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 { if (schedstat_enabled()) { var++; } } while (0) 35 #define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0) 36 #define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0) 37 #define schedstat_val(var) (var) 38 #define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0) 39 40 #else /* !CONFIG_SCHEDSTATS */ 41 static inline void 42 rq_sched_info_arrive(struct rq *rq, unsigned long long delta) 43 {} 44 static inline void 45 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) 46 {} 47 static inline void 48 rq_sched_info_depart(struct rq *rq, unsigned long long delta) 49 {} 50 #define schedstat_enabled() 0 51 #define schedstat_inc(var) do { } while (0) 52 #define schedstat_add(var, amt) do { } while (0) 53 #define schedstat_set(var, val) do { } while (0) 54 #define schedstat_val(var) 0 55 #define schedstat_val_or_zero(var) 0 56 #endif /* CONFIG_SCHEDSTATS */ 57 58 #ifdef CONFIG_SCHED_INFO 59 static inline void sched_info_reset_dequeued(struct task_struct *t) 60 { 61 t->sched_info.last_queued = 0; 62 } 63 64 /* 65 * We are interested in knowing how long it was from the *first* time a 66 * task was queued to the time that it finally hit a cpu, we call this routine 67 * from dequeue_task() to account for possible rq->clock skew across cpus. The 68 * delta taken on each cpu would annul the skew. 69 */ 70 static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t) 71 { 72 unsigned long long now = rq_clock(rq), delta = 0; 73 74 if (unlikely(sched_info_on())) 75 if (t->sched_info.last_queued) 76 delta = now - t->sched_info.last_queued; 77 sched_info_reset_dequeued(t); 78 t->sched_info.run_delay += delta; 79 80 rq_sched_info_dequeued(rq, delta); 81 } 82 83 /* 84 * Called when a task finally hits the cpu. We can now calculate how 85 * long it was waiting to run. We also note when it began so that we 86 * can keep stats on how long its timeslice is. 87 */ 88 static void sched_info_arrive(struct rq *rq, struct task_struct *t) 89 { 90 unsigned long long now = rq_clock(rq), delta = 0; 91 92 if (t->sched_info.last_queued) 93 delta = now - t->sched_info.last_queued; 94 sched_info_reset_dequeued(t); 95 t->sched_info.run_delay += delta; 96 t->sched_info.last_arrival = now; 97 t->sched_info.pcount++; 98 99 rq_sched_info_arrive(rq, delta); 100 } 101 102 /* 103 * This function is only called from enqueue_task(), but also only updates 104 * the timestamp if it is already not set. It's assumed that 105 * sched_info_dequeued() will clear that stamp when appropriate. 106 */ 107 static inline void sched_info_queued(struct rq *rq, struct task_struct *t) 108 { 109 if (unlikely(sched_info_on())) 110 if (!t->sched_info.last_queued) 111 t->sched_info.last_queued = rq_clock(rq); 112 } 113 114 /* 115 * Called when a process ceases being the active-running process involuntarily 116 * due, typically, to expiring its time slice (this may also be called when 117 * switching to the idle task). Now we can calculate how long we ran. 118 * Also, if the process is still in the TASK_RUNNING state, call 119 * sched_info_queued() to mark that it has now again started waiting on 120 * the runqueue. 121 */ 122 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 123 { 124 unsigned long long delta = rq_clock(rq) - 125 t->sched_info.last_arrival; 126 127 rq_sched_info_depart(rq, delta); 128 129 if (t->state == TASK_RUNNING) 130 sched_info_queued(rq, t); 131 } 132 133 /* 134 * Called when tasks are switched involuntarily due, typically, to expiring 135 * their time slice. (This may also be called when switching to or from 136 * the idle task.) We are only called when prev != next. 137 */ 138 static inline void 139 __sched_info_switch(struct rq *rq, 140 struct task_struct *prev, struct task_struct *next) 141 { 142 /* 143 * prev now departs the cpu. It's not interesting to record 144 * stats about how efficient we were at scheduling the idle 145 * process, however. 146 */ 147 if (prev != rq->idle) 148 sched_info_depart(rq, prev); 149 150 if (next != rq->idle) 151 sched_info_arrive(rq, next); 152 } 153 static inline void 154 sched_info_switch(struct rq *rq, 155 struct task_struct *prev, struct task_struct *next) 156 { 157 if (unlikely(sched_info_on())) 158 __sched_info_switch(rq, prev, next); 159 } 160 #else 161 #define sched_info_queued(rq, t) do { } while (0) 162 #define sched_info_reset_dequeued(t) do { } while (0) 163 #define sched_info_dequeued(rq, t) do { } while (0) 164 #define sched_info_depart(rq, t) do { } while (0) 165 #define sched_info_arrive(rq, next) do { } while (0) 166 #define sched_info_switch(rq, t, next) do { } while (0) 167 #endif /* CONFIG_SCHED_INFO */ 168