From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654Ab2AZPEr (ORCPT ); Thu, 26 Jan 2012 10:04:47 -0500 Received: from cpanel23.proisp.no ([88.87.44.74]:32939 "EHLO cpanel23.proisp.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752583Ab2AZPEq (ORCPT ); Thu, 26 Jan 2012 10:04:46 -0500 Message-ID: <4F216B85.7010208@numascale.com> Date: Thu, 26 Jan 2012 16:04:37 +0100 From: Steffen Persvold User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: Daniel J Blueman , Dipankar Sarma , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: RCU qsmask !=0 warnings on large-SMP... References: <4F1FCF02.9060209@numascale-asia.com> <20120125140029.GA2534@linux.vnet.ibm.com> <4F200F4D.5000201@numascale.com> <20120125181441.GD2849@linux.vnet.ibm.com> <4F2070B9.2000104@numascale.com> <20120125213450.GJ2849@linux.vnet.ibm.com> <4F2086DA.4040203@numascale.com> <20120126015843.GN2849@linux.vnet.ibm.com> In-Reply-To: <20120126015843.GN2849@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cpanel23.proisp.no X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - numascale.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/26/2012 02:58, Paul E. McKenney wrote: > On Wed, Jan 25, 2012 at 11:48:58PM +0100, Steffen Persvold wrote: [] > > This looks like it will produce useful information, but I am not seeing > output from it below. > > Thanx, Paul > >> This run it was CPU24 that triggered the issue : >> This line is the printout for the root level : >> [ 231.572688] CPU 24, treason uncloaked, rsp @ ffffffff81a1cd80 (rcu_sched), rnp @ ffffffff81a1cd80(r) qsmask=0x1f, c=5132 g=5132 nc=5132 ng=5133 sc=5132 sg=5133 mc=5132 mg=5133 (this is the WARN_ON printout) : >> [ 231.576167] ------------[ cut here ]------------ >> [ 231.576167] WARNING: at kernel/rcutree_plugin.h:1011 rcu_preempt_check_blocked_tasks+0x27/0x30() >> [ 231.576167] Hardware name: H8QI6 >> [ 231.576167] Modules linked in: rcutorture >> [ 231.576167] Pid: 4603, comm: rcu_torture_rea Not tainted 3.2.1-numaconnect10+ #77 >> [ 231.576167] Call Trace: >> [ 231.576167] [] ? rcu_preempt_check_blocked_tasks+0x27/0x30 >> [ 231.576167] [] warn_slowpath_common+0x8b/0xc0 >> [ 231.576167] [] warn_slowpath_null+0x15/0x20 >> [ 231.576167] [] rcu_preempt_check_blocked_tasks+0x27/0x30 >> [ 231.576167] [] rcu_start_gp+0x110/0x1b0 >> [ 231.576167] [] __rcu_process_callbacks+0x8b/0xd0 >> [ 231.576167] [] rcu_process_callbacks+0x20/0x40 >> [ 231.576167] [] __do_softirq+0x9d/0x140 >> [ 231.576167] [] call_softirq+0x1c/0x30 >> [ 231.576167] [] do_softirq+0x4a/0x80 >> [ 231.576167] [] irq_exit+0x43/0x60 >> [ 231.576167] [] smp_apic_timer_interrupt+0x45/0x60 >> [ 231.576167] [] apic_timer_interrupt+0x6b/0x70 >> [ 231.576167] [] ? finish_task_switch+0x59/0xc0 >> [ 231.576167] [] __schedule+0x337/0x710 >> [ 231.576167] [] ? sched_clock_local+0x15/0x80 >> [ 231.576167] [] ? lock_timer_base+0x36/0x70 >> [ 231.576167] [] ? mod_timer+0xf2/0x1d0 >> [ 231.576167] [] ? rcu_torture_shuffle+0x80/0x80 [rcutorture] >> [ 231.576167] [] schedule+0x3a/0x60 >> [ 231.576167] [] rcu_torture_reader+0x130/0x230 [rcutorture] >> [ 231.576167] [] ? rcu_torture_writer+0x160/0x160 [rcutorture] >> [ 231.576167] [] ? rcu_torture_shuffle+0x80/0x80 [rcutorture] >> [ 231.576167] [] kthread+0x96/0xa0 >> [ 231.576167] [] kernel_thread_helper+0x4/0x10 >> [ 231.576167] [] ? kthread_stop+0x70/0x70 >> [ 231.576167] [] ? gs_change+0xb/0xb >> [ 231.576167] ---[ end trace 828c8d7afbd02d1b ]--- >> I didn't include the leaf node printout, but the counters were indentical to the root printout (with the exception of the rnp address and qsmask of course). Cheers, -- Steffen Persvold, Chief Architect NumaChip Numascale AS - www.numascale.com Tel: +47 92 49 25 54 Skype: spersvold