Re: PROBLEM: Unusually high load average when idle in 2.6.35,2.6.35.1 and later

From: Greg KH
Date: Fri Oct 01 2010 - 14:42:16 EST


On Thu, Sep 30, 2010 at 11:53:21PM -0400, tmhikaru@xxxxxxxxx wrote:

<snip>

> Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Date: Thu Apr 22 21:50:19 2010 +0200
>
> sched: Cure load average vs NO_HZ woes
>
> Chase reported that due to us decrementing calc_load_task prematurely
> (before the next LOAD_FREQ sample), the load average could be scewed
> by as much as the number of CPUs in the machine.
>
> This patch, based on Chase's patch, cures the problem by keeping the
> delta of the CPU going into NO_HZ idle separately and folding that in
> on the next LOAD_FREQ update.
>
> This restores the balance and we get strict LOAD_FREQ period samples.
>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Acked-by: Chase Douglas <chase.douglas@xxxxxxxxxxxxx>
> LKML-Reference: <1271934490.1776.343.camel@laptop>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

Care to resend this and cc: Peter, Chase, and Ingo?

thanks,

greg k-h
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