linux-kernel - Re: [PATCH] sched/fair: Drop the redundant setting of recent_used

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Message-ID: <c4e8cbef-4708-cd4d-306f-6eab5bb32b95@arm.com>
Date:   Thu, 30 Sep 2021 10:34:09 +0200
From:   Dietmar Eggemann <dietmar.eggemann@....com>
To:     Li RongQing <lirongqing@...du.com>, linux-kernel@...r.kernel.org,
        mingo@...hat.com, peterz@...radead.org
Subject: Re: [PATCH] sched/fair: Drop the redundant setting of recent_used_cpu

On 30/09/2021 08:59, Li RongQing wrote:
> recent_used_cpu has been set to prev before check
> 
> Signed-off-by: Li RongQing <lirongqing@...du.com>
> ---
>  kernel/sched/fair.c |    8 +-------
>  1 files changed, 1 insertions(+), 7 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 7b9fe8c..ec42eaa 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6437,14 +6437,8 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
>  	    cpus_share_cache(recent_used_cpu, target) &&
>  	    (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) &&
>  	    cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
> -	    asym_fits_capacity(task_util, recent_used_cpu)) {
> -		/*
> -		 * Replace recent_used_cpu with prev as it is a potential
> -		 * candidate for the next wake:
> -		 */
> -		p->recent_used_cpu = prev;
> +	    asym_fits_capacity(task_util, recent_used_cpu))
>  		return recent_used_cpu;
> -	}
>  
>  	/*
>  	 * For asymmetric CPU capacity systems, our domain of interest is
> 

Looks like this has been already fixed in:

https://lore.kernel.org/r/20210928103544.27489-1-vincent.guittot@linaro.org