From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752763AbdKHPYd (ORCPT ); Wed, 8 Nov 2017 10:24:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22042 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752648AbdKHPYc (ORCPT ); Wed, 8 Nov 2017 10:24:32 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5A5555AFC7 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=mst@redhat.com Date: Wed, 8 Nov 2017 17:24:30 +0200 From: "Michael S. Tsirkin" To: Arnd Bergmann Cc: Greg Kroah-Hartman , Philippe Ombredanne , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] virtio_balloon: fix build regression Message-ID: <20171108172156-mutt-send-email-mst@kernel.org> References: <20171108120740.3137853-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171108120740.3137853-1-arnd@arndb.de> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 08 Nov 2017 15:24:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 08, 2017 at 01:07:10PM +0100, Arnd Bergmann wrote: > The new balloon_page_push/balloon_page_pop helpers got added > inside of an #ifdef, causing a build failure when CONFIG_BALLOON_COMPACTION > is disabled: > > drivers/virtio/virtio_balloon.c: In function 'fill_balloon': > drivers/virtio/virtio_balloon.c:164:3: error: implicit declaration of function 'balloon_page_push' > > This adds another empty stub function for the case that > CONFIG_BALLOON_COMPACTION is disabled. > > Fixes: f09517b35de8 ("virtio_balloon: fix deadlock on OOM") > Signed-off-by: Arnd Bergmann > --- > I couldn't easily figure out whether the new functions were indeed > intended to be only used when BALLOON_COMPACTION is enabled, or > whether they should always be there. In case I picked the wrong > one of the two, the answer would obviously be to move the > definitions outside of the #ifdef, or into a different file. Hmm no, I think we actually need these to work. I'll fix it up, thanks for the report. > --- > include/linux/balloon_compaction.h | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h > index 36734ff07213..730b962fd572 100644 > --- a/include/linux/balloon_compaction.h > +++ b/include/linux/balloon_compaction.h > @@ -223,6 +223,15 @@ static inline int balloon_page_migrate(struct page *newpage, > return 0; > } > > +static inline void balloon_page_push(struct list_head *pages, struct page *page) > +{ > +} > + > +static inline struct page *balloon_page_pop(struct list_head *pages) > +{ > + return NULL; > +} > + > static inline gfp_t balloon_mapping_gfp_mask(void) > { > return GFP_HIGHUSER; > -- > 2.9.0