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 rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { } 45 static inline void rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) { } 46 static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { } 47 # define schedstat_enabled() 0 48 # define __schedstat_inc(var) do { } while (0) 49 # define schedstat_inc(var) do { } while (0) 50 # define __schedstat_add(var, amt) do { } while (0) 51 # define schedstat_add(var, amt) do { } while (0) 52 # define __schedstat_set(var, val) 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 /* 116 * Called when a process ceases being the active-running process involuntarily 117 * due, typically, to expiring its time slice (this may also be called when 118 * switching to the idle task). Now we can calculate how long we ran. 119 * Also, if the process is still in the TASK_RUNNING state, call 120 * sched_info_queued() to mark that it has now again started waiting on 121 * the runqueue. 122 */ 123 static inline void sched_info_depart(struct rq *rq, struct task_struct *t) 124 { 125 unsigned long long delta = rq_clock(rq) - 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, struct task_struct *prev, struct task_struct *next) 140 { 141 /* 142 * prev now departs the CPU. It's not interesting to record 143 * stats about how efficient we were at scheduling the idle 144 * process, however. 145 */ 146 if (prev != rq->idle) 147 sched_info_depart(rq, prev); 148 149 if (next != rq->idle) 150 sched_info_arrive(rq, next); 151 } 152 153 static inline void 154 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) 155 { 156 if (unlikely(sched_info_on())) 157 __sched_info_switch(rq, prev, next); 158 } 159 160 #else /* !CONFIG_SCHED_INFO: */ 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