Subject: Re: [PATCH] mm: Implement swap prefetching tweaks
From: Lee Revell <rlrevell@joe-job.com>
To: Mike Galbraith <efault@gmx.de>
Cc: Con Kolivas <kernel@kolivas.org>, Andrew Morton <akpm@osdl.org>,
       linux-kernel@vger.kernel.org, ck@vds.kolivas.org
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Date: Sat, 11 Mar 2006 23:54:42 -0500
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On Sat, 2006-03-11 at 08:51 +0100, Mike Galbraith wrote:
> There used to be a pages in flight 'restrictor plate' in there that
> would have probably helped this situation at least a little.  But in
> any case, it sounds like you'll have to find a way to submit the IO in
> itty bitty synchronous pieces. 

echo 64 > /sys/block/hd*/queue/max_sectors_kb

There is basically a straight linear relation between whatever you set
this to and the maximum scheduling latency you see.  It was developed to
solve the exact problem you are describing.

Lee

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