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From: Chengming Zhou <zhouchengming@bytedance.com>
To: mingo@redhat.com, peterz@infradead.org,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, vschneid@redhat.com
Cc: linux-kernel@vger.kernel.org,
	Chengming Zhou <zhouchengming@bytedance.com>
Subject: [PATCH v2 02/10] sched/fair: update comments in enqueue/dequeue_entity()
Date: Wed, 13 Jul 2022 12:04:22 +0800	[thread overview]
Message-ID: <20220713040430.25778-3-zhouchengming@bytedance.com> (raw)
In-Reply-To: <20220713040430.25778-1-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 0689b94ed70b..2a3e12ead144 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4443,7 +4443,8 @@ 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
@@ -4533,7 +4534,8 @@ 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


  parent reply	other threads:[~2022-07-13  4:05 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-13  4:04 [PATCH v2 00/10] sched: task load tracking optimization and cleanup Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 01/10] sched/fair: combine detach into dequeue when migrating task Chengming Zhou
2022-07-13  4:04 ` Chengming Zhou [this message]
2022-07-13  4:04 ` [PATCH v2 03/10] sched/fair: maintain task se depth in set_task_rq() Chengming Zhou
2022-07-14 12:30   ` Dietmar Eggemann
2022-07-14 13:03     ` [External] " Chengming Zhou
2022-07-18  7:16   ` Vincent Guittot
2022-07-13  4:04 ` [PATCH v2 04/10] sched/fair: remove redundant cpu_cgrp_subsys->fork() Chengming Zhou
2022-07-14 12:31   ` Dietmar Eggemann
2022-07-14 13:06     ` [External] " Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 05/10] sched/fair: reset sched_avg last_update_time before set_task_rq() Chengming Zhou
2022-07-14 12:31   ` Dietmar Eggemann
2022-07-19  8:49   ` Vincent Guittot
2022-07-13  4:04 ` [PATCH v2 06/10] sched/fair: delete superfluous SKIP_AGE_LOAD Chengming Zhou
2022-07-14 12:33   ` Dietmar Eggemann
2022-07-14 13:24     ` [External] " Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 07/10] sched/fair: use update_load_avg() to attach/detach entity load_avg Chengming Zhou
2022-07-15 11:18   ` Dietmar Eggemann
2022-07-15 16:21     ` [External] " Chengming Zhou
2022-07-19 10:29       ` Vincent Guittot
2022-07-20 13:40         ` Chengming Zhou
2022-07-20 15:34           ` Vincent Guittot
2022-07-21 13:56             ` Chengming Zhou
2022-07-21 14:13               ` Vincent Guittot
2022-07-19 15:02       ` Dietmar Eggemann
2022-07-20 13:43         ` Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 08/10] sched/fair: fix load tracking for new forked !fair task Chengming Zhou
2022-07-19 12:35   ` Vincent Guittot
2022-07-20 13:48     ` [External] " Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 09/10] sched/fair: stop load tracking when task switched_from_fair() Chengming Zhou
2022-07-14 12:33   ` Dietmar Eggemann
2022-07-14 13:43     ` [External] " Chengming Zhou
2022-07-15 11:15       ` Dietmar Eggemann
2022-07-15 16:35         ` Chengming Zhou
2022-07-19 13:20   ` Vincent Guittot
2022-07-27 10:55     ` Chengming Zhou
2022-07-13  4:04 ` [PATCH v2 10/10] sched/fair: delete superfluous set_task_rq_fair() Chengming Zhou

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