From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263747AbTKRRNx (ORCPT ); Tue, 18 Nov 2003 12:13:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263740AbTKRRNw (ORCPT ); Tue, 18 Nov 2003 12:13:52 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.105]:40166 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S263726AbTKRRNv (ORCPT ); Tue, 18 Nov 2003 12:13:51 -0500 Date: Tue, 18 Nov 2003 09:38:32 -0800 From: "Martin J. Bligh" To: Zwane Mwaikambo , Linus Torvalds cc: Ingo Molnar , Andrew Morton , Linux Kernel , linux-mm@kvack.org, Hugh Dickins Subject: Re: [PATCH][2.6-mm] Fix 4G/4G X11/vm86 oops Message-ID: <149480000.1069177112@flay> In-Reply-To: References: X-Mailer: Mulberry/2.1.2 (Linux/x86) 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 >> Btw, you seem to compile with debugging, which makes the assembly >> language pretty much unreadable and accounts for most of the >> differences: the line numbers change. If you compile a kernel where the >> line numbers don't change (by commenting _out_ the printk rather than >> removing the whole line), your diff would be more readable. > > Aha! Thanks for mentioning that, noted. > >> Anyway, there are _zero_ differences. >> >> Just for fun, try this: move the "printk()" to _below_ the "asm" >> statement. It will never actually get executed, but if it's an issue of >> some subtle code or data placement things (cache lines etc), maybe that >> also hides the oops, since all the same code and data will be generated, >> just not run... > > Ok i just tried that and it still fails. Matt Mackall suggested i also try > writing a minimal printk which has the same effect. The other thing I've found printks to hide before is timing bugs / races. Unfortunately I can't see one here, but maybe someone else can ;-) Maybe inserting a 1ms delay or something in place of the printk would have the same effect? M.