LXR linux/include/linux/sched/cputime.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_SCHED_CPUTIME_H
   3#define _LINUX_SCHED_CPUTIME_H
   4
   5#include <linux/sched/signal.h>
   6
   7/*
   8 * cputime accounting APIs:
   9 */
  10
  11#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
  12#include <asm/cputime.h>
  13
  14#ifndef cputime_to_nsecs
  15# define cputime_to_nsecs(__ct) \
  16        (cputime_to_usecs(__ct) * NSEC_PER_USEC)
  17#endif
  18#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
  19
  20#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
  21extern void task_cputime(struct task_struct *t,
  22                         u64 *utime, u64 *stime);
  23extern u64 task_gtime(struct task_struct *t);
  24#else
  25static inline void task_cputime(struct task_struct *t,
  26                                u64 *utime, u64 *stime)
  27{
  28        *utime = t->utime;
  29        *stime = t->stime;
  30}
  31
  32static inline u64 task_gtime(struct task_struct *t)
  33{
  34        return t->gtime;
  35}
  36#endif
  37
  38#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
  39static inline void task_cputime_scaled(struct task_struct *t,
  40                                       u64 *utimescaled,
  41                                       u64 *stimescaled)
  42{
  43        *utimescaled = t->utimescaled;
  44        *stimescaled = t->stimescaled;
  45}
  46#else
  47static inline void task_cputime_scaled(struct task_struct *t,
  48                                       u64 *utimescaled,
  49                                       u64 *stimescaled)
  50{
  51        task_cputime(t, utimescaled, stimescaled);
  52}
  53#endif
  54
  55extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
  56extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
  57
  58
  59/*
  60 * Thread group CPU time accounting.
  61 */
  62void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
  63void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
  64
  65
  66/*
  67 * The following are functions that support scheduler-internal time accounting.
  68 * These functions are generally called at the timer tick.  None of this depends
  69 * on CONFIG_SCHEDSTATS.
  70 */
  71
  72/**
  73 * get_running_cputimer - return &tsk->signal->cputimer if cputimer is running
  74 *
  75 * @tsk:        Pointer to target task.
  76 */
  77#ifdef CONFIG_POSIX_TIMERS
  78static inline
  79struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
  80{
  81        struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
  82
  83        /* Check if cputimer isn't running. This is accessed without locking. */
  84        if (!READ_ONCE(cputimer->running))
  85                return NULL;
  86
  87        /*
  88         * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
  89         * in __exit_signal(), we won't account to the signal struct further
  90         * cputime consumed by that task, even though the task can still be
  91         * ticking after __exit_signal().
  92         *
  93         * In order to keep a consistent behaviour between thread group cputime
  94         * and thread group cputimer accounting, lets also ignore the cputime
  95         * elapsing after __exit_signal() in any thread group timer running.
  96         *
  97         * This makes sure that POSIX CPU clocks and timers are synchronized, so
  98         * that a POSIX CPU timer won't expire while the corresponding POSIX CPU
  99         * clock delta is behind the expiring timer value.
 100         */
 101        if (unlikely(!tsk->sighand))
 102                return NULL;
 103
 104        return cputimer;
 105}
 106#else
 107static inline
 108struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
 109{
 110        return NULL;
 111}
 112#endif
 113
 114/**
 115 * account_group_user_time - Maintain utime for a thread group.
 116 *
 117 * @tsk:        Pointer to task structure.
 118 * @cputime:    Time value by which to increment the utime field of the
 119 *              thread_group_cputime structure.
 120 *
 121 * If thread group time is being maintained, get the structure for the
 122 * running CPU and update the utime field there.
 123 */
 124static inline void account_group_user_time(struct task_struct *tsk,
 125                                           u64 cputime)
 126{
 127        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 128
 129        if (!cputimer)
 130                return;
 131
 132        atomic64_add(cputime, &cputimer->cputime_atomic.utime);
 133}
 134
 135/**
 136 * account_group_system_time - Maintain stime for a thread group.
 137 *
 138 * @tsk:        Pointer to task structure.
 139 * @cputime:    Time value by which to increment the stime field of the
 140 *              thread_group_cputime structure.
 141 *
 142 * If thread group time is being maintained, get the structure for the
 143 * running CPU and update the stime field there.
 144 */
 145static inline void account_group_system_time(struct task_struct *tsk,
 146                                             u64 cputime)
 147{
 148        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 149
 150        if (!cputimer)
 151                return;
 152
 153        atomic64_add(cputime, &cputimer->cputime_atomic.stime);
 154}
 155
 156/**
 157 * account_group_exec_runtime - Maintain exec runtime for a thread group.
 158 *
 159 * @tsk:        Pointer to task structure.
 160 * @ns:         Time value by which to increment the sum_exec_runtime field
 161 *              of the thread_group_cputime structure.
 162 *
 163 * If thread group time is being maintained, get the structure for the
 164 * running CPU and update the sum_exec_runtime field there.
 165 */
 166static inline void account_group_exec_runtime(struct task_struct *tsk,
 167                                              unsigned long long ns)
 168{
 169        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 170
 171        if (!cputimer)
 172                return;
 173
 174        atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime);
 175}
 176
 177static inline void prev_cputime_init(struct prev_cputime *prev)
 178{
 179#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 180        prev->utime = prev->stime = 0;
 181        raw_spin_lock_init(&prev->lock);
 182#endif
 183}
 184
 185extern unsigned long long
 186task_sched_runtime(struct task_struct *task);
 187
 188#endif /* _LINUX_SCHED_CPUTIME_H */
 189