From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757357AbZBTI2X (ORCPT ); Fri, 20 Feb 2009 03:28:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753960AbZBTI2P (ORCPT ); Fri, 20 Feb 2009 03:28:15 -0500 Received: from cantor.suse.de ([195.135.220.2]:54600 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753798AbZBTI2O (ORCPT ); Fri, 20 Feb 2009 03:28:14 -0500 Subject: Re: [PATCH] x86: remove unneeded endless loop in BUG() From: Petr Tesarik To: "H. Peter Anvin" Cc: Jeremy Fitzhardinge , Ingo Molnar , LKML In-Reply-To: <499DC5A6.1080305@zytor.com> References: <1235068713.15053.99.camel@nathan.suse.cz> <20090219185935.GA21820@elte.hu> <499DB8BA.3050708@zytor.com> <499DC545.2030402@goop.org> <499DC5A6.1080305@zytor.com> Content-Type: text/plain; charset="UTF-8" Organization: SUSE LINUX Date: Fri, 20 Feb 2009 09:28:08 +0100 Message-Id: <1235118488.15053.102.camel@nathan.suse.cz> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org H. Peter Anvin píše v Čt 19. 02. 2009 v 12:48 -0800: > Jeremy Fitzhardinge wrote: > > > > There's no reason to expect an "asm volatile" to stay put; the > > "volatile" has nothing to do with preventing code motion. The only way > > to make an asm stick in one place is with data dependencies, and I'm not > > sure what the dependency for __builtin_trap might be. I'm guessing its > > a "memory" clobber, but that's pure guesswork. > > > > I looked through this with HJL; the bottom line is that although it > probably would work, it's not worth it. > > I submitted GCC bug 39252 to get __builtin_not_reached(); instead. Thank you! I like it this way, too. Petr Tesarik