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Date: Wed, 2 May 2007 15:28:49 -0400
From: Theodore Tso <tytso@mit.edu>
To: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       "Cabot, Mason B" <mason.b.cabot@intel.com>,
       linux-kernel@vger.kernel.org
Subject: Re: Ext3 vs NTFS performance
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On Wed, May 02, 2007 at 08:40:35PM +0200, Andi Kleen wrote:
> Theodore Tso <tytso@mit.edu> writes:
> 
> > On Wed, May 02, 2007 at 02:21:40PM +0200, Andi Kleen wrote:
> > > Andrew Morton <akpm@linux-foundation.org> writes:
> > > > 
> > > > Conceivably we could address this in the filesystem without mucking other
> > > > things up.  But I'd have thought the simplest damage-control would be to
> > > > detect this pattern in samba and to then use glibc's fallocate().
> > > 
> > > The advantage of detecting it in kernel would be that it would handle
> > > Linux applications that do this (I suspect there are some) too.
> > 
> > Um, which applications do you suspect?  So we can hunt down those user
> > space applications programmers and slap them silly?  Or rather,
> > unsilly, since that there's no good reason to ever suspect that
> > writing a byte every 128k would result in a good allocation layout on disk?
> 
> Anything that uses glibc fallocate() ?

Glibc's fallocate current writes all zeros, not 1 byte every
128kbytes.  And once we wire up the new sys_fallocate() support, we'll
have the right preallocation support in ext4.

					- Ted
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