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From: bert hubert <bert.hubert@netherlabs.nl>
To: P@draigBrady.com
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: optimal file order for reading from disk
Date: Tue, 14 Jun 2005 14:13:20 +0200	[thread overview]
Message-ID: <20050614121320.GA4739@outpost.ds9a.nl> (raw)
In-Reply-To: <42AEBDC4.2050907@draigBrady.com>

On Tue, Jun 14, 2005 at 12:21:40PM +0100, P@draigBrady.com wrote:
> I know this will be dependent on filesystem, I/O scheduler, ...
> but given a list of files, what is the best (filesystem
> agnostic) order to read from disk (to minimise seeks).
> 
> Should I sort by path, inode number, getdents, or something else?

I know several projects that sort on inode number and benefit from that,
sometimes in a big way. The effect of this will probably be less on a
matured filesystem image.

I can't really explain why it helps though. I don't think the kernel will do
'crossfile readahead', although your disk might do so.

Google on 'orlov allocator', is enlightning.

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://netherlabs.nl              Open and Closed source services

  reply	other threads:[~2005-06-14 12:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-14 11:21 optimal file order for reading from disk P
2005-06-14 12:13 ` bert hubert [this message]
2005-06-14 13:59   ` P
2005-06-14 17:39     ` Nikita Danilov
2005-06-14 18:12       ` dean gaudet

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