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From: Chengming Zhou <zhouchengming@bytedance.com>
To: vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org,
	bsegall@google.com, vschneid@redhat.com
Cc: linux-kernel@vger.kernel.org, tj@kernel.org,
	Chengming Zhou <zhouchengming@bytedance.com>
Subject: [PATCH v6 4/9] sched/fair: update comments in enqueue/dequeue_entity()
Date: Thu, 18 Aug 2022 20:48:00 +0800	[thread overview]
Message-ID: <20220818124805.601-5-zhouchengming@bytedance.com> (raw)
In-Reply-To: <20220818124805.601-1-zhouchengming@bytedance.com>

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>
Acked-by: Vincent Guittot <vincent.guittot@linaro.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


  parent reply	other threads:[~2022-08-18 12:48 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-18 12:47 [PATCH v6 0/9] sched/fair: task load tracking optimization and cleanup Chengming Zhou
2022-08-18 12:47 ` [PATCH v6 1/9] sched/fair: maintain task se depth in set_task_rq() Chengming Zhou
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Maintain " tip-bot2 for Chengming Zhou
2022-08-18 12:47 ` [PATCH v6 2/9] sched/fair: remove redundant cpu_cgrp_subsys->fork() Chengming Zhou
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Chengming Zhou
2022-08-18 12:47 ` [PATCH v6 3/9] sched/fair: reset sched_avg last_update_time before set_task_rq() Chengming Zhou
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Reset " tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` Chengming Zhou [this message]
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Update comments in enqueue/dequeue_entity() tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` [PATCH v6 5/9] sched/fair: combine detach into dequeue when migrating task Chengming Zhou
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Combine " tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` [PATCH v6 6/9] sched/fair: fix another detach on unattached task corner case Chengming Zhou
2022-08-23  7:06   ` Vincent Guittot
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Fix " tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` [PATCH v6 7/9] sched/fair: allow changing cgroup of new forked task Chengming Zhou
2022-08-23  7:54   ` Vincent Guittot
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Allow " tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` [PATCH v6 8/9] sched/fair: move task sched_avg attach to enqueue_task_fair() Chengming Zhou
2022-08-23  7:48   ` Vincent Guittot
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Move " tip-bot2 for Chengming Zhou
2022-08-18 12:48 ` [PATCH v6 9/9] sched/fair: don't init util/runnable_avg for !fair task Chengming Zhou
2022-08-23  7:49   ` Vincent Guittot
2022-08-23  9:27   ` [tip: sched/core] sched/fair: Don't " tip-bot2 for Chengming Zhou

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