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Date:   Wed, 7 Dec 2022 22:24:55 +0800
From:   Chen Yu <yu.c.chen@intel.com>
To:     Josh Don <joshdon@google.com>
CC:     Vincent Guittot <vincent.guittot@linaro.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Honglei Wang <wanghonglei@didichuxing.com>,
        "Peter Zijlstra" <peterz@infradead.org>,
        Tim Chen <tim.c.chen@intel.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Juri Lelli <juri.lelli@redhat.com>,
        "Rik van Riel" <riel@surriel.com>, Aaron Lu <aaron.lu@intel.com>,
        Abel Wu <wuyun.abel@bytedance.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        "Yicong Yang" <yangyicong@hisilicon.com>,
        "Gautham R . Shenoy" <gautham.shenoy@amd.com>,
        Ingo Molnar <mingo@redhat.com>,
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        Hillf Danton <hdanton@sina.com>,
        Len Brown <len.brown@intel.com>,
        Chen Yu <yu.chen.surf@gmail.com>,
        "Tianchen Ding" <dtcccc@linux.alibaba.com>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/2] sched/fair: Introduce short duration task check
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Hi Josh,
On 2022-12-06 at 18:23:47 -0800, Josh Don wrote:
> > We don't want to add more dedicated knobs. So using
> > sysctl_sched_min_granularity as you are doing in this patch looks ok
> 
> If not a knob, then maybe at least a smaller hardcoded value? Several
> milliseconds seems like too long for this optimization; the
> opportunity cost of not doing the idle search likely doesn't make
> sense if the waker is going to be active for several additional
> milliseconds. I would have guessed something on the order of 100us.
> 
> Chen, what is the run duration of tasks in your ping pong example?
OK, I'll measure the duration of all the tests and summarize the data later.

thanks,
Chenyu