Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755883Ab3JXSRR (ORCPT ); Thu, 24 Oct 2013 14:17:17 -0400 Received: from mail-yh0-f53.google.com ([209.85.213.53]:63364 "EHLO mail-yh0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754747Ab3JXSRQ (ORCPT ); Thu, 24 Oct 2013 14:17:16 -0400 Date: Thu, 24 Oct 2013 14:25:06 -0400 (EDT) From: Vince Weaver To: linux-kernel@vger.kernel.org cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Dave Jones , Steven Rostedt , Frederic Weisbecker Subject: Re: perf/ftrace lockup on 3.12-rc6 with trigger code In-Reply-To: Message-ID: References: User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1046 Lines: 29 On Thu, 24 Oct 2013, Vince Weaver wrote: > after a month of trying I finally got a small test-case out of my > perf_fuzzer suite that triggers a system lockup with just one syscall. > > Attached is the code that triggers it. And it turns out you can only trigger this specific problem if advanced ftrace options are enabled. CONFIG_KPROBES_ON_FTRACE=y CONFIG_FUNCTION_TRACER=y CONFIG_FUNCTION_GRAPH_TRACER=y CONFIG_STACK_TRACER=y CONFIG_DYNAMIC_FTRACE=y CONFIG_DYNAMIC_FTRACE_WITH_REGS=y CONFIG_FUNCTION_PROFILER=y CONFIG_FTRACE_MCOUNT_RECORD=y Urgh, I had turned those on to try to debug something and forgot to disable. I feel like I saw this problem before I had those enabled so I guess I have to start from scratch fuzzing to see if I can get a more generally reproducible trace. 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/