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 */
8 static inline void
rq_sched_info_arrive(struct rq * rq,unsigned long long delta)9 rq_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 */
20 static inline void
rq_sched_info_depart(struct rq * rq,unsigned long long delta)21 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
22 {
23 if (rq)
24 rq->rq_cpu_time += delta;
25 }
26
27 static inline void
rq_sched_info_dequeued(struct rq * rq,unsigned long long delta)28 rq_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: */
rq_sched_info_arrive(struct rq * rq,unsigned long long delta)44 static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
rq_sched_info_dequeued(struct rq * rq,unsigned long long delta)45 static inline void rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) { }
rq_sched_info_depart(struct rq * rq,unsigned long long delta)46 static 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 */
psi_enqueue(struct task_struct * p,bool wakeup)65 static 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
psi_dequeue(struct task_struct * p,bool sleep)85 static 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
psi_ttwu_dequeue(struct task_struct * p)103 static 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
psi_task_tick(struct rq * rq)129 static 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 */
psi_enqueue(struct task_struct * p,bool wakeup)138 static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
psi_dequeue(struct task_struct * p,bool sleep)139 static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
psi_ttwu_dequeue(struct task_struct * p)140 static inline void psi_ttwu_dequeue(struct task_struct *p) {}
psi_task_tick(struct rq * rq)141 static inline void psi_task_tick(struct rq *rq) {}
142 #endif /* CONFIG_PSI */
143
144 #ifdef CONFIG_SCHED_INFO
sched_info_reset_dequeued(struct task_struct * t)145 static 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 */
sched_info_dequeued(struct rq * rq,struct task_struct * t)156 static 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 (sched_info_on()) {
161 if (t->sched_info.last_queued)
162 delta = now - t->sched_info.last_queued;
163 }
164 sched_info_reset_dequeued(t);
165 t->sched_info.run_delay += delta;
166
167 rq_sched_info_dequeued(rq, delta);
168 }
169
170 /*
171 * Called when a task finally hits the CPU. We can now calculate how
172 * long it was waiting to run. We also note when it began so that we
173 * can keep stats on how long its timeslice is.
174 */
sched_info_arrive(struct rq * rq,struct task_struct * t)175 static void sched_info_arrive(struct rq *rq, struct task_struct *t)
176 {
177 unsigned long long now = rq_clock(rq), delta = 0;
178
179 if (t->sched_info.last_queued)
180 delta = now - t->sched_info.last_queued;
181 sched_info_reset_dequeued(t);
182 t->sched_info.run_delay += delta;
183 t->sched_info.last_arrival = now;
184 t->sched_info.pcount++;
185
186 rq_sched_info_arrive(rq, delta);
187 }
188
189 /*
190 * This function is only called from enqueue_task(), but also only updates
191 * the timestamp if it is already not set. It's assumed that
192 * sched_info_dequeued() will clear that stamp when appropriate.
193 */
sched_info_queued(struct rq * rq,struct task_struct * t)194 static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
195 {
196 if (sched_info_on()) {
197 if (!t->sched_info.last_queued)
198 t->sched_info.last_queued = rq_clock(rq);
199 }
200 }
201
202 /*
203 * Called when a process ceases being the active-running process involuntarily
204 * due, typically, to expiring its time slice (this may also be called when
205 * switching to the idle task). Now we can calculate how long we ran.
206 * Also, if the process is still in the TASK_RUNNING state, call
207 * sched_info_queued() to mark that it has now again started waiting on
208 * the runqueue.
209 */
sched_info_depart(struct rq * rq,struct task_struct * t)210 static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
211 {
212 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
213
214 rq_sched_info_depart(rq, delta);
215
216 if (t->state == TASK_RUNNING)
217 sched_info_queued(rq, t);
218 }
219
220 /*
221 * Called when tasks are switched involuntarily due, typically, to expiring
222 * their time slice. (This may also be called when switching to or from
223 * the idle task.) We are only called when prev != next.
224 */
225 static inline void
__sched_info_switch(struct rq * rq,struct task_struct * prev,struct task_struct * next)226 __sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
227 {
228 /*
229 * prev now departs the CPU. It's not interesting to record
230 * stats about how efficient we were at scheduling the idle
231 * process, however.
232 */
233 if (prev != rq->idle)
234 sched_info_depart(rq, prev);
235
236 if (next != rq->idle)
237 sched_info_arrive(rq, next);
238 }
239
240 static inline void
sched_info_switch(struct rq * rq,struct task_struct * prev,struct task_struct * next)241 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
242 {
243 if (sched_info_on())
244 __sched_info_switch(rq, prev, next);
245 }
246
247 #else /* !CONFIG_SCHED_INFO: */
248 # define sched_info_queued(rq, t) do { } while (0)
249 # define sched_info_reset_dequeued(t) do { } while (0)
250 # define sched_info_dequeued(rq, t) do { } while (0)
251 # define sched_info_depart(rq, t) do { } while (0)
252 # define sched_info_arrive(rq, next) do { } while (0)
253 # define sched_info_switch(rq, t, next) do { } while (0)
254 #endif /* CONFIG_SCHED_INFO */
255