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1
2#ifdef CONFIG_SCHEDSTATS
3
4/*
5 * Expects runqueue lock to be held for atomicity of update
6 */
7static inline void
8rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
9{
10 if (rq) {
11 rq->rq_sched_info.run_delay += delta;
12 rq->rq_sched_info.pcount++;
13 }
14}
15
16/*
17 * Expects runqueue lock to be held for atomicity of update
18 */
19static inline void
20rq_sched_info_depart(struct rq *rq, unsigned long long delta)
21{
22 if (rq)
23 rq->rq_cpu_time += delta;
24}
25
26static inline void
27rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
28{
29 if (rq)
30 rq->rq_sched_info.run_delay += delta;
31}
32# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
33# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
34# define schedstat_set(var, val) do { var = (val); } while (0)
35#else /* !CONFIG_SCHEDSTATS */
36static inline void
37rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
38{}
39static inline void
40rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
41{}
42static inline void
43rq_sched_info_depart(struct rq *rq, unsigned long long delta)
44{}
45# define schedstat_inc(rq, field) do { } while (0)
46# define schedstat_add(rq, field, amt) do { } while (0)
47# define schedstat_set(var, val) do { } while (0)
48#endif
49
50#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
51static inline void sched_info_reset_dequeued(struct task_struct *t)
52{
53 t->sched_info.last_queued = 0;
54}
55
56/*
57 * We are interested in knowing how long it was from the *first* time a
58 * task was queued to the time that it finally hit a cpu, we call this routine
59 * from dequeue_task() to account for possible rq->clock skew across cpus. The
60 * delta taken on each cpu would annul the skew.
61 */
62static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
63{
64 unsigned long long now = rq_clock(rq), delta = 0;
65
66 if (unlikely(sched_info_on()))
67 if (t->sched_info.last_queued)
68 delta = now - t->sched_info.last_queued;
69 sched_info_reset_dequeued(t);
70 t->sched_info.run_delay += delta;
71
72 rq_sched_info_dequeued(rq, delta);
73}
74
75/*
76 * Called when a task finally hits the cpu. We can now calculate how
77 * long it was waiting to run. We also note when it began so that we
78 * can keep stats on how long its timeslice is.
79 */
80static void sched_info_arrive(struct rq *rq, struct task_struct *t)
81{
82 unsigned long long now = rq_clock(rq), delta = 0;
83
84 if (t->sched_info.last_queued)
85 delta = now - t->sched_info.last_queued;
86 sched_info_reset_dequeued(t);
87 t->sched_info.run_delay += delta;
88 t->sched_info.last_arrival = now;
89 t->sched_info.pcount++;
90
91 rq_sched_info_arrive(rq, delta);
92}
93
94/*
95 * This function is only called from enqueue_task(), but also only updates
96 * the timestamp if it is already not set. It's assumed that
97 * sched_info_dequeued() will clear that stamp when appropriate.
98 */
99static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
100{
101 if (unlikely(sched_info_on()))
102 if (!t->sched_info.last_queued)
103 t->sched_info.last_queued = rq_clock(rq);
104}
105
106/*
107 * Called when a process ceases being the active-running process involuntarily
108 * due, typically, to expiring its time slice (this may also be called when
109 * switching to the idle task). Now we can calculate how long we ran.
110 * Also, if the process is still in the TASK_RUNNING state, call
111 * sched_info_queued() to mark that it has now again started waiting on
112 * the runqueue.
113 */
114static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
115{
116 unsigned long long delta = rq_clock(rq) -
117 t->sched_info.last_arrival;
118
119 rq_sched_info_depart(rq, delta);
120
121 if (t->state == TASK_RUNNING)
122 sched_info_queued(rq, t);
123}
124
125/*
126 * Called when tasks are switched involuntarily due, typically, to expiring
127 * their time slice. (This may also be called when switching to or from
128 * the idle task.) We are only called when prev != next.
129 */
130static inline void
131__sched_info_switch(struct rq *rq,
132 struct task_struct *prev, struct task_struct *next)
133{
134 /*
135 * prev now departs the cpu. It's not interesting to record
136 * stats about how efficient we were at scheduling the idle
137 * process, however.
138 */
139 if (prev != rq->idle)
140 sched_info_depart(rq, prev);
141
142 if (next != rq->idle)
143 sched_info_arrive(rq, next);
144}
145static inline void
146sched_info_switch(struct rq *rq,
147 struct task_struct *prev, struct task_struct *next)
148{
149 if (unlikely(sched_info_on()))
150 __sched_info_switch(rq, prev, next);
151}
152#else
153#define sched_info_queued(rq, t) do { } while (0)
154#define sched_info_reset_dequeued(t) do { } while (0)
155#define sched_info_dequeued(rq, t) do { } while (0)
156#define sched_info_depart(rq, t) do { } while (0)
157#define sched_info_arrive(rq, next) do { } while (0)
158#define sched_info_switch(rq, t, next) do { } while (0)
159#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
160
161/*
162 * The following are functions that support scheduler-internal time accounting.
163 * These functions are generally called at the timer tick. None of this depends
164 * on CONFIG_SCHEDSTATS.
165 */
166
167/**
168 * cputimer_running - return true if cputimer is running
169 *
170 * @tsk: Pointer to target task.
171 */
172static inline bool cputimer_running(struct task_struct *tsk)
173
174{
175 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
176
177 if (!cputimer->running)
178 return false;
179
180 /*
181 * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
182 * in __exit_signal(), we won't account to the signal struct further
183 * cputime consumed by that task, even though the task can still be
184 * ticking after __exit_signal().
185 *
186 * In order to keep a consistent behaviour between thread group cputime
187 * and thread group cputimer accounting, lets also ignore the cputime
188 * elapsing after __exit_signal() in any thread group timer running.
189 *
190 * This makes sure that POSIX CPU clocks and timers are synchronized, so
191 * that a POSIX CPU timer won't expire while the corresponding POSIX CPU
192 * clock delta is behind the expiring timer value.
193 */
194 if (unlikely(!tsk->sighand))
195 return false;
196
197 return true;
198}
199
200/**
201 * account_group_user_time - Maintain utime for a thread group.
202 *
203 * @tsk: Pointer to task structure.
204 * @cputime: Time value by which to increment the utime field of the
205 * thread_group_cputime structure.
206 *
207 * If thread group time is being maintained, get the structure for the
208 * running CPU and update the utime field there.
209 */
210static inline void account_group_user_time(struct task_struct *tsk,
211 cputime_t cputime)
212{
213 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
214
215 if (!cputimer_running(tsk))
216 return;
217
218 raw_spin_lock(&cputimer->lock);
219 cputimer->cputime.utime += cputime;
220 raw_spin_unlock(&cputimer->lock);
221}
222
223/**
224 * account_group_system_time - Maintain stime for a thread group.
225 *
226 * @tsk: Pointer to task structure.
227 * @cputime: Time value by which to increment the stime field of the
228 * thread_group_cputime structure.
229 *
230 * If thread group time is being maintained, get the structure for the
231 * running CPU and update the stime field there.
232 */
233static inline void account_group_system_time(struct task_struct *tsk,
234 cputime_t cputime)
235{
236 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
237
238 if (!cputimer_running(tsk))
239 return;
240
241 raw_spin_lock(&cputimer->lock);
242 cputimer->cputime.stime += cputime;
243 raw_spin_unlock(&cputimer->lock);
244}
245
246/**
247 * account_group_exec_runtime - Maintain exec runtime for a thread group.
248 *
249 * @tsk: Pointer to task structure.
250 * @ns: Time value by which to increment the sum_exec_runtime field
251 * of the thread_group_cputime structure.
252 *
253 * If thread group time is being maintained, get the structure for the
254 * running CPU and update the sum_exec_runtime field there.
255 */
256static inline void account_group_exec_runtime(struct task_struct *tsk,
257 unsigned long long ns)
258{
259 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
260
261 if (!cputimer_running(tsk))
262 return;
263
264 raw_spin_lock(&cputimer->lock);
265 cputimer->cputime.sum_exec_runtime += ns;
266 raw_spin_unlock(&cputimer->lock);
267}
1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifdef CONFIG_SCHEDSTATS
4
5/*
6 * Expects runqueue lock to be held for atomicity of update
7 */
8static inline void
9rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
10{
11 if (rq) {
12 rq->rq_sched_info.run_delay += delta;
13 rq->rq_sched_info.pcount++;
14 }
15}
16
17/*
18 * Expects runqueue lock to be held for atomicity of update
19 */
20static inline void
21rq_sched_info_depart(struct rq *rq, unsigned long long delta)
22{
23 if (rq)
24 rq->rq_cpu_time += delta;
25}
26
27static inline void
28rq_sched_info_dequeue(struct rq *rq, unsigned long long delta)
29{
30 if (rq)
31 rq->rq_sched_info.run_delay += delta;
32}
33#define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
34#define __schedstat_inc(var) do { var++; } while (0)
35#define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0)
36#define __schedstat_add(var, amt) do { var += (amt); } while (0)
37#define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0)
38#define __schedstat_set(var, val) do { var = (val); } while (0)
39#define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
40#define schedstat_val(var) (var)
41#define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0)
42
43#else /* !CONFIG_SCHEDSTATS: */
44static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
45static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { }
46static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { }
47# define schedstat_enabled() 0
48# define __schedstat_inc(var) do { } while (0)
49# define schedstat_inc(var) do { } while (0)
50# define __schedstat_add(var, amt) do { } while (0)
51# define schedstat_add(var, amt) do { } while (0)
52# define __schedstat_set(var, val) do { } while (0)
53# define schedstat_set(var, val) do { } while (0)
54# define schedstat_val(var) 0
55# define schedstat_val_or_zero(var) 0
56#endif /* CONFIG_SCHEDSTATS */
57
58#ifdef CONFIG_PSI
59/*
60 * PSI tracks state that persists across sleeps, such as iowaits and
61 * memory stalls. As a result, it has to distinguish between sleeps,
62 * where a task's runnable state changes, and requeues, where a task
63 * and its state are being moved between CPUs and runqueues.
64 */
65static inline void psi_enqueue(struct task_struct *p, bool wakeup)
66{
67 int clear = 0, set = TSK_RUNNING;
68
69 if (static_branch_likely(&psi_disabled))
70 return;
71
72 if (!wakeup || p->sched_psi_wake_requeue) {
73 if (p->in_memstall)
74 set |= TSK_MEMSTALL;
75 if (p->sched_psi_wake_requeue)
76 p->sched_psi_wake_requeue = 0;
77 } else {
78 if (p->in_iowait)
79 clear |= TSK_IOWAIT;
80 }
81
82 psi_task_change(p, clear, set);
83}
84
85static inline void psi_dequeue(struct task_struct *p, bool sleep)
86{
87 int clear = TSK_RUNNING;
88
89 if (static_branch_likely(&psi_disabled))
90 return;
91
92 /*
93 * A voluntary sleep is a dequeue followed by a task switch. To
94 * avoid walking all ancestors twice, psi_task_switch() handles
95 * TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU.
96 * Do nothing here.
97 */
98 if (sleep)
99 return;
100
101 if (p->in_memstall)
102 clear |= TSK_MEMSTALL;
103
104 psi_task_change(p, clear, 0);
105}
106
107static inline void psi_ttwu_dequeue(struct task_struct *p)
108{
109 if (static_branch_likely(&psi_disabled))
110 return;
111 /*
112 * Is the task being migrated during a wakeup? Make sure to
113 * deregister its sleep-persistent psi states from the old
114 * queue, and let psi_enqueue() know it has to requeue.
115 */
116 if (unlikely(p->in_iowait || p->in_memstall)) {
117 struct rq_flags rf;
118 struct rq *rq;
119 int clear = 0;
120
121 if (p->in_iowait)
122 clear |= TSK_IOWAIT;
123 if (p->in_memstall)
124 clear |= TSK_MEMSTALL;
125
126 rq = __task_rq_lock(p, &rf);
127 psi_task_change(p, clear, 0);
128 p->sched_psi_wake_requeue = 1;
129 __task_rq_unlock(rq, &rf);
130 }
131}
132
133static inline void psi_sched_switch(struct task_struct *prev,
134 struct task_struct *next,
135 bool sleep)
136{
137 if (static_branch_likely(&psi_disabled))
138 return;
139
140 psi_task_switch(prev, next, sleep);
141}
142
143#else /* CONFIG_PSI */
144static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
145static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
146static inline void psi_ttwu_dequeue(struct task_struct *p) {}
147static inline void psi_sched_switch(struct task_struct *prev,
148 struct task_struct *next,
149 bool sleep) {}
150#endif /* CONFIG_PSI */
151
152#ifdef CONFIG_SCHED_INFO
153/*
154 * We are interested in knowing how long it was from the *first* time a
155 * task was queued to the time that it finally hit a CPU, we call this routine
156 * from dequeue_task() to account for possible rq->clock skew across CPUs. The
157 * delta taken on each CPU would annul the skew.
158 */
159static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
160{
161 unsigned long long delta = 0;
162
163 if (!t->sched_info.last_queued)
164 return;
165
166 delta = rq_clock(rq) - t->sched_info.last_queued;
167 t->sched_info.last_queued = 0;
168 t->sched_info.run_delay += delta;
169
170 rq_sched_info_dequeue(rq, delta);
171}
172
173/*
174 * Called when a task finally hits the CPU. We can now calculate how
175 * long it was waiting to run. We also note when it began so that we
176 * can keep stats on how long its timeslice is.
177 */
178static void sched_info_arrive(struct rq *rq, struct task_struct *t)
179{
180 unsigned long long now, delta = 0;
181
182 if (!t->sched_info.last_queued)
183 return;
184
185 now = rq_clock(rq);
186 delta = now - t->sched_info.last_queued;
187 t->sched_info.last_queued = 0;
188 t->sched_info.run_delay += delta;
189 t->sched_info.last_arrival = now;
190 t->sched_info.pcount++;
191
192 rq_sched_info_arrive(rq, delta);
193}
194
195/*
196 * This function is only called from enqueue_task(), but also only updates
197 * the timestamp if it is already not set. It's assumed that
198 * sched_info_dequeue() will clear that stamp when appropriate.
199 */
200static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t)
201{
202 if (!t->sched_info.last_queued)
203 t->sched_info.last_queued = rq_clock(rq);
204}
205
206/*
207 * Called when a process ceases being the active-running process involuntarily
208 * due, typically, to expiring its time slice (this may also be called when
209 * switching to the idle task). Now we can calculate how long we ran.
210 * Also, if the process is still in the TASK_RUNNING state, call
211 * sched_info_enqueue() to mark that it has now again started waiting on
212 * the runqueue.
213 */
214static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
215{
216 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
217
218 rq_sched_info_depart(rq, delta);
219
220 if (task_is_running(t))
221 sched_info_enqueue(rq, t);
222}
223
224/*
225 * Called when tasks are switched involuntarily due, typically, to expiring
226 * their time slice. (This may also be called when switching to or from
227 * the idle task.) We are only called when prev != next.
228 */
229static inline void
230sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
231{
232 /*
233 * prev now departs the CPU. It's not interesting to record
234 * stats about how efficient we were at scheduling the idle
235 * process, however.
236 */
237 if (prev != rq->idle)
238 sched_info_depart(rq, prev);
239
240 if (next != rq->idle)
241 sched_info_arrive(rq, next);
242}
243
244#else /* !CONFIG_SCHED_INFO: */
245# define sched_info_enqueue(rq, t) do { } while (0)
246# define sched_info_dequeue(rq, t) do { } while (0)
247# define sched_info_switch(rq, t, next) do { } while (0)
248#endif /* CONFIG_SCHED_INFO */