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 45 rq_sched_info_arrive(struct rq *rq, unsigned long long delta) 46 {} 47 static inline void 48 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) 49 {} 50 static inline void 51 rq_sched_info_depart(struct rq *rq, unsigned long long delta) 52 {} 53 #define schedstat_enabled() 0 54 #define __schedstat_inc(var) do { } while (0) 55 #define schedstat_inc(var) do { } while (0) 56 #define __schedstat_add(var, amt) do { } while (0) 57 #define schedstat_add(var, amt) do { } while (0) 58 #define __schedstat_set(var, val) do { } while (0) 59 #define schedstat_set(var, val) do { } while (0) 60 #define schedstat_val(var) 0 61 #define schedstat_val_or_zero(var) 0 62 #endif /* CONFIG_SCHEDSTATS */ 63 64 #ifdef CONFIG_SCHED_INFO 65 static inline void sched_info_reset_dequeued(struct task_struct *t) 66 { 67 t->sched_info.last_queued = 0; 68 } 69 70 /* 71 * We are interested in knowing how long it was from the *first* time a 72 * task was queued to the time that it finally hit a cpu, we call this routine 73 * from dequeue_task() to account for possible rq->clock skew across cpus. The 74 * delta taken on each cpu would annul the skew. 75 */ 76 static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) 77 { 78 unsigned long long now = rq_clock(rq), delta = 0; 79 80 if (unlikely(sched_info_on())) 81 if (t->sched_info.last_queued) 82 delta = now - t->sched_info.last_queued; 83 sched_info_reset_dequeued(t); 84 t->sched_info.run_delay += delta; 85 86 rq_sched_info_dequeued(rq, delta); 87 } 88 89 /* 90 * Called when a task finally hits the cpu. We can now calculate how 91 * long it was waiting to run. We also note when it began so that we 92 * can keep stats on how long its timeslice is. 93 */ 94 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 95 { 96 unsigned long long now = rq_clock(rq), delta = 0; 97 98 if (t->sched_info.last_queued) 99 delta = now - t->sched_info.last_queued; 100 sched_info_reset_dequeued(t); 101 t->sched_info.run_delay += delta; 102 t->sched_info.last_arrival = now; 103 t->sched_info.pcount++; 104 105 rq_sched_info_arrive(rq, delta); 106 } 107 108 /* 109 * This function is only called from enqueue_task(), but also only updates 110 * the timestamp if it is already not set. It's assumed that 111 * sched_info_dequeued() will clear that stamp when appropriate. 112 */ 113 static inline void sched_info_queued(struct rq *rq, struct task_struct *t) 114 { 115 if (unlikely(sched_info_on())) 116 if (!t->sched_info.last_queued) 117 t->sched_info.last_queued = rq_clock(rq); 118 } 119 120 /* 121 * Called when a process ceases being the active-running process involuntarily 122 * due, typically, to expiring its time slice (this may also be called when 123 * switching to the idle task). Now we can calculate how long we ran. 124 * Also, if the process is still in the TASK_RUNNING state, call 125 * sched_info_queued() to mark that it has now again started waiting on 126 * the runqueue. 127 */ 128 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 129 { 130 unsigned long long delta = rq_clock(rq) - 131 t->sched_info.last_arrival; 132 133 rq_sched_info_depart(rq, delta); 134 135 if (t->state == TASK_RUNNING) 136 sched_info_queued(rq, t); 137 } 138 139 /* 140 * Called when tasks are switched involuntarily due, typically, to expiring 141 * their time slice. (This may also be called when switching to or from 142 * the idle task.) We are only called when prev != next. 143 */ 144 static inline void 145 __sched_info_switch(struct rq *rq, 146 struct task_struct *prev, struct task_struct *next) 147 { 148 /* 149 * prev now departs the cpu. It's not interesting to record 150 * stats about how efficient we were at scheduling the idle 151 * process, however. 152 */ 153 if (prev != rq->idle) 154 sched_info_depart(rq, prev); 155 156 if (next != rq->idle) 157 sched_info_arrive(rq, next); 158 } 159 static inline void 160 sched_info_switch(struct rq *rq, 161 struct task_struct *prev, struct task_struct *next) 162 { 163 if (unlikely(sched_info_on())) 164 __sched_info_switch(rq, prev, next); 165 } 166 #else 167 #define sched_info_queued(rq, t) do { } while (0) 168 #define sched_info_reset_dequeued(t) do { } while (0) 169 #define sched_info_dequeued(rq, t) do { } while (0) 170 #define sched_info_depart(rq, t) do { } while (0) 171 #define sched_info_arrive(rq, next) do { } while (0) 172 #define sched_info_switch(rq, t, next) do { } while (0) 173 #endif /* CONFIG_SCHED_INFO */ 174