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
12 extern bool task_cputime(struct task_struct *t,
13 u64 *utime, u64 *stime);
14 extern u64 task_gtime(struct task_struct *t);
15 #else
16 static 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
24 static inline u64 task_gtime(struct task_struct *t)
25 {
26 return t->gtime;
27 }
28 #endif
29
30 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
31 static 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
39 static inline void task_cputime_scaled(struct task_struct *t,
40 u64 *utimescaled,
41 u64 *stimescaled)
42 {
43 task_cputime(t, utimescaled, stimescaled);
44 }
45 #endif
46
47 extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
48 extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
49 extern 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 */
55 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
56 void 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
70 static inline
71 struct 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
102 static inline
103 struct 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 */
119 static 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(cputime, &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 */
140 static 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(cputime, &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 */
161 static 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(ns, &cputimer->cputime_atomic.sum_exec_runtime);
170 }
171
172 static 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
180 extern unsigned long long
181 task_sched_runtime(struct task_struct *task);
182
183 #endif /* _LINUX_SCHED_CPUTIME_H */
184
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