On Fri, Aug 07, 2009 at 08:56:52AM -0500, Steven Pratt wrote:

Chris Mason wrote:

quoted

On Tue, Jul 28, 2009 at 04:10:41PM -0500, Steven Pratt wrote:

quoted

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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.

quoted

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