From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932255AbVKJXS7 (ORCPT ); Thu, 10 Nov 2005 18:18:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932254AbVKJXS7 (ORCPT ); Thu, 10 Nov 2005 18:18:59 -0500 Received: from mail.kroah.org ([69.55.234.183]:53671 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S932253AbVKJXS6 (ORCPT ); Thu, 10 Nov 2005 18:18:58 -0500 Date: Thu, 10 Nov 2005 15:01:26 -0800 From: Greg KH To: Jan Beulich Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/39] NLKD - early/late CPU up/down notification Message-ID: <20051110230126.GA5381@kroah.com> 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> <437307BC.76F0.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <437307BC.76F0.0078.0@novell.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 10, 2005 at 08:41:32AM +0100, Jan Beulich wrote: > >>> 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). When you try to load the module, you will get the error again, right in your kernel/system log, which explicitly shows that you had a 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... Don't try to do things to fix your prior problems in your patch, with changes today so that you don't do it again in the future :) The build process properly notifies the builder of the problem, if they ignore it, there's really nothing more we can do about it, right? thanks, greg k-h