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From:   Vincent Guittot <vincent.guittot@linaro.org>
Date:   Wed, 6 Apr 2022 17:21:58 +0200
Message-ID: <CAKfTPtCv=pBDsvWDguFXtf_YZDf2Yx+xrpc3hDevQFz6BoadJA@mail.gmail.com>
Subject: Re: [PATCH] sched/fair: Move calculate of avg_load to a better location
To:     zgpeng <zgpeng.linux@gmail.com>
Cc:     mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
        dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com,
        mgorman@suse.de, bristot@redhat.com, linux-kernel@vger.kernel.org
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On Wed, 6 Apr 2022 at 11:57, zgpeng <zgpeng.linux@gmail.com> wrote:
>
> In calculate_imbalance function, when the value of local->avg_load is
> greater than or equal to busiest->avg_load, the calculated sds->avg_load is
> not used. So this calculation can be placed in a more appropriate position.
>
> Signed-off-by: zgpeng <zgpeng@tencent.com>
> Reviewed-by: Samuel Liao <samuelliao@tencent.com>

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

> ---
>  kernel/sched/fair.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index d4bd299..601f8bd 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9460,8 +9460,6 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
>                 local->avg_load = (local->group_load * SCHED_CAPACITY_SCALE) /
>                                   local->group_capacity;
>
> -               sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
> -                               sds->total_capacity;
>                 /*
>                  * If the local group is more loaded than the selected
>                  * busiest group don't try to pull any tasks.
> @@ -9470,6 +9468,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
>                         env->imbalance = 0;
>                         return;
>                 }
> +
> +               sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
> +                               sds->total_capacity;
>         }
>
>         /*
> --
> 2.9.5
>