From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755925AbYLLLbx (ORCPT ); Fri, 12 Dec 2008 06:31:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752390AbYLLLbm (ORCPT ); Fri, 12 Dec 2008 06:31:42 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:51115 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755875AbYLLLbl (ORCPT ); Fri, 12 Dec 2008 06:31:41 -0500 Date: Fri, 12 Dec 2008 12:31:26 +0100 From: Ingo Molnar To: Steven Rostedt Cc: =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Linux Kernel Subject: Re: [crash] Re: [PATCH 1/3] tracing/function-graph-tracer: introduce __notrace_funcgraph to filter special functions Message-ID: <20081212113126.GG32640@elte.hu> References: <4939E600.804@gmail.com> <20081208141406.GA14856@elte.hu> <20081208155018.GB405@elte.hu> <20081209023822.GA3602@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > > On Tue, 9 Dec 2008, Fr?d?ric Weisbecker wrote: > > 2008/12/9 Fr?d?ric Weisbecker : > > > > > > I built this config on an smp x86-64 and booted several times (and > > tested the function tracer manually) with and without the following > > options: > > > > initcall_debug apic=verbose sysrq_always_enabled ignore_loglevel > > selinux=0 nmi_watchdog=2 idle=poll > > > > And I can't reproduce this bug.... That might be a very nasty race condition... > > Neither can I :-( > > Ingo, is this on the box that stresses NMIs? yes. You could try to inject even more NMIs than i normally do, artificially, by picking up tip/master and running KernelTop with a 100,000 cycles IRQ interval: http://redhat.com/~mingo/perfcounters/kerneltop.c run it like this: ./kerneltop -c 100000 and run an infinite loop per process: while :; do :; done & to get the NMIs going intensely: ------------------------------------------------------------------------------ KernelTop: 115437 irqs/sec [NMI, 100000 cycles], (all, 16 CPUs) ------------------------------------------------------------------------------ events RIP kernel function ______ ______ ________________ _______________ 81224.00 - ffffffffff6001a4 : vread_hpet 3119.00 - ffffffff8027cf99 : perf_read 2484.00 - ffffffff802227d5 : read_hpet 1157.00 - ffffffff8056b69a : mutex_lock 1041.00 - ffffffffff600000 : vgettimeofday 986.00 - ffffffff80333db5 : avc_has_perm_noaudit 896.00 - ffffffff8026be2d : audit_syscall_exit 653.00 - ffffffff8056c8f5 : _spin_lock 577.00 - ffffffff802ecd14 : dnotify_parent 528.00 - ffffffff8033679c : file_has_perm 489.00 - ffffffff802bc060 : dput 470.00 - ffffffff8026c366 : audit_syscall_entry Ingo