Re: filesystem benchmarking fun

[Chris Mason <chris.mason@oracle.com>]

On Wed, May 16, 2007 at 08:12:09PM +0200, Jan Engelhardt wrote:
> 
> On May 16 2007 10:42, Chris Mason wrote:
> >
> >For example, I'll pick on xfs for a minute.  compilebench shows the
> >default FS you get from mkfs.xfs is pretty slow for untarring a bunch of
> >kernel trees.
> 
> I suppose you used 'nobarrier'? [ http://lkml.org/lkml/2006/5/19/33 ]

Oddly, xfs fails barriers on this sata drive although the other filesystems
don't.  But yes, I tried both ways.

> 
> >Dave Chinner gave me some mount options that make it
> >dramatically better,
> 
> and `mkfs.xfs -l version=2` is also said to make it better

I used mkfs.xfs -l size=128m,version=2
mount -o logbsize=256k,nobarrier 

> 
> >but it still writes at 10MB/s on a sata drive that
> >can do 80MB/s.  Ext3 is better, but still only 20MB/s. 
> >
> >Both are presumably picking a reasonable file and directory layout.
> >Still, our writeback algorithms are clearly not optimized for this kind
> >of workload.  Should we fix it?
> 
> Also try with tmpfs.
> 
Sorry, I'm not entirely clear on what we learn from trying tmpfs?

-chris