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->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 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->in_memstall) 94 clear |= TSK_MEMSTALL; 95 } else { 96 /* 97 * When a task sleeps, schedule() dequeues it before 98 * switching to the next one. Merge the clearing of 99 * TSK_RUNNING and TSK_ONCPU to save an unnecessary 100 * psi_task_change() call in psi_sched_switch(). 101 */ 102 clear |= TSK_ONCPU; 103 104 if (p->in_iowait) 105 set |= TSK_IOWAIT; 106 } 107 108 psi_task_change(p, clear, set); 109 } 110 111 static inline void psi_ttwu_dequeue(struct task_struct *p) 112 { 113 if (static_branch_likely(&psi_disabled)) 114 return; 115 /* 116 * Is the task being migrated during a wakeup? Make sure to 117 * deregister its sleep-persistent psi states from the old 118 * queue, and let psi_enqueue() know it has to requeue. 119 */ 120 if (unlikely(p->in_iowait || p->in_memstall)) { 121 struct rq_flags rf; 122 struct rq *rq; 123 int clear = 0; 124 125 if (p->in_iowait) 126 clear |= TSK_IOWAIT; 127 if (p->in_memstall) 128 clear |= TSK_MEMSTALL; 129 130 rq = __task_rq_lock(p, &rf); 131 psi_task_change(p, clear, 0); 132 p->sched_psi_wake_requeue = 1; 133 __task_rq_unlock(rq, &rf); 134 } 135 } 136 137 static inline void psi_sched_switch(struct task_struct *prev, 138 struct task_struct *next, 139 bool sleep) 140 { 141 if (static_branch_likely(&psi_disabled)) 142 return; 143 144 psi_task_switch(prev, next, sleep); 145 } 146 147 static inline void psi_task_tick(struct rq *rq) 148 { 149 if (static_branch_likely(&psi_disabled)) 150 return; 151 152 if (unlikely(rq->curr->in_memstall)) 153 psi_memstall_tick(rq->curr, cpu_of(rq)); 154 } 155 #else /* CONFIG_PSI */ 156 static inline void psi_enqueue(struct task_struct *p, bool wakeup) {} 157 static inline void psi_dequeue(struct task_struct *p, bool sleep) {} 158 static inline void psi_ttwu_dequeue(struct task_struct *p) {} 159 static inline void psi_sched_switch(struct task_struct *prev, 160 struct task_struct *next, 161 bool sleep) {} 162 static inline void psi_task_tick(struct rq *rq) {} 163 #endif /* CONFIG_PSI */ 164 165 #ifdef CONFIG_SCHED_INFO 166 static inline void sched_info_reset_dequeued(struct task_struct *t) 167 { 168 t->sched_info.last_queued = 0; 169 } 170 171 /* 172 * We are interested in knowing how long it was from the *first* time a 173 * task was queued to the time that it finally hit a CPU, we call this routine 174 * from dequeue_task() to account for possible rq->clock skew across CPUs. The 175 * delta taken on each CPU would annul the skew. 176 */ 177 static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) 178 { 179 unsigned long long now = rq_clock(rq), delta = 0; 180 181 if (sched_info_on()) { 182 if (t->sched_info.last_queued) 183 delta = now - t->sched_info.last_queued; 184 } 185 sched_info_reset_dequeued(t); 186 t->sched_info.run_delay += delta; 187 188 rq_sched_info_dequeued(rq, delta); 189 } 190 191 /* 192 * Called when a task finally hits the CPU. We can now calculate how 193 * long it was waiting to run. We also note when it began so that we 194 * can keep stats on how long its timeslice is. 195 */ 196 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 197 { 198 unsigned long long now = rq_clock(rq), delta = 0; 199 200 if (t->sched_info.last_queued) 201 delta = now - t->sched_info.last_queued; 202 sched_info_reset_dequeued(t); 203 t->sched_info.run_delay += delta; 204 t->sched_info.last_arrival = now; 205 t->sched_info.pcount++; 206 207 rq_sched_info_arrive(rq, delta); 208 } 209 210 /* 211 * This function is only called from enqueue_task(), but also only updates 212 * the timestamp if it is already not set. It's assumed that 213 * sched_info_dequeued() will clear that stamp when appropriate. 214 */ 215 static inline void sched_info_queued(struct rq *rq, struct task_struct *t) 216 { 217 if (sched_info_on()) { 218 if (!t->sched_info.last_queued) 219 t->sched_info.last_queued = rq_clock(rq); 220 } 221 } 222 223 /* 224 * Called when a process ceases being the active-running process involuntarily 225 * due, typically, to expiring its time slice (this may also be called when 226 * switching to the idle task). Now we can calculate how long we ran. 227 * Also, if the process is still in the TASK_RUNNING state, call 228 * sched_info_queued() to mark that it has now again started waiting on 229 * the runqueue. 230 */ 231 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 232 { 233 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival; 234 235 rq_sched_info_depart(rq, delta); 236 237 if (t->state == TASK_RUNNING) 238 sched_info_queued(rq, t); 239 } 240 241 /* 242 * Called when tasks are switched involuntarily due, typically, to expiring 243 * their time slice. (This may also be called when switching to or from 244 * the idle task.) We are only called when prev != next. 245 */ 246 static inline void 247 __sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 248 { 249 /* 250 * prev now departs the CPU. It's not interesting to record 251 * stats about how efficient we were at scheduling the idle 252 * process, however. 253 */ 254 if (prev != rq->idle) 255 sched_info_depart(rq, prev); 256 257 if (next != rq->idle) 258 sched_info_arrive(rq, next); 259 } 260 261 static inline void 262 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 263 { 264 if (sched_info_on()) 265 __sched_info_switch(rq, prev, next); 266 } 267 268 #else /* !CONFIG_SCHED_INFO: */ 269 # define sched_info_queued(rq, t) do { } while (0) 270 # define sched_info_reset_dequeued(t) do { } while (0) 271 # define sched_info_dequeued(rq, t) do { } while (0) 272 # define sched_info_depart(rq, t) do { } while (0) 273 # define sched_info_arrive(rq, next) do { } while (0) 274 # define sched_info_switch(rq, t, next) do { } while (0) 275 #endif /* CONFIG_SCHED_INFO */ 276