Date: Thu, 11 Jan 2007 19:04:50 -0800 (PST)
From: Christoph Lameter <clameter@sgi.com>
To: Nick Piggin <nickpiggin@yahoo.com.au>
cc: David Chinner <dgc@sgi.com>, linux-kernel@vger.kernel.org,
       linux-mm@kvack.org
Subject: Re: [REGRESSION] 2.6.19/2.6.20-rc3 buffered write slowdown
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On Fri, 12 Jan 2007, Nick Piggin wrote:

> Ah yes... Can't you force it on if you have a NUMA complied kernel?

But it wont do anything since it only comes into action if you have an off 
node allocation. If you run a NUMA kernel on an SMP system then you only 
have one node. There is no way that an off node allocation can occur.

> > zone reclaim was already in 2.6.16.
> 
> Well it was a long shot, but that is something that has had a few
> changes recently and is something that could interact badly with
> the global pdflush.

zone reclaim is not touching dirty pages in its default configuration. It 
would only remove up clean pagecache pages.


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