From: Peter Zijlstra <peterz@infradead.org>
Date: Wed, 12 May 2021 11:32:37 +0000 (+0200)
Subject: sched,stats: Further simplify sched_info
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=90a0ff4ec9c65cae3085d23301933172cea3f38a;p=linux.git

sched,stats: Further simplify sched_info

There's no point doing delta==0 updates.

Suggested-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---

diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 33ffd41935bab..111072ee96638 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -160,10 +160,11 @@ static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
 {
 	unsigned long long delta = 0;
 
-	if (t->sched_info.last_queued) {
-		delta = rq_clock(rq) - t->sched_info.last_queued;
-		t->sched_info.last_queued = 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);
@@ -176,12 +177,14 @@ static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
  */
 static void sched_info_arrive(struct rq *rq, struct task_struct *t)
 {
-	unsigned long long now = rq_clock(rq), delta = 0;
+	unsigned long long now, delta = 0;
 
-	if (t->sched_info.last_queued) {
-		delta = now - t->sched_info.last_queued;
-		t->sched_info.last_queued = 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++;