From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757473AbaCRSVx (ORCPT ); Tue, 18 Mar 2014 14:21:53 -0400 Received: from www.linutronix.de ([62.245.132.108]:56322 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753109AbaCRSVv (ORCPT ); Tue, 18 Mar 2014 14:21:51 -0400 Date: Tue, 18 Mar 2014 19:21:56 +0100 (CET) From: Thomas Gleixner To: Vince Weaver cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ingo Molnar Subject: Re: rb tree hrtimer lockup bug (found by perf_fuzzer) In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) 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 Tue, 18 Mar 2014, Vince Weaver wrote: > > The perf_fuzzer can quickly cause a machine to lockup with an hrtimer > related rb tree related oops. I've had a hard time debugging this in any > useful manner, but I can trigger it on both core2 and haswell test systems > on 3.14-rc7. > > This involves making a large number of perf_event events of all types and > then forking a lot. Can you enable debugobjects please? The should give us an hint what corrupts the rbtree. Thanks, tglx