Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755260Ab2BFRWj (ORCPT ); Mon, 6 Feb 2012 12:22:39 -0500 Received: from acsinet15.oracle.com ([141.146.126.227]:25198 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754464Ab2BFRWi convert rfc822-to-8bit (ORCPT ); Mon, 6 Feb 2012 12:22:38 -0500 MIME-Version: 1.0 Message-ID: <69f22464-d460-450c-a81b-77bda8cc7568@default> Date: Mon, 6 Feb 2012 09:22:26 -0800 (PST) From: Dan Magenheimer To: Konrad Wilk , Jan Beulich Cc: Jeremy Fitzhardinge , xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org Subject: RE: [PATCH] xen/tmem: cleanup References: <4F2C06A00200007800071071@nat28.tlf.novell.com> <4F2F998202000078000714CD@nat28.tlf.novell.com> <4F3012B602000078000716AB@nat28.tlf.novell.com> <20120206170224.GD23240@phenom.dumpdata.com> In-Reply-To: <20120206170224.GD23240@phenom.dumpdata.com> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 2.0.1.6 (510070) [OL 12.0.6607.1000 (x86)] Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090209.4F300C55.00C4,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2844 Lines: 66 > From: Konrad Rzeszutek Wilk > Subject: Re: [PATCH] xen/tmem: cleanup > > On Mon, Feb 06, 2012 at 04:49:42PM +0000, Jan Beulich wrote: > > >>> On 06.02.12 at 17:37, Dan Magenheimer wrote: > > >> From: Jan Beulich [mailto:JBeulich@suse.com] > > >> Sent: Monday, February 06, 2012 1:13 AM > > >> To: Dan Magenheimer > > >> Cc: Jeremy Fitzhardinge; xen-devel@lists.xensource.com; Konrad Wilk; > > > linux-kernel@vger.kernel.org > > >> Subject: RE: [PATCH] xen/tmem: cleanup > > >> > > >> >>> On 04.02.12 at 17:42, Dan Magenheimer wrote: > > >> >> From: Jan Beulich [mailto:JBeulich@suse.com] > > >> >> Subject: [PATCH] xen/tmem: cleanup > > >> >> > > >> >> Use 'bool' for boolean variables. Do proper section placement. > > >> >> Eliminate an unnecessary export. > > >> >> > > >> >> Signed-off-by: Jan Beulich > > >> >> Cc: Dan Magenheimer > > >> >> > > >> >> -int tmem_enabled __read_mostly; > > >> >> -EXPORT_SYMBOL(tmem_enabled); > > >> >> +bool __read_mostly tmem_enabled = false; > > >> > > > >> > tmem_enabled is used in xen/drivers/xen-selfballoon.c > > >> > > >> Which can't be built as a module, and hence the symbol doesn't need > > >> exporting. This patch (of course, I'm tempted to say) survived build > > >> testing. > > > > > > Yes, correct. BUT... I think only the reason xen-selfballoon.c > > > can't be built as a module is because the MM variable vm_committed_as > > > (or an access function) is not exported. Ideally xen-selfballoon.c > > > probably should be a module but putting a core MM change in > > > the critical path of a Xen-only-related enhancement seemed > > > a recipe for sure failure. > > > > No, this isn't the main reason (as you say further down, this could > > easily be adjusted for) afaict. The main reason is that > > register_xen_selfballooning() is being called from non-modular > > code (xen-balloon.c), which could be made a module too, but in > > turn has at least one reference that wouldn't be nice to become > > an export (balloon_set_new_target()). Jan, you're right, I had forgotten about that "chained" dependency. Thanks and FWIW, on the entire original patch: Acked-by: Dan Magenheimer > It would be nice if all of it could become modules. That way HVM > device driver domains could load the whole thing without having much > built-in code in the kernel. > > Is it possible to do that? Konrad, my module expertise is very low, so I will leave that to Jan or someone else to answer or look into. Dan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/