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From: fweisbec@gmail.com (Frederic Weisbecker)
To: linux-arm-kernel@lists.infradead.org
Subject: a bug on NO_HZ_FULL_ALL
Date: Thu, 14 Nov 2013 12:42:56 +0100	[thread overview]
Message-ID: <20131114114253.GA16501@localhost.localdomain> (raw)
In-Reply-To: <52848547.9080604@linaro.org>

On Thu, Nov 14, 2013 at 01:39:43PM +0530, viresh kumar wrote:
> On Thursday 14 November 2013 01:35 PM, Vincent Guittot wrote:
> > AFAICT, It's a none issue. In full nohz, a timer fires periodically
> > (around 4sec period on ARM IIRC) on one cpu (cpu0).
> 
> Timer should always be running on CPU0, its out of nohz-full domain. Its
> cpu 1, where it will fire after long delays..
> 
> 
> https://wiki.linaro.org/WorkingGroups/PowerManagement/Doc/AdaptiveTickless

Right. CPU 0 stays pure periodic unless you select CONFIG_NO_HZ_FULL_SYSIDLE=y
then it can be also nohz when the full system is idle. I strongly recommend for power
consumption.

      parent reply	other threads:[~2013-11-14 11:42 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CANHzE=2EOJmjFqLUDSfxTvgQhrUogOxH8Qux9hBFTGf8HiWWEw@mail.gmail.com>
2013-11-14  2:41 ` a bug on NO_HZ_FULL_ALL Alex Shi
2013-11-14  7:46   ` Alex Shi
2013-11-14  8:05     ` Vincent Guittot
2013-11-14  8:09       ` viresh kumar
2013-11-14  9:54         ` Shaojie Sun
2013-11-14 11:50           ` Frederic Weisbecker
     [not found]             ` <548C3FF8E9B1F945A9FEE3533A16C6CD4E9BF1DA@szxema507-mbs.china.huawei.com>
2013-11-14 12:59               ` 答复: " Frederic Weisbecker
2013-11-14 11:53           ` Frederic Weisbecker
2013-11-14 12:08             ` Russell King - ARM Linux
2013-11-14 12:37               ` Frederic Weisbecker
2013-11-14 13:08               ` Alex Shi
2013-11-14 13:15                 ` Frederic Weisbecker
2013-11-19  3:03           ` Alex Shi
     [not found]             ` <548C3FF8E9B1F945A9FEE3533A16C6CD4E9C319D@szxema507-mbs.china.huawei.com>
2013-11-19  3:15               ` 答复: " Alex Shi
2013-11-14 11:42         ` Frederic Weisbecker [this message]

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