From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Mason <chris.mason@oracle.com>
Subject: Re: Updated performance results
Date: Fri, 7 Aug 2009 19:12:40 -0400
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Cc: linux-btrfs <linux-btrfs@vger.kernel.org>
To: Steven Pratt <slpratt@austin.ibm.com>
Return-path: <linux-btrfs-owner@vger.kernel.org>
In-Reply-To: <4A7C32A4.9070106@austin.ibm.com>
List-ID: <linux-btrfs.vger.kernel.org>

On Fri, Aug 07, 2009 at 08:56:52AM -0500, Steven Pratt wrote:
> Chris Mason wrote:
> >On Tue, Jul 28, 2009 at 04:10:41PM -0500, Steven Pratt wrote:
> >>>Hi Steve,
> >>>
> >>>I think I'm going to start tuning something other than the
> >>>random-writes, there is definitely low hanging fruit in the large file
> >>>creates workload ;)  Thanks again for posting all of these.
> >>Sure, no problem.
> >>
> >>>The history graph has 2.6.31-rc btrfs against 2.6.29-rc ext4.  Have you
> >>>done more recent runs on ext4?
> >>>
> >>Yes, thanks for pointing that out, had so many issues I forgot to
> >>update the graphs for other file systems.  Just pushed new graphs
> >>with data for 2.6.30-rc7 for all the other file systems.  This was
> >>from your "newformat" branch from June 6th.
> >
> >I've been tuning the 128 thread large file streaming writes, and found
> >some easy optimizations.  While I'm fixing up these patches, could you
> >please do a streaming O_DIRECT write test run for me?  I think buffered
> >writeback in general has some problems right now on high end arrays.
> >
> >On my box 2.6.31-rc5 streaming buffered write with xfs only got at
> >200MB/s (with the 128 thread ffsb workload).  Buffered btrfs goes at
> >175MB/s.
> >
> >O_DIRECT btrfs runs at 390MB/s, while XFS varies a bit between 330MB/s
> >and 250MB/s.
> >
> >I'm using a 1MB write blocksize.
> On my todo list, but am swamped this week trying to get ready for
> vacation.  Will try to get to it as soon as I can.

Ok, I've pushed out a very raw version of my buffered write fixes to
a new branch named performance on btrfs-unstable.

Please try this with the streaming large file create workload.  I'm also
curious to see if it improves on your box when you mount with

mount -o thread_pool=128

-chris