Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932309AbbFSOPn (ORCPT ); Fri, 19 Jun 2015 10:15:43 -0400 Received: from mail-qg0-f50.google.com ([209.85.192.50]:36172 "EHLO mail-qg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932126AbbFSOPf (ORCPT ); Fri, 19 Jun 2015 10:15:35 -0400 From: Vince Weaver X-Google-Original-From: Vince Weaver Date: Fri, 19 Jun 2015 10:21:30 -0400 (EDT) To: Peter Zijlstra cc: Alexander Shishkin , Vince Weaver , linux-kernel@vger.kernel.org, Ingo Molnar , Arnaldo Carvalho de Melo , Stephane Eranian Subject: Re: perf: aux area related crash and warnings In-Reply-To: <20150618103249.GK19282@twins.programming.kicks-ass.net> Message-ID: References:

<20150615122054.GY3644@twins.programming.kicks-ass.net> <87egld2l2o.fsf@ashishki-desk.ger.corp.intel.com> <87381rg9zx.fsf@ashishki-desk.ger.corp.intel.com> <20150618103249.GK19282@twins.programming.kicks-ass.net> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) 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: 4577 Lines: 81 On Thu, 18 Jun 2015, Peter Zijlstra wrote: > On Tue, Jun 16, 2015 at 02:37:06PM +0300, Alexander Shishkin wrote: > > Ok, here's what I propose for this one. > > As discussed yesterday, I think we want to change to how we do reference > counting for the regular buffers, but that will require quite a bit of > work. > > For the interim we can avoid the issue by something like the below; > compile tested only. I did manage to crash the system with Alexander Shishkin's patch applied (See below). I will try with this updated patch instead, but the bug usually takes a few days to trigger with the fuzzer and I won't be able to let it run that long this time. Vince [183592.949539] BUG: spinlock recursion on CPU#2, perf_fuzzer/434 [183592.956559] lock: pool_lock+0x0/0x40, .magic: dead4ead, .owner: perf_fuzzer/434, .owner_cpu: 2 [183592.966783] CPU: 2 PID: 434 Comm: perf_fuzzer Tainted: G W 4.1.0-rc8+ #157 [183592.976228] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS 01/26/2014 [183592.984997] ffffffff81cc2120 ffff88011ea85970 ffffffff816d7419 0000000000000053 [183592.993871] ffff8800cf26a8d0 ffff88011ea85990 ffffffff810c28a5 ffffffff81cc2120 [183593.002787] ffffffff81a1e4d1 ffff88011ea859b0 ffffffff810c2926 ffffffff81cc2120 [183593.011632] Call Trace: [183593.015016] [] dump_stack+0x45/0x57 [183593.021966] [] spin_dump+0x85/0xe0 [183593.028153] [] spin_bug+0x26/0x30 [183593.034234] [] do_raw_spin_lock+0x13f/0x180 [183593.041233] [] _raw_spin_lock+0x39/0x40 [183593.047849] [] ? __debug_object_init+0xad/0x450 [183593.055189] [] __debug_object_init+0xad/0x450 [183593.062375] [] debug_object_init+0x1b/0x20 [183593.069267] [] rcuhead_fixup_activate+0x28/0x40 [183593.076638] [] debug_object_activate+0xf1/0x1e0 [183593.083969] [] ? free_event_rcu+0x40/0x40 [183593.090781] [] __call_rcu.constprop.58+0x3b/0x340 [183593.098321] [] ? irq_work_queue+0x6c/0x80 [183593.105123] [] call_rcu_sched+0x17/0x20 [183593.111709] [] rb_free_aux+0x40/0x90 [183593.118046] [] perf_aux_output_end+0xb7/0xf0 [183593.125089] [] intel_bts_interrupt+0x8e/0xd0 [183593.132069] [] intel_pmu_handle_irq+0x4f/0x450 [183593.139335] [] perf_event_nmi_handler+0x2b/0x50 [183593.146687] [] nmi_handle+0xa0/0x150 [183593.153012] [] ? nmi_handle+0x5/0x150 [183593.159406] [] default_do_nmi+0x4a/0x140 [183593.166117] [] do_nmi+0x98/0xe0 [183593.171983] [] end_repeat_nmi+0x1e/0x2e [183593.178613] [] ? do_raw_spin_trylock+0x50/0x50 [183593.185823] [] ? do_raw_spin_trylock+0x50/0x50 [183593.193059] [] ? do_raw_spin_trylock+0x50/0x50 [183593.200306] <> [] ? _raw_spin_unlock+0x2b/0x40 [183593.208107] [] __debug_object_init+0x16d/0x450 [183593.215328] [] ? debug_object_activate+0x8a/0x1e0 [183593.222812] [] ? debug_object_activate+0xda/0x1e0 [183593.230328] [] debug_object_init+0x1b/0x20 [183593.237143] [] rcuhead_fixup_activate+0x28/0x40 [183593.244413] [] debug_object_activate+0xf1/0x1e0 [183593.251702] [] ? perf_unpin_context+0x40/0x40 [183593.258799] [] __call_rcu.constprop.58+0x3b/0x340 [183593.266311] [] ? __static_key_slow_dec+0x27/0xc0 [183593.273694] [] call_rcu_sched+0x17/0x20 [183593.280180] [] _free_event+0x109/0x290 [183593.286619] [] put_event+0x10f/0x160 [183593.292855] [] ? put_event+0x30/0x160 [183593.299153] [] perf_release+0x15/0x20 [183593.305442] [] __fput+0xdc/0x1f0 [183593.311296] [] ____fput+0xe/0x10 [183593.317138] [] task_work_run+0xb7/0xf0 [183593.323509] [] do_notify_resume+0x59/0x80 [183593.330207] [] int_signal+0x12/0x17 [183602.817462] ------------[ cut here ]------------ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/