linux-kernel - Re: stat benchmark

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Message-ID: <20080425194845.GE21193@mit.edu>
Date:	Fri, 25 Apr 2008 15:48:46 -0400
From:	Theodore Tso <tytso@....edu>
To:	Soeren Sandmann <sandmann@...mi.au.dk>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: stat benchmark

On Thu, Apr 24, 2008 at 10:59:10PM +0200, Soeren Sandmann wrote:
> 
> Under the theory that disk seeks are killing us, one idea is to add a
> 'multistat' system call that would allow statting of many files at a
> time, which would give the disk scheduler more to work with. 

Why don't you try this version of your stat-benchmark first?  If you
give it the -s option, it will sort the files by inode number first.
I think you will find this should make a significant difference.

If it works, something that would be really great if someone were to
make a generic library which could be used instead of readdir().  I
have something which works as an LD_PRELOAD, but apparently it's been
blowing up on 64-bit systems, and I haven't had time to debug it.
It's probably better to do it as a library which userspace
applications linked against, anyway.  Would you or someone you know be
interesed in maybe taking this idea and running with it?

Regards,

						- Ted

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