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Subject: Re: 2.6.19-rc1: Slowdown in lmbench's fork
From: Tim Chen <tim.c.chen@linux.intel.com>
Reply-To: tim.c.chen@linux.intel.com
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org
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Organization: Intel
Date: Thu, 02 Nov 2006 10:34:13 -0800
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On Thu, 2006-11-02 at 11:33 -0700, Eric W. Biederman wrote:

> 
> My only partial guess is that it might be worth adding the per cpu
> variables my patch adds without any of the corresponding code changes.
> And see if adding variables to the per cpu area is what is causing the
> change.
> 
> The two tests I can see in this line are:
> - to add the percpu vector_irq variable.
> - to increase NR_IRQs.

Increasing the NR_IRQs resulted in the regression.
Adding the percpu vector_irq variable did not cause any changes.  

Tim