[Ocfs2-devel] [PATCH] xen: cleancache shim to Xen Transcendent Memory

[Ian Campbell]

On Fri, 2011-04-15 at 23:53 +0100, Dan Magenheimer wrote:
> > From: Ian Campbell [mailto:Ian.Campbell at citrix.com]
> > Sent: Friday, April 15, 2011 4:02 PM
> > Subject: Re: [PATCH] xen: cleancache shim to Xen Transcendent Memory
> > 
> > On Thu, 2011-04-14 at 14:20 -0700, Dan Magenheimer wrote:
> > > [PATCH] xen: cleancache shim to Xen Transcendent Memory
> > >
> > > This patch provides a shim between the kernel-internal cleancache
> > > API (see Documentation/mm/cleancache.txt) and the Xen Transcendent
> > > Memory ABI (see http://oss.oracle.com/projects/tmem).
> > 
> > There's no need to build this into a kernel which doesn't have
> > cleancache (or one of the other frontends), is there? I think there
> > should be a Kconfig option (even if its not a user visible one) with
> > the appropriate depends/selects.
> 
> Yes, you're right.  It should eventually depend on
> 
> CONFIG_CLEANCACHE || CONFIG_FRONTSWAP
> 
> though there's no sense merging this xen cleancache
> shim at all unless/until Linus merges cleancache
> (and hopefully later some evolution of frontswap).

Cleancache isn't in already? I thought I saw references to it in
drivers/staging?

> And once cleancache (and/or frontswap) is merged,
> there's very little reason NOT to enable one or
> both on a Xen guest kernel.

There are software knobs to allow the host- and guest-admin to opt in or
out as they desire though, right?

Ian.