Re: [PATCH 2/2] sched/fair: Delete useless condition in tg_unthrottle_up()

From: Benjamin Segall
Date: Thu Apr 07 2022 - 17:01:01 EST


Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> writes:

> Fully decayed cfs_rq is impossible to have queued entities,
> the first condition "!cfs_rq_is_decayed(cfs_rq)" is enough
> to cover.

In particular, cfs_rq->load.weight is part of cfs_rq_is_decayed.

Reviewed-by: Ben Segall <bsegall@xxxxxxxxxx>

>
> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
> ---
> kernel/sched/fair.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index e6fa5d1141b4..17c13c38b1c2 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4850,7 +4850,7 @@ static int tg_unthrottle_up(struct task_group *tg, void *data)
> cfs_rq->throttled_clock_task;
>
> /* Add cfs_rq with load or one or more already running entities to the list */
> - if (!cfs_rq_is_decayed(cfs_rq) || cfs_rq->nr_running)
> + if (!cfs_rq_is_decayed(cfs_rq))
> list_add_leaf_cfs_rq(cfs_rq);
> }