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, bool migrate) 131 { 132 int clear = 0, set = 0; 133 134 if (static_branch_likely(&psi_disabled)) 135 return; 136 137 if (p->se.sched_delayed) { 138 /* CPU migration of "sleeping" task */ 139 SCHED_WARN_ON(!migrate); 140 if (p->in_memstall) 141 set |= TSK_MEMSTALL; 142 if (p->in_iowait) 143 set |= TSK_IOWAIT; 144 } else if (migrate) { 145 /* CPU migration of runnable task */ 146 set = TSK_RUNNING; 147 if (p->in_memstall) 148 set |= TSK_MEMSTALL | TSK_MEMSTALL_RUNNING; 149 } else { 150 /* Wakeup of new or sleeping task */ 151 if (p->in_iowait) 152 clear |= TSK_IOWAIT; 153 set = TSK_RUNNING; 154 if (p->in_memstall) 155 set |= TSK_MEMSTALL_RUNNING; 156 } 157 158 psi_task_change(p, clear, set); 159 } 160 161 static inline void psi_dequeue(struct task_struct *p, bool migrate) 162 { 163 if (static_branch_likely(&psi_disabled)) 164 return; 165 166 /* 167 * When migrating a task to another CPU, clear all psi 168 * state. The enqueue callback above will work it out. 169 */ 170 if (migrate) 171 psi_task_change(p, p->psi_flags, 0); 172 173 /* 174 * A voluntary sleep is a dequeue followed by a task switch. To 175 * avoid walking all ancestors twice, psi_task_switch() handles 176 * TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU. 177 * Do nothing here. 178 */ 179 } 180 181 static inline void psi_ttwu_dequeue(struct task_struct *p) 182 { 183 if (static_branch_likely(&psi_disabled)) 184 return; 185 /* 186 * Is the task being migrated during a wakeup? Make sure to 187 * deregister its sleep-persistent psi states from the old 188 * queue, and let psi_enqueue() know it has to requeue. 189 */ 190 if (unlikely(p->psi_flags)) { 191 struct rq_flags rf; 192 struct rq *rq; 193 194 rq = __task_rq_lock(p, &rf); 195 psi_task_change(p, p->psi_flags, 0); 196 __task_rq_unlock(rq, &rf); 197 } 198 } 199 200 static inline void psi_sched_switch(struct task_struct *prev, 201 struct task_struct *next, 202 bool sleep) 203 { 204 if (static_branch_likely(&psi_disabled)) 205 return; 206 207 psi_task_switch(prev, next, sleep); 208 } 209 210 #else /* CONFIG_PSI */ 211 static inline void psi_enqueue(struct task_struct *p, bool migrate) {} 212 static inline void psi_dequeue(struct task_struct *p, bool migrate) {} 213 static inline void psi_ttwu_dequeue(struct task_struct *p) {} 214 static inline void psi_sched_switch(struct task_struct *prev, 215 struct task_struct *next, 216 bool sleep) {} 217 static inline void psi_account_irqtime(struct rq *rq, struct task_struct *curr, 218 struct task_struct *prev) {} 219 #endif /* CONFIG_PSI */ 220 221 #ifdef CONFIG_SCHED_INFO 222 /* 223 * We are interested in knowing how long it was from the *first* time a 224 * task was queued to the time that it finally hit a CPU, we call this routine 225 * from dequeue_task() to account for possible rq->clock skew across CPUs. The 226 * delta taken on each CPU would annul the skew. 227 */ 228 static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t) 229 { 230 unsigned long long delta = 0; 231 232 if (!t->sched_info.last_queued) 233 return; 234 235 delta = rq_clock(rq) - t->sched_info.last_queued; 236 t->sched_info.last_queued = 0; 237 t->sched_info.run_delay += delta; 238 239 rq_sched_info_dequeue(rq, delta); 240 } 241 242 /* 243 * Called when a task finally hits the CPU. We can now calculate how 244 * long it was waiting to run. We also note when it began so that we 245 * can keep stats on how long its time-slice is. 246 */ 247 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 248 { 249 unsigned long long now, delta = 0; 250 251 if (!t->sched_info.last_queued) 252 return; 253 254 now = rq_clock(rq); 255 delta = now - t->sched_info.last_queued; 256 t->sched_info.last_queued = 0; 257 t->sched_info.run_delay += delta; 258 t->sched_info.last_arrival = now; 259 t->sched_info.pcount++; 260 261 rq_sched_info_arrive(rq, delta); 262 } 263 264 /* 265 * This function is only called from enqueue_task(), but also only updates 266 * the timestamp if it is already not set. It's assumed that 267 * sched_info_dequeue() will clear that stamp when appropriate. 268 */ 269 static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t) 270 { 271 if (!t->sched_info.last_queued) 272 t->sched_info.last_queued = rq_clock(rq); 273 } 274 275 /* 276 * Called when a process ceases being the active-running process involuntarily 277 * due, typically, to expiring its time slice (this may also be called when 278 * switching to the idle task). Now we can calculate how long we ran. 279 * Also, if the process is still in the TASK_RUNNING state, call 280 * sched_info_enqueue() to mark that it has now again started waiting on 281 * the runqueue. 282 */ 283 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 284 { 285 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival; 286 287 rq_sched_info_depart(rq, delta); 288 289 if (task_is_running(t)) 290 sched_info_enqueue(rq, t); 291 } 292 293 /* 294 * Called when tasks are switched involuntarily due, typically, to expiring 295 * their time slice. (This may also be called when switching to or from 296 * the idle task.) We are only called when prev != next. 297 */ 298 static inline void 299 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 300 { 301 /* 302 * prev now departs the CPU. It's not interesting to record 303 * stats about how efficient we were at scheduling the idle 304 * process, however. 305 */ 306 if (prev != rq->idle) 307 sched_info_depart(rq, prev); 308 309 if (next != rq->idle) 310 sched_info_arrive(rq, next); 311 } 312 313 #else /* !CONFIG_SCHED_INFO: */ 314 # define sched_info_enqueue(rq, t) do { } while (0) 315 # define sched_info_dequeue(rq, t) do { } while (0) 316 # define sched_info_switch(rq, t, next) do { } while (0) 317 #endif /* CONFIG_SCHED_INFO */ 318 319 #endif /* _KERNEL_STATS_H */ 320