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_dequeued(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_dequeued(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->flags & PF_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, set = 0;
88
89 if (static_branch_likely(&psi_disabled))
90 return;
91
92 if (!sleep) {
93 if (p->flags & PF_MEMSTALL)
94 clear |= TSK_MEMSTALL;
95 } else {
96 if (p->in_iowait)
97 set |= TSK_IOWAIT;
98 }
99
100 psi_task_change(p, clear, set);
101}
102
103static inline void psi_ttwu_dequeue(struct task_struct *p)
104{
105 if (static_branch_likely(&psi_disabled))
106 return;
107 /*
108 * Is the task being migrated during a wakeup? Make sure to
109 * deregister its sleep-persistent psi states from the old
110 * queue, and let psi_enqueue() know it has to requeue.
111 */
112 if (unlikely(p->in_iowait || (p->flags & PF_MEMSTALL))) {
113 struct rq_flags rf;
114 struct rq *rq;
115 int clear = 0;
116
117 if (p->in_iowait)
118 clear |= TSK_IOWAIT;
119 if (p->flags & PF_MEMSTALL)
120 clear |= TSK_MEMSTALL;
121
122 rq = __task_rq_lock(p, &rf);
123 psi_task_change(p, clear, 0);
124 p->sched_psi_wake_requeue = 1;
125 __task_rq_unlock(rq, &rf);
126 }
127}
128
129static inline void psi_task_tick(struct rq *rq)
130{
131 if (static_branch_likely(&psi_disabled))
132 return;
133
134 if (unlikely(rq->curr->flags & PF_MEMSTALL))
135 psi_memstall_tick(rq->curr, cpu_of(rq));
136}
137#else /* CONFIG_PSI */
138static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
139static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
140static inline void psi_ttwu_dequeue(struct task_struct *p) {}
141static inline void psi_task_tick(struct rq *rq) {}
142#endif /* CONFIG_PSI */
143
144#ifdef CONFIG_SCHED_INFO
145static inline void sched_info_reset_dequeued(struct task_struct *t)
146{
147 t->sched_info.last_queued = 0;
148}
149
150/*
151 * We are interested in knowing how long it was from the *first* time a
152 * task was queued to the time that it finally hit a CPU, we call this routine
153 * from dequeue_task() to account for possible rq->clock skew across CPUs. The
154 * delta taken on each CPU would annul the skew.
155 */
156static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
157{
158 unsigned long long now = rq_clock(rq), delta = 0;
159
160 if (unlikely(sched_info_on()))
161 if (t->sched_info.last_queued)
162 delta = now - t->sched_info.last_queued;
163 sched_info_reset_dequeued(t);
164 t->sched_info.run_delay += delta;
165
166 rq_sched_info_dequeued(rq, delta);
167}
168
169/*
170 * Called when a task finally hits the CPU. We can now calculate how
171 * long it was waiting to run. We also note when it began so that we
172 * can keep stats on how long its timeslice is.
173 */
174static void sched_info_arrive(struct rq *rq, struct task_struct *t)
175{
176 unsigned long long now = rq_clock(rq), delta = 0;
177
178 if (t->sched_info.last_queued)
179 delta = now - t->sched_info.last_queued;
180 sched_info_reset_dequeued(t);
181 t->sched_info.run_delay += delta;
182 t->sched_info.last_arrival = now;
183 t->sched_info.pcount++;
184
185 rq_sched_info_arrive(rq, delta);
186}
187
188/*
189 * This function is only called from enqueue_task(), but also only updates
190 * the timestamp if it is already not set. It's assumed that
191 * sched_info_dequeued() will clear that stamp when appropriate.
192 */
193static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
194{
195 if (unlikely(sched_info_on())) {
196 if (!t->sched_info.last_queued)
197 t->sched_info.last_queued = rq_clock(rq);
198 }
199}
200
201/*
202 * Called when a process ceases being the active-running process involuntarily
203 * due, typically, to expiring its time slice (this may also be called when
204 * switching to the idle task). Now we can calculate how long we ran.
205 * Also, if the process is still in the TASK_RUNNING state, call
206 * sched_info_queued() to mark that it has now again started waiting on
207 * the runqueue.
208 */
209static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
210{
211 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
212
213 rq_sched_info_depart(rq, delta);
214
215 if (t->state == TASK_RUNNING)
216 sched_info_queued(rq, t);
217}
218
219/*
220 * Called when tasks are switched involuntarily due, typically, to expiring
221 * their time slice. (This may also be called when switching to or from
222 * the idle task.) We are only called when prev != next.
223 */
224static inline void
225__sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
226{
227 /*
228 * prev now departs the CPU. It's not interesting to record
229 * stats about how efficient we were at scheduling the idle
230 * process, however.
231 */
232 if (prev != rq->idle)
233 sched_info_depart(rq, prev);
234
235 if (next != rq->idle)
236 sched_info_arrive(rq, next);
237}
238
239static inline void
240sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
241{
242 if (unlikely(sched_info_on()))
243 __sched_info_switch(rq, prev, next);
244}
245
246#else /* !CONFIG_SCHED_INFO: */
247# define sched_info_queued(rq, t) do { } while (0)
248# define sched_info_reset_dequeued(t) do { } while (0)
249# define sched_info_dequeued(rq, t) do { } while (0)
250# define sched_info_depart(rq, t) do { } while (0)
251# define sched_info_arrive(rq, next) do { } while (0)
252# define sched_info_switch(rq, t, next) do { } while (0)
253#endif /* CONFIG_SCHED_INFO */
254