v4.19.13 snapshot.
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
new file mode 100644
index 0000000..8aea199
--- /dev/null
+++ b/kernel/sched/stats.h
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifdef CONFIG_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_dequeued(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)
+
+#else /* !CONFIG_SCHEDSTATS: */
+static inline void rq_sched_info_arrive (struct rq *rq, unsigned long long delta) { }
+static inline void rq_sched_info_dequeued(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
+#endif /* CONFIG_SCHEDSTATS */
+
+#ifdef CONFIG_SCHED_INFO
+static inline void sched_info_reset_dequeued(struct task_struct *t)
+{
+ t->sched_info.last_queued = 0;
+}
+
+/*
+ * 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_dequeued(struct rq *rq, struct task_struct *t)
+{
+ unsigned long long now = rq_clock(rq), delta = 0;
+
+ if (unlikely(sched_info_on()))
+ if (t->sched_info.last_queued)
+ delta = now - t->sched_info.last_queued;
+ sched_info_reset_dequeued(t);
+ t->sched_info.run_delay += delta;
+
+ rq_sched_info_dequeued(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 = rq_clock(rq), delta = 0;
+
+ if (t->sched_info.last_queued)
+ delta = now - t->sched_info.last_queued;
+ sched_info_reset_dequeued(t);
+ 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_dequeued() will clear that stamp when appropriate.
+ */
+static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
+{
+ if (unlikely(sched_info_on())) {
+ 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_queued() 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 (t->state == TASK_RUNNING)
+ sched_info_queued(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);
+}
+
+static inline void
+sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
+{
+ if (unlikely(sched_info_on()))
+ __sched_info_switch(rq, prev, next);
+}
+
+#else /* !CONFIG_SCHED_INFO: */
+# define sched_info_queued(rq, t) do { } while (0)
+# define sched_info_reset_dequeued(t) do { } while (0)
+# define sched_info_dequeued(rq, t) do { } while (0)
+# define sched_info_depart(rq, t) do { } while (0)
+# define sched_info_arrive(rq, next) do { } while (0)
+# define sched_info_switch(rq, t, next) do { } while (0)
+#endif /* CONFIG_SCHED_INFO */