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 /* 111 * PSI tracks state that persists across sleeps, such as iowaits and 112 * memory stalls. As a result, it has to distinguish between sleeps, 113 * where a task's runnable state changes, and requeues, where a task 114 * and its state are being moved between CPUs and runqueues. 115 */ 116 static inline void psi_enqueue(struct task_struct *p, bool wakeup) 117 { 118 int clear = 0, set = TSK_RUNNING; 119 120 if (static_branch_likely(&psi_disabled)) 121 return; 122 123 if (p->in_memstall) 124 set |= TSK_MEMSTALL_RUNNING; 125 126 if (!wakeup || p->sched_psi_wake_requeue) { 127 if (p->in_memstall) 128 set |= TSK_MEMSTALL; 129 if (p->sched_psi_wake_requeue) 130 p->sched_psi_wake_requeue = 0; 131 } else { 132 if (p->in_iowait) 133 clear |= TSK_IOWAIT; 134 } 135 136 psi_task_change(p, clear, set); 137 } 138 139 static inline void psi_dequeue(struct task_struct *p, bool sleep) 140 { 141 int clear = TSK_RUNNING; 142 143 if (static_branch_likely(&psi_disabled)) 144 return; 145 146 /* 147 * A voluntary sleep is a dequeue followed by a task switch. To 148 * avoid walking all ancestors twice, psi_task_switch() handles 149 * TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU. 150 * Do nothing here. 151 */ 152 if (sleep) 153 return; 154 155 if (p->in_memstall) 156 clear |= (TSK_MEMSTALL | TSK_MEMSTALL_RUNNING); 157 158 psi_task_change(p, clear, 0); 159 } 160 161 static inline void psi_ttwu_dequeue(struct task_struct *p) 162 { 163 if (static_branch_likely(&psi_disabled)) 164 return; 165 /* 166 * Is the task being migrated during a wakeup? Make sure to 167 * deregister its sleep-persistent psi states from the old 168 * queue, and let psi_enqueue() know it has to requeue. 169 */ 170 if (unlikely(p->in_iowait || p->in_memstall)) { 171 struct rq_flags rf; 172 struct rq *rq; 173 int clear = 0; 174 175 if (p->in_iowait) 176 clear |= TSK_IOWAIT; 177 if (p->in_memstall) 178 clear |= TSK_MEMSTALL; 179 180 rq = __task_rq_lock(p, &rf); 181 psi_task_change(p, clear, 0); 182 p->sched_psi_wake_requeue = 1; 183 __task_rq_unlock(rq, &rf); 184 } 185 } 186 187 static inline void psi_sched_switch(struct task_struct *prev, 188 struct task_struct *next, 189 bool sleep) 190 { 191 if (static_branch_likely(&psi_disabled)) 192 return; 193 194 psi_task_switch(prev, next, sleep); 195 } 196 197 #else /* CONFIG_PSI */ 198 static inline void psi_enqueue(struct task_struct *p, bool wakeup) {} 199 static inline void psi_dequeue(struct task_struct *p, bool sleep) {} 200 static inline void psi_ttwu_dequeue(struct task_struct *p) {} 201 static inline void psi_sched_switch(struct task_struct *prev, 202 struct task_struct *next, 203 bool sleep) {} 204 #endif /* CONFIG_PSI */ 205 206 #ifdef CONFIG_SCHED_INFO 207 /* 208 * We are interested in knowing how long it was from the *first* time a 209 * task was queued to the time that it finally hit a CPU, we call this routine 210 * from dequeue_task() to account for possible rq->clock skew across CPUs. The 211 * delta taken on each CPU would annul the skew. 212 */ 213 static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t) 214 { 215 unsigned long long delta = 0; 216 217 if (!t->sched_info.last_queued) 218 return; 219 220 delta = rq_clock(rq) - t->sched_info.last_queued; 221 t->sched_info.last_queued = 0; 222 t->sched_info.run_delay += delta; 223 224 rq_sched_info_dequeue(rq, delta); 225 } 226 227 /* 228 * Called when a task finally hits the CPU. We can now calculate how 229 * long it was waiting to run. We also note when it began so that we 230 * can keep stats on how long its timeslice is. 231 */ 232 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 233 { 234 unsigned long long now, delta = 0; 235 236 if (!t->sched_info.last_queued) 237 return; 238 239 now = rq_clock(rq); 240 delta = now - t->sched_info.last_queued; 241 t->sched_info.last_queued = 0; 242 t->sched_info.run_delay += delta; 243 t->sched_info.last_arrival = now; 244 t->sched_info.pcount++; 245 246 rq_sched_info_arrive(rq, delta); 247 } 248 249 /* 250 * This function is only called from enqueue_task(), but also only updates 251 * the timestamp if it is already not set. It's assumed that 252 * sched_info_dequeue() will clear that stamp when appropriate. 253 */ 254 static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t) 255 { 256 if (!t->sched_info.last_queued) 257 t->sched_info.last_queued = rq_clock(rq); 258 } 259 260 /* 261 * Called when a process ceases being the active-running process involuntarily 262 * due, typically, to expiring its time slice (this may also be called when 263 * switching to the idle task). Now we can calculate how long we ran. 264 * Also, if the process is still in the TASK_RUNNING state, call 265 * sched_info_enqueue() to mark that it has now again started waiting on 266 * the runqueue. 267 */ 268 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 269 { 270 unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival; 271 272 rq_sched_info_depart(rq, delta); 273 274 if (task_is_running(t)) 275 sched_info_enqueue(rq, t); 276 } 277 278 /* 279 * Called when tasks are switched involuntarily due, typically, to expiring 280 * their time slice. (This may also be called when switching to or from 281 * the idle task.) We are only called when prev != next. 282 */ 283 static inline void 284 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 285 { 286 /* 287 * prev now departs the CPU. It's not interesting to record 288 * stats about how efficient we were at scheduling the idle 289 * process, however. 290 */ 291 if (prev != rq->idle) 292 sched_info_depart(rq, prev); 293 294 if (next != rq->idle) 295 sched_info_arrive(rq, next); 296 } 297 298 #else /* !CONFIG_SCHED_INFO: */ 299 # define sched_info_enqueue(rq, t) do { } while (0) 300 # define sched_info_dequeue(rq, t) do { } while (0) 301 # define sched_info_switch(rq, t, next) do { } while (0) 302 #endif /* CONFIG_SCHED_INFO */ 303 304 #endif /* _KERNEL_STATS_H */ 305