From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 58184900086 for ; Mon, 18 Apr 2011 12:03:52 -0400 (EDT) Subject: RE: [PATCH] xen: cleancache shim to Xen Transcendent Memory From: Ian Campbell In-Reply-To: <276f7410-ff4d-4a3b-ab9c-fd1b5fe8c952@default> References: <20110414212002.GA27846@ca-server1.us.oracle.com> <1302904935.22658.9.camel@localhost.localdomain> <5d23c6c4-5d68-4c2e-af24-2a08f592cb8e@default 1303116441.5997.107.camel@zakaz.uk.xensource.com> <276f7410-ff4d-4a3b-ab9c-fd1b5fe8c952@default> Content-Type: text/plain; charset="UTF-8" Date: Mon, 18 Apr 2011 17:03:47 +0100 Message-ID: <1303142627.5997.125.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dan Magenheimer Cc: Chris Mason , viro@zeniv.linux.org.uk, akpm@linux-foundation.org, adilger.kernel@dilger.ca, tytso@mit.edu, mfasheh@suse.com, jlbec@evilplan.org, matthew@wil.cx, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-mm@kvack.org, hch@infradead.org, ngupta@vflare.org, jeremy@goop.org, JBeulich@novell.com, Kurt Hackel , npiggin@kernel.dk, Dave Mccracken , riel@redhat.com, avi@redhat.com, Konrad Wilk , mel@csn.ul.ie, yinghan@google.com, gthelen@google.com, torvalds@linux-foundation.org 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org