![Patrick Bellasi](/assets/img/avatar_default.png)
The util_avg signal computed by PELT is too variable for some use-cases. For example, a big task waking up after a long sleep period will have its utilization almost completely decayed. This introduces some latency before schedutil will be able to pick the best frequency to run a task. The same issue can affect task placement. Indeed, since the task utilization is already decayed at wakeup, when the task is enqueued in a CPU, this can result in a CPU running a big task as being temporarily represented as being almost empty. This leads to a race condition where other tasks can be potentially allocated on a CPU which just started to run a big task which slept for a relatively long period. Moreover, the PELT utilization of a task can be updated every [ms], thus making it a continuously changing value for certain longer running tasks. This means that the instantaneous PELT utilization of a RUNNING task is not really meaningful to properly support scheduler decisions. For all these reasons, a more stable signal can do a better job of representing the expected/estimated utilization of a task/cfs_rq. Such a signal can be easily created on top of PELT by still using it as an estimator which produces values to be aggregated on meaningful events. This patch adds a simple implementation of util_est, a new signal built on top of PELT's util_avg where: util_est(task) = max(task::util_avg, f(task::util_avg@dequeue)) This allows to remember how big a task has been reported by PELT in its previous activations via f(task::util_avg@dequeue), which is the new _task_util_est(struct task_struct*) function added by this patch. If a task should change its behavior and it runs longer in a new activation, after a certain time its util_est will just track the original PELT signal (i.e. task::util_avg). The estimated utilization of cfs_rq is defined only for root ones. That's because the only sensible consumer of this signal are the scheduler and schedutil when looking for the overall CPU utilization due to FAIR tasks. For this reason, the estimated utilization of a root cfs_rq is simply defined as: util_est(cfs_rq) = max(cfs_rq::util_avg, cfs_rq::util_est::enqueued) where: cfs_rq::util_est::enqueued = sum(_task_util_est(task)) for each RUNNABLE task on that root cfs_rq It's worth noting that the estimated utilization is tracked only for objects of interests, specifically: - Tasks: to better support tasks placement decisions - root cfs_rqs: to better support both tasks placement decisions as well as frequencies selection Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@android.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20180309095245.11071-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
1720 lines
47 KiB
C
1720 lines
47 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SCHED_H
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#define _LINUX_SCHED_H
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/*
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* Define 'struct task_struct' and provide the main scheduler
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* APIs (schedule(), wakeup variants, etc.)
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*/
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#include <uapi/linux/sched.h>
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#include <asm/current.h>
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#include <linux/pid.h>
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#include <linux/sem.h>
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#include <linux/shm.h>
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#include <linux/kcov.h>
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#include <linux/mutex.h>
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#include <linux/plist.h>
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#include <linux/hrtimer.h>
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#include <linux/seccomp.h>
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#include <linux/nodemask.h>
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#include <linux/rcupdate.h>
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#include <linux/resource.h>
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#include <linux/latencytop.h>
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#include <linux/sched/prio.h>
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#include <linux/signal_types.h>
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#include <linux/mm_types_task.h>
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#include <linux/task_io_accounting.h>
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/* task_struct member predeclarations (sorted alphabetically): */
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struct audit_context;
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struct backing_dev_info;
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struct bio_list;
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struct blk_plug;
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struct cfs_rq;
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struct fs_struct;
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struct futex_pi_state;
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struct io_context;
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struct mempolicy;
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struct nameidata;
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struct nsproxy;
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struct perf_event_context;
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struct pid_namespace;
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struct pipe_inode_info;
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struct rcu_node;
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struct reclaim_state;
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struct robust_list_head;
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struct sched_attr;
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struct sched_param;
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struct seq_file;
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struct sighand_struct;
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struct signal_struct;
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struct task_delay_info;
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struct task_group;
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/*
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* Task state bitmask. NOTE! These bits are also
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* encoded in fs/proc/array.c: get_task_state().
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*
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* We have two separate sets of flags: task->state
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* is about runnability, while task->exit_state are
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* about the task exiting. Confusing, but this way
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* modifying one set can't modify the other one by
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* mistake.
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*/
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/* Used in tsk->state: */
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#define TASK_RUNNING 0x0000
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#define TASK_INTERRUPTIBLE 0x0001
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#define TASK_UNINTERRUPTIBLE 0x0002
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#define __TASK_STOPPED 0x0004
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#define __TASK_TRACED 0x0008
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/* Used in tsk->exit_state: */
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#define EXIT_DEAD 0x0010
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#define EXIT_ZOMBIE 0x0020
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#define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
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/* Used in tsk->state again: */
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#define TASK_PARKED 0x0040
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#define TASK_DEAD 0x0080
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#define TASK_WAKEKILL 0x0100
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#define TASK_WAKING 0x0200
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#define TASK_NOLOAD 0x0400
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#define TASK_NEW 0x0800
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#define TASK_STATE_MAX 0x1000
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/* Convenience macros for the sake of set_current_state: */
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#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
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#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
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#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
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#define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
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/* Convenience macros for the sake of wake_up(): */
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#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
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/* get_task_state(): */
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#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
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TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
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__TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
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TASK_PARKED)
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#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
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#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
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#define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
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#define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
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(task->flags & PF_FROZEN) == 0 && \
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(task->state & TASK_NOLOAD) == 0)
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#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
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#define __set_current_state(state_value) \
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do { \
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current->task_state_change = _THIS_IP_; \
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current->state = (state_value); \
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} while (0)
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#define set_current_state(state_value) \
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do { \
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current->task_state_change = _THIS_IP_; \
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smp_store_mb(current->state, (state_value)); \
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} while (0)
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#else
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/*
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* set_current_state() includes a barrier so that the write of current->state
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* is correctly serialised wrt the caller's subsequent test of whether to
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* actually sleep:
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*
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* for (;;) {
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* set_current_state(TASK_UNINTERRUPTIBLE);
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* if (!need_sleep)
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* break;
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*
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* schedule();
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* }
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* __set_current_state(TASK_RUNNING);
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*
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* If the caller does not need such serialisation (because, for instance, the
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* condition test and condition change and wakeup are under the same lock) then
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* use __set_current_state().
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*
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* The above is typically ordered against the wakeup, which does:
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*
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* need_sleep = false;
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* wake_up_state(p, TASK_UNINTERRUPTIBLE);
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*
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* Where wake_up_state() (and all other wakeup primitives) imply enough
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* barriers to order the store of the variable against wakeup.
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*
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* Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
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* once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
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* TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
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*
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* This is obviously fine, since they both store the exact same value.
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*
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* Also see the comments of try_to_wake_up().
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*/
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#define __set_current_state(state_value) do { current->state = (state_value); } while (0)
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#define set_current_state(state_value) smp_store_mb(current->state, (state_value))
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#endif
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/* Task command name length: */
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#define TASK_COMM_LEN 16
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extern void scheduler_tick(void);
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#define MAX_SCHEDULE_TIMEOUT LONG_MAX
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extern long schedule_timeout(long timeout);
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extern long schedule_timeout_interruptible(long timeout);
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extern long schedule_timeout_killable(long timeout);
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extern long schedule_timeout_uninterruptible(long timeout);
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extern long schedule_timeout_idle(long timeout);
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asmlinkage void schedule(void);
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extern void schedule_preempt_disabled(void);
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extern int __must_check io_schedule_prepare(void);
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extern void io_schedule_finish(int token);
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extern long io_schedule_timeout(long timeout);
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extern void io_schedule(void);
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/**
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* struct prev_cputime - snapshot of system and user cputime
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* @utime: time spent in user mode
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* @stime: time spent in system mode
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* @lock: protects the above two fields
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*
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* Stores previous user/system time values such that we can guarantee
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* monotonicity.
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*/
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struct prev_cputime {
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#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
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u64 utime;
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u64 stime;
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raw_spinlock_t lock;
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#endif
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};
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/**
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* struct task_cputime - collected CPU time counts
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* @utime: time spent in user mode, in nanoseconds
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* @stime: time spent in kernel mode, in nanoseconds
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* @sum_exec_runtime: total time spent on the CPU, in nanoseconds
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*
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* This structure groups together three kinds of CPU time that are tracked for
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* threads and thread groups. Most things considering CPU time want to group
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* these counts together and treat all three of them in parallel.
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*/
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struct task_cputime {
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u64 utime;
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u64 stime;
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unsigned long long sum_exec_runtime;
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};
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/* Alternate field names when used on cache expirations: */
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#define virt_exp utime
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#define prof_exp stime
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#define sched_exp sum_exec_runtime
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enum vtime_state {
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/* Task is sleeping or running in a CPU with VTIME inactive: */
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VTIME_INACTIVE = 0,
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/* Task runs in userspace in a CPU with VTIME active: */
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VTIME_USER,
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/* Task runs in kernelspace in a CPU with VTIME active: */
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VTIME_SYS,
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};
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struct vtime {
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seqcount_t seqcount;
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unsigned long long starttime;
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enum vtime_state state;
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u64 utime;
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u64 stime;
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u64 gtime;
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};
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struct sched_info {
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#ifdef CONFIG_SCHED_INFO
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/* Cumulative counters: */
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/* # of times we have run on this CPU: */
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unsigned long pcount;
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/* Time spent waiting on a runqueue: */
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unsigned long long run_delay;
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/* Timestamps: */
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/* When did we last run on a CPU? */
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unsigned long long last_arrival;
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/* When were we last queued to run? */
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unsigned long long last_queued;
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#endif /* CONFIG_SCHED_INFO */
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};
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/*
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* Integer metrics need fixed point arithmetic, e.g., sched/fair
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* has a few: load, load_avg, util_avg, freq, and capacity.
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*
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* We define a basic fixed point arithmetic range, and then formalize
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* all these metrics based on that basic range.
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*/
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# define SCHED_FIXEDPOINT_SHIFT 10
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# define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
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struct load_weight {
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unsigned long weight;
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u32 inv_weight;
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};
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/**
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* struct util_est - Estimation utilization of FAIR tasks
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* @enqueued: instantaneous estimated utilization of a task/cpu
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* @ewma: the Exponential Weighted Moving Average (EWMA)
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* utilization of a task
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*
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* Support data structure to track an Exponential Weighted Moving Average
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* (EWMA) of a FAIR task's utilization. New samples are added to the moving
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* average each time a task completes an activation. Sample's weight is chosen
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* so that the EWMA will be relatively insensitive to transient changes to the
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* task's workload.
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*
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* The enqueued attribute has a slightly different meaning for tasks and cpus:
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* - task: the task's util_avg at last task dequeue time
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* - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
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* Thus, the util_est.enqueued of a task represents the contribution on the
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* estimated utilization of the CPU where that task is currently enqueued.
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*
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* Only for tasks we track a moving average of the past instantaneous
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* estimated utilization. This allows to absorb sporadic drops in utilization
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* of an otherwise almost periodic task.
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*/
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struct util_est {
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unsigned int enqueued;
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unsigned int ewma;
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#define UTIL_EST_WEIGHT_SHIFT 2
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};
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/*
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* The load_avg/util_avg accumulates an infinite geometric series
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* (see __update_load_avg() in kernel/sched/fair.c).
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*
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* [load_avg definition]
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*
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* load_avg = runnable% * scale_load_down(load)
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*
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* where runnable% is the time ratio that a sched_entity is runnable.
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* For cfs_rq, it is the aggregated load_avg of all runnable and
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* blocked sched_entities.
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*
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* load_avg may also take frequency scaling into account:
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*
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* load_avg = runnable% * scale_load_down(load) * freq%
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*
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* where freq% is the CPU frequency normalized to the highest frequency.
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*
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* [util_avg definition]
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*
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* util_avg = running% * SCHED_CAPACITY_SCALE
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*
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* where running% is the time ratio that a sched_entity is running on
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* a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
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* and blocked sched_entities.
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*
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* util_avg may also factor frequency scaling and CPU capacity scaling:
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*
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* util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
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*
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* where freq% is the same as above, and capacity% is the CPU capacity
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* normalized to the greatest capacity (due to uarch differences, etc).
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*
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* N.B., the above ratios (runnable%, running%, freq%, and capacity%)
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* themselves are in the range of [0, 1]. To do fixed point arithmetics,
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* we therefore scale them to as large a range as necessary. This is for
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* example reflected by util_avg's SCHED_CAPACITY_SCALE.
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*
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* [Overflow issue]
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*
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* The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
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* with the highest load (=88761), always runnable on a single cfs_rq,
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* and should not overflow as the number already hits PID_MAX_LIMIT.
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*
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* For all other cases (including 32-bit kernels), struct load_weight's
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* weight will overflow first before we do, because:
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*
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* Max(load_avg) <= Max(load.weight)
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*
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* Then it is the load_weight's responsibility to consider overflow
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* issues.
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*/
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struct sched_avg {
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u64 last_update_time;
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u64 load_sum;
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u64 runnable_load_sum;
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u32 util_sum;
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u32 period_contrib;
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unsigned long load_avg;
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unsigned long runnable_load_avg;
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unsigned long util_avg;
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struct util_est util_est;
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};
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struct sched_statistics {
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#ifdef CONFIG_SCHEDSTATS
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u64 wait_start;
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u64 wait_max;
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u64 wait_count;
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u64 wait_sum;
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u64 iowait_count;
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u64 iowait_sum;
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u64 sleep_start;
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u64 sleep_max;
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s64 sum_sleep_runtime;
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u64 block_start;
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u64 block_max;
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u64 exec_max;
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u64 slice_max;
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u64 nr_migrations_cold;
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u64 nr_failed_migrations_affine;
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u64 nr_failed_migrations_running;
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u64 nr_failed_migrations_hot;
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u64 nr_forced_migrations;
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u64 nr_wakeups;
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u64 nr_wakeups_sync;
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u64 nr_wakeups_migrate;
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u64 nr_wakeups_local;
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u64 nr_wakeups_remote;
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u64 nr_wakeups_affine;
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u64 nr_wakeups_affine_attempts;
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u64 nr_wakeups_passive;
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u64 nr_wakeups_idle;
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#endif
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};
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struct sched_entity {
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/* For load-balancing: */
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struct load_weight load;
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unsigned long runnable_weight;
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struct rb_node run_node;
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struct list_head group_node;
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unsigned int on_rq;
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u64 exec_start;
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u64 sum_exec_runtime;
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u64 vruntime;
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u64 prev_sum_exec_runtime;
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u64 nr_migrations;
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struct sched_statistics statistics;
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#ifdef CONFIG_FAIR_GROUP_SCHED
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int depth;
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struct sched_entity *parent;
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/* rq on which this entity is (to be) queued: */
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struct cfs_rq *cfs_rq;
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/* rq "owned" by this entity/group: */
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struct cfs_rq *my_q;
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#endif
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#ifdef CONFIG_SMP
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/*
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* Per entity load average tracking.
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*
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* Put into separate cache line so it does not
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* collide with read-mostly values above.
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*/
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struct sched_avg avg ____cacheline_aligned_in_smp;
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#endif
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};
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struct sched_rt_entity {
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struct list_head run_list;
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unsigned long timeout;
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unsigned long watchdog_stamp;
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unsigned int time_slice;
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unsigned short on_rq;
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unsigned short on_list;
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|
|
struct sched_rt_entity *back;
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
struct sched_rt_entity *parent;
|
|
/* rq on which this entity is (to be) queued: */
|
|
struct rt_rq *rt_rq;
|
|
/* rq "owned" by this entity/group: */
|
|
struct rt_rq *my_q;
|
|
#endif
|
|
} __randomize_layout;
|
|
|
|
struct sched_dl_entity {
|
|
struct rb_node rb_node;
|
|
|
|
/*
|
|
* Original scheduling parameters. Copied here from sched_attr
|
|
* during sched_setattr(), they will remain the same until
|
|
* the next sched_setattr().
|
|
*/
|
|
u64 dl_runtime; /* Maximum runtime for each instance */
|
|
u64 dl_deadline; /* Relative deadline of each instance */
|
|
u64 dl_period; /* Separation of two instances (period) */
|
|
u64 dl_bw; /* dl_runtime / dl_period */
|
|
u64 dl_density; /* dl_runtime / dl_deadline */
|
|
|
|
/*
|
|
* Actual scheduling parameters. Initialized with the values above,
|
|
* they are continously updated during task execution. Note that
|
|
* the remaining runtime could be < 0 in case we are in overrun.
|
|
*/
|
|
s64 runtime; /* Remaining runtime for this instance */
|
|
u64 deadline; /* Absolute deadline for this instance */
|
|
unsigned int flags; /* Specifying the scheduler behaviour */
|
|
|
|
/*
|
|
* Some bool flags:
|
|
*
|
|
* @dl_throttled tells if we exhausted the runtime. If so, the
|
|
* task has to wait for a replenishment to be performed at the
|
|
* next firing of dl_timer.
|
|
*
|
|
* @dl_boosted tells if we are boosted due to DI. If so we are
|
|
* outside bandwidth enforcement mechanism (but only until we
|
|
* exit the critical section);
|
|
*
|
|
* @dl_yielded tells if task gave up the CPU before consuming
|
|
* all its available runtime during the last job.
|
|
*
|
|
* @dl_non_contending tells if the task is inactive while still
|
|
* contributing to the active utilization. In other words, it
|
|
* indicates if the inactive timer has been armed and its handler
|
|
* has not been executed yet. This flag is useful to avoid race
|
|
* conditions between the inactive timer handler and the wakeup
|
|
* code.
|
|
*
|
|
* @dl_overrun tells if the task asked to be informed about runtime
|
|
* overruns.
|
|
*/
|
|
unsigned int dl_throttled : 1;
|
|
unsigned int dl_boosted : 1;
|
|
unsigned int dl_yielded : 1;
|
|
unsigned int dl_non_contending : 1;
|
|
unsigned int dl_overrun : 1;
|
|
|
|
/*
|
|
* Bandwidth enforcement timer. Each -deadline task has its
|
|
* own bandwidth to be enforced, thus we need one timer per task.
|
|
*/
|
|
struct hrtimer dl_timer;
|
|
|
|
/*
|
|
* Inactive timer, responsible for decreasing the active utilization
|
|
* at the "0-lag time". When a -deadline task blocks, it contributes
|
|
* to GRUB's active utilization until the "0-lag time", hence a
|
|
* timer is needed to decrease the active utilization at the correct
|
|
* time.
|
|
*/
|
|
struct hrtimer inactive_timer;
|
|
};
|
|
|
|
union rcu_special {
|
|
struct {
|
|
u8 blocked;
|
|
u8 need_qs;
|
|
u8 exp_need_qs;
|
|
|
|
/* Otherwise the compiler can store garbage here: */
|
|
u8 pad;
|
|
} b; /* Bits. */
|
|
u32 s; /* Set of bits. */
|
|
};
|
|
|
|
enum perf_event_task_context {
|
|
perf_invalid_context = -1,
|
|
perf_hw_context = 0,
|
|
perf_sw_context,
|
|
perf_nr_task_contexts,
|
|
};
|
|
|
|
struct wake_q_node {
|
|
struct wake_q_node *next;
|
|
};
|
|
|
|
struct task_struct {
|
|
#ifdef CONFIG_THREAD_INFO_IN_TASK
|
|
/*
|
|
* For reasons of header soup (see current_thread_info()), this
|
|
* must be the first element of task_struct.
|
|
*/
|
|
struct thread_info thread_info;
|
|
#endif
|
|
/* -1 unrunnable, 0 runnable, >0 stopped: */
|
|
volatile long state;
|
|
|
|
/*
|
|
* This begins the randomizable portion of task_struct. Only
|
|
* scheduling-critical items should be added above here.
|
|
*/
|
|
randomized_struct_fields_start
|
|
|
|
void *stack;
|
|
atomic_t usage;
|
|
/* Per task flags (PF_*), defined further below: */
|
|
unsigned int flags;
|
|
unsigned int ptrace;
|
|
|
|
#ifdef CONFIG_SMP
|
|
struct llist_node wake_entry;
|
|
int on_cpu;
|
|
#ifdef CONFIG_THREAD_INFO_IN_TASK
|
|
/* Current CPU: */
|
|
unsigned int cpu;
|
|
#endif
|
|
unsigned int wakee_flips;
|
|
unsigned long wakee_flip_decay_ts;
|
|
struct task_struct *last_wakee;
|
|
|
|
/*
|
|
* recent_used_cpu is initially set as the last CPU used by a task
|
|
* that wakes affine another task. Waker/wakee relationships can
|
|
* push tasks around a CPU where each wakeup moves to the next one.
|
|
* Tracking a recently used CPU allows a quick search for a recently
|
|
* used CPU that may be idle.
|
|
*/
|
|
int recent_used_cpu;
|
|
int wake_cpu;
|
|
#endif
|
|
int on_rq;
|
|
|
|
int prio;
|
|
int static_prio;
|
|
int normal_prio;
|
|
unsigned int rt_priority;
|
|
|
|
const struct sched_class *sched_class;
|
|
struct sched_entity se;
|
|
struct sched_rt_entity rt;
|
|
#ifdef CONFIG_CGROUP_SCHED
|
|
struct task_group *sched_task_group;
|
|
#endif
|
|
struct sched_dl_entity dl;
|
|
|
|
#ifdef CONFIG_PREEMPT_NOTIFIERS
|
|
/* List of struct preempt_notifier: */
|
|
struct hlist_head preempt_notifiers;
|
|
#endif
|
|
|
|
#ifdef CONFIG_BLK_DEV_IO_TRACE
|
|
unsigned int btrace_seq;
|
|
#endif
|
|
|
|
unsigned int policy;
|
|
int nr_cpus_allowed;
|
|
cpumask_t cpus_allowed;
|
|
|
|
#ifdef CONFIG_PREEMPT_RCU
|
|
int rcu_read_lock_nesting;
|
|
union rcu_special rcu_read_unlock_special;
|
|
struct list_head rcu_node_entry;
|
|
struct rcu_node *rcu_blocked_node;
|
|
#endif /* #ifdef CONFIG_PREEMPT_RCU */
|
|
|
|
#ifdef CONFIG_TASKS_RCU
|
|
unsigned long rcu_tasks_nvcsw;
|
|
u8 rcu_tasks_holdout;
|
|
u8 rcu_tasks_idx;
|
|
int rcu_tasks_idle_cpu;
|
|
struct list_head rcu_tasks_holdout_list;
|
|
#endif /* #ifdef CONFIG_TASKS_RCU */
|
|
|
|
struct sched_info sched_info;
|
|
|
|
struct list_head tasks;
|
|
#ifdef CONFIG_SMP
|
|
struct plist_node pushable_tasks;
|
|
struct rb_node pushable_dl_tasks;
|
|
#endif
|
|
|
|
struct mm_struct *mm;
|
|
struct mm_struct *active_mm;
|
|
|
|
/* Per-thread vma caching: */
|
|
struct vmacache vmacache;
|
|
|
|
#ifdef SPLIT_RSS_COUNTING
|
|
struct task_rss_stat rss_stat;
|
|
#endif
|
|
int exit_state;
|
|
int exit_code;
|
|
int exit_signal;
|
|
/* The signal sent when the parent dies: */
|
|
int pdeath_signal;
|
|
/* JOBCTL_*, siglock protected: */
|
|
unsigned long jobctl;
|
|
|
|
/* Used for emulating ABI behavior of previous Linux versions: */
|
|
unsigned int personality;
|
|
|
|
/* Scheduler bits, serialized by scheduler locks: */
|
|
unsigned sched_reset_on_fork:1;
|
|
unsigned sched_contributes_to_load:1;
|
|
unsigned sched_migrated:1;
|
|
unsigned sched_remote_wakeup:1;
|
|
/* Force alignment to the next boundary: */
|
|
unsigned :0;
|
|
|
|
/* Unserialized, strictly 'current' */
|
|
|
|
/* Bit to tell LSMs we're in execve(): */
|
|
unsigned in_execve:1;
|
|
unsigned in_iowait:1;
|
|
#ifndef TIF_RESTORE_SIGMASK
|
|
unsigned restore_sigmask:1;
|
|
#endif
|
|
#ifdef CONFIG_MEMCG
|
|
unsigned memcg_may_oom:1;
|
|
#ifndef CONFIG_SLOB
|
|
unsigned memcg_kmem_skip_account:1;
|
|
#endif
|
|
#endif
|
|
#ifdef CONFIG_COMPAT_BRK
|
|
unsigned brk_randomized:1;
|
|
#endif
|
|
#ifdef CONFIG_CGROUPS
|
|
/* disallow userland-initiated cgroup migration */
|
|
unsigned no_cgroup_migration:1;
|
|
#endif
|
|
|
|
unsigned long atomic_flags; /* Flags requiring atomic access. */
|
|
|
|
struct restart_block restart_block;
|
|
|
|
pid_t pid;
|
|
pid_t tgid;
|
|
|
|
#ifdef CONFIG_CC_STACKPROTECTOR
|
|
/* Canary value for the -fstack-protector GCC feature: */
|
|
unsigned long stack_canary;
|
|
#endif
|
|
/*
|
|
* Pointers to the (original) parent process, youngest child, younger sibling,
|
|
* older sibling, respectively. (p->father can be replaced with
|
|
* p->real_parent->pid)
|
|
*/
|
|
|
|
/* Real parent process: */
|
|
struct task_struct __rcu *real_parent;
|
|
|
|
/* Recipient of SIGCHLD, wait4() reports: */
|
|
struct task_struct __rcu *parent;
|
|
|
|
/*
|
|
* Children/sibling form the list of natural children:
|
|
*/
|
|
struct list_head children;
|
|
struct list_head sibling;
|
|
struct task_struct *group_leader;
|
|
|
|
/*
|
|
* 'ptraced' is the list of tasks this task is using ptrace() on.
|
|
*
|
|
* This includes both natural children and PTRACE_ATTACH targets.
|
|
* 'ptrace_entry' is this task's link on the p->parent->ptraced list.
|
|
*/
|
|
struct list_head ptraced;
|
|
struct list_head ptrace_entry;
|
|
|
|
/* PID/PID hash table linkage. */
|
|
struct pid_link pids[PIDTYPE_MAX];
|
|
struct list_head thread_group;
|
|
struct list_head thread_node;
|
|
|
|
struct completion *vfork_done;
|
|
|
|
/* CLONE_CHILD_SETTID: */
|
|
int __user *set_child_tid;
|
|
|
|
/* CLONE_CHILD_CLEARTID: */
|
|
int __user *clear_child_tid;
|
|
|
|
u64 utime;
|
|
u64 stime;
|
|
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
|
|
u64 utimescaled;
|
|
u64 stimescaled;
|
|
#endif
|
|
u64 gtime;
|
|
struct prev_cputime prev_cputime;
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
|
|
struct vtime vtime;
|
|
#endif
|
|
|
|
#ifdef CONFIG_NO_HZ_FULL
|
|
atomic_t tick_dep_mask;
|
|
#endif
|
|
/* Context switch counts: */
|
|
unsigned long nvcsw;
|
|
unsigned long nivcsw;
|
|
|
|
/* Monotonic time in nsecs: */
|
|
u64 start_time;
|
|
|
|
/* Boot based time in nsecs: */
|
|
u64 real_start_time;
|
|
|
|
/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
|
|
unsigned long min_flt;
|
|
unsigned long maj_flt;
|
|
|
|
#ifdef CONFIG_POSIX_TIMERS
|
|
struct task_cputime cputime_expires;
|
|
struct list_head cpu_timers[3];
|
|
#endif
|
|
|
|
/* Process credentials: */
|
|
|
|
/* Tracer's credentials at attach: */
|
|
const struct cred __rcu *ptracer_cred;
|
|
|
|
/* Objective and real subjective task credentials (COW): */
|
|
const struct cred __rcu *real_cred;
|
|
|
|
/* Effective (overridable) subjective task credentials (COW): */
|
|
const struct cred __rcu *cred;
|
|
|
|
/*
|
|
* executable name, excluding path.
|
|
*
|
|
* - normally initialized setup_new_exec()
|
|
* - access it with [gs]et_task_comm()
|
|
* - lock it with task_lock()
|
|
*/
|
|
char comm[TASK_COMM_LEN];
|
|
|
|
struct nameidata *nameidata;
|
|
|
|
#ifdef CONFIG_SYSVIPC
|
|
struct sysv_sem sysvsem;
|
|
struct sysv_shm sysvshm;
|
|
#endif
|
|
#ifdef CONFIG_DETECT_HUNG_TASK
|
|
unsigned long last_switch_count;
|
|
#endif
|
|
/* Filesystem information: */
|
|
struct fs_struct *fs;
|
|
|
|
/* Open file information: */
|
|
struct files_struct *files;
|
|
|
|
/* Namespaces: */
|
|
struct nsproxy *nsproxy;
|
|
|
|
/* Signal handlers: */
|
|
struct signal_struct *signal;
|
|
struct sighand_struct *sighand;
|
|
sigset_t blocked;
|
|
sigset_t real_blocked;
|
|
/* Restored if set_restore_sigmask() was used: */
|
|
sigset_t saved_sigmask;
|
|
struct sigpending pending;
|
|
unsigned long sas_ss_sp;
|
|
size_t sas_ss_size;
|
|
unsigned int sas_ss_flags;
|
|
|
|
struct callback_head *task_works;
|
|
|
|
struct audit_context *audit_context;
|
|
#ifdef CONFIG_AUDITSYSCALL
|
|
kuid_t loginuid;
|
|
unsigned int sessionid;
|
|
#endif
|
|
struct seccomp seccomp;
|
|
|
|
/* Thread group tracking: */
|
|
u32 parent_exec_id;
|
|
u32 self_exec_id;
|
|
|
|
/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
|
|
spinlock_t alloc_lock;
|
|
|
|
/* Protection of the PI data structures: */
|
|
raw_spinlock_t pi_lock;
|
|
|
|
struct wake_q_node wake_q;
|
|
|
|
#ifdef CONFIG_RT_MUTEXES
|
|
/* PI waiters blocked on a rt_mutex held by this task: */
|
|
struct rb_root_cached pi_waiters;
|
|
/* Updated under owner's pi_lock and rq lock */
|
|
struct task_struct *pi_top_task;
|
|
/* Deadlock detection and priority inheritance handling: */
|
|
struct rt_mutex_waiter *pi_blocked_on;
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUG_MUTEXES
|
|
/* Mutex deadlock detection: */
|
|
struct mutex_waiter *blocked_on;
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
unsigned int irq_events;
|
|
unsigned long hardirq_enable_ip;
|
|
unsigned long hardirq_disable_ip;
|
|
unsigned int hardirq_enable_event;
|
|
unsigned int hardirq_disable_event;
|
|
int hardirqs_enabled;
|
|
int hardirq_context;
|
|
unsigned long softirq_disable_ip;
|
|
unsigned long softirq_enable_ip;
|
|
unsigned int softirq_disable_event;
|
|
unsigned int softirq_enable_event;
|
|
int softirqs_enabled;
|
|
int softirq_context;
|
|
#endif
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
# define MAX_LOCK_DEPTH 48UL
|
|
u64 curr_chain_key;
|
|
int lockdep_depth;
|
|
unsigned int lockdep_recursion;
|
|
struct held_lock held_locks[MAX_LOCK_DEPTH];
|
|
#endif
|
|
|
|
#ifdef CONFIG_UBSAN
|
|
unsigned int in_ubsan;
|
|
#endif
|
|
|
|
/* Journalling filesystem info: */
|
|
void *journal_info;
|
|
|
|
/* Stacked block device info: */
|
|
struct bio_list *bio_list;
|
|
|
|
#ifdef CONFIG_BLOCK
|
|
/* Stack plugging: */
|
|
struct blk_plug *plug;
|
|
#endif
|
|
|
|
/* VM state: */
|
|
struct reclaim_state *reclaim_state;
|
|
|
|
struct backing_dev_info *backing_dev_info;
|
|
|
|
struct io_context *io_context;
|
|
|
|
/* Ptrace state: */
|
|
unsigned long ptrace_message;
|
|
siginfo_t *last_siginfo;
|
|
|
|
struct task_io_accounting ioac;
|
|
#ifdef CONFIG_TASK_XACCT
|
|
/* Accumulated RSS usage: */
|
|
u64 acct_rss_mem1;
|
|
/* Accumulated virtual memory usage: */
|
|
u64 acct_vm_mem1;
|
|
/* stime + utime since last update: */
|
|
u64 acct_timexpd;
|
|
#endif
|
|
#ifdef CONFIG_CPUSETS
|
|
/* Protected by ->alloc_lock: */
|
|
nodemask_t mems_allowed;
|
|
/* Seqence number to catch updates: */
|
|
seqcount_t mems_allowed_seq;
|
|
int cpuset_mem_spread_rotor;
|
|
int cpuset_slab_spread_rotor;
|
|
#endif
|
|
#ifdef CONFIG_CGROUPS
|
|
/* Control Group info protected by css_set_lock: */
|
|
struct css_set __rcu *cgroups;
|
|
/* cg_list protected by css_set_lock and tsk->alloc_lock: */
|
|
struct list_head cg_list;
|
|
#endif
|
|
#ifdef CONFIG_INTEL_RDT
|
|
u32 closid;
|
|
u32 rmid;
|
|
#endif
|
|
#ifdef CONFIG_FUTEX
|
|
struct robust_list_head __user *robust_list;
|
|
#ifdef CONFIG_COMPAT
|
|
struct compat_robust_list_head __user *compat_robust_list;
|
|
#endif
|
|
struct list_head pi_state_list;
|
|
struct futex_pi_state *pi_state_cache;
|
|
#endif
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
|
|
struct mutex perf_event_mutex;
|
|
struct list_head perf_event_list;
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_PREEMPT
|
|
unsigned long preempt_disable_ip;
|
|
#endif
|
|
#ifdef CONFIG_NUMA
|
|
/* Protected by alloc_lock: */
|
|
struct mempolicy *mempolicy;
|
|
short il_prev;
|
|
short pref_node_fork;
|
|
#endif
|
|
#ifdef CONFIG_NUMA_BALANCING
|
|
int numa_scan_seq;
|
|
unsigned int numa_scan_period;
|
|
unsigned int numa_scan_period_max;
|
|
int numa_preferred_nid;
|
|
unsigned long numa_migrate_retry;
|
|
/* Migration stamp: */
|
|
u64 node_stamp;
|
|
u64 last_task_numa_placement;
|
|
u64 last_sum_exec_runtime;
|
|
struct callback_head numa_work;
|
|
|
|
struct list_head numa_entry;
|
|
struct numa_group *numa_group;
|
|
|
|
/*
|
|
* numa_faults is an array split into four regions:
|
|
* faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
|
|
* in this precise order.
|
|
*
|
|
* faults_memory: Exponential decaying average of faults on a per-node
|
|
* basis. Scheduling placement decisions are made based on these
|
|
* counts. The values remain static for the duration of a PTE scan.
|
|
* faults_cpu: Track the nodes the process was running on when a NUMA
|
|
* hinting fault was incurred.
|
|
* faults_memory_buffer and faults_cpu_buffer: Record faults per node
|
|
* during the current scan window. When the scan completes, the counts
|
|
* in faults_memory and faults_cpu decay and these values are copied.
|
|
*/
|
|
unsigned long *numa_faults;
|
|
unsigned long total_numa_faults;
|
|
|
|
/*
|
|
* numa_faults_locality tracks if faults recorded during the last
|
|
* scan window were remote/local or failed to migrate. The task scan
|
|
* period is adapted based on the locality of the faults with different
|
|
* weights depending on whether they were shared or private faults
|
|
*/
|
|
unsigned long numa_faults_locality[3];
|
|
|
|
unsigned long numa_pages_migrated;
|
|
#endif /* CONFIG_NUMA_BALANCING */
|
|
|
|
struct tlbflush_unmap_batch tlb_ubc;
|
|
|
|
struct rcu_head rcu;
|
|
|
|
/* Cache last used pipe for splice(): */
|
|
struct pipe_inode_info *splice_pipe;
|
|
|
|
struct page_frag task_frag;
|
|
|
|
#ifdef CONFIG_TASK_DELAY_ACCT
|
|
struct task_delay_info *delays;
|
|
#endif
|
|
|
|
#ifdef CONFIG_FAULT_INJECTION
|
|
int make_it_fail;
|
|
unsigned int fail_nth;
|
|
#endif
|
|
/*
|
|
* When (nr_dirtied >= nr_dirtied_pause), it's time to call
|
|
* balance_dirty_pages() for a dirty throttling pause:
|
|
*/
|
|
int nr_dirtied;
|
|
int nr_dirtied_pause;
|
|
/* Start of a write-and-pause period: */
|
|
unsigned long dirty_paused_when;
|
|
|
|
#ifdef CONFIG_LATENCYTOP
|
|
int latency_record_count;
|
|
struct latency_record latency_record[LT_SAVECOUNT];
|
|
#endif
|
|
/*
|
|
* Time slack values; these are used to round up poll() and
|
|
* select() etc timeout values. These are in nanoseconds.
|
|
*/
|
|
u64 timer_slack_ns;
|
|
u64 default_timer_slack_ns;
|
|
|
|
#ifdef CONFIG_KASAN
|
|
unsigned int kasan_depth;
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/* Index of current stored address in ret_stack: */
|
|
int curr_ret_stack;
|
|
|
|
/* Stack of return addresses for return function tracing: */
|
|
struct ftrace_ret_stack *ret_stack;
|
|
|
|
/* Timestamp for last schedule: */
|
|
unsigned long long ftrace_timestamp;
|
|
|
|
/*
|
|
* Number of functions that haven't been traced
|
|
* because of depth overrun:
|
|
*/
|
|
atomic_t trace_overrun;
|
|
|
|
/* Pause tracing: */
|
|
atomic_t tracing_graph_pause;
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRACING
|
|
/* State flags for use by tracers: */
|
|
unsigned long trace;
|
|
|
|
/* Bitmask and counter of trace recursion: */
|
|
unsigned long trace_recursion;
|
|
#endif /* CONFIG_TRACING */
|
|
|
|
#ifdef CONFIG_KCOV
|
|
/* Coverage collection mode enabled for this task (0 if disabled): */
|
|
enum kcov_mode kcov_mode;
|
|
|
|
/* Size of the kcov_area: */
|
|
unsigned int kcov_size;
|
|
|
|
/* Buffer for coverage collection: */
|
|
void *kcov_area;
|
|
|
|
/* KCOV descriptor wired with this task or NULL: */
|
|
struct kcov *kcov;
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG
|
|
struct mem_cgroup *memcg_in_oom;
|
|
gfp_t memcg_oom_gfp_mask;
|
|
int memcg_oom_order;
|
|
|
|
/* Number of pages to reclaim on returning to userland: */
|
|
unsigned int memcg_nr_pages_over_high;
|
|
#endif
|
|
|
|
#ifdef CONFIG_UPROBES
|
|
struct uprobe_task *utask;
|
|
#endif
|
|
#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
|
|
unsigned int sequential_io;
|
|
unsigned int sequential_io_avg;
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
|
|
unsigned long task_state_change;
|
|
#endif
|
|
int pagefault_disabled;
|
|
#ifdef CONFIG_MMU
|
|
struct task_struct *oom_reaper_list;
|
|
#endif
|
|
#ifdef CONFIG_VMAP_STACK
|
|
struct vm_struct *stack_vm_area;
|
|
#endif
|
|
#ifdef CONFIG_THREAD_INFO_IN_TASK
|
|
/* A live task holds one reference: */
|
|
atomic_t stack_refcount;
|
|
#endif
|
|
#ifdef CONFIG_LIVEPATCH
|
|
int patch_state;
|
|
#endif
|
|
#ifdef CONFIG_SECURITY
|
|
/* Used by LSM modules for access restriction: */
|
|
void *security;
|
|
#endif
|
|
|
|
/*
|
|
* New fields for task_struct should be added above here, so that
|
|
* they are included in the randomized portion of task_struct.
|
|
*/
|
|
randomized_struct_fields_end
|
|
|
|
/* CPU-specific state of this task: */
|
|
struct thread_struct thread;
|
|
|
|
/*
|
|
* WARNING: on x86, 'thread_struct' contains a variable-sized
|
|
* structure. It *MUST* be at the end of 'task_struct'.
|
|
*
|
|
* Do not put anything below here!
|
|
*/
|
|
};
|
|
|
|
static inline struct pid *task_pid(struct task_struct *task)
|
|
{
|
|
return task->pids[PIDTYPE_PID].pid;
|
|
}
|
|
|
|
static inline struct pid *task_tgid(struct task_struct *task)
|
|
{
|
|
return task->group_leader->pids[PIDTYPE_PID].pid;
|
|
}
|
|
|
|
/*
|
|
* Without tasklist or RCU lock it is not safe to dereference
|
|
* the result of task_pgrp/task_session even if task == current,
|
|
* we can race with another thread doing sys_setsid/sys_setpgid.
|
|
*/
|
|
static inline struct pid *task_pgrp(struct task_struct *task)
|
|
{
|
|
return task->group_leader->pids[PIDTYPE_PGID].pid;
|
|
}
|
|
|
|
static inline struct pid *task_session(struct task_struct *task)
|
|
{
|
|
return task->group_leader->pids[PIDTYPE_SID].pid;
|
|
}
|
|
|
|
/*
|
|
* the helpers to get the task's different pids as they are seen
|
|
* from various namespaces
|
|
*
|
|
* task_xid_nr() : global id, i.e. the id seen from the init namespace;
|
|
* task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
|
|
* current.
|
|
* task_xid_nr_ns() : id seen from the ns specified;
|
|
*
|
|
* see also pid_nr() etc in include/linux/pid.h
|
|
*/
|
|
pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
|
|
|
|
static inline pid_t task_pid_nr(struct task_struct *tsk)
|
|
{
|
|
return tsk->pid;
|
|
}
|
|
|
|
static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
|
|
}
|
|
|
|
static inline pid_t task_pid_vnr(struct task_struct *tsk)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
|
|
}
|
|
|
|
|
|
static inline pid_t task_tgid_nr(struct task_struct *tsk)
|
|
{
|
|
return tsk->tgid;
|
|
}
|
|
|
|
/**
|
|
* pid_alive - check that a task structure is not stale
|
|
* @p: Task structure to be checked.
|
|
*
|
|
* Test if a process is not yet dead (at most zombie state)
|
|
* If pid_alive fails, then pointers within the task structure
|
|
* can be stale and must not be dereferenced.
|
|
*
|
|
* Return: 1 if the process is alive. 0 otherwise.
|
|
*/
|
|
static inline int pid_alive(const struct task_struct *p)
|
|
{
|
|
return p->pids[PIDTYPE_PID].pid != NULL;
|
|
}
|
|
|
|
static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
|
|
}
|
|
|
|
static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
|
|
}
|
|
|
|
|
|
static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
|
|
}
|
|
|
|
static inline pid_t task_session_vnr(struct task_struct *tsk)
|
|
{
|
|
return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
|
|
}
|
|
|
|
static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns);
|
|
}
|
|
|
|
static inline pid_t task_tgid_vnr(struct task_struct *tsk)
|
|
{
|
|
return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL);
|
|
}
|
|
|
|
static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
pid_t pid = 0;
|
|
|
|
rcu_read_lock();
|
|
if (pid_alive(tsk))
|
|
pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
|
|
rcu_read_unlock();
|
|
|
|
return pid;
|
|
}
|
|
|
|
static inline pid_t task_ppid_nr(const struct task_struct *tsk)
|
|
{
|
|
return task_ppid_nr_ns(tsk, &init_pid_ns);
|
|
}
|
|
|
|
/* Obsolete, do not use: */
|
|
static inline pid_t task_pgrp_nr(struct task_struct *tsk)
|
|
{
|
|
return task_pgrp_nr_ns(tsk, &init_pid_ns);
|
|
}
|
|
|
|
#define TASK_REPORT_IDLE (TASK_REPORT + 1)
|
|
#define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
|
|
|
|
static inline unsigned int task_state_index(struct task_struct *tsk)
|
|
{
|
|
unsigned int tsk_state = READ_ONCE(tsk->state);
|
|
unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
|
|
|
|
BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
|
|
|
|
if (tsk_state == TASK_IDLE)
|
|
state = TASK_REPORT_IDLE;
|
|
|
|
return fls(state);
|
|
}
|
|
|
|
static inline char task_index_to_char(unsigned int state)
|
|
{
|
|
static const char state_char[] = "RSDTtXZPI";
|
|
|
|
BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
|
|
|
|
return state_char[state];
|
|
}
|
|
|
|
static inline char task_state_to_char(struct task_struct *tsk)
|
|
{
|
|
return task_index_to_char(task_state_index(tsk));
|
|
}
|
|
|
|
/**
|
|
* is_global_init - check if a task structure is init. Since init
|
|
* is free to have sub-threads we need to check tgid.
|
|
* @tsk: Task structure to be checked.
|
|
*
|
|
* Check if a task structure is the first user space task the kernel created.
|
|
*
|
|
* Return: 1 if the task structure is init. 0 otherwise.
|
|
*/
|
|
static inline int is_global_init(struct task_struct *tsk)
|
|
{
|
|
return task_tgid_nr(tsk) == 1;
|
|
}
|
|
|
|
extern struct pid *cad_pid;
|
|
|
|
/*
|
|
* Per process flags
|
|
*/
|
|
#define PF_IDLE 0x00000002 /* I am an IDLE thread */
|
|
#define PF_EXITING 0x00000004 /* Getting shut down */
|
|
#define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
|
|
#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
|
|
#define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
|
|
#define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
|
|
#define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
|
|
#define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
|
|
#define PF_DUMPCORE 0x00000200 /* Dumped core */
|
|
#define PF_SIGNALED 0x00000400 /* Killed by a signal */
|
|
#define PF_MEMALLOC 0x00000800 /* Allocating memory */
|
|
#define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
|
|
#define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
|
|
#define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
|
|
#define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
|
|
#define PF_FROZEN 0x00010000 /* Frozen for system suspend */
|
|
#define PF_KSWAPD 0x00020000 /* I am kswapd */
|
|
#define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
|
|
#define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
|
|
#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
|
|
#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
|
|
#define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
|
|
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
|
|
#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
|
|
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
|
|
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
|
|
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
|
|
#define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
|
|
|
|
/*
|
|
* Only the _current_ task can read/write to tsk->flags, but other
|
|
* tasks can access tsk->flags in readonly mode for example
|
|
* with tsk_used_math (like during threaded core dumping).
|
|
* There is however an exception to this rule during ptrace
|
|
* or during fork: the ptracer task is allowed to write to the
|
|
* child->flags of its traced child (same goes for fork, the parent
|
|
* can write to the child->flags), because we're guaranteed the
|
|
* child is not running and in turn not changing child->flags
|
|
* at the same time the parent does it.
|
|
*/
|
|
#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
|
|
#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
|
|
#define clear_used_math() clear_stopped_child_used_math(current)
|
|
#define set_used_math() set_stopped_child_used_math(current)
|
|
|
|
#define conditional_stopped_child_used_math(condition, child) \
|
|
do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
|
|
|
|
#define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
|
|
|
|
#define copy_to_stopped_child_used_math(child) \
|
|
do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
|
|
|
|
/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
|
|
#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
|
|
#define used_math() tsk_used_math(current)
|
|
|
|
static inline bool is_percpu_thread(void)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
return (current->flags & PF_NO_SETAFFINITY) &&
|
|
(current->nr_cpus_allowed == 1);
|
|
#else
|
|
return true;
|
|
#endif
|
|
}
|
|
|
|
/* Per-process atomic flags. */
|
|
#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
|
|
#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
|
|
#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
|
|
|
|
|
|
#define TASK_PFA_TEST(name, func) \
|
|
static inline bool task_##func(struct task_struct *p) \
|
|
{ return test_bit(PFA_##name, &p->atomic_flags); }
|
|
|
|
#define TASK_PFA_SET(name, func) \
|
|
static inline void task_set_##func(struct task_struct *p) \
|
|
{ set_bit(PFA_##name, &p->atomic_flags); }
|
|
|
|
#define TASK_PFA_CLEAR(name, func) \
|
|
static inline void task_clear_##func(struct task_struct *p) \
|
|
{ clear_bit(PFA_##name, &p->atomic_flags); }
|
|
|
|
TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
|
|
TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
|
|
|
|
TASK_PFA_TEST(SPREAD_PAGE, spread_page)
|
|
TASK_PFA_SET(SPREAD_PAGE, spread_page)
|
|
TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
|
|
|
|
TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
|
|
TASK_PFA_SET(SPREAD_SLAB, spread_slab)
|
|
TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
|
|
|
|
static inline void
|
|
current_restore_flags(unsigned long orig_flags, unsigned long flags)
|
|
{
|
|
current->flags &= ~flags;
|
|
current->flags |= orig_flags & flags;
|
|
}
|
|
|
|
extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
|
|
extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
|
|
#ifdef CONFIG_SMP
|
|
extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
|
|
extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
|
|
#else
|
|
static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
|
|
{
|
|
}
|
|
static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
|
|
{
|
|
if (!cpumask_test_cpu(0, new_mask))
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifndef cpu_relax_yield
|
|
#define cpu_relax_yield() cpu_relax()
|
|
#endif
|
|
|
|
extern int yield_to(struct task_struct *p, bool preempt);
|
|
extern void set_user_nice(struct task_struct *p, long nice);
|
|
extern int task_prio(const struct task_struct *p);
|
|
|
|
/**
|
|
* task_nice - return the nice value of a given task.
|
|
* @p: the task in question.
|
|
*
|
|
* Return: The nice value [ -20 ... 0 ... 19 ].
|
|
*/
|
|
static inline int task_nice(const struct task_struct *p)
|
|
{
|
|
return PRIO_TO_NICE((p)->static_prio);
|
|
}
|
|
|
|
extern int can_nice(const struct task_struct *p, const int nice);
|
|
extern int task_curr(const struct task_struct *p);
|
|
extern int idle_cpu(int cpu);
|
|
extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
|
|
extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
|
|
extern int sched_setattr(struct task_struct *, const struct sched_attr *);
|
|
extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
|
|
extern struct task_struct *idle_task(int cpu);
|
|
|
|
/**
|
|
* is_idle_task - is the specified task an idle task?
|
|
* @p: the task in question.
|
|
*
|
|
* Return: 1 if @p is an idle task. 0 otherwise.
|
|
*/
|
|
static inline bool is_idle_task(const struct task_struct *p)
|
|
{
|
|
return !!(p->flags & PF_IDLE);
|
|
}
|
|
|
|
extern struct task_struct *curr_task(int cpu);
|
|
extern void ia64_set_curr_task(int cpu, struct task_struct *p);
|
|
|
|
void yield(void);
|
|
|
|
union thread_union {
|
|
#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
|
|
struct task_struct task;
|
|
#endif
|
|
#ifndef CONFIG_THREAD_INFO_IN_TASK
|
|
struct thread_info thread_info;
|
|
#endif
|
|
unsigned long stack[THREAD_SIZE/sizeof(long)];
|
|
};
|
|
|
|
#ifndef CONFIG_THREAD_INFO_IN_TASK
|
|
extern struct thread_info init_thread_info;
|
|
#endif
|
|
|
|
extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
|
|
|
|
#ifdef CONFIG_THREAD_INFO_IN_TASK
|
|
static inline struct thread_info *task_thread_info(struct task_struct *task)
|
|
{
|
|
return &task->thread_info;
|
|
}
|
|
#elif !defined(__HAVE_THREAD_FUNCTIONS)
|
|
# define task_thread_info(task) ((struct thread_info *)(task)->stack)
|
|
#endif
|
|
|
|
/*
|
|
* find a task by one of its numerical ids
|
|
*
|
|
* find_task_by_pid_ns():
|
|
* finds a task by its pid in the specified namespace
|
|
* find_task_by_vpid():
|
|
* finds a task by its virtual pid
|
|
*
|
|
* see also find_vpid() etc in include/linux/pid.h
|
|
*/
|
|
|
|
extern struct task_struct *find_task_by_vpid(pid_t nr);
|
|
extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
|
|
|
|
/*
|
|
* find a task by its virtual pid and get the task struct
|
|
*/
|
|
extern struct task_struct *find_get_task_by_vpid(pid_t nr);
|
|
|
|
extern int wake_up_state(struct task_struct *tsk, unsigned int state);
|
|
extern int wake_up_process(struct task_struct *tsk);
|
|
extern void wake_up_new_task(struct task_struct *tsk);
|
|
|
|
#ifdef CONFIG_SMP
|
|
extern void kick_process(struct task_struct *tsk);
|
|
#else
|
|
static inline void kick_process(struct task_struct *tsk) { }
|
|
#endif
|
|
|
|
extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
|
|
|
|
static inline void set_task_comm(struct task_struct *tsk, const char *from)
|
|
{
|
|
__set_task_comm(tsk, from, false);
|
|
}
|
|
|
|
extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
|
|
#define get_task_comm(buf, tsk) ({ \
|
|
BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
|
|
__get_task_comm(buf, sizeof(buf), tsk); \
|
|
})
|
|
|
|
#ifdef CONFIG_SMP
|
|
void scheduler_ipi(void);
|
|
extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
|
|
#else
|
|
static inline void scheduler_ipi(void) { }
|
|
static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Set thread flags in other task's structures.
|
|
* See asm/thread_info.h for TIF_xxxx flags available:
|
|
*/
|
|
static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
|
|
{
|
|
set_ti_thread_flag(task_thread_info(tsk), flag);
|
|
}
|
|
|
|
static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
|
|
{
|
|
clear_ti_thread_flag(task_thread_info(tsk), flag);
|
|
}
|
|
|
|
static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
|
|
{
|
|
return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
|
|
}
|
|
|
|
static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
|
|
{
|
|
return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
|
|
}
|
|
|
|
static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
|
|
{
|
|
return test_ti_thread_flag(task_thread_info(tsk), flag);
|
|
}
|
|
|
|
static inline void set_tsk_need_resched(struct task_struct *tsk)
|
|
{
|
|
set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
|
|
}
|
|
|
|
static inline void clear_tsk_need_resched(struct task_struct *tsk)
|
|
{
|
|
clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
|
|
}
|
|
|
|
static inline int test_tsk_need_resched(struct task_struct *tsk)
|
|
{
|
|
return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
|
|
}
|
|
|
|
/*
|
|
* cond_resched() and cond_resched_lock(): latency reduction via
|
|
* explicit rescheduling in places that are safe. The return
|
|
* value indicates whether a reschedule was done in fact.
|
|
* cond_resched_lock() will drop the spinlock before scheduling,
|
|
* cond_resched_softirq() will enable bhs before scheduling.
|
|
*/
|
|
#ifndef CONFIG_PREEMPT
|
|
extern int _cond_resched(void);
|
|
#else
|
|
static inline int _cond_resched(void) { return 0; }
|
|
#endif
|
|
|
|
#define cond_resched() ({ \
|
|
___might_sleep(__FILE__, __LINE__, 0); \
|
|
_cond_resched(); \
|
|
})
|
|
|
|
extern int __cond_resched_lock(spinlock_t *lock);
|
|
|
|
#define cond_resched_lock(lock) ({ \
|
|
___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
|
|
__cond_resched_lock(lock); \
|
|
})
|
|
|
|
extern int __cond_resched_softirq(void);
|
|
|
|
#define cond_resched_softirq() ({ \
|
|
___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
|
|
__cond_resched_softirq(); \
|
|
})
|
|
|
|
static inline void cond_resched_rcu(void)
|
|
{
|
|
#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
|
|
rcu_read_unlock();
|
|
cond_resched();
|
|
rcu_read_lock();
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Does a critical section need to be broken due to another
|
|
* task waiting?: (technically does not depend on CONFIG_PREEMPT,
|
|
* but a general need for low latency)
|
|
*/
|
|
static inline int spin_needbreak(spinlock_t *lock)
|
|
{
|
|
#ifdef CONFIG_PREEMPT
|
|
return spin_is_contended(lock);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static __always_inline bool need_resched(void)
|
|
{
|
|
return unlikely(tif_need_resched());
|
|
}
|
|
|
|
/*
|
|
* Wrappers for p->thread_info->cpu access. No-op on UP.
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
|
|
static inline unsigned int task_cpu(const struct task_struct *p)
|
|
{
|
|
#ifdef CONFIG_THREAD_INFO_IN_TASK
|
|
return p->cpu;
|
|
#else
|
|
return task_thread_info(p)->cpu;
|
|
#endif
|
|
}
|
|
|
|
extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
|
|
|
|
#else
|
|
|
|
static inline unsigned int task_cpu(const struct task_struct *p)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* In order to reduce various lock holder preemption latencies provide an
|
|
* interface to see if a vCPU is currently running or not.
|
|
*
|
|
* This allows us to terminate optimistic spin loops and block, analogous to
|
|
* the native optimistic spin heuristic of testing if the lock owner task is
|
|
* running or not.
|
|
*/
|
|
#ifndef vcpu_is_preempted
|
|
# define vcpu_is_preempted(cpu) false
|
|
#endif
|
|
|
|
extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
|
|
extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
|
|
|
|
#ifndef TASK_SIZE_OF
|
|
#define TASK_SIZE_OF(tsk) TASK_SIZE
|
|
#endif
|
|
|
|
#endif
|