From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753017Ab2GSML1 (ORCPT ); Thu, 19 Jul 2012 08:11:27 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:33314 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752363Ab2GSMLU (ORCPT ); Thu, 19 Jul 2012 08:11:20 -0400 Message-ID: <5007F8FA.7000203@linux.vnet.ibm.com> Date: Thu, 19 Jul 2012 17:39:30 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: "Paul E. McKenney" CC: "linux-kernel@vger.kernel.org" , "Srivatsa S. Bhat" Subject: WARNING: at kernel/rcutree.c:1550 __rcu_process_callbacks+0x46f/0x4b0() Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12071912-2674-0000-0000-0000054E206C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, While running a CPU hotplug stress test on v3.5-rc7+ (mainline commit 8a7298b7805ab) I hit this warning. I haven't tried to debug this yet... Line number 1550 maps to: WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); inside rcu_do_batch(). Regards, Srivatsa S. Bhat [ 1206.095436] CPU 3 is now offline [ 1206.097086] CPU 3 offline: Remove Rx thread [ 1206.099133] CPU 2 MCA banks CMCI:0 CMCI:1 CMCI:3 [ 1206.103750] ------------[ cut here ]------------ [ 1206.103758] WARNING: at kernel/rcutree.c:1550 __rcu_process_callbacks+0x46f/0x4b0() [ 1206.103759] Hardware name: 4180F59 [ 1206.103759] Modules linked in: tcp_lp lp ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat xt_CHECKSUM iptable_mangle bridge stp llc ppdev parport_pc parport fuse be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser ip6t_ipv6header rdma_cm ib_cm iw_cm ib_sa lockd ip6t_REJECT ib_mad ib_core nf_conntrack_ipv6 nf_defrag_ipv6 xt_limit ib_addr iscsi_tcp nf_conntrack_ipv4 libiscsi_tcp libiscsi nf_defrag_ipv4 xt_state nf_conntrack scsi_transport_iscsi ip6table_filter ip6_tables snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep arc4 iwlwifi snd_seq snd_seq_device snd_pcm mac80211 snd_timer thinkpad_acpi snd sunrpc vhost_net macvtap uvcvideo macvlan tun videobuf2_core kvm_intel cfg80211 videodev media videobuf2_vmalloc tpm_tis kvm i2c_i801 e1000e joydev tpm videobuf2_memops soundcore snd_page_alloc rfkill lpc_ich mfd_core tpm_bios microcode binfmt_misc uinput sdhci_pci sdhci mmc_core nouveau i915 ttm drm_kms_helper drm mxm_wmi i2! c_algo_bit i2c_core video wmi [ 1206.103829] [last unloaded: scsi_wait_scan] [ 1206.103832] Pid: 6217, comm: migration/1 Not tainted 3.5.0-rc7-mandeep #1 [ 1206.103833] Call Trace: [ 1206.103834] [] warn_slowpath_common+0x7f/0xc0 [ 1206.103840] [] warn_slowpath_null+0x1a/0x20 [ 1206.103843] [] __rcu_process_callbacks+0x46f/0x4b0 [ 1206.103845] [] ? __run_hrtimer+0x84/0x3a0 [ 1206.103848] [] ? _raw_spin_unlock_irqrestore+0x77/0x80 [ 1206.103852] [] ? account_system_vtime+0xdd/0xf0 [ 1206.103855] [] rcu_process_callbacks+0x33/0x290 [ 1206.103857] [] __do_softirq+0xc8/0x3e0 [ 1206.103860] [] ? lapic_next_event+0x1d/0x30 [ 1206.103863] [] call_softirq+0x1c/0x30 [ 1206.103866] [] do_softirq+0xa5/0xe0 [ 1206.103870] [] irq_exit+0xbe/0xf0 [ 1206.103872] [] smp_apic_timer_interrupt+0x6e/0x99 [ 1206.103875] [] apic_timer_interrupt+0x6f/0x80 [ 1206.103878] [] ? stop_machine_cpu_stop+0xc3/0x110 [ 1206.103883] [] cpu_stopper_thread+0xd9/0x1b0 [ 1206.103884] [] ? queue_stop_cpus_work+0xf0/0xf0 [ 1206.103893] [] ? __schedule+0x431/0xa20 [ 1206.103896] [] ? trace_hardirqs_on_caller+0x11d/0x1b0 [ 1206.103900] [] ? cpu_stop_signal_done+0x40/0x40 [ 1206.103902] [] kthread+0xae/0xc0 [ 1206.103905] [] ? trace_hardirqs_on+0xd/0x10 [ 1206.103908] [] kernel_thread_helper+0x4/0x10 [ 1206.103911] [] ? retint_restore_args+0x13/0x13 [ 1206.103913] [] ? __init_kthread_worker+0x70/0x70 [ 1206.103916] [] ? gs_change+0x13/0x13 [ 1206.103918] ---[ end trace cbc247c5c233d6e7 ]--- [ 1206.104125] CPU 1 is now offline