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Date:   Mon, 29 Aug 2022 13:36:10 +0100
From:   Mel Gorman <mgorman@techsingularity.net>
To:     Abel Wu <wuyun.abel@bytedance.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Mel Gorman <mgorman@suse.de>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Josh Don <joshdon@google.com>, Chen Yu <yu.c.chen@intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] sched/fair: default to false in test_idle_cores
Message-ID: <20220829123610.iooaxujglh2l43x6@techsingularity.net>
References: <20220712082036.5130-1-wuyun.abel@bytedance.com>
 <20220712082036.5130-3-wuyun.abel@bytedance.com>
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On Tue, Jul 12, 2022 at 04:20:33PM +0800, Abel Wu wrote:
> It's uncertain whether idle cores exist or not if shared sched-
> domains are not ready, so returning "no idle cores" usually
> makes sense.
> 
> While __update_idle_core() is an exception, it checks status
> of this core and set to shared sched-domain if necessary. So
> the whole logic depends on the existence of sds, and can bail
> out early if !sds.
> 
> It's somehow a little tricky, and as Josh suggested that it
> should be transient while the domain isn't ready. So remove
> the self-defined default value to make things more clearer,
> while introduce little overhead in idle path.
> 
> Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
> Reviewed-by: Josh Don <joshdon@google.com>

Acked-by: Mel Gorman <mgorman@techsingularity.net>

-- 
Mel Gorman
SUSE Labs