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_GEN
12extern bool task_cputime(struct task_struct *t,
13 u64 *utime, u64 *stime);
14extern u64 task_gtime(struct task_struct *t);
15#else
16static inline bool task_cputime(struct task_struct *t,
17 u64 *utime, u64 *stime)
18{
19 *utime = t->utime;
20 *stime = t->stime;
21 return false;
22}
23
24static inline u64 task_gtime(struct task_struct *t)
25{
26 return t->gtime;
27}
28#endif
29
30#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
31static inline void task_cputime_scaled(struct task_struct *t,
32 u64 *utimescaled,
33 u64 *stimescaled)
34{
35 *utimescaled = t->utimescaled;
36 *stimescaled = t->stimescaled;
37}
38#else
39static inline void task_cputime_scaled(struct task_struct *t,
40 u64 *utimescaled,
41 u64 *stimescaled)
42{
43 task_cputime(t, utime: utimescaled, stime: stimescaled);
44}
45#endif
46
47extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
48extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
49extern void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
50 u64 *ut, u64 *st);
51
52/*
53 * Thread group CPU time accounting.
54 */
55void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
56void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples);
57
58/*
59 * The following are functions that support scheduler-internal time accounting.
60 * These functions are generally called at the timer tick. None of this depends
61 * on CONFIG_SCHEDSTATS.
62 */
63
64/**
65 * get_running_cputimer - return &tsk->signal->cputimer if cputimers are active
66 *
67 * @tsk: Pointer to target task.
68 */
69#ifdef CONFIG_POSIX_TIMERS
70static inline
71struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
72{
73 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
74
75 /*
76 * Check whether posix CPU timers are active. If not the thread
77 * group accounting is not active either. Lockless check.
78 */
79 if (!READ_ONCE(tsk->signal->posix_cputimers.timers_active))
80 return NULL;
81
82 /*
83 * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
84 * in __exit_signal(), we won't account to the signal struct further
85 * cputime consumed by that task, even though the task can still be
86 * ticking after __exit_signal().
87 *
88 * In order to keep a consistent behaviour between thread group cputime
89 * and thread group cputimer accounting, lets also ignore the cputime
90 * elapsing after __exit_signal() in any thread group timer running.
91 *
92 * This makes sure that POSIX CPU clocks and timers are synchronized, so
93 * that a POSIX CPU timer won't expire while the corresponding POSIX CPU
94 * clock delta is behind the expiring timer value.
95 */
96 if (unlikely(!tsk->sighand))
97 return NULL;
98
99 return cputimer;
100}
101#else
102static inline
103struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
104{
105 return NULL;
106}
107#endif
108
109/**
110 * account_group_user_time - Maintain utime for a thread group.
111 *
112 * @tsk: Pointer to task structure.
113 * @cputime: Time value by which to increment the utime field of the
114 * thread_group_cputime structure.
115 *
116 * If thread group time is being maintained, get the structure for the
117 * running CPU and update the utime field there.
118 */
119static inline void account_group_user_time(struct task_struct *tsk,
120 u64 cputime)
121{
122 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
123
124 if (!cputimer)
125 return;
126
127 atomic64_add(i: cputime, v: &cputimer->cputime_atomic.utime);
128}
129
130/**
131 * account_group_system_time - Maintain stime for a thread group.
132 *
133 * @tsk: Pointer to task structure.
134 * @cputime: Time value by which to increment the stime field of the
135 * thread_group_cputime structure.
136 *
137 * If thread group time is being maintained, get the structure for the
138 * running CPU and update the stime field there.
139 */
140static inline void account_group_system_time(struct task_struct *tsk,
141 u64 cputime)
142{
143 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
144
145 if (!cputimer)
146 return;
147
148 atomic64_add(i: cputime, v: &cputimer->cputime_atomic.stime);
149}
150
151/**
152 * account_group_exec_runtime - Maintain exec runtime for a thread group.
153 *
154 * @tsk: Pointer to task structure.
155 * @ns: Time value by which to increment the sum_exec_runtime field
156 * of the thread_group_cputime structure.
157 *
158 * If thread group time is being maintained, get the structure for the
159 * running CPU and update the sum_exec_runtime field there.
160 */
161static inline void account_group_exec_runtime(struct task_struct *tsk,
162 unsigned long long ns)
163{
164 struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
165
166 if (!cputimer)
167 return;
168
169 atomic64_add(i: ns, v: &cputimer->cputime_atomic.sum_exec_runtime);
170}
171
172static inline void prev_cputime_init(struct prev_cputime *prev)
173{
174#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
175 prev->utime = prev->stime = 0;
176 raw_spin_lock_init(&prev->lock);
177#endif
178}
179
180extern unsigned long long
181task_sched_runtime(struct task_struct *task);
182
183#endif /* _LINUX_SCHED_CPUTIME_H */
184