Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753353Ab3GAJP3 (ORCPT ); Mon, 1 Jul 2013 05:15:29 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44438 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752966Ab3GAJPZ (ORCPT ); Mon, 1 Jul 2013 05:15:25 -0400 Date: Mon, 1 Jul 2013 11:07:13 +0200 From: Peter Zijlstra To: Vince Weaver Cc: linux-kernel@vger.kernel.org, Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , trinity@vger.kernel.org Subject: Re: [testcase] perf: yet another fuzzer triggered crash Message-ID: <20130701090713.GO6626@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1296 Lines: 34 On Fri, Jun 28, 2013 at 05:07:38PM -0400, Vince Weaver wrote: > On Fri, 28 Jun 2013, Vince Weaver wrote: > > > On Fri, 14 Jun 2013, Vince Weaver wrote: > > > > > OK, I haven't managed to get a small reproducible test case for the system > > > crash yet > > > > I wasted the last 2 days bisecting a 10000 syscall trace, but below is a > > 20-syscall testcase that rapidly makes a core2 machine running 3.10-rc7 > > unusable. > > and it turns out I might have bisected down too much, as though that > crashes my core2 system it doesn't crash newer machines. > > I'm too lazy to re-bisect today, but the much longer program here: > http://web.eece.maine.edu/~vweaver/files/nmi_bug_snb.c > reliably causes the same crash on a Sandybridge machine I have running 3.9 OK, so on my westmere it triggers that WARN in task_ctx_sched_out() a _lot_ (I removed the ONCE for easier debugging earlier -- still kinda stumped there). Then this thing causes an RCU stall and starts triggering NMI watchdog msgs.. so YAY! :-) I'll see what I can find. -- 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/