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);
  57extern void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
  58                           u64 *ut, u64 *st);
  59
  60/*
  61 * Thread group CPU time accounting.
  62 */
  63void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
  64void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples);
  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 cputimers are active
  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        /*
  84         * Check whether posix CPU timers are active. If not the thread
  85         * group accounting is not active either. Lockless check.
  86         */
  87        if (!READ_ONCE(tsk->signal->posix_cputimers.timers_active))
  88                return NULL;
  89
  90        /*
  91         * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
  92         * in __exit_signal(), we won't account to the signal struct further
  93         * cputime consumed by that task, even though the task can still be
  94         * ticking after __exit_signal().
  95         *
  96         * In order to keep a consistent behaviour between thread group cputime
  97         * and thread group cputimer accounting, lets also ignore the cputime
  98         * elapsing after __exit_signal() in any thread group timer running.
  99         *
 100         * This makes sure that POSIX CPU clocks and timers are synchronized, so
 101         * that a POSIX CPU timer won't expire while the corresponding POSIX CPU
 102         * clock delta is behind the expiring timer value.
 103         */
 104        if (unlikely(!tsk->sighand))
 105                return NULL;
 106
 107        return cputimer;
 108}
 109#else
 110static inline
 111struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
 112{
 113        return NULL;
 114}
 115#endif
 116
 117/**
 118 * account_group_user_time - Maintain utime for a thread group.
 119 *
 120 * @tsk:        Pointer to task structure.
 121 * @cputime:    Time value by which to increment the utime field of the
 122 *              thread_group_cputime structure.
 123 *
 124 * If thread group time is being maintained, get the structure for the
 125 * running CPU and update the utime field there.
 126 */
 127static inline void account_group_user_time(struct task_struct *tsk,
 128                                           u64 cputime)
 129{
 130        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 131
 132        if (!cputimer)
 133                return;
 134
 135        atomic64_add(cputime, &cputimer->cputime_atomic.utime);
 136}
 137
 138/**
 139 * account_group_system_time - Maintain stime for a thread group.
 140 *
 141 * @tsk:        Pointer to task structure.
 142 * @cputime:    Time value by which to increment the stime field of the
 143 *              thread_group_cputime structure.
 144 *
 145 * If thread group time is being maintained, get the structure for the
 146 * running CPU and update the stime field there.
 147 */
 148static inline void account_group_system_time(struct task_struct *tsk,
 149                                             u64 cputime)
 150{
 151        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 152
 153        if (!cputimer)
 154                return;
 155
 156        atomic64_add(cputime, &cputimer->cputime_atomic.stime);
 157}
 158
 159/**
 160 * account_group_exec_runtime - Maintain exec runtime for a thread group.
 161 *
 162 * @tsk:        Pointer to task structure.
 163 * @ns:         Time value by which to increment the sum_exec_runtime field
 164 *              of the thread_group_cputime structure.
 165 *
 166 * If thread group time is being maintained, get the structure for the
 167 * running CPU and update the sum_exec_runtime field there.
 168 */
 169static inline void account_group_exec_runtime(struct task_struct *tsk,
 170                                              unsigned long long ns)
 171{
 172        struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
 173
 174        if (!cputimer)
 175                return;
 176
 177        atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime);
 178}
 179
 180static inline void prev_cputime_init(struct prev_cputime *prev)
 181{
 182#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 183        prev->utime = prev->stime = 0;
 184        raw_spin_lock_init(&prev->lock);
 185#endif
 186}
 187
 188extern unsigned long long
 189task_sched_runtime(struct task_struct *task);
 190
 191#endif /* _LINUX_SCHED_CPUTIME_H */
 192