From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752712AbbCKURM (ORCPT ); Wed, 11 Mar 2015 16:17:12 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:53090 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752647AbbCKURI (ORCPT ); Wed, 11 Mar 2015 16:17:08 -0400 Date: Wed, 11 Mar 2015 13:17:04 -0700 From: "Paul E. McKenney" To: Sasha Levin Cc: Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , LKML , Dave Jones Subject: Re: rcu: frequent rcu lockups Message-ID: <20150311201704.GL5412@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <55009E2C.7070100@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55009E2C.7070100@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15031120-0025-0000-0000-0000092DF424 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 11, 2015 at 03:57:32PM -0400, Sasha Levin wrote: > Hi all, > > I've started seeing the following hang pretty often during my fuzzing. The > system proceeds to lock up after that. > > [ 3209.655703] INFO: rcu_preempt detected stalls on CPUs/tasks: > [ 3209.655703] Tasks blocked on level-1 rcu_node (CPUs 16-31): > [ 3209.655703] (detected by 0, t=30502 jiffies, g=48799, c=48798, q=1730) > [ 3209.655703] All QSes seen, last rcu_preempt kthread activity 1 (4295246069-4295246068), jiffies_till_next_fqs=1, root ->qsmask 0x2 > [ 3209.655703] trinity-c24 R running task 26944 9338 9110 0x10080000 > [ 3209.655703] 0000000000002396 00000000e68fa48e ffff880050607dc8 ffffffffa427679b > [ 3209.655703] ffff880050607d98 ffffffffb1b36000 0000000000000001 00000001000440f4 > [ 3209.655703] ffffffffb1b351c8 dffffc0000000000 ffff880050622000 ffffffffb1721000 > [ 3209.655703] Call Trace: > [ 3209.655703] sched_show_task (kernel/sched/core.c:4542) > [ 3209.655703] rcu_check_callbacks (kernel/rcu/tree.c:1225 kernel/rcu/tree.c:1331 kernel/rcu/tree.c:3389 kernel/rcu/tree.c:3453 kernel/rcu/tree.c:2683) > [ 3209.655703] ? acct_account_cputime (kernel/tsacct.c:168) > [ 3209.655703] update_process_times (./arch/x86/include/asm/preempt.h:22 kernel/time/timer.c:1386) > [ 3209.655703] tick_periodic (kernel/time/tick-common.c:92) > [ 3209.655703] ? tick_handle_periodic (kernel/time/tick-common.c:105) > [ 3209.655703] tick_handle_periodic (kernel/time/tick-common.c:105) > [ 3209.655703] local_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:891) > [ 3209.655703] smp_trace_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:934 include/linux/jump_label.h:114 ./arch/x86/include/asm/trace/irq_vectors.h:45 arch/x86/kernel/apic/apic.c:935) > [ 3209.655703] trace_apic_timer_interrupt (arch/x86/kernel/entry_64.S:920) > [ 3209.655703] ? add_wait_queue (include/linux/wait.h:116 kernel/sched/wait.c:29) > [ 3209.655703] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191) > [ 3209.655703] add_wait_queue (kernel/sched/wait.c:31) > [ 3209.655703] do_wait (kernel/exit.c:1473) > [ 3209.655703] ? trace_rcu_dyntick (include/trace/events/rcu.h:363 (discriminator 19)) > [ 3209.655703] ? wait_consider_task (kernel/exit.c:1465) > [ 3209.655703] ? find_get_pid (kernel/pid.c:490) > [ 3209.655703] SyS_wait4 (kernel/exit.c:1618 kernel/exit.c:1586) > [ 3209.655703] ? perf_syscall_exit (kernel/trace/trace_syscalls.c:549) > [ 3209.655703] ? SyS_waitid (kernel/exit.c:1586) > [ 3209.655703] ? kill_orphaned_pgrp (kernel/exit.c:1444) > [ 3209.655703] ? syscall_trace_enter_phase2 (arch/x86/kernel/ptrace.c:1592) > [ 3209.655703] ? trace_hardirqs_on_thunk (arch/x86/lib/thunk_64.S:42) > [ 3209.655703] tracesys_phase2 (arch/x86/kernel/entry_64.S:347) OK, that is not good. What version are you running and what is your .config? Thanx, Paul