Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755480Ab2BFQtv (ORCPT ); Mon, 6 Feb 2012 11:49:51 -0500 Received: from nat28.tlf.novell.com ([130.57.49.28]:32016 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755337Ab2BFQtu convert rfc822-to-8bit (ORCPT ); Mon, 6 Feb 2012 11:49:50 -0500 Message-Id: <4F3012B602000078000716AB@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.0 Date: Mon, 06 Feb 2012 16:49:42 +0000 From: "Jan Beulich" To: "Dan Magenheimer" Cc: "Jeremy Fitzhardinge" , , "Konrad Wilk" , Subject: RE: [PATCH] xen/tmem: cleanup References: <4F2C06A00200007800071071@nat28.tlf.novell.com> <4F2F998202000078000714CD@nat28.tlf.novell.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2390 Lines: 60 >>> 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 > Konrad, if you (1) disagree entirely, or (2) want to remove the > tmem_enabled EXPORT_SYMBOL now and add it back later if/when > the core MM change happens, I'll leave that up to you. > > If (2), the MM change should be added to the minor-tmem-related- > changes-that-need-to-be-eventually-upstreamed list ;-) > > 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/