From: Song Muchun <smuchun@gmail.com>
Date: Sun, 14 Oct 2018 11:26:12 +0000 (+0800)
Subject: sched/fair: Fix the min_vruntime update logic in dequeue_entity()
X-Git-Tag: v4.9.137~121
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2530be5401885114c0b0b634ba218b2e963063b3;p=platform%2Fkernel%2Flinux-amlogic.git

sched/fair: Fix the min_vruntime update logic in dequeue_entity()

[ Upstream commit 9845c49cc9bbb317a0bc9e9cf78d8e09d54c9af0 ]

The comment and the code around the update_min_vruntime() call in
dequeue_entity() are not in agreement.

>From commit:

  b60205c7c558 ("sched/fair: Fix min_vruntime tracking")

I think that we want to update min_vruntime when a task is sleeping/migrating.
So, the check is inverted there - fix it.

Signed-off-by: Song Muchun <smuchun@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: b60205c7c558 ("sched/fair: Fix min_vruntime tracking")
Link: http://lkml.kernel.org/r/20181014112612.2614-1-smuchun@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5ad109ccec35..0c91d72f3e8f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3502,7 +3502,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 * put back on, and if we advance min_vruntime, we'll be placed back
 	 * further than we started -- ie. we'll be penalized.
 	 */
-	if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
+	if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) != DEQUEUE_SAVE)
 		update_min_vruntime(cfs_rq);
 }