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/refcount.h>
25 #include <linux/resource.h>
26 #include <linux/latencytop.h>
27 #include <linux/sched/prio.h>
28 #include <linux/sched/types.h>
29 #include <linux/signal_types.h>
30 #include <linux/mm_types_task.h>
31 #include <linux/task_io_accounting.h>
32 #include <linux/posix-timers.h>
33 #include <linux/rseq.h>
35 /* task_struct member predeclarations (sorted alphabetically): */
37 struct backing_dev_info;
40 struct capture_control;
43 struct futex_pi_state;
48 struct perf_event_context;
50 struct pipe_inode_info;
53 struct robust_list_head;
59 struct sighand_struct;
61 struct task_delay_info;
65 * Task state bitmask. NOTE! These bits are also
66 * encoded in fs/proc/array.c: get_task_state().
68 * We have two separate sets of flags: task->state
69 * is about runnability, while task->exit_state are
70 * about the task exiting. Confusing, but this way
71 * modifying one set can't modify the other one by
75 /* Used in tsk->state: */
76 #define TASK_RUNNING 0x0000
77 #define TASK_INTERRUPTIBLE 0x0001
78 #define TASK_UNINTERRUPTIBLE 0x0002
79 #define __TASK_STOPPED 0x0004
80 #define __TASK_TRACED 0x0008
81 /* Used in tsk->exit_state: */
82 #define EXIT_DEAD 0x0010
83 #define EXIT_ZOMBIE 0x0020
84 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
85 /* Used in tsk->state again: */
86 #define TASK_PARKED 0x0040
87 #define TASK_DEAD 0x0080
88 #define TASK_WAKEKILL 0x0100
89 #define TASK_WAKING 0x0200
90 #define TASK_NOLOAD 0x0400
91 #define TASK_NEW 0x0800
92 #define TASK_STATE_MAX 0x1000
94 /* Convenience macros for the sake of set_current_state: */
95 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
96 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
97 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
99 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
101 /* Convenience macros for the sake of wake_up(): */
102 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
104 /* get_task_state(): */
105 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
106 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
107 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
110 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
112 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
114 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
116 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
117 (task->flags & PF_FROZEN) == 0 && \
118 (task->state & TASK_NOLOAD) == 0)
120 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
123 * Special states are those that do not use the normal wait-loop pattern. See
124 * the comment with set_special_state().
126 #define is_special_task_state(state) \
127 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
129 #define __set_current_state(state_value) \
131 WARN_ON_ONCE(is_special_task_state(state_value));\
132 current->task_state_change = _THIS_IP_; \
133 current->state = (state_value); \
136 #define set_current_state(state_value) \
138 WARN_ON_ONCE(is_special_task_state(state_value));\
139 current->task_state_change = _THIS_IP_; \
140 smp_store_mb(current->state, (state_value)); \
143 #define set_special_state(state_value) \
145 unsigned long flags; /* may shadow */ \
146 WARN_ON_ONCE(!is_special_task_state(state_value)); \
147 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
148 current->task_state_change = _THIS_IP_; \
149 current->state = (state_value); \
150 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
154 * set_current_state() includes a barrier so that the write of current->state
155 * is correctly serialised wrt the caller's subsequent test of whether to
159 * set_current_state(TASK_UNINTERRUPTIBLE);
165 * __set_current_state(TASK_RUNNING);
167 * If the caller does not need such serialisation (because, for instance, the
168 * condition test and condition change and wakeup are under the same lock) then
169 * use __set_current_state().
171 * The above is typically ordered against the wakeup, which does:
173 * need_sleep = false;
174 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
176 * where wake_up_state() executes a full memory barrier before accessing the
179 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
180 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
181 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
183 * However, with slightly different timing the wakeup TASK_RUNNING store can
184 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
185 * a problem either because that will result in one extra go around the loop
186 * and our @cond test will save the day.
188 * Also see the comments of try_to_wake_up().
190 #define __set_current_state(state_value) \
191 current->state = (state_value)
193 #define set_current_state(state_value) \
194 smp_store_mb(current->state, (state_value))
197 * set_special_state() should be used for those states when the blocking task
198 * can not use the regular condition based wait-loop. In that case we must
199 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
200 * will not collide with our state change.
202 #define set_special_state(state_value) \
204 unsigned long flags; /* may shadow */ \
205 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
206 current->state = (state_value); \
207 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
212 /* Task command name length: */
213 #define TASK_COMM_LEN 16
215 extern void scheduler_tick(void);
217 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
219 extern long schedule_timeout(long timeout);
220 extern long schedule_timeout_interruptible(long timeout);
221 extern long schedule_timeout_killable(long timeout);
222 extern long schedule_timeout_uninterruptible(long timeout);
223 extern long schedule_timeout_idle(long timeout);
224 asmlinkage void schedule(void);
225 extern void schedule_preempt_disabled(void);
226 asmlinkage void preempt_schedule_irq(void);
228 extern int __must_check io_schedule_prepare(void);
229 extern void io_schedule_finish(int token);
230 extern long io_schedule_timeout(long timeout);
231 extern void io_schedule(void);
234 * struct prev_cputime - snapshot of system and user cputime
235 * @utime: time spent in user mode
236 * @stime: time spent in system mode
237 * @lock: protects the above two fields
239 * Stores previous user/system time values such that we can guarantee
242 struct prev_cputime {
243 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
251 /* Task is sleeping or running in a CPU with VTIME inactive: */
253 /* Task runs in userspace in a CPU with VTIME active: */
255 /* Task runs in kernelspace in a CPU with VTIME active: */
261 unsigned long long starttime;
262 enum vtime_state state;
269 * Utilization clamp constraints.
270 * @UCLAMP_MIN: Minimum utilization
271 * @UCLAMP_MAX: Maximum utilization
272 * @UCLAMP_CNT: Utilization clamp constraints count
281 extern struct root_domain def_root_domain;
282 extern struct mutex sched_domains_mutex;
286 #ifdef CONFIG_SCHED_INFO
287 /* Cumulative counters: */
289 /* # of times we have run on this CPU: */
290 unsigned long pcount;
292 /* Time spent waiting on a runqueue: */
293 unsigned long long run_delay;
297 /* When did we last run on a CPU? */
298 unsigned long long last_arrival;
300 /* When were we last queued to run? */
301 unsigned long long last_queued;
303 #endif /* CONFIG_SCHED_INFO */
307 * Integer metrics need fixed point arithmetic, e.g., sched/fair
308 * has a few: load, load_avg, util_avg, freq, and capacity.
310 * We define a basic fixed point arithmetic range, and then formalize
311 * all these metrics based on that basic range.
313 # define SCHED_FIXEDPOINT_SHIFT 10
314 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
316 /* Increase resolution of cpu_capacity calculations */
317 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
318 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
321 unsigned long weight;
326 * struct util_est - Estimation utilization of FAIR tasks
327 * @enqueued: instantaneous estimated utilization of a task/cpu
328 * @ewma: the Exponential Weighted Moving Average (EWMA)
329 * utilization of a task
331 * Support data structure to track an Exponential Weighted Moving Average
332 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
333 * average each time a task completes an activation. Sample's weight is chosen
334 * so that the EWMA will be relatively insensitive to transient changes to the
337 * The enqueued attribute has a slightly different meaning for tasks and cpus:
338 * - task: the task's util_avg at last task dequeue time
339 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
340 * Thus, the util_est.enqueued of a task represents the contribution on the
341 * estimated utilization of the CPU where that task is currently enqueued.
343 * Only for tasks we track a moving average of the past instantaneous
344 * estimated utilization. This allows to absorb sporadic drops in utilization
345 * of an otherwise almost periodic task.
348 unsigned int enqueued;
350 #define UTIL_EST_WEIGHT_SHIFT 2
351 } __attribute__((__aligned__(sizeof(u64))));
354 * The load_avg/util_avg accumulates an infinite geometric series
355 * (see __update_load_avg() in kernel/sched/fair.c).
357 * [load_avg definition]
359 * load_avg = runnable% * scale_load_down(load)
361 * where runnable% is the time ratio that a sched_entity is runnable.
362 * For cfs_rq, it is the aggregated load_avg of all runnable and
363 * blocked sched_entities.
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 * load_avg and util_avg don't direcly factor frequency scaling and CPU
374 * capacity scaling. The scaling is done through the rq_clock_pelt that
375 * is used for computing those signals (see update_rq_clock_pelt())
377 * N.B., the above ratios (runnable% and running%) themselves are in the
378 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
379 * to as large a range as necessary. This is for example reflected by
380 * util_avg's SCHED_CAPACITY_SCALE.
384 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
385 * with the highest load (=88761), always runnable on a single cfs_rq,
386 * and should not overflow as the number already hits PID_MAX_LIMIT.
388 * For all other cases (including 32-bit kernels), struct load_weight's
389 * weight will overflow first before we do, because:
391 * Max(load_avg) <= Max(load.weight)
393 * Then it is the load_weight's responsibility to consider overflow
397 u64 last_update_time;
399 u64 runnable_load_sum;
402 unsigned long load_avg;
403 unsigned long runnable_load_avg;
404 unsigned long util_avg;
405 struct util_est util_est;
406 } ____cacheline_aligned;
408 struct sched_statistics {
409 #ifdef CONFIG_SCHEDSTATS
419 s64 sum_sleep_runtime;
426 u64 nr_migrations_cold;
427 u64 nr_failed_migrations_affine;
428 u64 nr_failed_migrations_running;
429 u64 nr_failed_migrations_hot;
430 u64 nr_forced_migrations;
434 u64 nr_wakeups_migrate;
435 u64 nr_wakeups_local;
436 u64 nr_wakeups_remote;
437 u64 nr_wakeups_affine;
438 u64 nr_wakeups_affine_attempts;
439 u64 nr_wakeups_passive;
444 struct sched_entity {
445 /* For load-balancing: */
446 struct load_weight load;
447 unsigned long runnable_weight;
448 struct rb_node run_node;
449 struct list_head group_node;
453 u64 sum_exec_runtime;
455 u64 prev_sum_exec_runtime;
459 struct sched_statistics statistics;
461 #ifdef CONFIG_FAIR_GROUP_SCHED
463 struct sched_entity *parent;
464 /* rq on which this entity is (to be) queued: */
465 struct cfs_rq *cfs_rq;
466 /* rq "owned" by this entity/group: */
472 * Per entity load average tracking.
474 * Put into separate cache line so it does not
475 * collide with read-mostly values above.
477 struct sched_avg avg;
481 struct sched_rt_entity {
482 struct list_head run_list;
483 unsigned long timeout;
484 unsigned long watchdog_stamp;
485 unsigned int time_slice;
486 unsigned short on_rq;
487 unsigned short on_list;
489 struct sched_rt_entity *back;
490 #ifdef CONFIG_RT_GROUP_SCHED
491 struct sched_rt_entity *parent;
492 /* rq on which this entity is (to be) queued: */
494 /* rq "owned" by this entity/group: */
497 } __randomize_layout;
499 struct sched_dl_entity {
500 struct rb_node rb_node;
503 * Original scheduling parameters. Copied here from sched_attr
504 * during sched_setattr(), they will remain the same until
505 * the next sched_setattr().
507 u64 dl_runtime; /* Maximum runtime for each instance */
508 u64 dl_deadline; /* Relative deadline of each instance */
509 u64 dl_period; /* Separation of two instances (period) */
510 u64 dl_bw; /* dl_runtime / dl_period */
511 u64 dl_density; /* dl_runtime / dl_deadline */
514 * Actual scheduling parameters. Initialized with the values above,
515 * they are continuously updated during task execution. Note that
516 * the remaining runtime could be < 0 in case we are in overrun.
518 s64 runtime; /* Remaining runtime for this instance */
519 u64 deadline; /* Absolute deadline for this instance */
520 unsigned int flags; /* Specifying the scheduler behaviour */
525 * @dl_throttled tells if we exhausted the runtime. If so, the
526 * task has to wait for a replenishment to be performed at the
527 * next firing of dl_timer.
529 * @dl_yielded tells if task gave up the CPU before consuming
530 * all its available runtime during the last job.
532 * @dl_non_contending tells if the task is inactive while still
533 * contributing to the active utilization. In other words, it
534 * indicates if the inactive timer has been armed and its handler
535 * has not been executed yet. This flag is useful to avoid race
536 * conditions between the inactive timer handler and the wakeup
539 * @dl_overrun tells if the task asked to be informed about runtime
542 unsigned int dl_throttled : 1;
543 unsigned int dl_yielded : 1;
544 unsigned int dl_non_contending : 1;
545 unsigned int dl_overrun : 1;
548 * Bandwidth enforcement timer. Each -deadline task has its
549 * own bandwidth to be enforced, thus we need one timer per task.
551 struct hrtimer dl_timer;
554 * Inactive timer, responsible for decreasing the active utilization
555 * at the "0-lag time". When a -deadline task blocks, it contributes
556 * to GRUB's active utilization until the "0-lag time", hence a
557 * timer is needed to decrease the active utilization at the correct
560 struct hrtimer inactive_timer;
562 #ifdef CONFIG_RT_MUTEXES
564 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
565 * pi_se points to the donor, otherwise points to the dl_se it belongs
566 * to (the original one/itself).
568 struct sched_dl_entity *pi_se;
572 #ifdef CONFIG_UCLAMP_TASK
573 /* Number of utilization clamp buckets (shorter alias) */
574 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
577 * Utilization clamp for a scheduling entity
578 * @value: clamp value "assigned" to a se
579 * @bucket_id: bucket index corresponding to the "assigned" value
580 * @active: the se is currently refcounted in a rq's bucket
581 * @user_defined: the requested clamp value comes from user-space
583 * The bucket_id is the index of the clamp bucket matching the clamp value
584 * which is pre-computed and stored to avoid expensive integer divisions from
587 * The active bit is set whenever a task has got an "effective" value assigned,
588 * which can be different from the clamp value "requested" from user-space.
589 * This allows to know a task is refcounted in the rq's bucket corresponding
590 * to the "effective" bucket_id.
592 * The user_defined bit is set whenever a task has got a task-specific clamp
593 * value requested from userspace, i.e. the system defaults apply to this task
594 * just as a restriction. This allows to relax default clamps when a less
595 * restrictive task-specific value has been requested, thus allowing to
596 * implement a "nice" semantic. For example, a task running with a 20%
597 * default boost can still drop its own boosting to 0%.
600 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
601 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
602 unsigned int active : 1;
603 unsigned int user_defined : 1;
605 #endif /* CONFIG_UCLAMP_TASK */
611 u8 exp_hint; /* Hint for performance. */
614 u32 s; /* Set of bits. */
617 enum perf_event_task_context {
618 perf_invalid_context = -1,
621 perf_nr_task_contexts,
625 struct wake_q_node *next;
629 #ifdef CONFIG_THREAD_INFO_IN_TASK
631 * For reasons of header soup (see current_thread_info()), this
632 * must be the first element of task_struct.
634 struct thread_info thread_info;
636 /* -1 unrunnable, 0 runnable, >0 stopped: */
640 * This begins the randomizable portion of task_struct. Only
641 * scheduling-critical items should be added above here.
643 randomized_struct_fields_start
647 /* Per task flags (PF_*), defined further below: */
652 struct llist_node wake_entry;
654 #ifdef CONFIG_THREAD_INFO_IN_TASK
658 unsigned int wakee_flips;
659 unsigned long wakee_flip_decay_ts;
660 struct task_struct *last_wakee;
663 * recent_used_cpu is initially set as the last CPU used by a task
664 * that wakes affine another task. Waker/wakee relationships can
665 * push tasks around a CPU where each wakeup moves to the next one.
666 * Tracking a recently used CPU allows a quick search for a recently
667 * used CPU that may be idle.
677 unsigned int rt_priority;
679 const struct sched_class *sched_class;
680 struct sched_entity se;
681 struct sched_rt_entity rt;
682 #ifdef CONFIG_CGROUP_SCHED
683 struct task_group *sched_task_group;
685 struct sched_dl_entity dl;
687 #ifdef CONFIG_UCLAMP_TASK
688 /* Clamp values requested for a scheduling entity */
689 struct uclamp_se uclamp_req[UCLAMP_CNT];
690 /* Effective clamp values used for a scheduling entity */
691 struct uclamp_se uclamp[UCLAMP_CNT];
694 #ifdef CONFIG_PREEMPT_NOTIFIERS
695 /* List of struct preempt_notifier: */
696 struct hlist_head preempt_notifiers;
699 #ifdef CONFIG_BLK_DEV_IO_TRACE
700 unsigned int btrace_seq;
705 const cpumask_t *cpus_ptr;
708 #ifdef CONFIG_PREEMPT_RCU
709 int rcu_read_lock_nesting;
710 union rcu_special rcu_read_unlock_special;
711 struct list_head rcu_node_entry;
712 struct rcu_node *rcu_blocked_node;
713 #endif /* #ifdef CONFIG_PREEMPT_RCU */
715 #ifdef CONFIG_TASKS_RCU
716 unsigned long rcu_tasks_nvcsw;
717 u8 rcu_tasks_holdout;
719 int rcu_tasks_idle_cpu;
720 struct list_head rcu_tasks_holdout_list;
721 #endif /* #ifdef CONFIG_TASKS_RCU */
723 struct sched_info sched_info;
725 struct list_head tasks;
727 struct plist_node pushable_tasks;
728 struct rb_node pushable_dl_tasks;
731 struct mm_struct *mm;
732 struct mm_struct *active_mm;
734 /* Per-thread vma caching: */
735 struct vmacache vmacache;
737 #ifdef SPLIT_RSS_COUNTING
738 struct task_rss_stat rss_stat;
743 /* The signal sent when the parent dies: */
745 /* JOBCTL_*, siglock protected: */
746 unsigned long jobctl;
748 /* Used for emulating ABI behavior of previous Linux versions: */
749 unsigned int personality;
751 /* Scheduler bits, serialized by scheduler locks: */
752 unsigned sched_reset_on_fork:1;
753 unsigned sched_contributes_to_load:1;
754 unsigned sched_migrated:1;
755 unsigned sched_remote_wakeup:1;
757 unsigned sched_psi_wake_requeue:1;
760 /* Force alignment to the next boundary: */
763 /* Unserialized, strictly 'current' */
765 /* Bit to tell LSMs we're in execve(): */
766 unsigned in_execve:1;
767 unsigned in_iowait:1;
768 #ifndef TIF_RESTORE_SIGMASK
769 unsigned restore_sigmask:1;
772 unsigned in_user_fault:1;
774 #ifdef CONFIG_COMPAT_BRK
775 unsigned brk_randomized:1;
777 #ifdef CONFIG_CGROUPS
778 /* disallow userland-initiated cgroup migration */
779 unsigned no_cgroup_migration:1;
780 /* task is frozen/stopped (used by the cgroup freezer) */
783 #ifdef CONFIG_BLK_CGROUP
784 /* to be used once the psi infrastructure lands upstream. */
785 unsigned use_memdelay:1;
788 unsigned long atomic_flags; /* Flags requiring atomic access. */
790 struct restart_block restart_block;
795 #ifdef CONFIG_STACKPROTECTOR
796 /* Canary value for the -fstack-protector GCC feature: */
797 unsigned long stack_canary;
800 * Pointers to the (original) parent process, youngest child, younger sibling,
801 * older sibling, respectively. (p->father can be replaced with
802 * p->real_parent->pid)
805 /* Real parent process: */
806 struct task_struct __rcu *real_parent;
808 /* Recipient of SIGCHLD, wait4() reports: */
809 struct task_struct __rcu *parent;
812 * Children/sibling form the list of natural children:
814 struct list_head children;
815 struct list_head sibling;
816 struct task_struct *group_leader;
819 * 'ptraced' is the list of tasks this task is using ptrace() on.
821 * This includes both natural children and PTRACE_ATTACH targets.
822 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
824 struct list_head ptraced;
825 struct list_head ptrace_entry;
827 /* PID/PID hash table linkage. */
828 struct pid *thread_pid;
829 struct hlist_node pid_links[PIDTYPE_MAX];
830 struct list_head thread_group;
831 struct list_head thread_node;
833 struct completion *vfork_done;
835 /* CLONE_CHILD_SETTID: */
836 int __user *set_child_tid;
838 /* CLONE_CHILD_CLEARTID: */
839 int __user *clear_child_tid;
843 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
848 struct prev_cputime prev_cputime;
849 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
853 #ifdef CONFIG_NO_HZ_FULL
854 atomic_t tick_dep_mask;
856 /* Context switch counts: */
858 unsigned long nivcsw;
860 /* Monotonic time in nsecs: */
863 /* Boot based time in nsecs: */
866 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
867 unsigned long min_flt;
868 unsigned long maj_flt;
870 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
871 struct posix_cputimers posix_cputimers;
873 /* Process credentials: */
875 /* Tracer's credentials at attach: */
876 const struct cred __rcu *ptracer_cred;
878 /* Objective and real subjective task credentials (COW): */
879 const struct cred __rcu *real_cred;
881 /* Effective (overridable) subjective task credentials (COW): */
882 const struct cred __rcu *cred;
885 /* Cached requested key. */
886 struct key *cached_requested_key;
890 * executable name, excluding path.
892 * - normally initialized setup_new_exec()
893 * - access it with [gs]et_task_comm()
894 * - lock it with task_lock()
896 char comm[TASK_COMM_LEN];
898 struct nameidata *nameidata;
900 #ifdef CONFIG_SYSVIPC
901 struct sysv_sem sysvsem;
902 struct sysv_shm sysvshm;
904 #ifdef CONFIG_DETECT_HUNG_TASK
905 unsigned long last_switch_count;
906 unsigned long last_switch_time;
908 /* Filesystem information: */
909 struct fs_struct *fs;
911 /* Open file information: */
912 struct files_struct *files;
915 struct nsproxy *nsproxy;
917 /* Signal handlers: */
918 struct signal_struct *signal;
919 struct sighand_struct *sighand;
921 sigset_t real_blocked;
922 /* Restored if set_restore_sigmask() was used: */
923 sigset_t saved_sigmask;
924 struct sigpending pending;
925 unsigned long sas_ss_sp;
927 unsigned int sas_ss_flags;
929 struct callback_head *task_works;
932 #ifdef CONFIG_AUDITSYSCALL
933 struct audit_context *audit_context;
936 unsigned int sessionid;
938 struct seccomp seccomp;
940 /* Thread group tracking: */
944 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
945 spinlock_t alloc_lock;
947 /* Protection of the PI data structures: */
948 raw_spinlock_t pi_lock;
950 struct wake_q_node wake_q;
952 #ifdef CONFIG_RT_MUTEXES
953 /* PI waiters blocked on a rt_mutex held by this task: */
954 struct rb_root_cached pi_waiters;
955 /* Updated under owner's pi_lock and rq lock */
956 struct task_struct *pi_top_task;
957 /* Deadlock detection and priority inheritance handling: */
958 struct rt_mutex_waiter *pi_blocked_on;
961 #ifdef CONFIG_DEBUG_MUTEXES
962 /* Mutex deadlock detection: */
963 struct mutex_waiter *blocked_on;
966 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
970 #ifdef CONFIG_TRACE_IRQFLAGS
971 unsigned int irq_events;
972 unsigned long hardirq_enable_ip;
973 unsigned long hardirq_disable_ip;
974 unsigned int hardirq_enable_event;
975 unsigned int hardirq_disable_event;
976 int hardirqs_enabled;
978 unsigned long softirq_disable_ip;
979 unsigned long softirq_enable_ip;
980 unsigned int softirq_disable_event;
981 unsigned int softirq_enable_event;
982 int softirqs_enabled;
986 #ifdef CONFIG_LOCKDEP
987 # define MAX_LOCK_DEPTH 48UL
990 unsigned int lockdep_recursion;
991 struct held_lock held_locks[MAX_LOCK_DEPTH];
995 unsigned int in_ubsan;
998 /* Journalling filesystem info: */
1001 /* Stacked block device info: */
1002 struct bio_list *bio_list;
1005 /* Stack plugging: */
1006 struct blk_plug *plug;
1010 struct reclaim_state *reclaim_state;
1012 struct backing_dev_info *backing_dev_info;
1014 struct io_context *io_context;
1016 #ifdef CONFIG_COMPACTION
1017 struct capture_control *capture_control;
1020 unsigned long ptrace_message;
1021 kernel_siginfo_t *last_siginfo;
1023 struct task_io_accounting ioac;
1025 /* Pressure stall state */
1026 unsigned int psi_flags;
1028 #ifdef CONFIG_TASK_XACCT
1029 /* Accumulated RSS usage: */
1031 /* Accumulated virtual memory usage: */
1033 /* stime + utime since last update: */
1036 #ifdef CONFIG_CPUSETS
1037 /* Protected by ->alloc_lock: */
1038 nodemask_t mems_allowed;
1039 /* Seqence number to catch updates: */
1040 seqcount_t mems_allowed_seq;
1041 int cpuset_mem_spread_rotor;
1042 int cpuset_slab_spread_rotor;
1044 #ifdef CONFIG_CGROUPS
1045 /* Control Group info protected by css_set_lock: */
1046 struct css_set __rcu *cgroups;
1047 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1048 struct list_head cg_list;
1050 #ifdef CONFIG_X86_CPU_RESCTRL
1055 struct robust_list_head __user *robust_list;
1056 #ifdef CONFIG_COMPAT
1057 struct compat_robust_list_head __user *compat_robust_list;
1059 struct list_head pi_state_list;
1060 struct futex_pi_state *pi_state_cache;
1061 struct mutex futex_exit_mutex;
1062 unsigned int futex_state;
1064 #ifdef CONFIG_PERF_EVENTS
1065 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1066 struct mutex perf_event_mutex;
1067 struct list_head perf_event_list;
1069 #ifdef CONFIG_DEBUG_PREEMPT
1070 unsigned long preempt_disable_ip;
1073 /* Protected by alloc_lock: */
1074 struct mempolicy *mempolicy;
1076 short pref_node_fork;
1078 #ifdef CONFIG_NUMA_BALANCING
1080 unsigned int numa_scan_period;
1081 unsigned int numa_scan_period_max;
1082 int numa_preferred_nid;
1083 unsigned long numa_migrate_retry;
1084 /* Migration stamp: */
1086 u64 last_task_numa_placement;
1087 u64 last_sum_exec_runtime;
1088 struct callback_head numa_work;
1091 * This pointer is only modified for current in syscall and
1092 * pagefault context (and for tasks being destroyed), so it can be read
1093 * from any of the following contexts:
1094 * - RCU read-side critical section
1095 * - current->numa_group from everywhere
1096 * - task's runqueue locked, task not running
1098 struct numa_group __rcu *numa_group;
1101 * numa_faults is an array split into four regions:
1102 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1103 * in this precise order.
1105 * faults_memory: Exponential decaying average of faults on a per-node
1106 * basis. Scheduling placement decisions are made based on these
1107 * counts. The values remain static for the duration of a PTE scan.
1108 * faults_cpu: Track the nodes the process was running on when a NUMA
1109 * hinting fault was incurred.
1110 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1111 * during the current scan window. When the scan completes, the counts
1112 * in faults_memory and faults_cpu decay and these values are copied.
1114 unsigned long *numa_faults;
1115 unsigned long total_numa_faults;
1118 * numa_faults_locality tracks if faults recorded during the last
1119 * scan window were remote/local or failed to migrate. The task scan
1120 * period is adapted based on the locality of the faults with different
1121 * weights depending on whether they were shared or private faults
1123 unsigned long numa_faults_locality[3];
1125 unsigned long numa_pages_migrated;
1126 #endif /* CONFIG_NUMA_BALANCING */
1129 struct rseq __user *rseq;
1132 * RmW on rseq_event_mask must be performed atomically
1133 * with respect to preemption.
1135 unsigned long rseq_event_mask;
1138 struct tlbflush_unmap_batch tlb_ubc;
1141 refcount_t rcu_users;
1142 struct rcu_head rcu;
1145 /* Cache last used pipe for splice(): */
1146 struct pipe_inode_info *splice_pipe;
1148 struct page_frag task_frag;
1150 #ifdef CONFIG_TASK_DELAY_ACCT
1151 struct task_delay_info *delays;
1154 #ifdef CONFIG_FAULT_INJECTION
1156 unsigned int fail_nth;
1159 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1160 * balance_dirty_pages() for a dirty throttling pause:
1163 int nr_dirtied_pause;
1164 /* Start of a write-and-pause period: */
1165 unsigned long dirty_paused_when;
1167 #ifdef CONFIG_LATENCYTOP
1168 int latency_record_count;
1169 struct latency_record latency_record[LT_SAVECOUNT];
1172 * Time slack values; these are used to round up poll() and
1173 * select() etc timeout values. These are in nanoseconds.
1176 u64 default_timer_slack_ns;
1179 unsigned int kasan_depth;
1182 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1183 /* Index of current stored address in ret_stack: */
1187 /* Stack of return addresses for return function tracing: */
1188 struct ftrace_ret_stack *ret_stack;
1190 /* Timestamp for last schedule: */
1191 unsigned long long ftrace_timestamp;
1194 * Number of functions that haven't been traced
1195 * because of depth overrun:
1197 atomic_t trace_overrun;
1199 /* Pause tracing: */
1200 atomic_t tracing_graph_pause;
1203 #ifdef CONFIG_TRACING
1204 /* State flags for use by tracers: */
1205 unsigned long trace;
1207 /* Bitmask and counter of trace recursion: */
1208 unsigned long trace_recursion;
1209 #endif /* CONFIG_TRACING */
1212 /* Coverage collection mode enabled for this task (0 if disabled): */
1213 unsigned int kcov_mode;
1215 /* Size of the kcov_area: */
1216 unsigned int kcov_size;
1218 /* Buffer for coverage collection: */
1221 /* KCOV descriptor wired with this task or NULL: */
1226 struct mem_cgroup *memcg_in_oom;
1227 gfp_t memcg_oom_gfp_mask;
1228 int memcg_oom_order;
1230 /* Number of pages to reclaim on returning to userland: */
1231 unsigned int memcg_nr_pages_over_high;
1233 /* Used by memcontrol for targeted memcg charge: */
1234 struct mem_cgroup *active_memcg;
1237 #ifdef CONFIG_BLK_CGROUP
1238 struct request_queue *throttle_queue;
1241 #ifdef CONFIG_UPROBES
1242 struct uprobe_task *utask;
1244 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1245 unsigned int sequential_io;
1246 unsigned int sequential_io_avg;
1248 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1249 unsigned long task_state_change;
1251 int pagefault_disabled;
1253 struct task_struct *oom_reaper_list;
1254 struct timer_list oom_reaper_timer;
1256 #ifdef CONFIG_VMAP_STACK
1257 struct vm_struct *stack_vm_area;
1259 #ifdef CONFIG_THREAD_INFO_IN_TASK
1260 /* A live task holds one reference: */
1261 refcount_t stack_refcount;
1263 #ifdef CONFIG_LIVEPATCH
1266 #ifdef CONFIG_SECURITY
1267 /* Used by LSM modules for access restriction: */
1271 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1272 unsigned long lowest_stack;
1273 unsigned long prev_lowest_stack;
1277 * New fields for task_struct should be added above here, so that
1278 * they are included in the randomized portion of task_struct.
1280 randomized_struct_fields_end
1282 /* CPU-specific state of this task: */
1283 struct thread_struct thread;
1286 * WARNING: on x86, 'thread_struct' contains a variable-sized
1287 * structure. It *MUST* be at the end of 'task_struct'.
1289 * Do not put anything below here!
1293 static inline struct pid *task_pid(struct task_struct *task)
1295 return task->thread_pid;
1299 * the helpers to get the task's different pids as they are seen
1300 * from various namespaces
1302 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1303 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1305 * task_xid_nr_ns() : id seen from the ns specified;
1307 * see also pid_nr() etc in include/linux/pid.h
1309 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1311 static inline pid_t task_pid_nr(struct task_struct *tsk)
1316 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1318 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1321 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1323 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1327 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1333 * pid_alive - check that a task structure is not stale
1334 * @p: Task structure to be checked.
1336 * Test if a process is not yet dead (at most zombie state)
1337 * If pid_alive fails, then pointers within the task structure
1338 * can be stale and must not be dereferenced.
1340 * Return: 1 if the process is alive. 0 otherwise.
1342 static inline int pid_alive(const struct task_struct *p)
1344 return p->thread_pid != NULL;
1347 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1349 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1352 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1354 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1358 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1360 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1363 static inline pid_t task_session_vnr(struct task_struct *tsk)
1365 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1368 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1370 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1373 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1375 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1378 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1384 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1390 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1392 return task_ppid_nr_ns(tsk, &init_pid_ns);
1395 /* Obsolete, do not use: */
1396 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1398 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1401 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1402 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1404 static inline unsigned int task_state_index(struct task_struct *tsk)
1406 unsigned int tsk_state = READ_ONCE(tsk->state);
1407 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1409 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1411 if (tsk_state == TASK_IDLE)
1412 state = TASK_REPORT_IDLE;
1417 static inline char task_index_to_char(unsigned int state)
1419 static const char state_char[] = "RSDTtXZPI";
1421 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1423 return state_char[state];
1426 static inline char task_state_to_char(struct task_struct *tsk)
1428 return task_index_to_char(task_state_index(tsk));
1432 * is_global_init - check if a task structure is init. Since init
1433 * is free to have sub-threads we need to check tgid.
1434 * @tsk: Task structure to be checked.
1436 * Check if a task structure is the first user space task the kernel created.
1438 * Return: 1 if the task structure is init. 0 otherwise.
1440 static inline int is_global_init(struct task_struct *tsk)
1442 return task_tgid_nr(tsk) == 1;
1445 extern struct pid *cad_pid;
1450 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1451 #define PF_EXITING 0x00000004 /* Getting shut down */
1452 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1453 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1454 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1455 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1456 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1457 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1458 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1459 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1460 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1461 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1462 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1463 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1464 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1465 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1466 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1467 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1468 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1469 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1470 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1471 #define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */
1472 #define PF_UMH 0x02000000 /* I'm an Usermodehelper process */
1473 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1474 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1475 #define PF_MEMALLOC_NOCMA 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
1476 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1477 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1480 * Only the _current_ task can read/write to tsk->flags, but other
1481 * tasks can access tsk->flags in readonly mode for example
1482 * with tsk_used_math (like during threaded core dumping).
1483 * There is however an exception to this rule during ptrace
1484 * or during fork: the ptracer task is allowed to write to the
1485 * child->flags of its traced child (same goes for fork, the parent
1486 * can write to the child->flags), because we're guaranteed the
1487 * child is not running and in turn not changing child->flags
1488 * at the same time the parent does it.
1490 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1491 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1492 #define clear_used_math() clear_stopped_child_used_math(current)
1493 #define set_used_math() set_stopped_child_used_math(current)
1495 #define conditional_stopped_child_used_math(condition, child) \
1496 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1498 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1500 #define copy_to_stopped_child_used_math(child) \
1501 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1503 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1504 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1505 #define used_math() tsk_used_math(current)
1507 static __always_inline bool is_percpu_thread(void)
1510 return (current->flags & PF_NO_SETAFFINITY) &&
1511 (current->nr_cpus_allowed == 1);
1517 /* Per-process atomic flags. */
1518 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1519 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1520 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1521 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1522 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1523 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1524 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1525 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1527 #define TASK_PFA_TEST(name, func) \
1528 static inline bool task_##func(struct task_struct *p) \
1529 { return test_bit(PFA_##name, &p->atomic_flags); }
1531 #define TASK_PFA_SET(name, func) \
1532 static inline void task_set_##func(struct task_struct *p) \
1533 { set_bit(PFA_##name, &p->atomic_flags); }
1535 #define TASK_PFA_CLEAR(name, func) \
1536 static inline void task_clear_##func(struct task_struct *p) \
1537 { clear_bit(PFA_##name, &p->atomic_flags); }
1539 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1540 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1542 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1543 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1544 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1546 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1547 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1548 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1550 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1551 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1552 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1554 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1555 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1556 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1558 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1559 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1561 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1562 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1563 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1565 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1566 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1569 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1571 current->flags &= ~flags;
1572 current->flags |= orig_flags & flags;
1575 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1576 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1578 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1579 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1581 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1584 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1586 if (!cpumask_test_cpu(0, new_mask))
1592 extern int yield_to(struct task_struct *p, bool preempt);
1593 extern void set_user_nice(struct task_struct *p, long nice);
1594 extern int task_prio(const struct task_struct *p);
1597 * task_nice - return the nice value of a given task.
1598 * @p: the task in question.
1600 * Return: The nice value [ -20 ... 0 ... 19 ].
1602 static inline int task_nice(const struct task_struct *p)
1604 return PRIO_TO_NICE((p)->static_prio);
1607 extern int can_nice(const struct task_struct *p, const int nice);
1608 extern int task_curr(const struct task_struct *p);
1609 extern int idle_cpu(int cpu);
1610 extern int available_idle_cpu(int cpu);
1611 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1612 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1613 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1614 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1615 extern struct task_struct *idle_task(int cpu);
1618 * is_idle_task - is the specified task an idle task?
1619 * @p: the task in question.
1621 * Return: 1 if @p is an idle task. 0 otherwise.
1623 static inline bool is_idle_task(const struct task_struct *p)
1625 return !!(p->flags & PF_IDLE);
1628 extern struct task_struct *curr_task(int cpu);
1629 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1633 union thread_union {
1634 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1635 struct task_struct task;
1637 #ifndef CONFIG_THREAD_INFO_IN_TASK
1638 struct thread_info thread_info;
1640 unsigned long stack[THREAD_SIZE/sizeof(long)];
1643 #ifndef CONFIG_THREAD_INFO_IN_TASK
1644 extern struct thread_info init_thread_info;
1647 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1649 #ifdef CONFIG_THREAD_INFO_IN_TASK
1650 static inline struct thread_info *task_thread_info(struct task_struct *task)
1652 return &task->thread_info;
1654 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1655 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1659 * find a task by one of its numerical ids
1661 * find_task_by_pid_ns():
1662 * finds a task by its pid in the specified namespace
1663 * find_task_by_vpid():
1664 * finds a task by its virtual pid
1666 * see also find_vpid() etc in include/linux/pid.h
1669 extern struct task_struct *find_task_by_vpid(pid_t nr);
1670 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1673 * find a task by its virtual pid and get the task struct
1675 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1677 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1678 extern int wake_up_process(struct task_struct *tsk);
1679 extern void wake_up_new_task(struct task_struct *tsk);
1682 extern void kick_process(struct task_struct *tsk);
1684 static inline void kick_process(struct task_struct *tsk) { }
1687 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1689 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1691 __set_task_comm(tsk, from, false);
1694 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1695 #define get_task_comm(buf, tsk) ({ \
1696 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1697 __get_task_comm(buf, sizeof(buf), tsk); \
1701 void scheduler_ipi(void);
1702 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1704 static inline void scheduler_ipi(void) { }
1705 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1712 * Set thread flags in other task's structures.
1713 * See asm/thread_info.h for TIF_xxxx flags available:
1715 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1717 set_ti_thread_flag(task_thread_info(tsk), flag);
1720 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1722 clear_ti_thread_flag(task_thread_info(tsk), flag);
1725 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1728 update_ti_thread_flag(task_thread_info(tsk), flag, value);
1731 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1733 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1736 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1738 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1741 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1743 return test_ti_thread_flag(task_thread_info(tsk), flag);
1746 static inline void set_tsk_need_resched(struct task_struct *tsk)
1748 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1751 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1753 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1756 static inline int test_tsk_need_resched(struct task_struct *tsk)
1758 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1762 * cond_resched() and cond_resched_lock(): latency reduction via
1763 * explicit rescheduling in places that are safe. The return
1764 * value indicates whether a reschedule was done in fact.
1765 * cond_resched_lock() will drop the spinlock before scheduling,
1767 #ifndef CONFIG_PREEMPTION
1768 extern int _cond_resched(void);
1770 static inline int _cond_resched(void) { return 0; }
1773 #define cond_resched() ({ \
1774 ___might_sleep(__FILE__, __LINE__, 0); \
1778 extern int __cond_resched_lock(spinlock_t *lock);
1780 #define cond_resched_lock(lock) ({ \
1781 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1782 __cond_resched_lock(lock); \
1785 static inline void cond_resched_rcu(void)
1787 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1795 * Does a critical section need to be broken due to another
1796 * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
1797 * but a general need for low latency)
1799 static inline int spin_needbreak(spinlock_t *lock)
1801 #ifdef CONFIG_PREEMPTION
1802 return spin_is_contended(lock);
1808 static __always_inline bool need_resched(void)
1810 return unlikely(tif_need_resched());
1814 * Wrappers for p->thread_info->cpu access. No-op on UP.
1818 static inline unsigned int task_cpu(const struct task_struct *p)
1820 #ifdef CONFIG_THREAD_INFO_IN_TASK
1821 return READ_ONCE(p->cpu);
1823 return READ_ONCE(task_thread_info(p)->cpu);
1827 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1831 static inline unsigned int task_cpu(const struct task_struct *p)
1836 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1840 #endif /* CONFIG_SMP */
1843 * In order to reduce various lock holder preemption latencies provide an
1844 * interface to see if a vCPU is currently running or not.
1846 * This allows us to terminate optimistic spin loops and block, analogous to
1847 * the native optimistic spin heuristic of testing if the lock owner task is
1850 #ifndef vcpu_is_preempted
1851 static inline bool vcpu_is_preempted(int cpu)
1857 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1858 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1860 #ifndef TASK_SIZE_OF
1861 #define TASK_SIZE_OF(tsk) TASK_SIZE
1867 * Map the event mask on the user-space ABI enum rseq_cs_flags
1868 * for direct mask checks.
1870 enum rseq_event_mask_bits {
1871 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1872 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1873 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1876 enum rseq_event_mask {
1877 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
1878 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
1879 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
1882 static inline void rseq_set_notify_resume(struct task_struct *t)
1885 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1888 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1890 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1891 struct pt_regs *regs)
1894 __rseq_handle_notify_resume(ksig, regs);
1897 static inline void rseq_signal_deliver(struct ksignal *ksig,
1898 struct pt_regs *regs)
1901 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
1903 rseq_handle_notify_resume(ksig, regs);
1906 /* rseq_preempt() requires preemption to be disabled. */
1907 static inline void rseq_preempt(struct task_struct *t)
1909 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1910 rseq_set_notify_resume(t);
1913 /* rseq_migrate() requires preemption to be disabled. */
1914 static inline void rseq_migrate(struct task_struct *t)
1916 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1917 rseq_set_notify_resume(t);
1921 * If parent process has a registered restartable sequences area, the
1922 * child inherits. Unregister rseq for a clone with CLONE_VM set.
1924 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1926 if (clone_flags & CLONE_VM) {
1929 t->rseq_event_mask = 0;
1931 t->rseq = current->rseq;
1932 t->rseq_sig = current->rseq_sig;
1933 t->rseq_event_mask = current->rseq_event_mask;
1937 static inline void rseq_execve(struct task_struct *t)
1941 t->rseq_event_mask = 0;
1946 static inline void rseq_set_notify_resume(struct task_struct *t)
1949 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1950 struct pt_regs *regs)
1953 static inline void rseq_signal_deliver(struct ksignal *ksig,
1954 struct pt_regs *regs)
1957 static inline void rseq_preempt(struct task_struct *t)
1960 static inline void rseq_migrate(struct task_struct *t)
1963 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1966 static inline void rseq_execve(struct task_struct *t)
1972 void __exit_umh(struct task_struct *tsk);
1974 static inline void exit_umh(struct task_struct *tsk)
1976 if (unlikely(tsk->flags & PF_UMH))
1980 #ifdef CONFIG_DEBUG_RSEQ
1982 void rseq_syscall(struct pt_regs *regs);
1986 static inline void rseq_syscall(struct pt_regs *regs)
1992 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
1993 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
1994 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
1996 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
1997 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
1998 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2000 int sched_trace_rq_cpu(struct rq *rq);
2002 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);