1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _KERNEL_STATS_H 3 #define _KERNEL_STATS_H 4 5 #ifdef CONFIG_SCHEDSTATS 6 7 extern struct static_key_false sched_schedstats; 8 9 /* 10 * Expects runqueue lock to be held for atomicity of update 11 */ 12 static inline void 13 rq_sched_info_arrive(struct rq *rq, unsigned long long delta) 14 { 15 if (rq) { 16 rq->rq_sched_info.run_delay += delta; 17 rq->rq_sched_info.pcount++; 18 } 19 } 20 21 /* 22 * Expects runqueue lock to be held for atomicity of update 23 */ 24 static inline void 25 rq_sched_info_depart(struct rq *rq, unsigned long long delta) 26 { 27 if (rq) 28 rq->rq_cpu_time += delta; 29 } 30 31 static inline void 32 rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) 33 { 34 if (rq) 35 rq->rq_sched_info.run_delay += delta; 36 } 37 #define schedstat_enabled() static_branch_unlikely(&sched_schedstats) 38 #define __schedstat_inc(var) do { var++; } while (0) 39 #define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0) 40 #define __schedstat_add(var, amt) do { var += (amt); } while (0) 41 #define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0) 42 #define __schedstat_set(var, val) do { var = (val); } while (0) 43 #define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0) 44 #define schedstat_val(var) (var) 45 #define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0) 46 47 void __update_stats_wait_start(struct rq *rq, struct task_struct *p, 48 struct sched_statistics *stats); 49 50 void __update_stats_wait_end(struct rq *rq, struct task_struct *p, 51 struct sched_statistics *stats); 52 void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p, 53 struct sched_statistics *stats); 54 55 static inline void 56 check_schedstat_required(void) 57 { 58 if (schedstat_enabled()) 59 return; 60 61 /* Force schedstat enabled if a dependent tracepoint is active */ 62 if (trace_sched_stat_wait_enabled() || 63 trace_sched_stat_sleep_enabled() || 64 trace_sched_stat_iowait_enabled() || 65 trace_sched_stat_blocked_enabled() || 66 trace_sched_stat_runtime_enabled()) 67 printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, stat_blocked and stat_runtime require the kernel parameter schedstats=enable or kernel.sched_schedstats=1\n"); 68 } 69 70 #else /* !CONFIG_SCHEDSTATS: */ 71 72 static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { } 73 static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { } 74 static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { } 75 # define schedstat_enabled() 0 76 # define __schedstat_inc(var) do { } while (0) 77 # define schedstat_inc(var) do { } while (0) 78 # define __schedstat_add(var, amt) do { } while (0) 79 # define schedstat_add(var, amt) do { } while (0) 80 # define __schedstat_set(var, val) do { } while (0) 81 # define schedstat_set(var, val) do { } while (0) 82 # define schedstat_val(var) 0 83 # define schedstat_val_or_zero(var) 0 84 85 # define __update_stats_wait_start(rq, p, stats) do { } while (0) 86 # define __update_stats_wait_end(rq, p, stats) do { } while (0) 87 # define __update_stats_enqueue_sleeper(rq, p, stats) do { } while (0) 88 # define check_schedstat_required() do { } while (0) 89 90 #endif /* CONFIG_SCHEDSTATS */ 91 92 #ifdef CONFIG_FAIR_GROUP_SCHED 93 struct sched_entity_stats { 94 struct sched_entity se; 95 struct sched_statistics stats; 96 } __no_randomize_layout; 97 #endif 98 99 static inline struct sched_statistics * 100 __schedstats_from_se(struct sched_entity *se) 101 { 102 #ifdef CONFIG_FAIR_GROUP_SCHED 103 if (!entity_is_task(se)) 104 return &container_of(se, struct sched_entity_stats, se)->stats; 105 #endif 106 return &task_of(se)->stats; 107 } 108 109 #ifdef CONFIG_PSI 110 void psi_task_change(struct task_struct *task, int clear, int set); 111 void psi_task_switch(struct task_struct *prev, struct task_struct *next, 112 bool sleep); 113 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 114 void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_struct *prev); 115 #else 116 static inline void psi_account_irqtime(struct rq *rq, struct task_struct *curr, 117 struct task_struct *prev) {} 118 #endif /*CONFIG_IRQ_TIME_ACCOUNTING */ 119 /* 120 * PSI tracks state that persists across sleeps, such as iowaits and 121 * memory stalls. As a result, it has to distinguish between sleeps, 122 * where a task's runnable state changes, and migrations, where a task 123 * and its runnable state are being moved between CPUs and runqueues. 124 * 125 * A notable case is a task whose dequeue is delayed. PSI considers 126 * those sleeping, but because they are still on the runqueue they can 127 * go through migration requeues. In this case, *sleeping* states need 128 * to be transferred. 129 */ 130 static inline void psi_enqueue(struct task_struct *p, int flags) 131 { 132 int clear = 0, set = 0; 133 134 if (static_branch_likely(&psi_disabled)) 135 return; 136 137 /* Same runqueue, nothing changed for psi */ 138 if (flags & ENQUEUE_RESTORE) 139 return; 140 141 if (p->se.sched_delayed) { 142 /* CPU migration of "sleeping" task */ 143 SCHED_WARN_ON(!(flags & ENQUEUE_MIGRATED)); 144 if (p->in_memstall) 145 set |= TSK_MEMSTALL; 146 if (p->in_iowait) 147 set |= TSK_IOWAIT; 148 } else if (flags & ENQUEUE_MIGRATED) { 149 /* CPU migration of runnable task */ 150 set = TSK_RUNNING; 151 if (p->in_memstall) 152 set |= TSK_MEMSTALL | TSK_MEMSTALL_RUNNING; 153 } else { 154 /* Wakeup of new or sleeping task */ 155 if (p->in_iowait) 156 clear |= TSK_IOWAIT; 157 set = TSK_RUNNING; 158 if (p->in_memstall) 159 set |= TSK_MEMSTALL_RUNNING; 160 } 161 162 psi_task_change(p, clear, set); 163 } 164 165 static inline void psi_dequeue(struct task_struct *p, int flags) 166 { 167 if (static_branch_likely(&psi_disabled)) 168 return; 169 170 /* Same runqueue, nothing changed for psi */ 171 if (flags & DEQUEUE_SAVE) 172 return; 173 174 /* 175 * A voluntary sleep is a dequeue followed by a task switch. To 176 * avoid walking all ancestors twice, psi_task_switch() handles 177 * TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU. 178 * Do nothing here. 179 */ 180 if (flags & DEQUEUE_SLEEP) 181 return; 182 183 /* 184 * When migrating a task to another CPU, clear all psi 185 * state. The enqueue callback above will work it out. 186 */ 187 psi_task_change(p, p->psi_flags, 0); 188 } 189 190 static inline void psi_ttwu_dequeue(struct task_struct *p) 191 { 192 if (static_branch_likely(&psi_disabled)) 193 return; 194 /* 195 * Is the task being migrated during a wakeup? Make sure to 196 * deregister its sleep-persistent psi states from the old 197 * queue, and let psi_enqueue() know it has to requeue. 198 */ 199 if (unlikely(p->psi_flags)) { 200 struct rq_flags rf; 201 struct rq *rq; 202 203 rq = __task_rq_lock(p, &rf); 204 psi_task_change(p, p->psi_flags, 0); 205 __task_rq_unlock(rq, &rf); 206 } 207 } 208 209 static inline void psi_sched_switch(struct task_struct *prev, 210 struct task_struct *next, 211 bool sleep) 212 { 213 if (static_branch_likely(&psi_disabled)) 214 return; 215 216 psi_task_switch(prev, next, sleep); 217 } 218 219 #else /* CONFIG_PSI */ 220 static inline void psi_enqueue(struct task_struct *p, bool migrate) {} 221 static inline void psi_dequeue(struct task_struct *p, bool migrate) {} 222 static inline void psi_ttwu_dequeue(struct task_struct *p) {} 223 static inline void psi_sched_switch(struct task_struct *prev, 224 struct task_struct *next, 225 bool sleep) {} 226 static inline void psi_account_irqtime(struct rq *rq, struct task_struct *curr, 227 struct task_struct *prev) {} 228 #endif /* CONFIG_PSI */ 229 230 #ifdef CONFIG_SCHED_INFO 231 /* 232 * We are interested in knowing how long it was from the *first* time a 233 * task was queued to the time that it finally hit a CPU, we call this routine 234 * from dequeue_task() to account for possible rq->clock skew across CPUs. The 235 * delta taken on each CPU would annul the skew. 236 */ 237 static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t) 238 { 239 unsigned long long delta = 0; 240 241 if (!t->sched_info.last_queued) 242 return; 243 244 delta = rq_clock(rq) - t->sched_info.last_queued; 245 t->sched_info.last_queued = 0; 246 t->sched_info.run_delay += delta; 247 if (delta > t->sched_info.max_run_delay) 248 t->sched_info.max_run_delay = delta; 249 if (delta && (!t->sched_info.min_run_delay || delta < t->sched_info.min_run_delay)) 250 t->sched_info.min_run_delay = delta; 251 rq_sched_info_dequeue(rq, delta); 252 } 253 254 /* 255 * Called when a task finally hits the CPU. We can now calculate how 256 * long it was waiting to run. We also note when it began so that we 257 * can keep stats on how long its time-slice is. 258 */ 259 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 260 { 261 unsigned long long now, delta = 0; 262 263 if (!t->sched_info.last_queued) 264 return; 265 266 now = rq_clock(rq); 267 delta = now - t->sched_info.last_queued; 268 t->sched_info.last_queued = 0; 269 t->sched_info.run_delay += delta; 270 t->sched_info.last_arrival = now; 271 t->sched_info.pcount++; 272 if (delta > t->sched_info.max_run_delay) 273 t->sched_info.max_run_delay = delta; 274 if (delta && (!t->sched_info.min_run_delay || delta < t->sched_info.min_run_delay)) 275 t->sched_info.min_run_delay = delta; 276 277 rq_sched_info_arrive(rq, delta); 278 } 279 280 /* 281 * This function is only called from enqueue_task(), but also only updates 282 * the timestamp if it is already not set. It's assumed that 283 * sched_info_dequeue() will clear that stamp when appropriate. 284 */ 285 static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t) 286 { 287 if (!t->sched_info.last_queued) 288 t->sched_info.last_queued = rq_clock(rq); 289 } 290 291 /* 292 * Called when a process ceases being the active-running process involuntarily 293 * due, typically, to expiring its time slice (this may also be called when 294 * switching to the idle task). Now we can calculate how long we ran. 295 * Also, if the process is still in the TASK_RUNNING state, call 296 * sched_info_enqueue() to mark that it has now again started waiting on 297 * the runqueue. 298 */ 299 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 300 { 301 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival; 302 303 rq_sched_info_depart(rq, delta); 304 305 if (task_is_running(t)) 306 sched_info_enqueue(rq, t); 307 } 308 309 /* 310 * Called when tasks are switched involuntarily due, typically, to expiring 311 * their time slice. (This may also be called when switching to or from 312 * the idle task.) We are only called when prev != next. 313 */ 314 static inline void 315 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 316 { 317 /* 318 * prev now departs the CPU. It's not interesting to record 319 * stats about how efficient we were at scheduling the idle 320 * process, however. 321 */ 322 if (prev != rq->idle) 323 sched_info_depart(rq, prev); 324 325 if (next != rq->idle) 326 sched_info_arrive(rq, next); 327 } 328 329 #else /* !CONFIG_SCHED_INFO: */ 330 # define sched_info_enqueue(rq, t) do { } while (0) 331 # define sched_info_dequeue(rq, t) do { } while (0) 332 # define sched_info_switch(rq, t, next) do { } while (0) 333 #endif /* CONFIG_SCHED_INFO */ 334 335 #endif /* _KERNEL_STATS_H */ 336