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From: Daniel Phillips <phillips@bonn-fries.net>
To: Andrew Morton <akpm@zip.com.au>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: [CFT] delayed allocation and multipage I/O patches for 2.5.6.
Date: Tue, 12 Mar 2002 12:18:01 +0100
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On March 12, 2002 07:00 am, Andrew Morton wrote:
>   Identifies readahead thrashing.
> 
>     Currently, it just performs a shrink on the readahead window when thrashing
>     occurs.  This greatly reduces the amount of pointless I/O which we perform,
>     and will reduce the CPU load.  The idea is that the readahead window
>     dynamically adjusts to a sustainable size.  It improves things, but not
>     hugely, experimentally.

The question is, does it wipe out a nasty corner case?  If so then the improvement
for the averge case is just a nice fringe benefit.  A carefully constructed test
that triggers the corner case would be most interesting.

-- 
Daniel
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