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Message-Id: <20220818124805.601-5-zhouchengming@bytedance.com>
Date:   Thu, 18 Aug 2022 20:48:00 +0800
From:   Chengming Zhou <zhouchengming@...edance.com>
To:     vincent.guittot@...aro.org, dietmar.eggemann@....com,
        mingo@...hat.com, peterz@...radead.org, rostedt@...dmis.org,
        bsegall@...gle.com, vschneid@...hat.com
Cc:     linux-kernel@...r.kernel.org, tj@...nel.org,
        Chengming Zhou <zhouchengming@...edance.com>
Subject: [PATCH v6 4/9] sched/fair: update comments in enqueue/dequeue_entity()

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@...edance.com>
Acked-by: Vincent Guittot <vincent.guittot@...aro.org>
---
 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 5a704109472a..372e5f4a49a3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4598,7 +4598,8 @@ 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
@@ -4683,7 +4684,8 @@ 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.
-- 
2.37.2

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