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Date: Tue, 06 Aug 2002 20:31:08 +1000
To: Jens Axboe <axboe@suse.de>
From: Lincoln Dale <ltd@cisco.com>
Subject: Re: Linux v2.4.19-rc5
Cc: Bill Davidsen <davidsen@tmr.com>, Steven Cole <elenstev@mesatop.com>,
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At 07:42 AM 6/08/2002 +0200, Jens Axboe wrote:
> > Call me an optimist, but after all the reliability problems we had win the
> > 2.5 series, I sort of hoped it would be better in performance, not
> > increasingly worse. Am I misreading this? Can we fall back to the faster
> > 2.4 code :-(
>
>try a work load that excercises the block i/o layer alone (O_DIRECT,
>raw, whatnot) and then compare 2.4 and 2.5. ibm had some slides on this
>from ols, unfortunately I don't know if they have then online.

the BIO in 2.5 kicks butt over the 2.4 BIO - both in terms of increased 
throughput and decreased cpu utilization.
see some testing i previously did: 
http://marc.theaimsgroup.com/?l=linux-kernel&m=102635456620627&w=2


cheers,

lincoln.

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