Re: XFS Fails Quality Assurance Tests on ARM

[David Chinner <dgc@sgi.com>]

On Fri, Sep 28, 2007 at 07:40:48AM +1000, Nick Piggin wrote:
> On Sunday 02 September 2007 08:14, Andi Kleen wrote:
> > David Miller <davem@davemloft.net> writes:
> > > From: Byron Bradley <byron.bbradley@gmail.com>
> > > Date: Fri, 31 Aug 2007 03:12:46 +0000 (UTC)
> > > > Anybody got any ideas of how we fix this?
> > >
> > > I don't know how much testing XFS gets on ARM, but one thing that some
> > > ARM chips have is D-cache aliasing problems and one thing XFS uses a
> > > lot is virtual remapping of various data structures via vmap().
> > >
> > > This might be what is causing the problems.
> >
> > AFAIK XFS uses vmap() mainly during log replay. If David's theory
> > was true then the failures must be seen during tests that do
> > this.
> 
> I think it can also do vmap for directory lookups, and it crashed
> in some directory lookup AFAIKS.
> 
> One way to verify would be to create the XFS filesystem with PAGE_SIZE
> directory blocks (mkfs.xfs -nsize=PAGE_SIZE) I believe. Dave will correct
> me if I'm wrong.

By default the directory block size is the same as the filesystem
block size which means it will be <= PAGE_SIZE unless some
special mkfs.xfs goo was used. What is the output of 'xfs_info <mntpt>'
on the machine in question?

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group