Re: [PATCH RFC] nilfs2: continuous snapshotting file system

[Dave Chinner <david@fromorbit.com>]

On Wed, Aug 20, 2008 at 02:39:16PM -0700, Andrew Morton wrote:
> On Thu, 21 Aug 2008 00:25:55 +0300 (MET DST)
> Szabolcs Szakacsits <szaka@ntfs-3g.org> wrote:
> > I ran compilebench on kernel 2.6.26 with freshly formatted volumes. 
> > The behavior of NILFS2 was interesting.
> > 
> > Its peformance rapidly degrades to the lowest ever measured level 
> > (< 1 MB/s) but after a while it recovers and gives consistent numbers.
> > However it's still very far from the current unstable btrfs performance. 
> > The results are reproducible.
> > 
> >                     MB/s    Runtime (s)
> >                    -----    -----------
> >   btrfs unstable   17.09        572
> >   ext3             13.24        877
> >   btrfs 0.16       12.33        793
> >   nilfs2 2nd+ runs 11.29        674
> >   ntfs-3g           8.55        865
> >   reiserfs          8.38        966
> >   nilfs2 1st run    4.95       3800
> >   xfs               1.88       3901
> 
> err, what the heck happened to xfs?  Is this usual?

No, definitely not usual. I suspect it's from an old mkfs and
barriers being used.  What is the output of the xfs.mkfs when
you make the filesystem and what mount options being used?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com