From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932751AbYEGHpF (ORCPT ); Wed, 7 May 2008 03:45:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759314AbYEGHop (ORCPT ); Wed, 7 May 2008 03:44:45 -0400 Received: from www.tglx.de ([62.245.132.106]:50063 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753295AbYEGHon (ORCPT ); Wed, 7 May 2008 03:44:43 -0400 Date: Wed, 7 May 2008 09:43:51 +0200 (CEST) From: Thomas Gleixner To: Jan Beulich cc: odie@cs.aau.dk, Ingo Molnar , Jeremy Fitzhardinge , Chuck Ebbert , linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: Please revert 709f744 (x86: bitops asm constraint fixes) In-Reply-To: <482175EF.76E4.0078.0@novell.com> Message-ID: References: <1209995129.5172.19.camel@odie.local> <20080506120155.GG32591@elte.hu> <482175EF.76E4.0078.0@novell.com> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 May 2008, Jan Beulich wrote: > >>> Ingo Molnar 06.05.08 14:01 >>> > >Jan, any ideas what's wrong with your commit? > > No, I have no idea at all (apart from considering mis-compilation as you > did. The best path I could suggest is to try and nail this down to one > (or more, if that happens to be the case) function(s) having been > changed - this is mostly because part of the changes are really > tightening things (which therefore I would think ought to be kept), > while the change to __test_and_change_bit() really weakens things > (which I nevertheless continue to think is correct and consistent with > other functions, but which then would be the primary suspect). Of > course, since no-one else has seen this so far, this would need to be > done by Simon. > Once down to a single (hopefully) function, it might be possible to just > statically compare the two vmlinux-es to perhaps spot whether this > indeed is mis-compilation. Jan, can you please provide a step by step conversion of those constraints on top of the revert. I'm a bit wary about this whole business as such constraint problems might hit us elsewhere as well. Thanks, tglx