Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758059Ab3GMBjj (ORCPT ); Fri, 12 Jul 2013 21:39:39 -0400 Received: from smtpauth05.mfg.siteprotect.com ([64.26.60.144]:48287 "EHLO smtpauth05.mfg.siteprotect.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757998Ab3GMBji (ORCPT ); Fri, 12 Jul 2013 21:39:38 -0400 Date: Fri, 12 Jul 2013 21:40:19 -0400 (EDT) From: Vince Weaver X-X-Sender: vince@pianoman.cluster.toy To: Dave Jones cc: Dave Hansen , Ingo Molnar , Markus Trippelsdorf , Thomas Gleixner , Linus Torvalds , Linux Kernel , Peter Anvin , Peter Zijlstra , Dave Hansen Subject: Re: Yet more softlockups. In-Reply-To: <20130712154521.GD1020@redhat.com> Message-ID: References: <20130705143821.GB325@redhat.com> <20130705160043.GF325@redhat.com> <20130706072408.GA14865@gmail.com> <20130710151324.GA11309@redhat.com> <20130710152015.GA757@x4> <20130710154029.GB11309@redhat.com> <20130712103117.GA14862@gmail.com> <51E0230C.9010509@intel.com> <20130712154521.GD1020@redhat.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-CTCH-Spam: Unknown X-CTCH-RefID: str=0001.0A020207.51E0AFD9.00E0,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1033 Lines: 33 On Fri, 12 Jul 2013, Dave Jones wrote: > > Here's a fun trick: > > trinity -c perf_event_open -C4 -q -l off > > Within about a minute, that brings any of my boxes to its knees. > The softlockup detector starts going nuts, and then the box wedges solid. are you running with the patch [PATCH 1/2] perf: Clone child context from parent context pmu https://lkml.org/lkml/2013/7/9/310 It hasn't hit Linus git yet. It fixes a bug that my perf_fuzzer would hit within seconds but it took me over a month of trace bisecting and kernel bisecting to isolate it. The symptoms were stuck processes and NMI tracebacks leading to hard locks. With the patch applied my perf_fuzzer (which uses the same perf_event_open syscall generator as trinity) runs for hours w/o problems. Vince -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/