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To: Voluspa <lista1@comhem.se>
Cc: akpm@osdl.org, Valdis.Kletnieks@vt.edu, diegocg@gmail.com,
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Subject: Re: adaptive readahead overheads
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From: Andi Kleen <ak@suse.de>
Date: 08 Jun 2006 15:05:38 +0200
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Voluspa <lista1@comhem.se> writes:

> On Thu, 8 Jun 2006 19:37:31 +0800 Fengguang Wu wrote:
> > I'd like to show some numbers on the pure software overheads come with
> > the adaptive readahead in daily operations.
> [...]
> > 
> > # time find /usr -type f -exec md5sum {} \; >/dev/null
> > 
> > ARA
> > 
> > 406.00s user 325.16s system 97% cpu 12:28.17 total
> 
> Just out of interest, all your figures show an almost maxed out CPU.

It might be because qemu has a poor IO model (old IDE) that is quite 
CPU intensive to drive.

-Andi