From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [GIT PULL] Ceph updates for 4.7-rc1 Date: Mon, 13 Jun 2016 15:06:51 +0200 Message-ID: <6717851.ptlac7jbfE@wuerfel> References: <3724610.gtEplKGO6B@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.126.133]:55186 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422821AbcFMNFf (ORCPT ); Mon, 13 Jun 2016 09:05:35 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Linus Torvalds Cc: Sage Weil , Linux Kernel Mailing List , ceph-devel , Ilya Dryomov On Friday, June 10, 2016 2:32:21 PM CEST Linus Torvalds wrote: > On Fri, Jun 10, 2016 at 1:42 PM, Arnd Bergmann wrote: > > > > What I see is that this one exported symbol has a __crc of a different > > type from all the others: > > > > $ nm net/ceph/mon_client.o | grep __crc > > 48c2e16e A __crc_ceph_monc_get_version > > 2360d633 A __crc_ceph_monc_get_version_async > > 0c50a10a A __crc_ceph_monc_got_map > > w __crc_ceph_monc_do_statfs > > A lower-case 'w' in a symbol list just means that it's a local weak > symbol (with a upper-case 'A' meaning it's an absolute global). > > Afaik, that simply means that it never got resolved, and genksyms > never generated that absolute value for it. > > As to _why_ that happens, that's more than I can guess. We've had > problems with genksyms before, and it tends to be hard to debug. > > Is it 100% reliable for you? Because the most common problem has been > issues with subtle build races, where just causing a re-build will fix > it. > > Your config doesn't work for me, when I do > > cp ~/genksyms-config.txt .config > make ARCH=i386 oldconfig > > I get something else than what you had. I tried with both current -git > and the commit you pinpointed, so I don't know how you generated that > config file.. I've tracked it down to the use of the 'typeof(((type *)0)->keyfld)' expression in DEFINE_RB_LOOKUP() now, and sent a patch with subject "ceph: fix symbol versioning for ceph_monc_do_statfs" that works around it by rewriting that line in a way that genksyms understands. Arnd