held_locks
[MAX_LOCK_DEPTH
];
934 unsigned int in_ubsan
;
937 /* Journalling filesystem info: */
940 /* Stacked block device info: */
941 struct bio_list
*bio_list
;
944 /* Stack plugging: */
945 struct blk_plug
*plug
;
949 struct reclaim_state
*reclaim_state
;
951 struct backing_dev_info
*backing_dev_info
;
953 struct io_context
*io_context
;
956 unsigned long ptrace_message
;
957 siginfo_t
*last_siginfo
;
959 struct task_io_accounting ioac
;
960 #ifdef CONFIG_TASK_XACCT
961 /* Accumulated RSS usage: */
963 /* Accumulated virtual memory usage: */
965 /* stime + utime since last update: */
968 #ifdef CONFIG_CPUSETS
969 /* Protected by ->alloc_lock: */
970 nodemask_t mems_allowed
;
971 /* Seqence number to catch updates: */
972 seqcount_t mems_allowed_seq
;
973 int cpuset_mem_spread_rotor
;
974 int cpuset_slab_spread_rotor
;
976 #ifdef CONFIG_CGROUPS
977 /* Control Group info protected by css_set_lock: */
978 struct css_set __rcu
*cgroups
;
979 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
980 struct list_head cg_list
;
982 #ifdef CONFIG_INTEL_RDT
987 struct robust_list_head __user
*robust_list
;
989 struct compat_robust_list_head __user
*compat_robust_list
;
991 struct list_head pi_state_list
;
992 struct futex_pi_state
*pi_state_cache
;
994 #ifdef CONFIG_PERF_EVENTS
995 struct perf_event_context
*perf_event_ctxp
[perf_nr_task_contexts
];
996 struct mutex perf_event_mutex
;
997 struct list_head perf_event_list
;
999 #ifdef CONFIG_DEBUG_PREEMPT
1000 unsigned long preempt_disable_ip
;
1003 /* Protected by alloc_lock: */
1004 struct mempolicy
*mempolicy
;
1006 short pref_node_fork
;
1008 #ifdef CONFIG_NUMA_BALANCING
1010 unsigned int numa_scan_period
;
1011 unsigned int numa_scan_period_max
;
1012 int numa_preferred_nid
;
1013 unsigned long numa_migrate_retry
;
1014 /* Migration stamp: */
1016 u64 last_task_numa_placement
;
1017 u64 last_sum_exec_runtime
;
1018 struct callback_head numa_work
;
1020 struct list_head numa_entry
;
1021 struct numa_group
*numa_group
;
1024 * numa_faults is an array split into four regions:
1025 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1026 * in this precise order.
1028 * faults_memory: Exponential decaying average of faults on a per-node
1029 * basis. Scheduling placement decisions are made based on these
1030 * counts. The values remain static for the duration of a PTE scan.
1031 * faults_cpu: Track the nodes the process was running on when a NUMA
1032 * hinting fault was incurred.
1033 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1034 * during the current scan window. When the scan completes, the counts
1035 * in faults_memory and faults_cpu decay and these values are copied.
1037 unsigned long *numa_faults
;
1038 unsigned long total_numa_faults
;
1041 * numa_faults_locality tracks if faults recorded during the last
1042 * scan window were remote/local or failed to migrate. The task scan
1043 * period is adapted based on the locality of the faults with different
1044 * weights depending on whether they were shared or private faults
1046 unsigned long numa_faults_locality
[3];
1048 unsigned long numa_pages_migrated
;
1049 #endif /* CONFIG_NUMA_BALANCING */
1052 struct rseq __user
*rseq
;
1056 * RmW on rseq_event_mask must be performed atomically
1057 * with respect to preemption.
1059 unsigned long rseq_event_mask
;
1062 struct tlbflush_unmap_batch tlb_ubc
;
1064 struct rcu_head rcu
;
1066 /* Cache last used pipe for splice(): */
1067 struct pipe_inode_info
*splice_pipe
;
1069 struct page_frag task_frag
;
1071 #ifdef CONFIG_TASK_DELAY_ACCT
1072 struct task_delay_info
*delays
;
1075 #ifdef CONFIG_FAULT_INJECTION
1077 unsigned int fail_nth
;
1080 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1081 * balance_dirty_pages() for a dirty throttling pause:
1084 int nr_dirtied_pause
;
1085 /* Start of a write-and-pause period: */
1086 unsigned long dirty_paused_when
;
1088 #ifdef CONFIG_LATENCYTOP
1089 int latency_record_count
;
1090 struct latency_record latency_record
[LT_SAVECOUNT
];
1093 * Time slack values; these are used to round up poll() and
1094 * select() etc timeout values. These are in nanoseconds.
1097 u64 default_timer_slack_ns
;
1100 unsigned int kasan_depth
;
1103 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1104 /* Index of current stored address in ret_stack: */
1107 /* Stack of return addresses for return function tracing: */
1108 struct ftrace_ret_stack
*ret_stack
;
1110 /* Timestamp for last schedule: */
1111 unsigned long long ftrace_timestamp
;
1114 * Number of functions that haven't been traced
1115 * because of depth overrun:
1117 atomic_t trace_overrun
;
1119 /* Pause tracing: */
1120 atomic_t tracing_graph_pause
;
1123 #ifdef CONFIG_TRACING
1124 /* State flags for use by tracers: */
1125 unsigned long trace
;
1127 /* Bitmask and counter of trace recursion: */
1128 unsigned long trace_recursion
;
1129 #endif /* CONFIG_TRACING */
1132 /* Coverage collection mode enabled for this task (0 if disabled): */
1133 unsigned int kcov_mode
;
1135 /* Size of the kcov_area: */
1136 unsigned int kcov_size
;
1138 /* Buffer for coverage collection: */
1141 /* KCOV descriptor wired with this task or NULL: */
1146 struct mem_cgroup
*memcg_in_oom
;
1147 gfp_t memcg_oom_gfp_mask
;
1148 int memcg_oom_order
;
1150 /* Number of pages to reclaim on returning to userland: */
1151 unsigned int memcg_nr_pages_over_high
;
1154 #ifdef CONFIG_UPROBES
1155 struct uprobe_task
*utask
;
1157 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1158 unsigned int sequential_io
;
1159 unsigned int sequential_io_avg
;
1161 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1162 unsigned long task_state_change
;
1164 int pagefault_disabled
;
1166 struct task_struct
*oom_reaper_list
;
1168 #ifdef CONFIG_VMAP_STACK
1169 struct vm_struct
*stack_vm_area
;
1171 #ifdef CONFIG_THREAD_INFO_IN_TASK
1172 /* A live task holds one reference: */
1173 atomic_t stack_refcount
;
1175 #ifdef CONFIG_LIVEPATCH
1178 #ifdef CONFIG_SECURITY
1179 /* Used by LSM modules for access restriction: */
1184 * New fields for task_struct should be added above here, so that
1185 * they are included in the randomized portion of task_struct.
1187 randomized_struct_fields_end
1189 /* CPU-specific state of this task: */
1190 struct thread_struct thread
;
1193 * WARNING: on x86, 'thread_struct' contains a variable-sized
1194 * structure. It *MUST* be at the end of 'task_struct'.
1196 * Do not put anything below here!
1200 static inline struct pid
*task_pid(struct task_struct
*task
)
1202 return task
->pids
[PIDTYPE_PID
].pid
;
1205 static inline struct pid
*task_tgid(struct task_struct
*task
)
1207 return task
->group_leader
->pids
[PIDTYPE_PID
].pid
;
1211 * Without tasklist or RCU lock it is not safe to dereference
1212 * the result of task_pgrp/task_session even if task == current,
1213 * we can race with another thread doing sys_setsid/sys_setpgid.
1215 static inline struct pid
*task_pgrp(struct task_struct
*task
)
1217 return task
->group_leader
->pids
[PIDTYPE_PGID
].pid
;
1220 static inline struct pid
*task_session(struct task_struct
*task
)
1222 return task
->group_leader
->pids
[PIDTYPE_SID
].pid
;
1226 * the helpers to get the task's different pids as they are seen
1227 * from various namespaces
1229 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1230 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1232 * task_xid_nr_ns() : id seen from the ns specified;
1234 * see also pid_nr() etc in include/linux/pid.h
1236 pid_t
__task_pid_nr_ns(struct task_struct
*task
, enum pid_type type
, struct pid_namespace
*ns
);
1238 static inline pid_t
task_pid_nr(struct task_struct
*tsk
)
1243 static inline pid_t
task_pid_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1245 return __task_pid_nr_ns(tsk
, PIDTYPE_PID
, ns
);
1248 static inline pid_t
task_pid_vnr(struct task_struct
*tsk
)
1250 return __task_pid_nr_ns(tsk
, PIDTYPE_PID
, NULL
);
1254 static inline pid_t
task_tgid_nr(struct task_struct
*tsk
)
1260 * pid_alive - check that a task structure is not stale
1261 * @p: Task structure to be checked.
1263 * Test if a process is not yet dead (at most zombie state)
1264 * If pid_alive fails, then pointers within the task structure
1265 * can be stale and must not be dereferenced.
1267 * Return: 1 if the process is alive. 0 otherwise.
1269 static inline int pid_alive(const struct task_struct
*p
)
1271 return p
->pids
[PIDTYPE_PID
].pid
!= NULL
;
1274 static inline pid_t
task_pgrp_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1276 return __task_pid_nr_ns(tsk
, PIDTYPE_PGID
, ns
);
1279 static inline pid_t
task_pgrp_vnr(struct task_struct
*tsk
)
1281 return __task_pid_nr_ns(tsk
, PIDTYPE_PGID
, NULL
);
1285 static inline pid_t
task_session_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1287 return __task_pid_nr_ns(tsk
, PIDTYPE_SID
, ns
);
1290 static inline pid_t
task_session_vnr(struct task_struct
*tsk
)
1292 return __task_pid_nr_ns(tsk
, PIDTYPE_SID
, NULL
);
1295 static inline pid_t
task_tgid_nr_ns(struct task_struct
*tsk
, struct pid_namespace
*ns
)
1297 return __task_pid_nr_ns(tsk
, __PIDTYPE_TGID
, ns
);
1300 static inline pid_t
task_tgid_vnr(struct task_struct
*tsk
)
1302 return __task_pid_nr_ns(tsk
, __PIDTYPE_TGID
, NULL
);
1305 static inline pid_t
task_ppid_nr_ns(const struct task_struct
*tsk
, struct pid_namespace
*ns
)
1311 pid
= task_tgid_nr_ns(rcu_dereference(tsk
->real_parent
), ns
);
1317 static inline pid_t
task_ppid_nr(const struct task_struct
*tsk
)
1319 return task_ppid_nr_ns(tsk
, &init_pid_ns
);
1322 /* Obsolete, do not use: */
1323 static inline pid_t
task_pgrp_nr(struct task_struct
*tsk
)
1325 return task_pgrp_nr_ns(tsk
, &init_pid_ns
);
1328 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1329 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1331 static inline unsigned int task_state_index(struct task_struct
*tsk
)
1333 unsigned int tsk_state
= READ_ONCE(tsk
->state
);
1334 unsigned int state
= (tsk_state
| tsk
->exit_state
) & TASK_REPORT
;
1336 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX
);
1338 if (tsk_state
== TASK_IDLE
)
1339 state
= TASK_REPORT_IDLE
;
1344 static inline char task_index_to_char(unsigned int state
)
1346 static const char state_char
[] = "RSDTtXZPI";
1348 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX
) != sizeof(state_char
) - 1);
1350 return state_char
[state
];
1353 static inline char task_state_to_char(struct task_struct
*tsk
)
1355 return task_index_to_char(task_state_index(tsk
));
1359 * is_global_init - check if a task structure is init. Since init
1360 * is free to have sub-threads we need to check tgid.
1361 * @tsk: Task structure to be checked.
1363 * Check if a task structure is the first user space task the kernel created.
1365 * Return: 1 if the task structure is init. 0 otherwise.
1367 static inline int is_global_init(struct task_struct
*tsk
)
1369 return task_tgid_nr(tsk
) == 1;
1372 extern struct pid
*cad_pid
;
1377 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1378 #define PF_EXITING 0x00000004 /* Getting shut down */
1379 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1380 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1381 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1382 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1383 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1384 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1385 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1386 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1387 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1388 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1389 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1390 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1391 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1392 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1393 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1394 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1395 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1396 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1397 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1398 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1399 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1400 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1401 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1402 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1403 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1404 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1407 * Only the _current_ task can read/write to tsk->flags, but other
1408 * tasks can access tsk->flags in readonly mode for example
1409 * with tsk_used_math (like during threaded core dumping).
1410 * There is however an exception to this rule during ptrace
1411 * or during fork: the ptracer task is allowed to write to the
1412 * child->flags of its traced child (same goes for fork, the parent
1413 * can write to the child->flags), because we're guaranteed the
1414 * child is not running and in turn not changing child->flags
1415 * at the same time the parent does it.
1417 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1418 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1419 #define clear_used_math() clear_stopped_child_used_math(current)
1420 #define set_used_math() set_stopped_child_used_math(current)
1422 #define conditional_stopped_child_used_math(condition, child) \
1423 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1425 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1427 #define copy_to_stopped_child_used_math(child) \
1428 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1430 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1431 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1432 #define used_math() tsk_used_math(current)
1434 static inline bool is_percpu_thread(void)
1437 return (current
->flags
& PF_NO_SETAFFINITY
) &&
1438 (current
->nr_cpus_allowed
== 1);
1444 /* Per-process atomic flags. */
1445 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1446 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1447 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1448 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1449 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1451 #define TASK_PFA_TEST(name, func) \
1452 static inline bool task_##func(struct task_struct *p) \
1453 { return test_bit(PFA_##name, &p->atomic_flags); }
1455 #define TASK_PFA_SET(name, func) \
1456 static inline void task_set_##func(struct task_struct *p) \
1457 { set_bit(PFA_##name, &p->atomic_flags); }
1459 #define TASK_PFA_CLEAR(name, func) \
1460 static inline void task_clear_##func(struct task_struct *p) \
1461 { clear_bit(PFA_##name, &p->atomic_flags); }
1463 TASK_PFA_TEST(NO_NEW_PRIVS
, no_new_privs
)
1464 TASK_PFA_SET(NO_NEW_PRIVS
, no_new_privs
)
1466 TASK_PFA_TEST(SPREAD_PAGE
, spread_page
)
1467 TASK_PFA_SET(SPREAD_PAGE
, spread_page
)
1468 TASK_PFA_CLEAR(SPREAD_PAGE
, spread_page
)
1470 TASK_PFA_TEST(SPREAD_SLAB
, spread_slab
)
1471 TASK_PFA_SET(SPREAD_SLAB
, spread_slab
)
1472 TASK_PFA_CLEAR(SPREAD_SLAB
, spread_slab
)
1474 TASK_PFA_TEST(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1475 TASK_PFA_SET(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1476 TASK_PFA_CLEAR(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1478 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1479 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1482 current_restore_flags(unsigned long orig_flags
, unsigned long flags
)
1484 current
->flags
&= ~flags
;
1485 current
->flags
|= orig_flags
& flags
;
1488 extern int cpuset_cpumask_can_shrink(const struct cpumask
*cur
, const struct cpumask
*trial
);
1489 extern int task_can_attach(struct task_struct
*p
, const struct cpumask
*cs_cpus_allowed
);
1491 extern void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
);
1492 extern int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
);
1494 static inline void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
)
1497 static inline int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
)
1499 if (!cpumask_test_cpu(0, new_mask
))
1505 #ifndef cpu_relax_yield
1506 #define cpu_relax_yield() cpu_relax()
1509 extern int yield_to(struct task_struct
*p
, bool preempt
);
1510 extern void set_user_nice(struct task_struct
*p
, long nice
);
1511 extern int task_prio(const struct task_struct
*p
);
1514 * task_nice - return the nice value of a given task.
1515 * @p: the task in question.
1517 * Return: The nice value [ -20 ... 0 ... 19 ].
1519 static inline int task_nice(const struct task_struct
*p
)
1521 return PRIO_TO_NICE((p
)->static_prio
);
1524 extern int can_nice(const struct task_struct
*p
, const int nice
);
1525 extern int task_curr(const struct task_struct
*p
);
1526 extern int idle_cpu(int cpu
);
1527 extern int available_idle_cpu(int cpu
);
1528 extern int sched_setscheduler(struct task_struct
*, int, const struct sched_param
*);
1529 extern int sched_setscheduler_nocheck(struct task_struct
*, int, const struct sched_param
*);
1530 extern int sched_setattr(struct task_struct
*, const struct sched_attr
*);
1531 extern int sched_setattr_nocheck(struct task_struct
*, const struct sched_attr
*);
1532 extern struct task_struct
*idle_task(int cpu
);
1535 * is_idle_task - is the specified task an idle task?
1536 * @p: the task in question.
1538 * Return: 1 if @p is an idle task. 0 otherwise.
1540 static inline bool is_idle_task(const struct task_struct
*p
)
1542 return !!(p
->flags
& PF_IDLE
);
1545 extern struct task_struct
*curr_task(int cpu
);
1546 extern void ia64_set_curr_task(int cpu
, struct task_struct
*p
);
1550 union thread_union
{
1551 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1552 struct task_struct task
;
1554 #ifndef CONFIG_THREAD_INFO_IN_TASK
1555 struct thread_info thread_info
;
1557 unsigned long stack
[THREAD_SIZE
/sizeof(long)];
1560 #ifndef CONFIG_THREAD_INFO_IN_TASK
1561 extern struct thread_info init_thread_info
;
1564 extern unsigned long init_stack
[THREAD_SIZE
/ sizeof(unsigned long)];
1566 #ifdef CONFIG_THREAD_INFO_IN_TASK
1567 static inline struct thread_info
*task_thread_info(struct task_struct
*task
)
1569 return &task
->thread_info
;
1571 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1572 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1576 * find a task by one of its numerical ids
1578 * find_task_by_pid_ns():
1579 * finds a task by its pid in the specified namespace
1580 * find_task_by_vpid():
1581 * finds a task by its virtual pid
1583 * see also find_vpid() etc in include/linux/pid.h
1586 extern struct task_struct
*find_task_by_vpid(pid_t nr
);
1587 extern struct task_struct
*find_task_by_pid_ns(pid_t nr
, struct pid_namespace
*ns
);
1590 * find a task by its virtual pid and get the task struct
1592 extern struct task_struct
*find_get_task_by_vpid(pid_t nr
);
1594 extern int wake_up_state(struct task_struct
*tsk
, unsigned int state
);
1595 extern int wake_up_process(struct task_struct
*tsk
);
1596 extern void wake_up_new_task(struct task_struct
*tsk
);
1599 extern void kick_process(struct task_struct
*tsk
);
1601 static inline void kick_process(struct task_struct
*tsk
) { }
1604 extern void __set_task_comm(struct task_struct
*tsk
, const char *from
, bool exec
);
1606 static inline void set_task_comm(struct task_struct
*tsk
, const char *from
)
1608 __set_task_comm(tsk
, from
, false);
1611 extern char *__get_task_comm(char *to
, size_t len
, struct task_struct
*tsk
);
1612 #define get_task_comm(buf, tsk) ({ \
1613 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1614 __get_task_comm(buf, sizeof(buf), tsk); \
1618 void scheduler_ipi(void);
1619 extern unsigned long wait_task_inactive(struct task_struct
*, long match_state
);
1621 static inline void scheduler_ipi(void) { }
1622 static inline unsigned long wait_task_inactive(struct task_struct
*p
, long match_state
)
1629 * Set thread flags in other task's structures.
1630 * See asm/thread_info.h for TIF_xxxx flags available:
1632 static inline void set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1634 set_ti_thread_flag(task_thread_info(tsk
), flag
);
1637 static inline void clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1639 clear_ti_thread_flag(task_thread_info(tsk
), flag
);
1642 static inline void update_tsk_thread_flag(struct task_struct
*tsk
, int flag
,
1645 update_ti_thread_flag(task_thread_info(tsk
), flag
, value
);
1648 static inline int test_and_set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1650 return test_and_set_ti_thread_flag(task_thread_info(tsk
), flag
);
1653 static inline int test_and_clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1655 return test_and_clear_ti_thread_flag(task_thread_info(tsk
), flag
);
1658 static inline int test_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1660 return test_ti_thread_flag(task_thread_info(tsk
), flag
);
1663 static inline void set_tsk_need_resched(struct task_struct
*tsk
)
1665 set_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
);
1668 static inline void clear_tsk_need_resched(struct task_struct
*tsk
)
1670 clear_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
);
1673 static inline int test_tsk_need_resched(struct task_struct
*tsk
)
1675 return unlikely(test_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
));
1679 * cond_resched() and cond_resched_lock(): latency reduction via
1680 * explicit rescheduling in places that are safe. The return
1681 * value indicates whether a reschedule was done in fact.
1682 * cond_resched_lock() will drop the spinlock before scheduling,
1684 #ifndef CONFIG_PREEMPT
1685 extern int _cond_resched(void);
1687 static inline int _cond_resched(void) { return 0; }
1690 #define cond_resched() ({ \
1691 ___might_sleep(__FILE__, __LINE__, 0); \
1695 extern int __cond_resched_lock(spinlock_t
*lock
);
1697 #define cond_resched_lock(lock) ({ \
1698 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1699 __cond_resched_lock(lock); \
1702 static inline void cond_resched_rcu(void)
1704 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1712 * Does a critical section need to be broken due to another
1713 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1714 * but a general need for low latency)
1716 static inline int spin_needbreak(spinlock_t
*lock
)
1718 #ifdef CONFIG_PREEMPT
1719 return spin_is_contended(lock
);
1725 static __always_inline
bool need_resched(void)
1727 return unlikely(tif_need_resched());
1731 * Wrappers for p->thread_info->cpu access. No-op on UP.
1735 static inline unsigned int task_cpu(const struct task_struct
*p
)
1737 #ifdef CONFIG_THREAD_INFO_IN_TASK
1740 return task_thread_info(p
)->cpu
;
1744 extern void set_task_cpu(struct task_struct
*p
, unsigned int cpu
);
1748 static inline unsigned int task_cpu(const struct task_struct
*p
)
1753 static inline void set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
1757 #endif /* CONFIG_SMP */
1760 * In order to reduce various lock holder preemption latencies provide an
1761 * interface to see if a vCPU is currently running or not.
1763 * This allows us to terminate optimistic spin loops and block, analogous to
1764 * the native optimistic spin heuristic of testing if the lock owner task is
1767 #ifndef vcpu_is_preempted
1768 # define vcpu_is_preempted(cpu) false
1771 extern long sched_setaffinity(pid_t pid
, const struct cpumask
*new_mask
);
1772 extern long sched_getaffinity(pid_t pid
, struct cpumask
*mask
);
1774 #ifndef TASK_SIZE_OF
1775 #define TASK_SIZE_OF(tsk) TASK_SIZE
1781 * Map the event mask on the user-space ABI enum rseq_cs_flags
1782 * for direct mask checks.
1784 enum rseq_event_mask_bits
{
1785 RSEQ_EVENT_PREEMPT_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT
,
1786 RSEQ_EVENT_SIGNAL_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT
,
1787 RSEQ_EVENT_MIGRATE_BIT
= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT
,
1790 enum rseq_event_mask
{
1791 RSEQ_EVENT_PREEMPT
= (1U << RSEQ_EVENT_PREEMPT_BIT
),
1792 RSEQ_EVENT_SIGNAL
= (1U << RSEQ_EVENT_SIGNAL_BIT
),
1793 RSEQ_EVENT_MIGRATE
= (1U << RSEQ_EVENT_MIGRATE_BIT
),
1796 static inline void rseq_set_notify_resume(struct task_struct
*t
)
1799 set_tsk_thread_flag(t
, TIF_NOTIFY_RESUME
);
1802 void __rseq_handle_notify_resume(struct ksignal
*sig
, struct pt_regs
*regs
);
1804 static inline void rseq_handle_notify_resume(struct ksignal
*ksig
,
1805 struct pt_regs
*regs
)
1808 __rseq_handle_notify_resume(ksig
, regs
);
1811 static inline void rseq_signal_deliver(struct ksignal
*ksig
,
1812 struct pt_regs
*regs
)
1815 __set_bit(RSEQ_EVENT_SIGNAL_BIT
, ¤t
->rseq_event_mask
);
1817 rseq_handle_notify_resume(ksig
, regs
);
1820 /* rseq_preempt() requires preemption to be disabled. */
1821 static inline void rseq_preempt(struct task_struct
*t
)
1823 __set_bit(RSEQ_EVENT_PREEMPT_BIT
, &t
->rseq_event_mask
);
1824 rseq_set_notify_resume(t
);
1827 /* rseq_migrate() requires preemption to be disabled. */
1828 static inline void rseq_migrate(struct task_struct
*t
)
1830 __set_bit(RSEQ_EVENT_MIGRATE_BIT
, &t
->rseq_event_mask
);
1831 rseq_set_notify_resume(t
);
1835 * If parent process has a registered restartable sequences area, the
1836 * child inherits. Only applies when forking a process, not a thread.
1838 static inline void rseq_fork(struct task_struct
*t
, unsigned long clone_flags
)
1840 if (clone_flags
& CLONE_THREAD
) {
1844 t
->rseq_event_mask
= 0;
1846 t
->rseq
= current
->rseq
;
1847 t
->rseq_len
= current
->rseq_len
;
1848 t
->rseq_sig
= current
->rseq_sig
;
1849 t
->rseq_event_mask
= current
->rseq_event_mask
;
1853 static inline void rseq_execve(struct task_struct
*t
)
1858 t
->rseq_event_mask
= 0;
1863 static inline void rseq_set_notify_resume(struct task_struct
*t
)
1866 static inline void rseq_handle_notify_resume(struct ksignal
*ksig
,
1867 struct pt_regs
*regs
)
1870 static inline void rseq_signal_deliver(struct ksignal
*ksig
,
1871 struct pt_regs
*regs
)
1874 static inline void rseq_preempt(struct task_struct
*t
)
1877 static inline void rseq_migrate(struct task_struct
*t
)
1880 static inline void rseq_fork(struct task_struct
*t
, unsigned long clone_flags
)
1883 static inline void rseq_execve(struct task_struct
*t
)
1889 #ifdef CONFIG_DEBUG_RSEQ
1891 void rseq_syscall(struct pt_regs
*regs
);
1895 static inline void rseq_syscall(struct pt_regs
*regs
)