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Message-ID: <b6dc758b-492d-1000-24e5-643e38d3166e@huawei.com>
Date:   Mon, 14 Feb 2022 17:40:55 +0800
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Subject: Re: Question about nohz and sysidle
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From:   Yu Liao <liaoyu15@huawei.com>
CC:     <paulmck@kernel.org>, <linux-kernel@vger.kernel.org>,
        <liwei391@huawei.com>
References: <b881759b-d281-fdc3-71b7-4429d84cd734@huawei.com>
To:     <frederic@kernel.org>
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Sorry, I sent to the old email address.

On 2022/2/14 16:28, Yu Liao wrote:
> Hi Frederic,
> 
> I'm working on an issue about nohz. When NO_HZ_FULL is enabled, CPU 0 
> handles the timekeeping duty on behalf of all other CPUs, which means 
> CPU 0 never stop tick even in sysidle state. This is a powersaving issue.
> 
> I found your patchset (nohz: Support sysidle) in the below link.
> https://lore.kernel.org/all/1406569056-30217-1-git-send-email-fweisbec@gmail.com/ 
> 
> But these patches haven't been merged into mainline yet and sysidle 
> state detection has been removed by commit fe5ac724d81a (rcu: Remove 
> nohz_full full-system-idle state machine) as well.
> 
> I tried your patches and it does work, why are we no longer 
> working on stopping timekeeping duty when all full dynticks CPUs are idle?
> 
> Thanks,
> Yu