From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751265AbVKJHkh (ORCPT ); Thu, 10 Nov 2005 02:40:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751266AbVKJHkh (ORCPT ); Thu, 10 Nov 2005 02:40:37 -0500 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:10925 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S1751265AbVKJHkg (ORCPT ); Thu, 10 Nov 2005 02:40:36 -0500 Message-Id: <437307BC.76F0.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0 Date: Thu, 10 Nov 2005 08:41:32 +0100 From: "Jan Beulich" To: "Greg KH" Cc: Subject: Re: [PATCH 3/39] NLKD - early/late CPU up/down notification References: <43720DAE.76F0.0078.0@novell.com> <43720E2E.76F0.0078.0@novell.com> <43720E72.76F0.0078.0@novell.com> <43720EAF.76F0.0078.0@novell.com> <20051109164544.GB32068@kroah.com> <43723B57.76F0.0078.0@novell.com> <20051109171919.GA32761@kroah.com> In-Reply-To: <20051109171919.GA32761@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>> Greg KH 09.11.05 18:19:19 >>> >On Wed, Nov 09, 2005 at 06:09:27PM +0100, Jan Beulich wrote: >> >>> Greg KH 09.11.05 17:45:44 >>> >> >#ifdef in the .h file is not needed. Please fix your email client to >> >send patches properly. >> >> It's not needed, sure, but by having it there I just wanted to make >> clear that this is something that never can be called from a module >> (after all, why should one find out at modpost time (and maybe even miss >> the message since there are so many past eventual symbol resolution >> warnings) when one can already at compile time. > >If it isn't present, and you do a build, you will still get the error at >build time, just during a different part of it. Adding #ifdef just to >move the error to a different part of the build isn't needed. Remember, >we want to not use #ifdef at all if we can ever help it. I understand that. But you don't see my point, so I'll try to explain the background: When discovering the reason for the kallsyms change (also posted with the other NLKD patches) not functioning with CONFIG_MODVERSIONS and binutils between 2.16.90 and 2.16.91.0.3 I realized that the warning messages from the modpost build stage are very easy to overlook (in fact, all reporters of the problem overlooked them as well as I did on the first build attempting to reproduce the problem). This basically means these messages are almost useless, and detection of the problem will likely be deferred to the first attempt to load an offending module (which, as in the case named, may lead to an unusable kernel). Hence, at least until this build problem gets addressed I continue to believe that adding the preprocessor conditional is the better way of dealing with potential issues. Sure I know that hundreds of other symbols possibly causing the same problem aren't protected... Jan