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From: Chengming Zhou <zhouchengming@bytedance.com>
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	bristot@redhat.com, vschneid@redhat.com
Cc: linux-kernel@vger.kernel.org,
	Chengming Zhou <zhouchengming@bytedance.com>
Subject: [PATCH] sched/fair: update comments in enqueue/dequeue_entity()
Date: Wed,  1 Jun 2022 11:55:45 +0800	[thread overview]
Message-ID: <20220601035545.82187-1-zhouchengming@bytedance.com> (raw)

When reading the sched_avg related code, I found the comments in
enqueue/dequeue_entity() are not updated with the current code.

We don't add/subtract entity's runnable_avg from cfs_rq->runnable_avg
during enqueue/dequeue_entity(), those are done only for attach/detach.

This patch updates the comments to reflect the current code working.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 kernel/sched/fair.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index b3371fa40548..e0cd4052e32f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4348,7 +4348,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	/*
 	 * When enqueuing a sched_entity, we must:
 	 *   - Update loads to have both entity and cfs_rq synced with now.
-	 *   - Add its load to cfs_rq->runnable_avg
+	 *   - For group_entity, update its runnable_weight to reflect the new
+	 *     h_nr_running of its group cfs_rq.
 	 *   - For group_entity, update its weight to reflect the new share of
 	 *     its group cfs_rq
 	 *   - Add its new weight to cfs_rq->load.weight
@@ -4433,7 +4434,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	/*
 	 * When dequeuing a sched_entity, we must:
 	 *   - Update loads to have both entity and cfs_rq synced with now.
-	 *   - Subtract its load from the cfs_rq->runnable_avg.
+	 *   - For group_entity, update its runnable_weight to reflect the new
+	 *     h_nr_running of its group cfs_rq.
 	 *   - Subtract its previous weight from cfs_rq->load.weight.
 	 *   - For group entity, update its weight to reflect the new share
 	 *     of its group cfs_rq.
-- 
2.36.1


             reply	other threads:[~2022-06-01  3:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-01  3:55 Chengming Zhou [this message]
2022-06-03 12:08 ` Vincent Guittot
2022-06-15 14:41   ` [External] " Chengming Zhou

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