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