Messages in this thread | | | Subject | RE: [PATCH] xen: cleancache shim to Xen Transcendent Memory | From | Ian Campbell <> | Date | Mon, 18 Apr 2011 17:03:47 +0100 |
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On Mon, 2011-04-18 at 07:12 -0700, Dan Magenheimer wrote: > > From: Ian Campbell [mailto:Ian.Campbell@eu.citrix.com] > > > > > > > > On Thu, 2011-04-14 at 14:20 -0700, Dan Magenheimer wrote: > > > > > > > > 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? > > Linus said he would review it after 2.6.39-rc1 was released, > but has neither given thumbs up nor thumbs down so I'm > assuming he didn't have time and it will be reconsidered > for 2.6.40. This latest patchset (V8) is updated in linux-next. > > Yes, zcache is in driver/staging and has references to it. > I guess that proves the chicken comes before the egg... > or was it vice versa? :-)
Ah, I didn't realise that the relaxations associated with staging allowed for unsatisfiable (due to the other half being out of tree) Kconfig items as well.
> > > 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? > > Definitely. Both Xen and a Linux guest have runtime > options, which currently default to off.
Good to know, thanks!
Ian.
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