Re: [PATCH 5/7] XFS: Unicode case-insensitive lookup implementation

[Jeremy Allison <jra@samba.org>]

On Thu, Apr 03, 2008 at 01:11:42PM -0500, Eric Sandeen wrote:
> Jeremy Allison wrote:
> > On Thu, Apr 03, 2008 at 01:14:50PM -0400, Christoph Hellwig wrote:
> >> Validating file names is not the filesystem job.  In fact it's utterly
> >> stupid, a unix filename is a sequence of bytes without special meaning
> >> except for ., .., / and \0
> > 
> > This patch will be extremely useful for users who are serving
> > Windows clients using Samba. It allow admins to turn off the
> > userspace case insensitivity we have to emulate and be a significant
> > speed increase.
> 
> I'd like to see the numbers... Simo tested an earlier version of this
> patch, and it was not faster.... Jeremy, what would be a representative
> test setup to use?

It very much depends on the usage case. We have many users who have
large numbers of files per directory, and not having to search these
in userspace when we get a stat cache miss is helpful. Just running a
generic "netbench" test won't show any difference, as that test
uses separate directories for each client with small numbers of
files per directory.

There's a reason I wrote this HOWTO (having to use an alternate
link as samba.org seems to be down right now):

http://man.chinaunix.net/newsoft/samba/docs/man/Samba-HOWTO-Collection/largefile.html

Jeremy.