On Fri, May 24, 2013 at 08:30:16AM +0100, James Dingwall wrote:
> Konrad Rzeszutek Wilk wrote:
> >On Thu, May 02, 2013 at 09:24:51AM +0100, James Dingwall wrote:
> >>Dave Chinner wrote:
> >>>On Wed, May 01, 2013 at 11:20:44AM -0500, Ben Myers wrote:
> >>>>Hi James,
> >Hey folks,
> >I am walking through my vacation-emails-mbox.
> >>>>On Wed, May 01, 2013 at 01:39:09PM +0100, James Dingwall wrote:
> >>>>>In reference to: http://oss.sgi.com/archives/xfs/2012-05/msg00046.html
> >>>>>$ grep -r cleancache fs/xfs
> >>>>>on the 3.9 kernel source suggests that no patch was submitted to
> >>>>>enable cleancache for the XFS filesystem. Since it was suggested
> >>>>>that this could be a one liner I've had a go and my first effort is
> >>>>>inline below. While this seems to compile OK I have no experience
> >>>>>in filesystems so I would appreciate it if anyone can point out that
> >>>>>it is obviously wrong and likely to eat my data before I try booting
> >>>>>the kernel.
> >>>>>If it seems a reasonable attempt what would be the best way to check
> >>>>>that it isn't doing nasty things?
> >>>>Hrm.. Looks like there is a doc in Documentation/vm/cleancache.txt which
> >>>>includes a list of attributes the filesystem needs to have to work
> >>>>with cleancache.
> >>>So, those points are:
> >>I had started to look at these too but I feel very out of my depth!
> >>I had similar conclusions to what Dave wrote but I don't think my
> >>thoughts should carry very much (any) weight. Anyway I gambled and
> >>booted my xen domU with this patch and so far so good... xen top
> >>shows that tmem is now being used where previously it wasn't. I'll
> >>try running the xfstests at the weekend after a couple more days up
> >>time to see what happens.
> >And how did it go?
> I am running the patch I created on 3.9.3 on half of my xen guests
> now and have not noticed any stability or filesystem problems. xl
> top with 'T' shows that the guests running with it are using
> ephemeral pages were those without do not. I did do some runs with
> xfstests which had some failures but they were present with and
> without the patch. The best I can really offer is that it works for
> me, ymmv. The patch is available as commit
> c725011c4fc5d47e12d131f61bd91a58a40036b5 in
> https://github.com/JKDingwall/linux.git xfs-enable-cleancache or in
> the first message of this thread.
I've run this patch on my local tree and it looks to work right. I am
saying "looks" as I am hitting some other issue that I believe are
unralted to the patch - but I need to figure them out before I can
comfortably say: "Yes, this looks right and works for me as well."