From: "Nicolas Kalkhof" <nkalkhof@web.de>
To: "Andi Kleen" <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Too many poll_idle cpu calls in kernel 3.2 rc-series
Date: Mon, 28 Nov 2011 21:31:13 +0100 (CET) [thread overview]
Message-ID: <492649473.3864850.1322512273580.JavaMail.fmail@mwmweb020> (raw)
Andi,
correct. The issue was introduced somewhere between 3.1 final and 3.2-rc1. I've tried to track down the bad commit but so far I haven't been successfull. The only workaround I found is to set the idle boot parameter to mwait and to disable CONFIG_INTEL_IDLE. Somehow the kernel seems to set idle to poll by default - no idea why :-(. I wonder if other mobile sandy bridge cpus are affected as well.
Regards,
Nic
-----Ursprüngliche Nachricht-----
Von: "Andi Kleen" <andi@firstfloor.org>
Gesendet: Nov 28, 2011 8:33:28 PM
An: "Nicolas Kalkhof" <nkalkhof@web.de>
Betreff: Re: Too many poll_idle cpu calls in kernel 3.2 rc-series
>"Nicolas Kalkhof" <nkalkhof@web.de> writes:
>
>> the kernel v3.2 series shows excessive poll_idle calls during system idle phases causing the cpu
>> (mobile i7 2620M) to heat up and draw additional 10% more power. All kernel versions between
>> 3.2-rc1 and 3.2-rc3 are affected. Perf Top and Powertop both show the same issue.
>> I've posted a similar bug report before: http://marc.info/?l=linux-kernel&m=132164909313594&w=2
>> and used perf top -U to verify the poll_idle calls as requested.
>
>So it didn't happen with earlier kernels?
>I would suggest a git bisect in this case.
>
>-Andi
>
>--
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next reply other threads:[~2011-11-28 20:31 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-28 20:31 Nicolas Kalkhof [this message]
2011-11-28 20:44 ` Too many poll_idle cpu calls in kernel 3.2 rc-series Andi Kleen
2011-11-29 11:07 ` Deepthi Dharwar
2011-12-10 7:33 ` Mike Galbraith
-- strict thread matches above, loose matches on Subject: below --
2011-11-30 11:54 Nicolas Kalkhof
2011-11-27 20:13 Nicolas Kalkhof
2011-11-28 19:33 ` Andi Kleen
2011-11-28 20:01 ` Srivatsa S. Bhat
2011-11-29 10:37 ` Deepthi Dharwar
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