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From: Andreas Dilger <adilger@turbolabs.com>
Date: Thu, 18 Oct 2001 14:17:14 -0600
To: "DICKENS,CARY (HP-Loveland,ex2)" <cary_dickens2@hp.com>
Cc: "'Andrew Morton'" <akpm@zip.com.au>,
        "Kernel Mailing List (E-mail)" <linux-kernel@vger.kernel.org>,
        "HABBINGA,ERIK (HP-Loveland,ex1)" <erik_habbinga@hp.com>
Subject: Re: Kernel performance in reference to 2.4.5pre1
Message-ID: <20011018141714.M1144@turbolinux.com>
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Andrew Morton [mailto:akpm@zip.com.au] wrote:
> SFS is a rather specialised workload, and synchronous NFS exports
> are not a thing which gets a lot of attention.  It could be one
> small, hitherto unnoticed change which caused this performance
> regression.  And it appears that the change occurred between 2.4.5
> and 2.4.7.

Cary, also note that Andrew did some work with ext3 which can greatly
improve the performance of synchronous I/O.  Granted, it doesn't fix
any performance issues in the VM or VFS that may have been introduced,
but if you are looking for good benchmark numbers, give ext3 a try.

Use a large journal to avoid journal flushes for sync I/O.  See:
http://marc.theaimsgroup.com/?l=linux-kernel&m=99650624414465&w=4

Cheers, Andreas
--
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert

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