From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: linux-next: block tree build failure Date: Fri, 4 Dec 2009 14:54:22 +0100 Message-ID: <20091204135422.GZ8742@kernel.dk> References: <20091204143612.f30db275.sfr@canb.auug.org.au> <20091204074341.GH8742@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:36120 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823AbZLDNyQ (ORCPT ); Fri, 4 Dec 2009 08:54:16 -0500 Content-Disposition: inline In-Reply-To: <20091204074341.GH8742@kernel.dk> Sender: linux-next-owner@vger.kernel.org List-ID: To: Stephen Rothwell Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Vivek Goyal On Fri, Dec 04 2009, Jens Axboe wrote: > On Fri, Dec 04 2009, Stephen Rothwell wrote: > > Hi Jens, > > > > Today's linux-next build (x86_64 allmodconfig) failed like this: > > > > block/built-in.o: In function `blkiocg_destroy': > > blk-cgroup.c:(.text+0x1bd48): undefined reference to `cfq_unlink_blkio_group' > > block/built-in.o: In function `blkiocg_weight_write': > > blk-cgroup.c:(.text+0x1c0d2): undefined reference to `cfq_update_blkio_group_weight' > > > > Caused by commits b1c3576961847da26c91b1e97f226bb66be5fa3f ("blkio: Take > > care of cgroup deletion and cfq group reference counting") and > > f8d461d692c341add957fb973fb5ee1f62039dc7 ("blkio: Propagate cgroup weight > > updation to cfq groups"). > > > > When adding code that is CONFIG dependent, please build test it with and > > without the relevant CONFIG setting (in this case > > CONFIG_CFQ_GROUP_IOSCHED). Also put the extern declarations of global > > functions into a header file. > > The problem looks like a circular dependency betwen BLK_CGROUP and CFQ. > The Kconfig dependencies doesn't express that blk-cgroup also calls into > cfq, so you can't have cfq=m (cfq doesn't even export those functions). > It looks pretty messy, to be honest. I'll see if I can fix it up. I pushed out the quick fix, just disallowing cfq=m and blk cgroup in Kconfig. So it should work now. -- Jens Axboe