From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965026Ab1JFPzn (ORCPT ); Thu, 6 Oct 2011 11:55:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58726 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756381Ab1JFPzk (ORCPT ); Thu, 6 Oct 2011 11:55:40 -0400 Date: Thu, 6 Oct 2011 11:55:37 -0400 From: Dave Jones To: Linux Kernel Subject: sig->cputimer.lock/rq->lock lockdep report Message-ID: <20111006155537.GA27563@redhat.com> Mail-Followup-To: Dave Jones , Linux Kernel MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This just started happening the last few days during boot. [ 35.629250] ======================================================= [ 35.630234] [ INFO: possible circular locking dependency detected ] [ 35.630234] 3.1.0-rc8+ #16 [ 35.630234] ------------------------------------------------------- [ 35.630234] modprobe/1036 is trying to acquire lock: [ 35.630234] (&(&sig->cputimer.lock)->rlock){-.....}, at: [] account_group_exec_runtime+0x32/0x49 [ 35.630234] [ 35.630234] but task is already holding lock: [ 35.630234] (&rq->lock){-.-.-.}, at: [] scheduler_tick+0x3d/0x238 [ 35.630234] [ 35.630234] which lock already depends on the new lock. [ 35.630234] [ 35.630234] [ 35.630234] the existing dependency chain (in reverse order) is: [ 35.630234] [ 35.630234] -> #2 (&rq->lock){-.-.-.}: [ 35.630234] [] lock_acquire+0xf3/0x13e [ 35.630234] [] _raw_spin_lock+0x40/0x73 [ 35.630234] [] __task_rq_lock+0x5e/0x8b [ 35.630234] [] wake_up_new_task+0x46/0x10d [ 35.630234] [] do_fork+0x201/0x2cd [ 35.630234] [] kernel_thread+0x75/0x77 [ 35.630234] [] rest_init+0x26/0xdc [ 35.630234] [] start_kernel+0x3ec/0x3f7 [ 35.630234] [] x86_64_start_reservations+0xaf/0xb3 [ 35.630234] [] x86_64_start_kernel+0x102/0x111 [ 35.630234] [ 35.630234] -> #1 (&p->pi_lock){-.-.-.}: [ 35.630234] [] lock_acquire+0xf3/0x13e [ 35.630234] [] _raw_spin_lock_irqsave+0x4f/0x89 [ 35.630234] [] thread_group_cputimer+0x32/0xbd [ 35.630234] [] cpu_timer_sample_group+0x2b/0x75 [ 35.630234] [] set_process_cpu_timer+0x36/0xe0 [ 35.630234] [] update_rlimit_cpu+0x3f/0x5a [ 35.630234] [] selinux_bprm_committing_creds+0xc6/0xcb [ 35.630234] [] security_bprm_committing_creds+0x13/0x15 [ 35.630234] [] install_exec_creds+0x13/0x52 [ 35.630234] [] load_elf_binary+0xf3b/0x1762 [ 35.630234] [] search_binary_handler+0xbf/0x263 [ 35.630234] [] do_execve_common+0x1e6/0x2dd [ 35.630234] [] do_execve+0x43/0x45 [ 35.630234] [] sys_execve+0x43/0x5a [ 35.630234] [] stub_execve+0x6c/0xc0 [ 35.630234] [ 35.630234] -> #0 (&(&sig->cputimer.lock)->rlock){-.....}: [ 35.630234] [] __lock_acquire+0xa2f/0xd0c [ 35.630234] [] lock_acquire+0xf3/0x13e [ 35.630234] [] _raw_spin_lock+0x40/0x73 [ 35.630234] [] account_group_exec_runtime+0x32/0x49 [ 35.630234] [] update_curr+0x112/0x134 [ 35.630234] [] task_tick_fair+0x2f/0x120 [ 35.630234] [] scheduler_tick+0xc6/0x238 [ 35.630234] [] update_process_times+0x65/0x75 [ 35.630234] [] tick_sched_timer+0x72/0x9b [ 35.630234] [] __run_hrtimer+0xed/0x1db [ 35.630234] [] hrtimer_interrupt+0xea/0x1b4 [ 35.630234] [] smp_apic_timer_interrupt+0x76/0x89 [ 35.630234] [] apic_timer_interrupt+0x73/0x80 [ 35.630234] [] _raw_spin_unlock_irq+0x32/0x5e [ 35.630234] [] update_rlimit_cpu+0x52/0x5a [ 35.630234] [] selinux_bprm_committing_creds+0xc6/0xcb [ 35.630234] [] security_bprm_committing_creds+0x13/0x15 [ 35.630234] [] install_exec_creds+0x13/0x52 [ 35.630234] [] load_elf_binary+0xf3b/0x1762 [ 35.630234] [] search_binary_handler+0xbf/0x263 [ 35.630234] [] do_execve_common+0x1e6/0x2dd [ 35.630234] [] do_execve+0x43/0x45 [ 35.630234] [] sys_execve+0x43/0x5a [ 35.630234] [] stub_execve+0x6c/0xc0 [ 35.630234] [ 35.630234] other info that might help us debug this: [ 35.630234] [ 35.630234] Chain exists of: [ 35.630234] &(&sig->cputimer.lock)->rlock --> &p->pi_lock --> &rq->lock [ 35.630234] [ 35.630234] Possible unsafe locking scenario: [ 35.630234] [ 35.630234] CPU0 CPU1 [ 35.630234] ---- ---- [ 35.630234] lock(&rq->lock); [ 35.630234] lock(&p->pi_lock); [ 35.630234] lock(&rq->lock); [ 35.630234] lock(&(&sig->cputimer.lock)->rlock); [ 35.630234] [ 35.630234] *** DEADLOCK *** [ 35.630234] [ 35.630234] 2 locks held by modprobe/1036: [ 35.630234] #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x2d/0x69 [ 35.630234] #1: (&rq->lock){-.-.-.}, at: [] scheduler_tick+0x3d/0x238 [ 35.630234] [ 35.630234] stack backtrace: [ 35.630234] Pid: 1036, comm: modprobe Not tainted 3.1.0-rc8+ #16 [ 35.630234] Call Trace: [ 35.630234] [] ? up+0x39/0x3e [ 35.630234] [] print_circular_bug+0x1f8/0x209 [ 35.630234] [] __lock_acquire+0xa2f/0xd0c [ 35.630234] [] ? __cycles_2_ns+0xe/0x3a [ 35.630234] [] ? local_clock+0x14/0x4c [ 35.630234] [] ? sched_clock+0x9/0xd [ 35.630234] [] ? account_group_exec_runtime+0x32/0x49 [ 35.630234] [] lock_acquire+0xf3/0x13e [ 35.630234] [] ? account_group_exec_runtime+0x32/0x49 [ 35.630234] [] ? put_lock_stats+0xe/0x29 [ 35.630234] [] ? tick_nohz_handler+0xe4/0xe4 [ 35.630234] [] _raw_spin_lock+0x40/0x73 [ 35.630234] [] ? account_group_exec_runtime+0x32/0x49 [ 35.630234] [] account_group_exec_runtime+0x32/0x49 [ 35.630234] [] update_curr+0x112/0x134 [ 35.630234] [] task_tick_fair+0x2f/0x120 [ 35.630234] [] scheduler_tick+0xc6/0x238 [ 35.630234] [] update_process_times+0x65/0x75 [ 35.630234] [] tick_sched_timer+0x72/0x9b [ 35.630234] [] __run_hrtimer+0xed/0x1db [ 35.630234] [] hrtimer_interrupt+0xea/0x1b4 [ 35.630234] [] smp_apic_timer_interrupt+0x76/0x89 [ 35.630234] [] apic_timer_interrupt+0x73/0x80 [ 35.630234] [] ? arch_local_irq_enable+0x8/0xd [ 35.630234] [] ? trace_hardirqs_on+0xd/0xf [ 35.630234] [] _raw_spin_unlock_irq+0x32/0x5e [ 35.630234] [] update_rlimit_cpu+0x52/0x5a [ 35.630234] [] selinux_bprm_committing_creds+0xc6/0xcb [ 35.630234] [] security_bprm_committing_creds+0x13/0x15 [ 35.630234] [] install_exec_creds+0x13/0x52 [ 35.630234] [] load_elf_binary+0xf3b/0x1762 [ 35.630234] [] ? sched_clock+0x9/0xd [ 35.630234] [] ? search_binary_handler+0xb6/0x263 [ 35.630234] [] ? _raw_read_unlock+0x32/0x54 [ 35.630234] [] search_binary_handler+0xbf/0x263 [ 35.630234] [] ? load_elf_library+0x23b/0x23b [ 35.630234] [] do_execve_common+0x1e6/0x2dd [ 35.630234] [] do_execve+0x43/0x45 [ 35.630234] [] sys_execve+0x43/0x5a [ 35.630234] [] stub_execve+0x6c/0xc0