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 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 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 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: */ 44 static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { } 45 static inline void rq_sched_info_dequeued(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 */ 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 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 } 102 103 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 } 128 129 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 */ 138 static inline void psi_enqueue(struct task_struct *p, bool wakeup) {} 139 static inline void psi_dequeue(struct task_struct *p, bool sleep) {} 140 static inline void psi_ttwu_dequeue(struct task_struct *p) {} 141 static inline void psi_task_tick(struct rq *rq) {} 142 #endif /* CONFIG_PSI */ 143 144 #ifdef CONFIG_SCHED_INFO 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 */ 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 (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 */ 174 static 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 */ 193 static 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 */ 209 static 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 */ 224 static 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 } 238 239 static inline void 240 sched_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