include/linux/sched/cputime.h

Source file repositories/reference/linux-study-clean/include/linux/sched/cputime.h

File Facts

System
Linux kernel
Corpus path
include/linux/sched/cputime.h
Extension
.h
Size
5544 bytes
Lines
202
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _LINUX_SCHED_CPUTIME_H
#define _LINUX_SCHED_CPUTIME_H

#include <linux/static_call_types.h>
#include <linux/sched/signal.h>

/*
 * cputime accounting APIs:
 */

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern bool task_cputime(struct task_struct *t,
			 u64 *utime, u64 *stime);
extern u64 task_gtime(struct task_struct *t);
#else
static inline bool task_cputime(struct task_struct *t,
				u64 *utime, u64 *stime)
{
	*utime = t->utime;
	*stime = t->stime;
	return false;
}

static inline u64 task_gtime(struct task_struct *t)
{
	return t->gtime;
}
#endif

#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
static inline void task_cputime_scaled(struct task_struct *t,
				       u64 *utimescaled,
				       u64 *stimescaled)
{
	*utimescaled = t->utimescaled;
	*stimescaled = t->stimescaled;
}
#else
static inline void task_cputime_scaled(struct task_struct *t,
				       u64 *utimescaled,
				       u64 *stimescaled)
{
	task_cputime(t, utimescaled, stimescaled);
}
#endif

extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
extern void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
			   u64 *ut, u64 *st);

/*
 * Thread group CPU time accounting.
 */
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples);

/*
 * The following are functions that support scheduler-internal time accounting.
 * These functions are generally called at the timer tick.  None of this depends
 * on CONFIG_SCHEDSTATS.
 */

/**
 * get_running_cputimer - return &tsk->signal->cputimer if cputimers are active
 *
 * @tsk:	Pointer to target task.
 */
#ifdef CONFIG_POSIX_TIMERS
static inline
struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
{
	struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;

	/*
	 * Check whether posix CPU timers are active. If not the thread
	 * group accounting is not active either. Lockless check.
	 */
	if (!READ_ONCE(tsk->signal->posix_cputimers.timers_active))
		return NULL;

	/*
	 * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
	 * in __exit_signal(), we won't account to the signal struct further
	 * cputime consumed by that task, even though the task can still be
	 * ticking after __exit_signal().
	 *
	 * In order to keep a consistent behaviour between thread group cputime
	 * and thread group cputimer accounting, lets also ignore the cputime
	 * elapsing after __exit_signal() in any thread group timer running.

Annotation

Implementation Notes