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>
13 #include <asm/processor.h>
14 #include <linux/thread_info.h>
15 #include <linux/preempt.h>
16 #include <linux/cpumask_types.h>
18 #include <linux/cache.h>
19 #include <linux/irqflags_types.h>
20 #include <linux/smp_types.h>
21 #include <linux/pid_types.h>
22 #include <linux/sem_types.h>
23 #include <linux/shm.h>
24 #include <linux/kmsan_types.h>
25 #include <linux/mutex_types.h>
26 #include <linux/plist_types.h>
27 #include <linux/hrtimer_types.h>
28 #include <linux/timer_types.h>
29 #include <linux/seccomp_types.h>
30 #include <linux/nodemask_types.h>
31 #include <linux/refcount_types.h>
32 #include <linux/resource.h>
33 #include <linux/latencytop.h>
34 #include <linux/sched/prio.h>
35 #include <linux/sched/types.h>
36 #include <linux/signal_types.h>
37 #include <linux/syscall_user_dispatch_types.h>
38 #include <linux/mm_types_task.h>
39 #include <linux/netdevice_xmit.h>
40 #include <linux/task_io_accounting.h>
41 #include <linux/posix-timers_types.h>
42 #include <linux/restart_block.h>
43 #include <uapi/linux/rseq.h>
44 #include <linux/seqlock_types.h>
45 #include <linux/kcsan.h>
47 #include <linux/livepatch_sched.h>
48 #include <linux/uidgid_types.h>
49 #include <asm/kmap_size.h>
51 /* task_struct member predeclarations (sorted alphabetically): */
55 struct bpf_local_storage
;
57 struct bpf_net_context
;
58 struct capture_control
;
61 struct futex_pi_state
;
67 struct perf_event_context
;
69 struct pipe_inode_info
;
72 struct robust_list_head
;
76 struct sched_dl_entity
;
78 struct sighand_struct
;
80 struct task_delay_info
;
85 #include <linux/sched/ext.h>
88 * Task state bitmask. NOTE! These bits are also
89 * encoded in fs/proc/array.c: get_task_state().
91 * We have two separate sets of flags: task->__state
92 * is about runnability, while task->exit_state are
93 * about the task exiting. Confusing, but this way
94 * modifying one set can't modify the other one by
98 /* Used in tsk->__state: */
99 #define TASK_RUNNING 0x00000000
100 #define TASK_INTERRUPTIBLE 0x00000001
101 #define TASK_UNINTERRUPTIBLE 0x00000002
102 #define __TASK_STOPPED 0x00000004
103 #define __TASK_TRACED 0x00000008
104 /* Used in tsk->exit_state: */
105 #define EXIT_DEAD 0x00000010
106 #define EXIT_ZOMBIE 0x00000020
107 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
108 /* Used in tsk->__state again: */
109 #define TASK_PARKED 0x00000040
110 #define TASK_DEAD 0x00000080
111 #define TASK_WAKEKILL 0x00000100
112 #define TASK_WAKING 0x00000200
113 #define TASK_NOLOAD 0x00000400
114 #define TASK_NEW 0x00000800
115 #define TASK_RTLOCK_WAIT 0x00001000
116 #define TASK_FREEZABLE 0x00002000
117 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
118 #define TASK_FROZEN 0x00008000
119 #define TASK_STATE_MAX 0x00010000
121 #define TASK_ANY (TASK_STATE_MAX-1)
124 * DO NOT ADD ANY NEW USERS !
126 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
128 /* Convenience macros for the sake of set_current_state: */
129 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
130 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
131 #define TASK_TRACED __TASK_TRACED
133 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
135 /* Convenience macros for the sake of wake_up(): */
136 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
138 /* get_task_state(): */
139 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
140 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
141 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
144 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
146 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
147 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
148 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
151 * Special states are those that do not use the normal wait-loop pattern. See
152 * the comment with set_special_state().
154 #define is_special_task_state(state) \
155 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | \
156 TASK_DEAD | TASK_FROZEN))
158 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
159 # define debug_normal_state_change(state_value) \
161 WARN_ON_ONCE(is_special_task_state(state_value)); \
162 current->task_state_change = _THIS_IP_; \
165 # define debug_special_state_change(state_value) \
167 WARN_ON_ONCE(!is_special_task_state(state_value)); \
168 current->task_state_change = _THIS_IP_; \
171 # define debug_rtlock_wait_set_state() \
173 current->saved_state_change = current->task_state_change;\
174 current->task_state_change = _THIS_IP_; \
177 # define debug_rtlock_wait_restore_state() \
179 current->task_state_change = current->saved_state_change;\
183 # define debug_normal_state_change(cond) do { } while (0)
184 # define debug_special_state_change(cond) do { } while (0)
185 # define debug_rtlock_wait_set_state() do { } while (0)
186 # define debug_rtlock_wait_restore_state() do { } while (0)
190 * set_current_state() includes a barrier so that the write of current->__state
191 * is correctly serialised wrt the caller's subsequent test of whether to
195 * set_current_state(TASK_UNINTERRUPTIBLE);
201 * __set_current_state(TASK_RUNNING);
203 * If the caller does not need such serialisation (because, for instance, the
204 * CONDITION test and condition change and wakeup are under the same lock) then
205 * use __set_current_state().
207 * The above is typically ordered against the wakeup, which does:
210 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
212 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
213 * accessing p->__state.
215 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
216 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
217 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
219 * However, with slightly different timing the wakeup TASK_RUNNING store can
220 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
221 * a problem either because that will result in one extra go around the loop
222 * and our @cond test will save the day.
224 * Also see the comments of try_to_wake_up().
226 #define __set_current_state(state_value) \
228 debug_normal_state_change((state_value)); \
229 WRITE_ONCE(current->__state, (state_value)); \
232 #define set_current_state(state_value) \
234 debug_normal_state_change((state_value)); \
235 smp_store_mb(current->__state, (state_value)); \
239 * set_special_state() should be used for those states when the blocking task
240 * can not use the regular condition based wait-loop. In that case we must
241 * serialize against wakeups such that any possible in-flight TASK_RUNNING
242 * stores will not collide with our state change.
244 #define set_special_state(state_value) \
246 unsigned long flags; /* may shadow */ \
248 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
249 debug_special_state_change((state_value)); \
250 WRITE_ONCE(current->__state, (state_value)); \
251 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
255 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
257 * RT's spin/rwlock substitutions are state preserving. The state of the
258 * task when blocking on the lock is saved in task_struct::saved_state and
259 * restored after the lock has been acquired. These operations are
260 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
261 * lock related wakeups while the task is blocked on the lock are
262 * redirected to operate on task_struct::saved_state to ensure that these
263 * are not dropped. On restore task_struct::saved_state is set to
264 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
266 * The lock operation looks like this:
268 * current_save_and_set_rtlock_wait_state();
272 * raw_spin_unlock_irq(&lock->wait_lock);
274 * raw_spin_lock_irq(&lock->wait_lock);
275 * set_current_state(TASK_RTLOCK_WAIT);
277 * current_restore_rtlock_saved_state();
279 #define current_save_and_set_rtlock_wait_state() \
281 lockdep_assert_irqs_disabled(); \
282 raw_spin_lock(¤t->pi_lock); \
283 current->saved_state = current->__state; \
284 debug_rtlock_wait_set_state(); \
285 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
286 raw_spin_unlock(¤t->pi_lock); \
289 #define current_restore_rtlock_saved_state() \
291 lockdep_assert_irqs_disabled(); \
292 raw_spin_lock(¤t->pi_lock); \
293 debug_rtlock_wait_restore_state(); \
294 WRITE_ONCE(current->__state, current->saved_state); \
295 current->saved_state = TASK_RUNNING; \
296 raw_spin_unlock(¤t->pi_lock); \
299 #define get_current_state() READ_ONCE(current->__state)
302 * Define the task command name length as enum, then it can be visible to
309 extern void sched_tick(void);
311 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
313 extern long schedule_timeout(long timeout
);
314 extern long schedule_timeout_interruptible(long timeout
);
315 extern long schedule_timeout_killable(long timeout
);
316 extern long schedule_timeout_uninterruptible(long timeout
);
317 extern long schedule_timeout_idle(long timeout
);
318 asmlinkage
void schedule(void);
319 extern void schedule_preempt_disabled(void);
320 asmlinkage
void preempt_schedule_irq(void);
321 #ifdef CONFIG_PREEMPT_RT
322 extern void schedule_rtlock(void);
325 extern int __must_check
io_schedule_prepare(void);
326 extern void io_schedule_finish(int token
);
327 extern long io_schedule_timeout(long timeout
);
328 extern void io_schedule(void);
331 * struct prev_cputime - snapshot of system and user cputime
332 * @utime: time spent in user mode
333 * @stime: time spent in system mode
334 * @lock: protects the above two fields
336 * Stores previous user/system time values such that we can guarantee
339 struct prev_cputime
{
340 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
348 /* Task is sleeping or running in a CPU with VTIME inactive: */
352 /* Task runs in kernelspace in a CPU with VTIME active: */
354 /* Task runs in userspace in a CPU with VTIME active: */
356 /* Task runs as guests in a CPU with VTIME active: */
362 unsigned long long starttime
;
363 enum vtime_state state
;
371 * Utilization clamp constraints.
372 * @UCLAMP_MIN: Minimum utilization
373 * @UCLAMP_MAX: Maximum utilization
374 * @UCLAMP_CNT: Utilization clamp constraints count
383 extern struct root_domain def_root_domain
;
384 extern struct mutex sched_domains_mutex
;
392 #ifdef CONFIG_SCHED_INFO
393 /* Cumulative counters: */
395 /* # of times we have run on this CPU: */
396 unsigned long pcount
;
398 /* Time spent waiting on a runqueue: */
399 unsigned long long run_delay
;
403 /* When did we last run on a CPU? */
404 unsigned long long last_arrival
;
406 /* When were we last queued to run? */
407 unsigned long long last_queued
;
409 #endif /* CONFIG_SCHED_INFO */
413 * Integer metrics need fixed point arithmetic, e.g., sched/fair
414 * has a few: load, load_avg, util_avg, freq, and capacity.
416 * We define a basic fixed point arithmetic range, and then formalize
417 * all these metrics based on that basic range.
419 # define SCHED_FIXEDPOINT_SHIFT 10
420 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
422 /* Increase resolution of cpu_capacity calculations */
423 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
424 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
427 unsigned long weight
;
432 * The load/runnable/util_avg accumulates an infinite geometric series
433 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
435 * [load_avg definition]
437 * load_avg = runnable% * scale_load_down(load)
439 * [runnable_avg definition]
441 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
443 * [util_avg definition]
445 * util_avg = running% * SCHED_CAPACITY_SCALE
447 * where runnable% is the time ratio that a sched_entity is runnable and
448 * running% the time ratio that a sched_entity is running.
450 * For cfs_rq, they are the aggregated values of all runnable and blocked
453 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
454 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
455 * for computing those signals (see update_rq_clock_pelt())
457 * N.B., the above ratios (runnable% and running%) themselves are in the
458 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
459 * to as large a range as necessary. This is for example reflected by
460 * util_avg's SCHED_CAPACITY_SCALE.
464 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
465 * with the highest load (=88761), always runnable on a single cfs_rq,
466 * and should not overflow as the number already hits PID_MAX_LIMIT.
468 * For all other cases (including 32-bit kernels), struct load_weight's
469 * weight will overflow first before we do, because:
471 * Max(load_avg) <= Max(load.weight)
473 * Then it is the load_weight's responsibility to consider overflow
477 u64 last_update_time
;
482 unsigned long load_avg
;
483 unsigned long runnable_avg
;
484 unsigned long util_avg
;
485 unsigned int util_est
;
486 } ____cacheline_aligned
;
489 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
490 * updates. When a task is dequeued, its util_est should not be updated if its
491 * util_avg has not been updated in the meantime.
492 * This information is mapped into the MSB bit of util_est at dequeue time.
493 * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
494 * it is safe to use MSB.
496 #define UTIL_EST_WEIGHT_SHIFT 2
497 #define UTIL_AVG_UNCHANGED 0x80000000
499 struct sched_statistics
{
500 #ifdef CONFIG_SCHEDSTATS
510 s64 sum_sleep_runtime
;
514 s64 sum_block_runtime
;
519 u64 nr_migrations_cold
;
520 u64 nr_failed_migrations_affine
;
521 u64 nr_failed_migrations_running
;
522 u64 nr_failed_migrations_hot
;
523 u64 nr_forced_migrations
;
527 u64 nr_wakeups_migrate
;
528 u64 nr_wakeups_local
;
529 u64 nr_wakeups_remote
;
530 u64 nr_wakeups_affine
;
531 u64 nr_wakeups_affine_attempts
;
532 u64 nr_wakeups_passive
;
535 #ifdef CONFIG_SCHED_CORE
536 u64 core_forceidle_sum
;
538 #endif /* CONFIG_SCHEDSTATS */
539 } ____cacheline_aligned
;
541 struct sched_entity
{
542 /* For load-balancing: */
543 struct load_weight load
;
544 struct rb_node run_node
;
549 struct list_head group_node
;
551 unsigned char sched_delayed
;
552 unsigned char rel_deadline
;
553 unsigned char custom_slice
;
557 u64 sum_exec_runtime
;
558 u64 prev_sum_exec_runtime
;
565 #ifdef CONFIG_FAIR_GROUP_SCHED
567 struct sched_entity
*parent
;
568 /* rq on which this entity is (to be) queued: */
569 struct cfs_rq
*cfs_rq
;
570 /* rq "owned" by this entity/group: */
572 /* cached value of my_q->h_nr_running */
573 unsigned long runnable_weight
;
578 * Per entity load average tracking.
580 * Put into separate cache line so it does not
581 * collide with read-mostly values above.
583 struct sched_avg avg
;
587 struct sched_rt_entity
{
588 struct list_head run_list
;
589 unsigned long timeout
;
590 unsigned long watchdog_stamp
;
591 unsigned int time_slice
;
592 unsigned short on_rq
;
593 unsigned short on_list
;
595 struct sched_rt_entity
*back
;
596 #ifdef CONFIG_RT_GROUP_SCHED
597 struct sched_rt_entity
*parent
;
598 /* rq on which this entity is (to be) queued: */
600 /* rq "owned" by this entity/group: */
603 } __randomize_layout
;
605 typedef bool (*dl_server_has_tasks_f
)(struct sched_dl_entity
*);
606 typedef struct task_struct
*(*dl_server_pick_f
)(struct sched_dl_entity
*);
608 struct sched_dl_entity
{
609 struct rb_node rb_node
;
612 * Original scheduling parameters. Copied here from sched_attr
613 * during sched_setattr(), they will remain the same until
614 * the next sched_setattr().
616 u64 dl_runtime
; /* Maximum runtime for each instance */
617 u64 dl_deadline
; /* Relative deadline of each instance */
618 u64 dl_period
; /* Separation of two instances (period) */
619 u64 dl_bw
; /* dl_runtime / dl_period */
620 u64 dl_density
; /* dl_runtime / dl_deadline */
623 * Actual scheduling parameters. Initialized with the values above,
624 * they are continuously updated during task execution. Note that
625 * the remaining runtime could be < 0 in case we are in overrun.
627 s64 runtime
; /* Remaining runtime for this instance */
628 u64 deadline
; /* Absolute deadline for this instance */
629 unsigned int flags
; /* Specifying the scheduler behaviour */
634 * @dl_throttled tells if we exhausted the runtime. If so, the
635 * task has to wait for a replenishment to be performed at the
636 * next firing of dl_timer.
638 * @dl_yielded tells if task gave up the CPU before consuming
639 * all its available runtime during the last job.
641 * @dl_non_contending tells if the task is inactive while still
642 * contributing to the active utilization. In other words, it
643 * indicates if the inactive timer has been armed and its handler
644 * has not been executed yet. This flag is useful to avoid race
645 * conditions between the inactive timer handler and the wakeup
648 * @dl_overrun tells if the task asked to be informed about runtime
651 * @dl_server tells if this is a server entity.
653 * @dl_defer tells if this is a deferred or regular server. For
654 * now only defer server exists.
656 * @dl_defer_armed tells if the deferrable server is waiting
657 * for the replenishment timer to activate it.
659 * @dl_defer_running tells if the deferrable server is actually
660 * running, skipping the defer phase.
662 unsigned int dl_throttled
: 1;
663 unsigned int dl_yielded
: 1;
664 unsigned int dl_non_contending
: 1;
665 unsigned int dl_overrun
: 1;
666 unsigned int dl_server
: 1;
667 unsigned int dl_defer
: 1;
668 unsigned int dl_defer_armed
: 1;
669 unsigned int dl_defer_running
: 1;
672 * Bandwidth enforcement timer. Each -deadline task has its
673 * own bandwidth to be enforced, thus we need one timer per task.
675 struct hrtimer dl_timer
;
678 * Inactive timer, responsible for decreasing the active utilization
679 * at the "0-lag time". When a -deadline task blocks, it contributes
680 * to GRUB's active utilization until the "0-lag time", hence a
681 * timer is needed to decrease the active utilization at the correct
684 struct hrtimer inactive_timer
;
687 * Bits for DL-server functionality. Also see the comment near
688 * dl_server_update().
690 * @rq the runqueue this server is for
692 * @server_has_tasks() returns true if @server_pick return a
696 dl_server_has_tasks_f server_has_tasks
;
697 dl_server_pick_f server_pick_task
;
699 #ifdef CONFIG_RT_MUTEXES
701 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
702 * pi_se points to the donor, otherwise points to the dl_se it belongs
703 * to (the original one/itself).
705 struct sched_dl_entity
*pi_se
;
709 #ifdef CONFIG_UCLAMP_TASK
710 /* Number of utilization clamp buckets (shorter alias) */
711 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
714 * Utilization clamp for a scheduling entity
715 * @value: clamp value "assigned" to a se
716 * @bucket_id: bucket index corresponding to the "assigned" value
717 * @active: the se is currently refcounted in a rq's bucket
718 * @user_defined: the requested clamp value comes from user-space
720 * The bucket_id is the index of the clamp bucket matching the clamp value
721 * which is pre-computed and stored to avoid expensive integer divisions from
724 * The active bit is set whenever a task has got an "effective" value assigned,
725 * which can be different from the clamp value "requested" from user-space.
726 * This allows to know a task is refcounted in the rq's bucket corresponding
727 * to the "effective" bucket_id.
729 * The user_defined bit is set whenever a task has got a task-specific clamp
730 * value requested from userspace, i.e. the system defaults apply to this task
731 * just as a restriction. This allows to relax default clamps when a less
732 * restrictive task-specific value has been requested, thus allowing to
733 * implement a "nice" semantic. For example, a task running with a 20%
734 * default boost can still drop its own boosting to 0%.
737 unsigned int value
: bits_per(SCHED_CAPACITY_SCALE
);
738 unsigned int bucket_id
: bits_per(UCLAMP_BUCKETS
);
739 unsigned int active
: 1;
740 unsigned int user_defined
: 1;
742 #endif /* CONFIG_UCLAMP_TASK */
748 u8 exp_hint
; /* Hint for performance. */
749 u8 need_mb
; /* Readers need smp_mb(). */
751 u32 s
; /* Set of bits. */
754 enum perf_event_task_context
{
755 perf_invalid_context
= -1,
758 perf_nr_task_contexts
,
762 * Number of contexts where an event can trigger:
763 * task, softirq, hardirq, nmi.
765 #define PERF_NR_CONTEXTS 4
768 struct wake_q_node
*next
;
772 #ifdef CONFIG_KMAP_LOCAL
774 pte_t pteval
[KM_MAX_IDX
];
779 #ifdef CONFIG_THREAD_INFO_IN_TASK
781 * For reasons of header soup (see current_thread_info()), this
782 * must be the first element of task_struct.
784 struct thread_info thread_info
;
786 unsigned int __state
;
788 /* saved state for "spinlock sleepers" */
789 unsigned int saved_state
;
792 * This begins the randomizable portion of task_struct. Only
793 * scheduling-critical items should be added above here.
795 randomized_struct_fields_start
799 /* Per task flags (PF_*), defined further below: */
803 #ifdef CONFIG_MEM_ALLOC_PROFILING
804 struct alloc_tag
*alloc_tag
;
809 struct __call_single_node wake_entry
;
810 unsigned int wakee_flips
;
811 unsigned long wakee_flip_decay_ts
;
812 struct task_struct
*last_wakee
;
815 * recent_used_cpu is initially set as the last CPU used by a task
816 * that wakes affine another task. Waker/wakee relationships can
817 * push tasks around a CPU where each wakeup moves to the next one.
818 * Tracking a recently used CPU allows a quick search for a recently
819 * used CPU that may be idle.
829 unsigned int rt_priority
;
831 struct sched_entity se
;
832 struct sched_rt_entity rt
;
833 struct sched_dl_entity dl
;
834 struct sched_dl_entity
*dl_server
;
835 #ifdef CONFIG_SCHED_CLASS_EXT
836 struct sched_ext_entity scx
;
838 const struct sched_class
*sched_class
;
840 #ifdef CONFIG_SCHED_CORE
841 struct rb_node core_node
;
842 unsigned long core_cookie
;
843 unsigned int core_occupation
;
846 #ifdef CONFIG_CGROUP_SCHED
847 struct task_group
*sched_task_group
;
851 #ifdef CONFIG_UCLAMP_TASK
853 * Clamp values requested for a scheduling entity.
854 * Must be updated with task_rq_lock() held.
856 struct uclamp_se uclamp_req
[UCLAMP_CNT
];
858 * Effective clamp values used for a scheduling entity.
859 * Must be updated with task_rq_lock() held.
861 struct uclamp_se uclamp
[UCLAMP_CNT
];
864 struct sched_statistics stats
;
866 #ifdef CONFIG_PREEMPT_NOTIFIERS
867 /* List of struct preempt_notifier: */
868 struct hlist_head preempt_notifiers
;
871 #ifdef CONFIG_BLK_DEV_IO_TRACE
872 unsigned int btrace_seq
;
876 unsigned long max_allowed_capacity
;
878 const cpumask_t
*cpus_ptr
;
879 cpumask_t
*user_cpus_ptr
;
881 void *migration_pending
;
883 unsigned short migration_disabled
;
885 unsigned short migration_flags
;
887 #ifdef CONFIG_PREEMPT_RCU
888 int rcu_read_lock_nesting
;
889 union rcu_special rcu_read_unlock_special
;
890 struct list_head rcu_node_entry
;
891 struct rcu_node
*rcu_blocked_node
;
892 #endif /* #ifdef CONFIG_PREEMPT_RCU */
894 #ifdef CONFIG_TASKS_RCU
895 unsigned long rcu_tasks_nvcsw
;
896 u8 rcu_tasks_holdout
;
898 int rcu_tasks_idle_cpu
;
899 struct list_head rcu_tasks_holdout_list
;
900 int rcu_tasks_exit_cpu
;
901 struct list_head rcu_tasks_exit_list
;
902 #endif /* #ifdef CONFIG_TASKS_RCU */
904 #ifdef CONFIG_TASKS_TRACE_RCU
905 int trc_reader_nesting
;
907 union rcu_special trc_reader_special
;
908 struct list_head trc_holdout_list
;
909 struct list_head trc_blkd_node
;
911 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
913 struct sched_info sched_info
;
915 struct list_head tasks
;
917 struct plist_node pushable_tasks
;
918 struct rb_node pushable_dl_tasks
;
921 struct mm_struct
*mm
;
922 struct mm_struct
*active_mm
;
923 struct address_space
*faults_disabled_mapping
;
928 /* The signal sent when the parent dies: */
930 /* JOBCTL_*, siglock protected: */
931 unsigned long jobctl
;
933 /* Used for emulating ABI behavior of previous Linux versions: */
934 unsigned int personality
;
936 /* Scheduler bits, serialized by scheduler locks: */
937 unsigned sched_reset_on_fork
:1;
938 unsigned sched_contributes_to_load
:1;
939 unsigned sched_migrated
:1;
941 /* Force alignment to the next boundary: */
944 /* Unserialized, strictly 'current' */
947 * This field must not be in the scheduler word above due to wakelist
948 * queueing no longer being serialized by p->on_cpu. However:
951 * schedule() if (p->on_rq && ..) // false
952 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
953 * deactivate_task() ttwu_queue_wakelist())
954 * p->on_rq = 0; p->sched_remote_wakeup = Y;
956 * guarantees all stores of 'current' are visible before
957 * ->sched_remote_wakeup gets used, so it can be in this word.
959 unsigned sched_remote_wakeup
:1;
960 #ifdef CONFIG_RT_MUTEXES
961 unsigned sched_rt_mutex
:1;
964 /* Bit to tell TOMOYO we're in execve(): */
965 unsigned in_execve
:1;
966 unsigned in_iowait
:1;
967 #ifndef TIF_RESTORE_SIGMASK
968 unsigned restore_sigmask
:1;
970 #ifdef CONFIG_MEMCG_V1
971 unsigned in_user_fault
:1;
973 #ifdef CONFIG_LRU_GEN
974 /* whether the LRU algorithm may apply to this access */
975 unsigned in_lru_fault
:1;
977 #ifdef CONFIG_COMPAT_BRK
978 unsigned brk_randomized
:1;
980 #ifdef CONFIG_CGROUPS
981 /* disallow userland-initiated cgroup migration */
982 unsigned no_cgroup_migration
:1;
983 /* task is frozen/stopped (used by the cgroup freezer) */
986 #ifdef CONFIG_BLK_CGROUP
987 unsigned use_memdelay
:1;
990 /* Stalled due to lack of memory */
991 unsigned in_memstall
:1;
993 #ifdef CONFIG_PAGE_OWNER
994 /* Used by page_owner=on to detect recursion in page tracking. */
995 unsigned in_page_owner
:1;
997 #ifdef CONFIG_EVENTFD
998 /* Recursion prevention for eventfd_signal() */
999 unsigned in_eventfd
:1;
1001 #ifdef CONFIG_ARCH_HAS_CPU_PASID
1002 unsigned pasid_activated
:1;
1004 #ifdef CONFIG_X86_BUS_LOCK_DETECT
1005 unsigned reported_split_lock
:1;
1007 #ifdef CONFIG_TASK_DELAY_ACCT
1008 /* delay due to memory thrashing */
1009 unsigned in_thrashing
:1;
1011 #ifdef CONFIG_PREEMPT_RT
1012 struct netdev_xmit net_xmit
;
1014 unsigned long atomic_flags
; /* Flags requiring atomic access. */
1016 struct restart_block restart_block
;
1021 #ifdef CONFIG_STACKPROTECTOR
1022 /* Canary value for the -fstack-protector GCC feature: */
1023 unsigned long stack_canary
;
1026 * Pointers to the (original) parent process, youngest child, younger sibling,
1027 * older sibling, respectively. (p->father can be replaced with
1028 * p->real_parent->pid)
1031 /* Real parent process: */
1032 struct task_struct __rcu
*real_parent
;
1034 /* Recipient of SIGCHLD, wait4() reports: */
1035 struct task_struct __rcu
*parent
;
1038 * Children/sibling form the list of natural children:
1040 struct list_head children
;
1041 struct list_head sibling
;
1042 struct task_struct
*group_leader
;
1045 * 'ptraced' is the list of tasks this task is using ptrace() on.
1047 * This includes both natural children and PTRACE_ATTACH targets.
1048 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1050 struct list_head ptraced
;
1051 struct list_head ptrace_entry
;
1053 /* PID/PID hash table linkage. */
1054 struct pid
*thread_pid
;
1055 struct hlist_node pid_links
[PIDTYPE_MAX
];
1056 struct list_head thread_node
;
1058 struct completion
*vfork_done
;
1060 /* CLONE_CHILD_SETTID: */
1061 int __user
*set_child_tid
;
1063 /* CLONE_CHILD_CLEARTID: */
1064 int __user
*clear_child_tid
;
1066 /* PF_KTHREAD | PF_IO_WORKER */
1067 void *worker_private
;
1071 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1076 struct prev_cputime prev_cputime
;
1077 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1081 #ifdef CONFIG_NO_HZ_FULL
1082 atomic_t tick_dep_mask
;
1084 /* Context switch counts: */
1085 unsigned long nvcsw
;
1086 unsigned long nivcsw
;
1088 /* Monotonic time in nsecs: */
1091 /* Boot based time in nsecs: */
1094 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1095 unsigned long min_flt
;
1096 unsigned long maj_flt
;
1098 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1099 struct posix_cputimers posix_cputimers
;
1101 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1102 struct posix_cputimers_work posix_cputimers_work
;
1105 /* Process credentials: */
1107 /* Tracer's credentials at attach: */
1108 const struct cred __rcu
*ptracer_cred
;
1110 /* Objective and real subjective task credentials (COW): */
1111 const struct cred __rcu
*real_cred
;
1113 /* Effective (overridable) subjective task credentials (COW): */
1114 const struct cred __rcu
*cred
;
1117 /* Cached requested key. */
1118 struct key
*cached_requested_key
;
1122 * executable name, excluding path.
1124 * - normally initialized begin_new_exec()
1125 * - set it with set_task_comm()
1126 * - strscpy_pad() to ensure it is always NUL-terminated and
1128 * - task_lock() to ensure the operation is atomic and the name is
1131 char comm
[TASK_COMM_LEN
];
1133 struct nameidata
*nameidata
;
1135 #ifdef CONFIG_SYSVIPC
1136 struct sysv_sem sysvsem
;
1137 struct sysv_shm sysvshm
;
1139 #ifdef CONFIG_DETECT_HUNG_TASK
1140 unsigned long last_switch_count
;
1141 unsigned long last_switch_time
;
1143 /* Filesystem information: */
1144 struct fs_struct
*fs
;
1146 /* Open file information: */
1147 struct files_struct
*files
;
1149 #ifdef CONFIG_IO_URING
1150 struct io_uring_task
*io_uring
;
1154 struct nsproxy
*nsproxy
;
1156 /* Signal handlers: */
1157 struct signal_struct
*signal
;
1158 struct sighand_struct __rcu
*sighand
;
1160 sigset_t real_blocked
;
1161 /* Restored if set_restore_sigmask() was used: */
1162 sigset_t saved_sigmask
;
1163 struct sigpending pending
;
1164 unsigned long sas_ss_sp
;
1166 unsigned int sas_ss_flags
;
1168 struct callback_head
*task_works
;
1171 #ifdef CONFIG_AUDITSYSCALL
1172 struct audit_context
*audit_context
;
1175 unsigned int sessionid
;
1177 struct seccomp seccomp
;
1178 struct syscall_user_dispatch syscall_dispatch
;
1180 /* Thread group tracking: */
1184 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1185 spinlock_t alloc_lock
;
1187 /* Protection of the PI data structures: */
1188 raw_spinlock_t pi_lock
;
1190 struct wake_q_node wake_q
;
1192 #ifdef CONFIG_RT_MUTEXES
1193 /* PI waiters blocked on a rt_mutex held by this task: */
1194 struct rb_root_cached pi_waiters
;
1195 /* Updated under owner's pi_lock and rq lock */
1196 struct task_struct
*pi_top_task
;
1197 /* Deadlock detection and priority inheritance handling: */
1198 struct rt_mutex_waiter
*pi_blocked_on
;
1201 #ifdef CONFIG_DEBUG_MUTEXES
1202 /* Mutex deadlock detection: */
1203 struct mutex_waiter
*blocked_on
;
1206 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1207 int non_block_count
;
1210 #ifdef CONFIG_TRACE_IRQFLAGS
1211 struct irqtrace_events irqtrace
;
1212 unsigned int hardirq_threaded
;
1213 u64 hardirq_chain_key
;
1214 int softirqs_enabled
;
1215 int softirq_context
;
1218 #ifdef CONFIG_PREEMPT_RT
1219 int softirq_disable_cnt
;
1222 #ifdef CONFIG_LOCKDEP
1223 # define MAX_LOCK_DEPTH 48UL
1226 unsigned int lockdep_recursion
;
1227 struct held_lock held_locks
[MAX_LOCK_DEPTH
];
1230 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1231 unsigned int in_ubsan
;
1234 /* Journalling filesystem info: */
1237 /* Stacked block device info: */
1238 struct bio_list
*bio_list
;
1240 /* Stack plugging: */
1241 struct blk_plug
*plug
;
1244 struct reclaim_state
*reclaim_state
;
1246 struct io_context
*io_context
;
1248 #ifdef CONFIG_COMPACTION
1249 struct capture_control
*capture_control
;
1252 unsigned long ptrace_message
;
1253 kernel_siginfo_t
*last_siginfo
;
1255 struct task_io_accounting ioac
;
1257 /* Pressure stall state */
1258 unsigned int psi_flags
;
1260 #ifdef CONFIG_TASK_XACCT
1261 /* Accumulated RSS usage: */
1263 /* Accumulated virtual memory usage: */
1265 /* stime + utime since last update: */
1268 #ifdef CONFIG_CPUSETS
1269 /* Protected by ->alloc_lock: */
1270 nodemask_t mems_allowed
;
1271 /* Sequence number to catch updates: */
1272 seqcount_spinlock_t mems_allowed_seq
;
1273 int cpuset_mem_spread_rotor
;
1275 #ifdef CONFIG_CGROUPS
1276 /* Control Group info protected by css_set_lock: */
1277 struct css_set __rcu
*cgroups
;
1278 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1279 struct list_head cg_list
;
1281 #ifdef CONFIG_X86_CPU_RESCTRL
1286 struct robust_list_head __user
*robust_list
;
1287 #ifdef CONFIG_COMPAT
1288 struct compat_robust_list_head __user
*compat_robust_list
;
1290 struct list_head pi_state_list
;
1291 struct futex_pi_state
*pi_state_cache
;
1292 struct mutex futex_exit_mutex
;
1293 unsigned int futex_state
;
1295 #ifdef CONFIG_PERF_EVENTS
1296 u8 perf_recursion
[PERF_NR_CONTEXTS
];
1297 struct perf_event_context
*perf_event_ctxp
;
1298 struct mutex perf_event_mutex
;
1299 struct list_head perf_event_list
;
1301 #ifdef CONFIG_DEBUG_PREEMPT
1302 unsigned long preempt_disable_ip
;
1305 /* Protected by alloc_lock: */
1306 struct mempolicy
*mempolicy
;
1309 short pref_node_fork
;
1311 #ifdef CONFIG_NUMA_BALANCING
1313 unsigned int numa_scan_period
;
1314 unsigned int numa_scan_period_max
;
1315 int numa_preferred_nid
;
1316 unsigned long numa_migrate_retry
;
1317 /* Migration stamp: */
1319 u64 last_task_numa_placement
;
1320 u64 last_sum_exec_runtime
;
1321 struct callback_head numa_work
;
1324 * This pointer is only modified for current in syscall and
1325 * pagefault context (and for tasks being destroyed), so it can be read
1326 * from any of the following contexts:
1327 * - RCU read-side critical section
1328 * - current->numa_group from everywhere
1329 * - task's runqueue locked, task not running
1331 struct numa_group __rcu
*numa_group
;
1334 * numa_faults is an array split into four regions:
1335 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1336 * in this precise order.
1338 * faults_memory: Exponential decaying average of faults on a per-node
1339 * basis. Scheduling placement decisions are made based on these
1340 * counts. The values remain static for the duration of a PTE scan.
1341 * faults_cpu: Track the nodes the process was running on when a NUMA
1342 * hinting fault was incurred.
1343 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1344 * during the current scan window. When the scan completes, the counts
1345 * in faults_memory and faults_cpu decay and these values are copied.
1347 unsigned long *numa_faults
;
1348 unsigned long total_numa_faults
;
1351 * numa_faults_locality tracks if faults recorded during the last
1352 * scan window were remote/local or failed to migrate. The task scan
1353 * period is adapted based on the locality of the faults with different
1354 * weights depending on whether they were shared or private faults
1356 unsigned long numa_faults_locality
[3];
1358 unsigned long numa_pages_migrated
;
1359 #endif /* CONFIG_NUMA_BALANCING */
1362 struct rseq __user
*rseq
;
1366 * RmW on rseq_event_mask must be performed atomically
1367 * with respect to preemption.
1369 unsigned long rseq_event_mask
;
1372 #ifdef CONFIG_SCHED_MM_CID
1373 int mm_cid
; /* Current cid in mm */
1374 int last_mm_cid
; /* Most recent cid in mm */
1375 int migrate_from_cpu
;
1376 int mm_cid_active
; /* Whether cid bitmap is active */
1377 struct callback_head cid_work
;
1380 struct tlbflush_unmap_batch tlb_ubc
;
1382 /* Cache last used pipe for splice(): */
1383 struct pipe_inode_info
*splice_pipe
;
1385 struct page_frag task_frag
;
1387 #ifdef CONFIG_TASK_DELAY_ACCT
1388 struct task_delay_info
*delays
;
1391 #ifdef CONFIG_FAULT_INJECTION
1393 unsigned int fail_nth
;
1396 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1397 * balance_dirty_pages() for a dirty throttling pause:
1400 int nr_dirtied_pause
;
1401 /* Start of a write-and-pause period: */
1402 unsigned long dirty_paused_when
;
1404 #ifdef CONFIG_LATENCYTOP
1405 int latency_record_count
;
1406 struct latency_record latency_record
[LT_SAVECOUNT
];
1409 * Time slack values; these are used to round up poll() and
1410 * select() etc timeout values. These are in nanoseconds.
1413 u64 default_timer_slack_ns
;
1415 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1416 unsigned int kasan_depth
;
1420 struct kcsan_ctx kcsan_ctx
;
1421 #ifdef CONFIG_TRACE_IRQFLAGS
1422 struct irqtrace_events kcsan_save_irqtrace
;
1424 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1425 int kcsan_stack_depth
;
1430 struct kmsan_ctx kmsan_ctx
;
1433 #if IS_ENABLED(CONFIG_KUNIT)
1434 struct kunit
*kunit_test
;
1437 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1438 /* Index of current stored address in ret_stack: */
1442 /* Stack of return addresses for return function tracing: */
1443 unsigned long *ret_stack
;
1445 /* Timestamp for last schedule: */
1446 unsigned long long ftrace_timestamp
;
1447 unsigned long long ftrace_sleeptime
;
1450 * Number of functions that haven't been traced
1451 * because of depth overrun:
1453 atomic_t trace_overrun
;
1455 /* Pause tracing: */
1456 atomic_t tracing_graph_pause
;
1459 #ifdef CONFIG_TRACING
1460 /* Bitmask and counter of trace recursion: */
1461 unsigned long trace_recursion
;
1462 #endif /* CONFIG_TRACING */
1465 /* See kernel/kcov.c for more details. */
1467 /* Coverage collection mode enabled for this task (0 if disabled): */
1468 unsigned int kcov_mode
;
1470 /* Size of the kcov_area: */
1471 unsigned int kcov_size
;
1473 /* Buffer for coverage collection: */
1476 /* KCOV descriptor wired with this task or NULL: */
1479 /* KCOV common handle for remote coverage collection: */
1482 /* KCOV sequence number: */
1485 /* Collect coverage from softirq context: */
1486 unsigned int kcov_softirq
;
1489 #ifdef CONFIG_MEMCG_V1
1490 struct mem_cgroup
*memcg_in_oom
;
1494 /* Number of pages to reclaim on returning to userland: */
1495 unsigned int memcg_nr_pages_over_high
;
1497 /* Used by memcontrol for targeted memcg charge: */
1498 struct mem_cgroup
*active_memcg
;
1500 /* Cache for current->cgroups->memcg->objcg lookups: */
1501 struct obj_cgroup
*objcg
;
1504 #ifdef CONFIG_BLK_CGROUP
1505 struct gendisk
*throttle_disk
;
1508 #ifdef CONFIG_UPROBES
1509 struct uprobe_task
*utask
;
1511 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1512 unsigned int sequential_io
;
1513 unsigned int sequential_io_avg
;
1515 struct kmap_ctrl kmap_ctrl
;
1516 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1517 unsigned long task_state_change
;
1518 # ifdef CONFIG_PREEMPT_RT
1519 unsigned long saved_state_change
;
1522 struct rcu_head rcu
;
1523 refcount_t rcu_users
;
1524 int pagefault_disabled
;
1526 struct task_struct
*oom_reaper_list
;
1527 struct timer_list oom_reaper_timer
;
1529 #ifdef CONFIG_VMAP_STACK
1530 struct vm_struct
*stack_vm_area
;
1532 #ifdef CONFIG_THREAD_INFO_IN_TASK
1533 /* A live task holds one reference: */
1534 refcount_t stack_refcount
;
1536 #ifdef CONFIG_LIVEPATCH
1539 #ifdef CONFIG_SECURITY
1540 /* Used by LSM modules for access restriction: */
1543 #ifdef CONFIG_BPF_SYSCALL
1544 /* Used by BPF task local storage */
1545 struct bpf_local_storage __rcu
*bpf_storage
;
1546 /* Used for BPF run context */
1547 struct bpf_run_ctx
*bpf_ctx
;
1549 /* Used by BPF for per-TASK xdp storage */
1550 struct bpf_net_context
*bpf_net_context
;
1552 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1553 unsigned long lowest_stack
;
1554 unsigned long prev_lowest_stack
;
1557 #ifdef CONFIG_X86_MCE
1558 void __user
*mce_vaddr
;
1563 __mce_reserved
: 62;
1564 struct callback_head mce_kill_me
;
1568 #ifdef CONFIG_KRETPROBES
1569 struct llist_head kretprobe_instances
;
1571 #ifdef CONFIG_RETHOOK
1572 struct llist_head rethooks
;
1575 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1577 * If L1D flush is supported on mm context switch
1578 * then we use this callback head to queue kill work
1579 * to kill tasks that are not running on SMT disabled
1582 struct callback_head l1d_flush_kill
;
1587 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1588 * If we find justification for more monitors, we can think
1589 * about adding more or developing a dynamic method. So far,
1590 * none of these are justified.
1592 union rv_task_monitor rv
[RV_PER_TASK_MONITORS
];
1595 #ifdef CONFIG_USER_EVENTS
1596 struct user_event_mm
*user_event_mm
;
1600 * New fields for task_struct should be added above here, so that
1601 * they are included in the randomized portion of task_struct.
1603 randomized_struct_fields_end
1605 /* CPU-specific state of this task: */
1606 struct thread_struct thread
;
1609 * WARNING: on x86, 'thread_struct' contains a variable-sized
1610 * structure. It *MUST* be at the end of 'task_struct'.
1612 * Do not put anything below here!
1616 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1617 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1619 static inline unsigned int __task_state_index(unsigned int tsk_state
,
1620 unsigned int tsk_exit_state
)
1622 unsigned int state
= (tsk_state
| tsk_exit_state
) & TASK_REPORT
;
1624 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX
);
1626 if ((tsk_state
& TASK_IDLE
) == TASK_IDLE
)
1627 state
= TASK_REPORT_IDLE
;
1630 * We're lying here, but rather than expose a completely new task state
1631 * to userspace, we can make this appear as if the task has gone through
1632 * a regular rt_mutex_lock() call.
1634 if (tsk_state
& TASK_RTLOCK_WAIT
)
1635 state
= TASK_UNINTERRUPTIBLE
;
1640 static inline unsigned int task_state_index(struct task_struct
*tsk
)
1642 return __task_state_index(READ_ONCE(tsk
->__state
), tsk
->exit_state
);
1645 static inline char task_index_to_char(unsigned int state
)
1647 static const char state_char
[] = "RSDTtXZPI";
1649 BUILD_BUG_ON(TASK_REPORT_MAX
* 2 != 1 << (sizeof(state_char
) - 1));
1651 return state_char
[state
];
1654 static inline char task_state_to_char(struct task_struct
*tsk
)
1656 return task_index_to_char(task_state_index(tsk
));
1659 extern struct pid
*cad_pid
;
1664 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1665 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1666 #define PF_EXITING 0x00000004 /* Getting shut down */
1667 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1668 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1669 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1670 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1671 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1672 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1673 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1674 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1675 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */
1676 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1677 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1678 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */
1679 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1680 #define PF__HOLE__00010000 0x00010000
1681 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1682 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */
1683 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */
1684 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1685 * I am cleaning dirty pages from some other bdi. */
1686 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1687 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1688 #define PF__HOLE__00800000 0x00800000
1689 #define PF__HOLE__01000000 0x01000000
1690 #define PF__HOLE__02000000 0x02000000
1691 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1692 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1693 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning.
1694 * See memalloc_pin_save() */
1695 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */
1696 #define PF__HOLE__40000000 0x40000000
1697 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1700 * Only the _current_ task can read/write to tsk->flags, but other
1701 * tasks can access tsk->flags in readonly mode for example
1702 * with tsk_used_math (like during threaded core dumping).
1703 * There is however an exception to this rule during ptrace
1704 * or during fork: the ptracer task is allowed to write to the
1705 * child->flags of its traced child (same goes for fork, the parent
1706 * can write to the child->flags), because we're guaranteed the
1707 * child is not running and in turn not changing child->flags
1708 * at the same time the parent does it.
1710 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1711 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1712 #define clear_used_math() clear_stopped_child_used_math(current)
1713 #define set_used_math() set_stopped_child_used_math(current)
1715 #define conditional_stopped_child_used_math(condition, child) \
1716 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1718 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1720 #define copy_to_stopped_child_used_math(child) \
1721 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1723 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1724 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1725 #define used_math() tsk_used_math(current)
1727 static __always_inline
bool is_percpu_thread(void)
1730 return (current
->flags
& PF_NO_SETAFFINITY
) &&
1731 (current
->nr_cpus_allowed
== 1);
1737 /* Per-process atomic flags. */
1738 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1739 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1740 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1741 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1742 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1743 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1744 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1745 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1747 #define TASK_PFA_TEST(name, func) \
1748 static inline bool task_##func(struct task_struct *p) \
1749 { return test_bit(PFA_##name, &p->atomic_flags); }
1751 #define TASK_PFA_SET(name, func) \
1752 static inline void task_set_##func(struct task_struct *p) \
1753 { set_bit(PFA_##name, &p->atomic_flags); }
1755 #define TASK_PFA_CLEAR(name, func) \
1756 static inline void task_clear_##func(struct task_struct *p) \
1757 { clear_bit(PFA_##name, &p->atomic_flags); }
1759 TASK_PFA_TEST(NO_NEW_PRIVS
, no_new_privs
)
1760 TASK_PFA_SET(NO_NEW_PRIVS
, no_new_privs
)
1762 TASK_PFA_TEST(SPREAD_PAGE
, spread_page
)
1763 TASK_PFA_SET(SPREAD_PAGE
, spread_page
)
1764 TASK_PFA_CLEAR(SPREAD_PAGE
, spread_page
)
1766 TASK_PFA_TEST(SPREAD_SLAB
, spread_slab
)
1767 TASK_PFA_SET(SPREAD_SLAB
, spread_slab
)
1768 TASK_PFA_CLEAR(SPREAD_SLAB
, spread_slab
)
1770 TASK_PFA_TEST(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1771 TASK_PFA_SET(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1772 TASK_PFA_CLEAR(SPEC_SSB_DISABLE
, spec_ssb_disable
)
1774 TASK_PFA_TEST(SPEC_SSB_NOEXEC
, spec_ssb_noexec
)
1775 TASK_PFA_SET(SPEC_SSB_NOEXEC
, spec_ssb_noexec
)
1776 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC
, spec_ssb_noexec
)
1778 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1779 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE
, spec_ssb_force_disable
)
1781 TASK_PFA_TEST(SPEC_IB_DISABLE
, spec_ib_disable
)
1782 TASK_PFA_SET(SPEC_IB_DISABLE
, spec_ib_disable
)
1783 TASK_PFA_CLEAR(SPEC_IB_DISABLE
, spec_ib_disable
)
1785 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE
, spec_ib_force_disable
)
1786 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE
, spec_ib_force_disable
)
1789 current_restore_flags(unsigned long orig_flags
, unsigned long flags
)
1791 current
->flags
&= ~flags
;
1792 current
->flags
|= orig_flags
& flags
;
1795 extern int cpuset_cpumask_can_shrink(const struct cpumask
*cur
, const struct cpumask
*trial
);
1796 extern int task_can_attach(struct task_struct
*p
);
1797 extern int dl_bw_alloc(int cpu
, u64 dl_bw
);
1798 extern void dl_bw_free(int cpu
, u64 dl_bw
);
1801 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1802 extern void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
);
1805 * set_cpus_allowed_ptr - set CPU affinity mask of a task
1807 * @new_mask: CPU affinity mask
1809 * Return: zero if successful, or a negative error code
1811 extern int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
);
1812 extern int dup_user_cpus_ptr(struct task_struct
*dst
, struct task_struct
*src
, int node
);
1813 extern void release_user_cpus_ptr(struct task_struct
*p
);
1814 extern int dl_task_check_affinity(struct task_struct
*p
, const struct cpumask
*mask
);
1815 extern void force_compatible_cpus_allowed_ptr(struct task_struct
*p
);
1816 extern void relax_compatible_cpus_allowed_ptr(struct task_struct
*p
);
1818 static inline void do_set_cpus_allowed(struct task_struct
*p
, const struct cpumask
*new_mask
)
1821 static inline int set_cpus_allowed_ptr(struct task_struct
*p
, const struct cpumask
*new_mask
)
1823 /* Opencoded cpumask_test_cpu(0, new_mask) to avoid dependency on cpumask.h */
1824 if ((*cpumask_bits(new_mask
) & 1) == 0)
1828 static inline int dup_user_cpus_ptr(struct task_struct
*dst
, struct task_struct
*src
, int node
)
1830 if (src
->user_cpus_ptr
)
1834 static inline void release_user_cpus_ptr(struct task_struct
*p
)
1836 WARN_ON(p
->user_cpus_ptr
);
1839 static inline int dl_task_check_affinity(struct task_struct
*p
, const struct cpumask
*mask
)
1845 extern int yield_to(struct task_struct
*p
, bool preempt
);
1846 extern void set_user_nice(struct task_struct
*p
, long nice
);
1847 extern int task_prio(const struct task_struct
*p
);
1850 * task_nice - return the nice value of a given task.
1851 * @p: the task in question.
1853 * Return: The nice value [ -20 ... 0 ... 19 ].
1855 static inline int task_nice(const struct task_struct
*p
)
1857 return PRIO_TO_NICE((p
)->static_prio
);
1860 extern int can_nice(const struct task_struct
*p
, const int nice
);
1861 extern int task_curr(const struct task_struct
*p
);
1862 extern int idle_cpu(int cpu
);
1863 extern int available_idle_cpu(int cpu
);
1864 extern int sched_setscheduler(struct task_struct
*, int, const struct sched_param
*);
1865 extern int sched_setscheduler_nocheck(struct task_struct
*, int, const struct sched_param
*);
1866 extern void sched_set_fifo(struct task_struct
*p
);
1867 extern void sched_set_fifo_low(struct task_struct
*p
);
1868 extern void sched_set_normal(struct task_struct
*p
, int nice
);
1869 extern int sched_setattr(struct task_struct
*, const struct sched_attr
*);
1870 extern int sched_setattr_nocheck(struct task_struct
*, const struct sched_attr
*);
1871 extern struct task_struct
*idle_task(int cpu
);
1874 * is_idle_task - is the specified task an idle task?
1875 * @p: the task in question.
1877 * Return: 1 if @p is an idle task. 0 otherwise.
1879 static __always_inline
bool is_idle_task(const struct task_struct
*p
)
1881 return !!(p
->flags
& PF_IDLE
);
1884 extern struct task_struct
*curr_task(int cpu
);
1885 extern void ia64_set_curr_task(int cpu
, struct task_struct
*p
);
1889 union thread_union
{
1890 struct task_struct task
;
1891 #ifndef CONFIG_THREAD_INFO_IN_TASK
1892 struct thread_info thread_info
;
1894 unsigned long stack
[THREAD_SIZE
/sizeof(long)];
1897 #ifndef CONFIG_THREAD_INFO_IN_TASK
1898 extern struct thread_info init_thread_info
;
1901 extern unsigned long init_stack
[THREAD_SIZE
/ sizeof(unsigned long)];
1903 #ifdef CONFIG_THREAD_INFO_IN_TASK
1904 # define task_thread_info(task) (&(task)->thread_info)
1906 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1910 * find a task by one of its numerical ids
1912 * find_task_by_pid_ns():
1913 * finds a task by its pid in the specified namespace
1914 * find_task_by_vpid():
1915 * finds a task by its virtual pid
1917 * see also find_vpid() etc in include/linux/pid.h
1920 extern struct task_struct
*find_task_by_vpid(pid_t nr
);
1921 extern struct task_struct
*find_task_by_pid_ns(pid_t nr
, struct pid_namespace
*ns
);
1924 * find a task by its virtual pid and get the task struct
1926 extern struct task_struct
*find_get_task_by_vpid(pid_t nr
);
1928 extern int wake_up_state(struct task_struct
*tsk
, unsigned int state
);
1929 extern int wake_up_process(struct task_struct
*tsk
);
1930 extern void wake_up_new_task(struct task_struct
*tsk
);
1933 extern void kick_process(struct task_struct
*tsk
);
1935 static inline void kick_process(struct task_struct
*tsk
) { }
1938 extern void __set_task_comm(struct task_struct
*tsk
, const char *from
, bool exec
);
1940 static inline void set_task_comm(struct task_struct
*tsk
, const char *from
)
1942 __set_task_comm(tsk
, from
, false);
1946 * - Why not use task_lock()?
1947 * User space can randomly change their names anyway, so locking for readers
1948 * doesn't make sense. For writers, locking is probably necessary, as a race
1949 * condition could lead to long-term mixed results.
1950 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is
1951 * always NUL-terminated and zero-padded. Therefore the race condition between
1952 * reader and writer is not an issue.
1954 * - BUILD_BUG_ON() can help prevent the buf from being truncated.
1955 * Since the callers don't perform any return value checks, this safeguard is
1958 #define get_task_comm(buf, tsk) ({ \
1959 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \
1960 strscpy_pad(buf, (tsk)->comm); \
1965 static __always_inline
void scheduler_ipi(void)
1968 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1969 * TIF_NEED_RESCHED remotely (for the first time) will also send
1972 preempt_fold_need_resched();
1975 static inline void scheduler_ipi(void) { }
1978 extern unsigned long wait_task_inactive(struct task_struct
*, unsigned int match_state
);
1981 * Set thread flags in other task's structures.
1982 * See asm/thread_info.h for TIF_xxxx flags available:
1984 static inline void set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1986 set_ti_thread_flag(task_thread_info(tsk
), flag
);
1989 static inline void clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
1991 clear_ti_thread_flag(task_thread_info(tsk
), flag
);
1994 static inline void update_tsk_thread_flag(struct task_struct
*tsk
, int flag
,
1997 update_ti_thread_flag(task_thread_info(tsk
), flag
, value
);
2000 static inline int test_and_set_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
2002 return test_and_set_ti_thread_flag(task_thread_info(tsk
), flag
);
2005 static inline int test_and_clear_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
2007 return test_and_clear_ti_thread_flag(task_thread_info(tsk
), flag
);
2010 static inline int test_tsk_thread_flag(struct task_struct
*tsk
, int flag
)
2012 return test_ti_thread_flag(task_thread_info(tsk
), flag
);
2015 static inline void set_tsk_need_resched(struct task_struct
*tsk
)
2017 set_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
);
2020 static inline void clear_tsk_need_resched(struct task_struct
*tsk
)
2022 atomic_long_andnot(_TIF_NEED_RESCHED
| _TIF_NEED_RESCHED_LAZY
,
2023 (atomic_long_t
*)&task_thread_info(tsk
)->flags
);
2026 static inline int test_tsk_need_resched(struct task_struct
*tsk
)
2028 return unlikely(test_tsk_thread_flag(tsk
,TIF_NEED_RESCHED
));
2032 * cond_resched() and cond_resched_lock(): latency reduction via
2033 * explicit rescheduling in places that are safe. The return
2034 * value indicates whether a reschedule was done in fact.
2035 * cond_resched_lock() will drop the spinlock before scheduling,
2037 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2038 extern int __cond_resched(void);
2040 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2042 void sched_dynamic_klp_enable(void);
2043 void sched_dynamic_klp_disable(void);
2045 DECLARE_STATIC_CALL(cond_resched
, __cond_resched
);
2047 static __always_inline
int _cond_resched(void)
2049 return static_call_mod(cond_resched
)();
2052 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2054 extern int dynamic_cond_resched(void);
2056 static __always_inline
int _cond_resched(void)
2058 return dynamic_cond_resched();
2061 #else /* !CONFIG_PREEMPTION */
2063 static inline int _cond_resched(void)
2065 klp_sched_try_switch();
2066 return __cond_resched();
2069 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2071 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2073 static inline int _cond_resched(void)
2075 klp_sched_try_switch();
2079 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2081 #define cond_resched() ({ \
2082 __might_resched(__FILE__, __LINE__, 0); \
2086 extern int __cond_resched_lock(spinlock_t
*lock
);
2087 extern int __cond_resched_rwlock_read(rwlock_t
*lock
);
2088 extern int __cond_resched_rwlock_write(rwlock_t
*lock
);
2090 #define MIGHT_RESCHED_RCU_SHIFT 8
2091 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2093 #ifndef CONFIG_PREEMPT_RT
2095 * Non RT kernels have an elevated preempt count due to the held lock,
2096 * but are not allowed to be inside a RCU read side critical section
2098 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2101 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2102 * cond_resched*lock() has to take that into account because it checks for
2103 * preempt_count() and rcu_preempt_depth().
2105 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2106 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2109 #define cond_resched_lock(lock) ({ \
2110 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2111 __cond_resched_lock(lock); \
2114 #define cond_resched_rwlock_read(lock) ({ \
2115 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2116 __cond_resched_rwlock_read(lock); \
2119 #define cond_resched_rwlock_write(lock) ({ \
2120 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2121 __cond_resched_rwlock_write(lock); \
2124 static __always_inline
bool need_resched(void)
2126 return unlikely(tif_need_resched());
2130 * Wrappers for p->thread_info->cpu access. No-op on UP.
2134 static inline unsigned int task_cpu(const struct task_struct
*p
)
2136 return READ_ONCE(task_thread_info(p
)->cpu
);
2139 extern void set_task_cpu(struct task_struct
*p
, unsigned int cpu
);
2143 static inline unsigned int task_cpu(const struct task_struct
*p
)
2148 static inline void set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
2152 #endif /* CONFIG_SMP */
2154 static inline bool task_is_runnable(struct task_struct
*p
)
2156 return p
->on_rq
&& !p
->se
.sched_delayed
;
2159 extern bool sched_task_on_rq(struct task_struct
*p
);
2160 extern unsigned long get_wchan(struct task_struct
*p
);
2161 extern struct task_struct
*cpu_curr_snapshot(int cpu
);
2163 #include <linux/spinlock.h>
2166 * In order to reduce various lock holder preemption latencies provide an
2167 * interface to see if a vCPU is currently running or not.
2169 * This allows us to terminate optimistic spin loops and block, analogous to
2170 * the native optimistic spin heuristic of testing if the lock owner task is
2173 #ifndef vcpu_is_preempted
2174 static inline bool vcpu_is_preempted(int cpu
)
2180 extern long sched_setaffinity(pid_t pid
, const struct cpumask
*new_mask
);
2181 extern long sched_getaffinity(pid_t pid
, struct cpumask
*mask
);
2183 #ifndef TASK_SIZE_OF
2184 #define TASK_SIZE_OF(tsk) TASK_SIZE
2188 static inline bool owner_on_cpu(struct task_struct
*owner
)
2191 * As lock holder preemption issue, we both skip spinning if
2192 * task is not on cpu or its cpu is preempted
2194 return READ_ONCE(owner
->on_cpu
) && !vcpu_is_preempted(task_cpu(owner
));
2197 /* Returns effective CPU energy utilization, as seen by the scheduler */
2198 unsigned long sched_cpu_util(int cpu
);
2199 #endif /* CONFIG_SMP */
2201 #ifdef CONFIG_SCHED_CORE
2202 extern void sched_core_free(struct task_struct
*tsk
);
2203 extern void sched_core_fork(struct task_struct
*p
);
2204 extern int sched_core_share_pid(unsigned int cmd
, pid_t pid
, enum pid_type type
,
2205 unsigned long uaddr
);
2206 extern int sched_core_idle_cpu(int cpu
);
2208 static inline void sched_core_free(struct task_struct
*tsk
) { }
2209 static inline void sched_core_fork(struct task_struct
*p
) { }
2210 static inline int sched_core_idle_cpu(int cpu
) { return idle_cpu(cpu
); }
2213 extern void sched_set_stop_task(int cpu
, struct task_struct
*stop
);
2215 #ifdef CONFIG_MEM_ALLOC_PROFILING
2216 static __always_inline
struct alloc_tag
*alloc_tag_save(struct alloc_tag
*tag
)
2218 swap(current
->alloc_tag
, tag
);
2222 static __always_inline
void alloc_tag_restore(struct alloc_tag
*tag
, struct alloc_tag
*old
)
2224 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
2225 WARN(current
->alloc_tag
!= tag
, "current->alloc_tag was changed:\n");
2227 current
->alloc_tag
= old
;
2230 #define alloc_tag_save(_tag) NULL
2231 #define alloc_tag_restore(_tag, _old) do {} while (0)