linux-kernel - [PATCH 2/2] sched/fair: Update comments regarding last and skip buddy

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Message-Id: <20241125021222.356881-3-adamli@os.amperecomputing.com>
Date: Mon, 25 Nov 2024 02:12:21 +0000
From: Adam Li <adamli@...amperecomputing.com>
To: peterz@...radead.org,
	mingo@...hat.com,
	juri.lelli@...hat.com,
	vincent.guittot@...aro.org
Cc: dietmar.eggemann@....com,
	rostedt@...dmis.org,
	bsegall@...gle.com,
	mgorman@...e.de,
	vschneid@...hat.com,
	linux-kernel@...r.kernel.org,
	patches@...erecomputing.com,
	cl@...ux.com,
	Adam Li <adamli@...amperecomputing.com>
Subject: [PATCH 2/2] sched/fair: Update comments regarding last and skip buddy

Commit 5e963f2bd465 ("sched/fair: Commit to EEVDF") removed the "last" and
"skip" buddy. Update comments in pick_next_entity().

Signed-off-by: Adam Li <adamli@...amperecomputing.com>
---
 kernel/sched/fair.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cd1188b7f3df..d8826a8e0c77 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5602,17 +5602,11 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 
 static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags);
 
-/*
- * Pick the next process, keeping these things in mind, in this order:
- * 1) keep things fair between processes/task groups
- * 2) pick the "next" process, since someone really wants that to run
- * 3) pick the "last" process, for cache locality
- * 4) do not run the "skip" process, if something else is available
- */
 static struct sched_entity *
 pick_next_entity(struct rq *rq, struct cfs_rq *cfs_rq)
 {
 	/*
+	 * Pick the "next" buddy, since someone really wants that to run.
 	 * Enabling NEXT_BUDDY will affect latency but not fairness.
 	 */
 	if (sched_feat(NEXT_BUDDY) &&
-- 
2.25.1