298 строки
8.8 KiB
C
298 строки
8.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifdef CONFIG_SCHEDSTATS
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extern struct static_key_false sched_schedstats;
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/*
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* Expects runqueue lock to be held for atomicity of update
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*/
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static inline void
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rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
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{
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if (rq) {
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rq->rq_sched_info.run_delay += delta;
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rq->rq_sched_info.pcount++;
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}
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}
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/*
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* Expects runqueue lock to be held for atomicity of update
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*/
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static inline void
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rq_sched_info_depart(struct rq *rq, unsigned long long delta)
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{
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if (rq)
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rq->rq_cpu_time += delta;
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}
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static inline void
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rq_sched_info_dequeue(struct rq *rq, unsigned long long delta)
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{
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if (rq)
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rq->rq_sched_info.run_delay += delta;
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}
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#define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
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#define __schedstat_inc(var) do { var++; } while (0)
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#define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0)
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#define __schedstat_add(var, amt) do { var += (amt); } while (0)
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#define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0)
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#define __schedstat_set(var, val) do { var = (val); } while (0)
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#define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
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#define schedstat_val(var) (var)
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#define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0)
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void __update_stats_wait_start(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats);
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void __update_stats_wait_end(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats);
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void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats);
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static inline void
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check_schedstat_required(void)
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{
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if (schedstat_enabled())
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return;
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/* Force schedstat enabled if a dependent tracepoint is active */
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if (trace_sched_stat_wait_enabled() ||
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trace_sched_stat_sleep_enabled() ||
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trace_sched_stat_iowait_enabled() ||
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trace_sched_stat_blocked_enabled() ||
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trace_sched_stat_runtime_enabled())
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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");
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}
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#else /* !CONFIG_SCHEDSTATS: */
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static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
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static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { }
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static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { }
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# define schedstat_enabled() 0
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# define __schedstat_inc(var) do { } while (0)
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# define schedstat_inc(var) do { } while (0)
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# define __schedstat_add(var, amt) do { } while (0)
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# define schedstat_add(var, amt) do { } while (0)
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# define __schedstat_set(var, val) do { } while (0)
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# define schedstat_set(var, val) do { } while (0)
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# define schedstat_val(var) 0
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# define schedstat_val_or_zero(var) 0
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# define __update_stats_wait_start(rq, p, stats) do { } while (0)
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# define __update_stats_wait_end(rq, p, stats) do { } while (0)
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# define __update_stats_enqueue_sleeper(rq, p, stats) do { } while (0)
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# define check_schedstat_required() do { } while (0)
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#endif /* CONFIG_SCHEDSTATS */
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#ifdef CONFIG_FAIR_GROUP_SCHED
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struct sched_entity_stats {
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struct sched_entity se;
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struct sched_statistics stats;
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} __no_randomize_layout;
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#endif
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static inline struct sched_statistics *
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__schedstats_from_se(struct sched_entity *se)
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{
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#ifdef CONFIG_FAIR_GROUP_SCHED
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if (!entity_is_task(se))
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return &container_of(se, struct sched_entity_stats, se)->stats;
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#endif
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return &task_of(se)->stats;
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}
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#ifdef CONFIG_PSI
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/*
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* PSI tracks state that persists across sleeps, such as iowaits and
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* memory stalls. As a result, it has to distinguish between sleeps,
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* where a task's runnable state changes, and requeues, where a task
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* and its state are being moved between CPUs and runqueues.
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*/
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static inline void psi_enqueue(struct task_struct *p, bool wakeup)
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{
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int clear = 0, set = TSK_RUNNING;
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if (static_branch_likely(&psi_disabled))
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return;
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if (!wakeup || p->sched_psi_wake_requeue) {
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if (p->in_memstall)
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set |= TSK_MEMSTALL;
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if (p->sched_psi_wake_requeue)
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p->sched_psi_wake_requeue = 0;
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} else {
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if (p->in_iowait)
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clear |= TSK_IOWAIT;
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}
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psi_task_change(p, clear, set);
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}
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static inline void psi_dequeue(struct task_struct *p, bool sleep)
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{
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int clear = TSK_RUNNING;
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if (static_branch_likely(&psi_disabled))
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return;
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/*
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* A voluntary sleep is a dequeue followed by a task switch. To
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* avoid walking all ancestors twice, psi_task_switch() handles
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* TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU.
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* Do nothing here.
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*/
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if (sleep)
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return;
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if (p->in_memstall)
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clear |= TSK_MEMSTALL;
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psi_task_change(p, clear, 0);
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}
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static inline void psi_ttwu_dequeue(struct task_struct *p)
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{
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if (static_branch_likely(&psi_disabled))
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return;
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/*
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* Is the task being migrated during a wakeup? Make sure to
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* deregister its sleep-persistent psi states from the old
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* queue, and let psi_enqueue() know it has to requeue.
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*/
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if (unlikely(p->in_iowait || p->in_memstall)) {
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struct rq_flags rf;
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struct rq *rq;
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int clear = 0;
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if (p->in_iowait)
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clear |= TSK_IOWAIT;
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if (p->in_memstall)
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clear |= TSK_MEMSTALL;
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rq = __task_rq_lock(p, &rf);
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psi_task_change(p, clear, 0);
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p->sched_psi_wake_requeue = 1;
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__task_rq_unlock(rq, &rf);
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}
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}
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static inline void psi_sched_switch(struct task_struct *prev,
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struct task_struct *next,
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bool sleep)
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{
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if (static_branch_likely(&psi_disabled))
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return;
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psi_task_switch(prev, next, sleep);
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}
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#else /* CONFIG_PSI */
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static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
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static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
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static inline void psi_ttwu_dequeue(struct task_struct *p) {}
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static inline void psi_sched_switch(struct task_struct *prev,
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struct task_struct *next,
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bool sleep) {}
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#endif /* CONFIG_PSI */
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#ifdef CONFIG_SCHED_INFO
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/*
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* We are interested in knowing how long it was from the *first* time a
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* task was queued to the time that it finally hit a CPU, we call this routine
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* from dequeue_task() to account for possible rq->clock skew across CPUs. The
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* delta taken on each CPU would annul the skew.
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*/
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static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
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{
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unsigned long long delta = 0;
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if (!t->sched_info.last_queued)
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return;
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delta = rq_clock(rq) - t->sched_info.last_queued;
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t->sched_info.last_queued = 0;
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t->sched_info.run_delay += delta;
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rq_sched_info_dequeue(rq, delta);
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}
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/*
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* Called when a task finally hits the CPU. We can now calculate how
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* long it was waiting to run. We also note when it began so that we
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* can keep stats on how long its timeslice is.
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*/
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static void sched_info_arrive(struct rq *rq, struct task_struct *t)
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{
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unsigned long long now, delta = 0;
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if (!t->sched_info.last_queued)
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return;
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now = rq_clock(rq);
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delta = now - t->sched_info.last_queued;
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t->sched_info.last_queued = 0;
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t->sched_info.run_delay += delta;
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t->sched_info.last_arrival = now;
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t->sched_info.pcount++;
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rq_sched_info_arrive(rq, delta);
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}
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/*
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* This function is only called from enqueue_task(), but also only updates
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* the timestamp if it is already not set. It's assumed that
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* sched_info_dequeue() will clear that stamp when appropriate.
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*/
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static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t)
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{
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if (!t->sched_info.last_queued)
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t->sched_info.last_queued = rq_clock(rq);
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}
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/*
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* Called when a process ceases being the active-running process involuntarily
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* due, typically, to expiring its time slice (this may also be called when
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* switching to the idle task). Now we can calculate how long we ran.
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* Also, if the process is still in the TASK_RUNNING state, call
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* sched_info_enqueue() to mark that it has now again started waiting on
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* the runqueue.
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*/
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static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
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{
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unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
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rq_sched_info_depart(rq, delta);
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if (task_is_running(t))
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sched_info_enqueue(rq, t);
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}
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/*
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* Called when tasks are switched involuntarily due, typically, to expiring
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* their time slice. (This may also be called when switching to or from
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* the idle task.) We are only called when prev != next.
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*/
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static inline void
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sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
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{
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/*
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* prev now departs the CPU. It's not interesting to record
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* stats about how efficient we were at scheduling the idle
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* process, however.
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*/
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if (prev != rq->idle)
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sched_info_depart(rq, prev);
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if (next != rq->idle)
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sched_info_arrive(rq, next);
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}
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#else /* !CONFIG_SCHED_INFO: */
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# define sched_info_enqueue(rq, t) do { } while (0)
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# define sched_info_dequeue(rq, t) do { } while (0)
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# define sched_info_switch(rq, t, next) do { } while (0)
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#endif /* CONFIG_SCHED_INFO */
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