From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967020AbcA1Ut4 (ORCPT ); Thu, 28 Jan 2016 15:49:56 -0500 Received: from www.linutronix.de ([62.245.132.108]:36286 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965691AbcA1UtV (ORCPT ); Thu, 28 Jan 2016 15:49:21 -0500 Date: Thu, 28 Jan 2016 21:48:13 +0100 (CET) From: Thomas Gleixner To: Jeffrey Merkey cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dzickus@redhat.com, uobergfe@redhat.com, atomlin@redhat.com, mhocko@suse.cz, fweisbec@gmail.com, tj@kernel.org, hidehiro.kawai.ez@hitachi.com, cmetcalf@ezchip.com Subject: Re: [PATCH 01/31] Add hard/soft lockup debugger entry points In-Reply-To: Message-ID: References: <1454010366-28416-1-git-send-email-jeffmerkey@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Jan 2016, Jeffrey Merkey wrote: > On 1/28/16, Thomas Gleixner wrote: > > I'm probably missing something obvious here. > > It's a pain in the butt to grep around through assembly language in a > function in watchdog.c that has everything declared static with no > symbols. It's a lot easier just to insert an INT3 in the section of > code that has the mouse caught in the trap (inside a function that > triggers the hard lockup) -- after all -- that's what the instruction > is for. AFAICT, debuggers can set breakpoints on arbitrary code lines without grepping through assembly language. If you don't have the debug information available, then using a debugger is pointless anyway. This is beyond silly. If we follow your argumentation we need another gazillion of conditional breakpoints in the kernel. Definitely not. Thanks, tglx