[RFC PATCH] sched: psi: Add psi events trace point

[Xuewen Yan]

Add trace point to psi triggers. This is useful to
observe the psi events in the kernel space.

Signed-off-by: Xuewen Yan <xuewen.yan@xxxxxxxxxx>
---
 include/trace/events/sched.h | 5 +++++
 kernel/sched/psi.c           | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 7b2645b50e78..c23cb2bc76fd 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -896,6 +896,11 @@ DECLARE_TRACE(sched_set_need_resched,
 	TP_PROTO(struct task_struct *tsk, int cpu, int tif),
 	TP_ARGS(tsk, cpu, tif));
 
+struct psi_trigger *t
+DECLARE_TRACE(psi_event,
+	TP_PROTO(struct psi_trigger *t),
+	TP_ARGS(t));
+
 #endif /* _TRACE_SCHED_H */
 
 /* This part must be outside protection */
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 59fdb7ebbf22..268fc1b9cf1d 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -509,6 +509,8 @@ static void update_triggers(struct psi_group *group, u64 now,
 		if (now < t->last_event_time + t->win.size)
 			continue;
 
+		trace_psi_event_tp(t);
+
 		/* Generate an event */
 		if (cmpxchg(&t->event, 0, 1) == 0) {
 			if (t->of)
-- 
2.25.1