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From: Eric Sandeen <sandeen@redhat.com>
To: linux-ext4@vger.kernel.org
Subject: Re: ext4 unlink performance
Date: Sat, 15 Nov 2008 17:08:09 -0600	[thread overview]
Message-ID: <491F5659.7010206@redhat.com> (raw)
In-Reply-To: <20081115204423.GA4671@untroubled.org>

Bruce Guenter wrote:
> On Fri, Nov 14, 2008 at 09:59:14AM -0500, Theodore Tso wrote:
>> This is beginning to perhaps sound like a layout problem of some kind.
> 
> To test this theory, I ran one test where I populated the filesystem
> with ext3 and then mounted as ext4 to do the unlinking.  This produced
> unlink times comparable with ext3.  That is, the degredation is occuring
> when the filesystem is populated, not when it is cleaned.

Maybe run the unlinking activity through seekwatcher* in both cases, to
see where the IO is happening.

(also, you're right w.r.t. lvm/dm; barriers don't pass and should get
disabled after the first attempt at a barrier write).

-Eric

*http://oss.oracle.com/~mason/seekwatcher/ (also packaged for fedora,
maybe other distros as well)

  reply	other threads:[~2008-11-15 23:08 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-13 18:57 ext4 unlink performance Bruce Guenter
2008-11-13 19:10 ` Bruce Guenter
2008-11-13 20:42   ` Theodore Tso
2008-11-14  4:11     ` Bruce Guenter
2008-11-14 14:59       ` Theodore Tso
2008-11-14 15:48         ` Bruce Guenter
2008-11-14 15:54           ` Theodore Tso
2008-11-15 20:44         ` Bruce Guenter
2008-11-15 23:08           ` Eric Sandeen [this message]
2008-11-16  0:56           ` Theodore Tso
2008-11-16  3:38             ` Bruce Guenter
2008-11-17  0:43             ` Andreas Dilger
     [not found]               ` <20081119024021.GA10185@mit.edu>
2008-11-19 18:10                 ` Andreas Dilger
2008-11-19 21:18                   ` Theodore Tso
2008-11-20 22:49                     ` Bruce Guenter
2008-11-13 19:46 ` Theodore Tso
2008-11-13 20:27   ` Bruce Guenter

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