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 bool task_cputime(struct task_struct *t,
22 			 u64 *utime, u64 *stime);
23 extern u64 task_gtime(struct task_struct *t);
24 #else
task_cputime(struct task_struct * t,u64 * utime,u64 * stime)25 static 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 
task_gtime(struct task_struct * t)33 static inline u64 task_gtime(struct task_struct *t)
34 {
35 	return t->gtime;
36 }
37 #endif
38 
39 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
task_cputime_scaled(struct task_struct * t,u64 * utimescaled,u64 * stimescaled)40 static 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
task_cputime_scaled(struct task_struct * t,u64 * utimescaled,u64 * stimescaled)48 static 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 
56 extern void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
57 extern void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st);
58 extern 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  */
64 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
65 void 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
79 static inline
get_running_cputimer(struct task_struct * tsk)80 struct 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
111 static inline
get_running_cputimer(struct task_struct * tsk)112 struct 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  */
account_group_user_time(struct task_struct * tsk,u64 cputime)128 static 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  */
account_group_system_time(struct task_struct * tsk,u64 cputime)149 static 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  */
account_group_exec_runtime(struct task_struct * tsk,unsigned long long ns)170 static 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 
prev_cputime_init(struct prev_cputime * prev)181 static 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 
189 extern unsigned long long
190 task_sched_runtime(struct task_struct *task);
191 
192 #endif /* _LINUX_SCHED_CPUTIME_H */
193