[Top] [All Lists]

Re: xfs performance problem

To: xfs@xxxxxxxxxxx
Subject: Re: xfs performance problem
From: Martin Steigerwald <Martin@xxxxxxxxxxxx>
Date: Fri, 29 Apr 2011 18:27:34 +0200
In-reply-to: <20110427023534.GF12436@dastard>
References: <4DB72084.8020205@xxxxxxxxxxx> <20110427023534.GF12436@dastard> (sfid-20110427_093124_345457_AD005F79)
User-agent: KMail/1.13.7 (Linux/; KDE/4.6.2; i686; ; )
Am Mittwoch, 27. April 2011 schrieb Dave Chinner:
> On Tue, Apr 26, 2011 at 09:44:04PM +0200, Benjamin Schindler wrote:
> > Hi
> > 
> > Since upgrading to newer kernels I have serious problems with xfs
> > performance on my root fs.
> > It runs on a software raid 0 with 2 disks. On the same two disks,
> > there are two more partitions running a software raid-1 with ext3.
> > On the ext3 system, I have no issue, so I assume the drives are
> > fine.
> > But on the xfs filesystem, extracting a linux kernel archive takes 5
> > minutes or more, running ldconfig similarily long. The harddrives are
> > sata-2.
> > I'm running gentoo linux with kernel 2.6.38-gentoo-r1. I'm attaching
> > the kernel config but I guess more info is needed - just let me know
> > what is needed.
> more than likely your problem is that barriers have been enabled for
> MD/DM devices on the new kernel, and they aren't on the old kernel.
> XFS uses barriers by default, ext3 does not. Hence XFS performance
> will change while ext3 will not. Check dmesg output when mounting
> the filesystems on the different kernels.

But didn't 2.6.38 replace barriers by explicit flushes the filesystem has to 
wait for - mitigating most of the performance problems with barriers?

Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

<Prev in Thread] Current Thread [Next in Thread>