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References: <1603372550-14680-1-git-send-email-Julia.Lawall@inria.fr>
In-Reply-To: <1603372550-14680-1-git-send-email-Julia.Lawall@inria.fr>
From:   Chen Yu <yu.chen.surf@gmail.com>
Date:   Sat, 24 Oct 2020 00:28:40 +0800
Message-ID: <CADjb_WSG-z78KYmS=f2cLYdYLeqi=eqmLw+Q=sMGOBEM7Bw2Ug@mail.gmail.com>
Subject: Re: [PATCH v2] sched/fair: check for idle core
To:     Julia Lawall <Julia.Lawall@inria.fr>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Fri, Oct 23, 2020 at 1:32 AM Julia Lawall <Julia.Lawall@inria.fr> wrote:
>
[cut]
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index aa4c6227cd6d..9b23dad883ee 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5804,6 +5804,9 @@ wake_affine_idle(int this_cpu, int prev_cpu, int sync)
>         if (sync && cpu_rq(this_cpu)->nr_running == 1)
>                 return this_cpu;
>
> +       if (available_idle_cpu(prev_cpu))
How about also taking  sched_idle_cpu(prev_cpu) into consideration?
if (available_idle_cpu(prev_cpu) || sched_idle_cpu(prev_cpu))

Thanks,
Chenyu