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_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
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 /* 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
108static inline
109struct 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 */
125static 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 */
146static 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 */
167static 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
178static 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
186extern unsigned long long
187task_sched_runtime(struct task_struct *task);
188
189#endif /* _LINUX_SCHED_CPUTIME_H */
190