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