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 bool task_cputime(struct task_struct *t,
22 u64 *utime, u64 *stime);
23extern u64 task_gtime(struct task_struct *t);
24#else
25static inline bool task_cputime(struct task_struct *t,
26 u64 *utime, u64 *stime)
27{
28 *utime = t->utime;
29 *stime = t->stime;
30 return false;
31}
32
33static inline u64 task_gtime(struct task_struct *t)
34{
35 return t->gtime;
36}
37#endif
38
39#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
40static inline void task_cputime_scaled(struct task_struct *t,
41 u64 *utimescaled,
42 u64 *stimescaled)
43{
44 *utimescaled = t->utimescaled;
45 *stimescaled = t->stimescaled;
46}
47#else
48static inline void task_cputime_scaled(struct task_struct *t,
49 u64 *utimescaled,
50 u64 *stimescaled)
51{
52 task_cputime(t, utimescaled, stimescaled);
53}
54#endif
55
56extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
57extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
58extern void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
59 u64 *ut, u64 *st);
60
61/*
62 * Thread group CPU time accounting.
63 */
64void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
65void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples);
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 cputimers are active
75 *
76 * @tsk: Pointer to target task.
77 */
78#ifdef CONFIG_POSIX_TIMERS
79static inline
80struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
81{
82 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
83
84 /*
85 * Check whether posix CPU timers are active. If not the thread
86 * group accounting is not active either. Lockless check.
87 */
88 if (!READ_ONCE(tsk->signal->posix_cputimers.timers_active))
89 return NULL;
90
91 /*
92 * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
93 * in __exit_signal(), we won't account to the signal struct further
94 * cputime consumed by that task, even though the task can still be
95 * ticking after __exit_signal().
96 *
97 * In order to keep a consistent behaviour between thread group cputime
98 * and thread group cputimer accounting, lets also ignore the cputime
99 * elapsing after __exit_signal() in any thread group timer running.
100 *
101 * This makes sure that POSIX CPU clocks and timers are synchronized, so
102 * that a POSIX CPU timer won't expire while the corresponding POSIX CPU
103 * clock delta is behind the expiring timer value.
104 */
105 if (unlikely(!tsk->sighand))
106 return NULL;
107
108 return cputimer;
109}
110#else
111static inline
112struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
113{
114 return NULL;
115}
116#endif
117
118/**
119 * account_group_user_time - Maintain utime for a thread group.
120 *
121 * @tsk: Pointer to task structure.
122 * @cputime: Time value by which to increment the utime field of the
123 * thread_group_cputime structure.
124 *
125 * If thread group time is being maintained, get the structure for the
126 * running CPU and update the utime field there.
127 */
128static inline void account_group_user_time(struct task_struct *tsk,
129 u64 cputime)
130{
131 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
132
133 if (!cputimer)
134 return;
135
136 atomic64_add(cputime, &cputimer->cputime_atomic.utime);
137}
138
139/**
140 * account_group_system_time - Maintain stime for a thread group.
141 *
142 * @tsk: Pointer to task structure.
143 * @cputime: Time value by which to increment the stime field of the
144 * thread_group_cputime structure.
145 *
146 * If thread group time is being maintained, get the structure for the
147 * running CPU and update the stime field there.
148 */
149static inline void account_group_system_time(struct task_struct *tsk,
150 u64 cputime)
151{
152 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
153
154 if (!cputimer)
155 return;
156
157 atomic64_add(cputime, &cputimer->cputime_atomic.stime);
158}
159
160/**
161 * account_group_exec_runtime - Maintain exec runtime for a thread group.
162 *
163 * @tsk: Pointer to task structure.
164 * @ns: Time value by which to increment the sum_exec_runtime field
165 * of the thread_group_cputime structure.
166 *
167 * If thread group time is being maintained, get the structure for the
168 * running CPU and update the sum_exec_runtime field there.
169 */
170static inline void account_group_exec_runtime(struct task_struct *tsk,
171 unsigned long long ns)
172{
173 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
174
175 if (!cputimer)
176 return;
177
178 atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime);
179}
180
181static inline void prev_cputime_init(struct prev_cputime *prev)
182{
183#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
184 prev->utime = prev->stime = 0;
185 raw_spin_lock_init(&prev->lock);
186#endif
187}
188
189extern unsigned long long
190task_sched_runtime(struct task_struct *task);
191
192#endif /* _LINUX_SCHED_CPUTIME_H */
193

source code of linux/include/linux/sched/cputime.h