From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752403Ab0DLC4g (ORCPT ); Sun, 11 Apr 2010 22:56:36 -0400 Received: from xenotime.net ([72.52.64.118]:54113 "HELO xenotime.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751184Ab0DLC4e (ORCPT ); Sun, 11 Apr 2010 22:56:34 -0400 Message-ID: <33355.71.245.98.113.1271040992.squirrel@www.xenotime.net> In-Reply-To: References: <20100411164701.GA7558@elf.ucw.cz> <20100412185136.GA13171@x200> <20100411201426.GC25294@elf.ucw.cz> Date: Sun, 11 Apr 2010 19:56:32 -0700 (PDT) Subject: Re: LOCALVERSION_AUTO considered harmful From: rdunlap@xenotime.net To: "Thomas Gleixner" Cc: "Pavel Machek" , "Geert Uytterhoeven" , "Alexey Dobriyan" , "kernel list" , "Linus Torvalds" , "Andrew Morton" User-Agent: SquirrelMail/1.5.1 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, April 11, 2010 3:24 pm, Thomas Gleixner wrote: > On Sun, 11 Apr 2010, Pavel Machek wrote: > > >> On Sun 2010-04-11 20:58:58, Geert Uytterhoeven wrote: >> >>> On Mon, Apr 12, 2010 at 20:51, Alexey Dobriyan >>> wrote: >>> >>>> On Sun, Apr 11, 2010 at 06:47:01PM +0200, Pavel Machek wrote: >>>> >>>>> @@ -99,6 +98,11 @@ config LOCALVERSION_AUTO >>>>>         appended after any matching localversion* files, and after >>>>> the value         set in CONFIG_LOCALVERSION. >>>>> >>>>> >>>>> +       Unfortunately, such finegrained versioning will mean that >>>>> you will +       not be able to use modules for development; even >>>>> "make modules" >>>>> +       will change module versions, making recompiled modules >>>>> impossible +       to insert into old kernel. >>>>> >>>> >>>> That's conditional BS. >>>> Turn off CONFIG_MODVERSIONS already. >>>> >>> >>> Yeah, I disabled it ages ago. Even then (before git, probably even >>> before bitkeeper) I had hard times inserting modules... >>> >> >> I _had_ it off >> >> >> # CONFIG_MODVERSIONS is not set >> >> >> It seems some checking survives CONFIG_MODVERSIONS unset and that >> checking is strict enough to refuse module load after one "make modules" >> with LOCALVERSION_AUTO on... > > So instead of fixing the CONFIG_MODVERSIONS=n case you go the easy way > of killing LOCALVERSION_AUTO ? Brilliant. Pavel's original example (afaik) was on April 5: Subject: 2.6.34-rc3: Can't insmod after make, because versions now differ?! Apr 5 07:33:16 amd kernel: udlfb: version magic '2.6.34-rc3-00345-ge8240f9-dirty SMP mod_unload CORE2 ' should be '2.6.34-rc3-00344-g548fc0a-dirty SMP mod_unload CORE2 ' So what do you suggest? If the "magic" strings contain "-dirty ", then ignore that and the 2 preceding hyphen-separated fields? That could be dangerous if some kernel internal structures have changed. I.e., user/developer beware. Maybe ignore those strings iff some override has been set somewhere? --- ~Randy