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-rw-r--r--kernel/sched/stats.h310
1 files changed, 310 insertions, 0 deletions
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
new file mode 100644
index 000000000..84a188913
--- /dev/null
+++ b/kernel/sched/stats.h
@@ -0,0 +1,310 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KERNEL_STATS_H
+#define _KERNEL_STATS_H
+
+#ifdef CONFIG_SCHEDSTATS
+
+extern struct static_key_false sched_schedstats;
+
+/*
+ * Expects runqueue lock to be held for atomicity of update
+ */
+static inline void
+rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
+{
+ if (rq) {
+ rq->rq_sched_info.run_delay += delta;
+ rq->rq_sched_info.pcount++;
+ }
+}
+
+/*
+ * Expects runqueue lock to be held for atomicity of update
+ */
+static inline void
+rq_sched_info_depart(struct rq *rq, unsigned long long delta)
+{
+ if (rq)
+ rq->rq_cpu_time += delta;
+}
+
+static inline void
+rq_sched_info_dequeue(struct rq *rq, unsigned long long delta)
+{
+ if (rq)
+ rq->rq_sched_info.run_delay += delta;
+}
+#define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
+#define __schedstat_inc(var) do { var++; } while (0)
+#define schedstat_inc(var) do { if (schedstat_enabled()) { var++; } } while (0)
+#define __schedstat_add(var, amt) do { var += (amt); } while (0)
+#define schedstat_add(var, amt) do { if (schedstat_enabled()) { var += (amt); } } while (0)
+#define __schedstat_set(var, val) do { var = (val); } while (0)
+#define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
+#define schedstat_val(var) (var)
+#define schedstat_val_or_zero(var) ((schedstat_enabled()) ? (var) : 0)
+
+void __update_stats_wait_start(struct rq *rq, struct task_struct *p,
+ struct sched_statistics *stats);
+
+void __update_stats_wait_end(struct rq *rq, struct task_struct *p,
+ struct sched_statistics *stats);
+void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p,
+ struct sched_statistics *stats);
+
+static inline void
+check_schedstat_required(void)
+{
+ if (schedstat_enabled())
+ return;
+
+ /* Force schedstat enabled if a dependent tracepoint is active */
+ if (trace_sched_stat_wait_enabled() ||
+ trace_sched_stat_sleep_enabled() ||
+ trace_sched_stat_iowait_enabled() ||
+ trace_sched_stat_blocked_enabled() ||
+ trace_sched_stat_runtime_enabled())
+ 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");
+}
+
+#else /* !CONFIG_SCHEDSTATS: */
+
+static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
+static inline void rq_sched_info_dequeue(struct rq *rq, unsigned long long delta) { }
+static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delta) { }
+# define schedstat_enabled() 0
+# define __schedstat_inc(var) do { } while (0)
+# define schedstat_inc(var) do { } while (0)
+# define __schedstat_add(var, amt) do { } while (0)
+# define schedstat_add(var, amt) do { } while (0)
+# define __schedstat_set(var, val) do { } while (0)
+# define schedstat_set(var, val) do { } while (0)
+# define schedstat_val(var) 0
+# define schedstat_val_or_zero(var) 0
+
+# define __update_stats_wait_start(rq, p, stats) do { } while (0)
+# define __update_stats_wait_end(rq, p, stats) do { } while (0)
+# define __update_stats_enqueue_sleeper(rq, p, stats) do { } while (0)
+# define check_schedstat_required() do { } while (0)
+
+#endif /* CONFIG_SCHEDSTATS */
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+struct sched_entity_stats {
+ struct sched_entity se;
+ struct sched_statistics stats;
+} __no_randomize_layout;
+#endif
+
+static inline struct sched_statistics *
+__schedstats_from_se(struct sched_entity *se)
+{
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ if (!entity_is_task(se))
+ return &container_of(se, struct sched_entity_stats, se)->stats;
+#endif
+ return &task_of(se)->stats;
+}
+
+#ifdef CONFIG_PSI
+void psi_task_change(struct task_struct *task, int clear, int set);
+void psi_task_switch(struct task_struct *prev, struct task_struct *next,
+ bool sleep);
+void psi_account_irqtime(struct task_struct *task, u32 delta);
+
+/*
+ * PSI tracks state that persists across sleeps, such as iowaits and
+ * memory stalls. As a result, it has to distinguish between sleeps,
+ * where a task's runnable state changes, and requeues, where a task
+ * and its state are being moved between CPUs and runqueues.
+ */
+static inline void psi_enqueue(struct task_struct *p, bool wakeup)
+{
+ int clear = 0, set = TSK_RUNNING;
+
+ if (static_branch_likely(&psi_disabled))
+ return;
+
+ if (p->in_memstall)
+ set |= TSK_MEMSTALL_RUNNING;
+
+ if (!wakeup || p->sched_psi_wake_requeue) {
+ if (p->in_memstall)
+ set |= TSK_MEMSTALL;
+ if (p->sched_psi_wake_requeue)
+ p->sched_psi_wake_requeue = 0;
+ } else {
+ if (p->in_iowait)
+ clear |= TSK_IOWAIT;
+ }
+
+ psi_task_change(p, clear, set);
+}
+
+static inline void psi_dequeue(struct task_struct *p, bool sleep)
+{
+ int clear = TSK_RUNNING;
+
+ if (static_branch_likely(&psi_disabled))
+ return;
+
+ /*
+ * A voluntary sleep is a dequeue followed by a task switch. To
+ * avoid walking all ancestors twice, psi_task_switch() handles
+ * TSK_RUNNING and TSK_IOWAIT for us when it moves TSK_ONCPU.
+ * Do nothing here.
+ */
+ if (sleep)
+ return;
+
+ if (p->in_memstall)
+ clear |= (TSK_MEMSTALL | TSK_MEMSTALL_RUNNING);
+
+ psi_task_change(p, clear, 0);
+}
+
+static inline void psi_ttwu_dequeue(struct task_struct *p)
+{
+ if (static_branch_likely(&psi_disabled))
+ return;
+ /*
+ * Is the task being migrated during a wakeup? Make sure to
+ * deregister its sleep-persistent psi states from the old
+ * queue, and let psi_enqueue() know it has to requeue.
+ */
+ if (unlikely(p->in_iowait || p->in_memstall)) {
+ struct rq_flags rf;
+ struct rq *rq;
+ int clear = 0;
+
+ if (p->in_iowait)
+ clear |= TSK_IOWAIT;
+ if (p->in_memstall)
+ clear |= TSK_MEMSTALL;
+
+ rq = __task_rq_lock(p, &rf);
+ psi_task_change(p, clear, 0);
+ p->sched_psi_wake_requeue = 1;
+ __task_rq_unlock(rq, &rf);
+ }
+}
+
+static inline void psi_sched_switch(struct task_struct *prev,
+ struct task_struct *next,
+ bool sleep)
+{
+ if (static_branch_likely(&psi_disabled))
+ return;
+
+ psi_task_switch(prev, next, sleep);
+}
+
+#else /* CONFIG_PSI */
+static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
+static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
+static inline void psi_ttwu_dequeue(struct task_struct *p) {}
+static inline void psi_sched_switch(struct task_struct *prev,
+ struct task_struct *next,
+ bool sleep) {}
+static inline void psi_account_irqtime(struct task_struct *task, u32 delta) {}
+#endif /* CONFIG_PSI */
+
+#ifdef CONFIG_SCHED_INFO
+/*
+ * We are interested in knowing how long it was from the *first* time a
+ * task was queued to the time that it finally hit a CPU, we call this routine
+ * from dequeue_task() to account for possible rq->clock skew across CPUs. The
+ * delta taken on each CPU would annul the skew.
+ */
+static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
+{
+ unsigned long long delta = 0;
+
+ if (!t->sched_info.last_queued)
+ return;
+
+ delta = rq_clock(rq) - t->sched_info.last_queued;
+ t->sched_info.last_queued = 0;
+ t->sched_info.run_delay += delta;
+
+ rq_sched_info_dequeue(rq, delta);
+}
+
+/*
+ * Called when a task finally hits the CPU. We can now calculate how
+ * long it was waiting to run. We also note when it began so that we
+ * can keep stats on how long its timeslice is.
+ */
+static void sched_info_arrive(struct rq *rq, struct task_struct *t)
+{
+ unsigned long long now, delta = 0;
+
+ if (!t->sched_info.last_queued)
+ return;
+
+ now = rq_clock(rq);
+ delta = now - t->sched_info.last_queued;
+ t->sched_info.last_queued = 0;
+ t->sched_info.run_delay += delta;
+ t->sched_info.last_arrival = now;
+ t->sched_info.pcount++;
+
+ rq_sched_info_arrive(rq, delta);
+}
+
+/*
+ * This function is only called from enqueue_task(), but also only updates
+ * the timestamp if it is already not set. It's assumed that
+ * sched_info_dequeue() will clear that stamp when appropriate.
+ */
+static inline void sched_info_enqueue(struct rq *rq, struct task_struct *t)
+{
+ if (!t->sched_info.last_queued)
+ t->sched_info.last_queued = rq_clock(rq);
+}
+
+/*
+ * Called when a process ceases being the active-running process involuntarily
+ * due, typically, to expiring its time slice (this may also be called when
+ * switching to the idle task). Now we can calculate how long we ran.
+ * Also, if the process is still in the TASK_RUNNING state, call
+ * sched_info_enqueue() to mark that it has now again started waiting on
+ * the runqueue.
+ */
+static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
+{
+ unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
+
+ rq_sched_info_depart(rq, delta);
+
+ if (task_is_running(t))
+ sched_info_enqueue(rq, t);
+}
+
+/*
+ * Called when tasks are switched involuntarily due, typically, to expiring
+ * their time slice. (This may also be called when switching to or from
+ * the idle task.) We are only called when prev != next.
+ */
+static inline void
+sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
+{
+ /*
+ * prev now departs the CPU. It's not interesting to record
+ * stats about how efficient we were at scheduling the idle
+ * process, however.
+ */
+ if (prev != rq->idle)
+ sched_info_depart(rq, prev);
+
+ if (next != rq->idle)
+ sched_info_arrive(rq, next);
+}
+
+#else /* !CONFIG_SCHED_INFO: */
+# define sched_info_enqueue(rq, t) do { } while (0)
+# define sched_info_dequeue(rq, t) do { } while (0)
+# define sched_info_switch(rq, t, next) do { } while (0)
+#endif /* CONFIG_SCHED_INFO */
+
+#endif /* _KERNEL_STATS_H */