From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: ovs inconsistent lock state Date: Thu, 13 Feb 2014 19:12:57 +0100 Message-ID: <20140213181257.GD2829@minipsycho.orion> References: <20140213171307.GC2829@minipsycho.orion> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev , Jesse Gross , "dev@openvswitch.org" To: Pravin Shelar Return-path: Received: from mail-ea0-f172.google.com ([209.85.215.172]:58373 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752397AbaBMSNA (ORCPT ); Thu, 13 Feb 2014 13:13:00 -0500 Received: by mail-ea0-f172.google.com with SMTP id l9so4648030eaj.17 for ; Thu, 13 Feb 2014 10:12:59 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Thu, Feb 13, 2014 at 06:42:03PM CET, pshelar@nicira.com wrote: >On Thu, Feb 13, 2014 at 9:13 AM, Jiri Pirko wrote: >> Hi. >> >> On current net-next I'm getting following message once I add a dp: >> >> [ 3014.523665] ================================= >> [ 3014.524118] [ INFO: inconsistent lock state ] >> [ 3014.524118] 3.14.0-rc2+ #1 Not tainted >> [ 3014.524118] --------------------------------- >> [ 3014.524118] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. >> [ 3014.524118] swapper/1/0 [HC0[0]:SC1[5]:HE1:SE0] takes: >> [ 3014.524118] (&(&flow->stats.stat->lock)->rlock){+.?...}, at: [] ovs_flow_stats_update+0x4f/0xd0 [openvswitch] >> [ 3014.524118] {SOFTIRQ-ON-W} state was registered at: >> [ 3014.524118] [] __lock_acquire+0x5a3/0x1c30 >> [ 3014.524118] [] lock_acquire+0xb0/0x150 >> [ 3014.524118] [] _raw_spin_lock+0x39/0x50 >> [ 3014.524118] [] ovs_flow_stats_get+0x163/0x1b0 [openvswitch] >> [ 3014.524118] [] ovs_flow_cmd_fill_info+0x165/0x2b0 [openvswitch] >> [ 3014.524118] [] ovs_flow_cmd_build_info.constprop.27+0x6c/0xa0 [openvswitch] >> [ 3014.524118] [] ovs_flow_cmd_new_or_set+0x499/0x4f0 [openvswitch] >> [ 3014.524118] [] genl_family_rcv_msg+0x199/0x390 >> [ 3014.524118] [] genl_rcv_msg+0x8e/0xd0 >> [ 3014.524118] [] netlink_rcv_skb+0xa9/0xc0 >> [ 3014.524118] [] genl_rcv+0x28/0x40 >> [ 3014.524118] [] netlink_unicast+0xf0/0x1b0 >> [ 3014.524118] [] netlink_sendmsg+0x2ff/0x740 >> [ 3014.524118] [] sock_sendmsg+0x8b/0xc0 >> [ 3014.524118] [] ___sys_sendmsg+0x389/0x3a0 >> [ 3014.524118] [] __sys_sendmsg+0x42/0x80 >> [ 3014.524118] [] SyS_sendmsg+0x12/0x20 >> [ 3014.524118] [] system_call_fastpath+0x16/0x1b >> [ 3014.524118] irq event stamp: 6163288 >> [ 3014.524118] hardirqs last enabled at (6163288): [] ip6_finish_output2+0x380/0x670 >> [ 3014.524118] hardirqs last disabled at (6163287): [] ip6_finish_output2+0x33b/0x670 >> [ 3014.524118] softirqs last enabled at (6163266): [] _local_bh_enable+0x22/0x50 >> [ 3014.524118] softirqs last disabled at (6163267): [] irq_exit+0xc5/0xd0 >> [ 3014.524118] >> other info that might help us debug this: >> [ 3014.524118] Possible unsafe locking scenario: >> >> [ 3014.524118] CPU0 >> [ 3014.524118] ---- >> [ 3014.524118] lock(&(&flow->stats.stat->lock)->rlock); >> [ 3014.524118] >> [ 3014.524118] lock(&(&flow->stats.stat->lock)->rlock); >> [ 3014.524118] >> *** DEADLOCK *** >> >> [ 3014.524118] 5 locks held by swapper/1/0: >> [ 3014.524118] #0: (((&idev->mc_ifc_timer))){+.-...}, at: [] call_timer_fn+0x5/0x180 >> [ 3014.524118] #1: (rcu_read_lock){.+.+..}, at: [] mld_sendpack+0x5/0x330 >> [ 3014.524118] #2: (rcu_read_lock_bh){.+....}, at: [] ip6_finish_output2+0x59/0x670 >> [ 3014.524118] #3: (rcu_read_lock_bh){.+....}, at: [] __dev_queue_xmit+0x5/0x6a0 >> [ 3014.524118] #4: (rcu_read_lock){.+.+..}, at: [] internal_dev_xmit+0x5/0x90 [openvswitch] >> [ 3014.524118] >> stack backtrace: >> [ 3014.524118] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.14.0-rc2+ #1 >> [ 3014.524118] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 3014.524118] ffffffff82338940 ffff8800bb2838f0 ffffffff816fd1ac ffff8800b6b33570 >> [ 3014.524118] ffff8800bb283940 ffffffff816f9144 0000000000000005 ffff880000000001 >> [ 3014.524118] ffff880000000000 0000000000000006 ffff8800b6b33570 ffffffff810d4380 >> [ 3014.524118] Call Trace: >> [ 3014.524118] [] dump_stack+0x4d/0x66 >> [ 3014.524118] [] print_usage_bug+0x1f3/0x204 >> [ 3014.524118] [] ? check_usage_backwards+0x130/0x130 >> [ 3014.524118] [] mark_lock+0x270/0x300 >> [ 3014.524118] [] __lock_acquire+0x478/0x1c30 >> [ 3014.524118] [] ? mark_held_locks+0xae/0x130 >> [ 3014.524118] [] ? find_bucket.isra.1+0x67/0x70 [openvswitch] >> [ 3014.524118] [] ? masked_flow_lookup+0x78/0x140 [openvswitch] >> [ 3014.524118] [] ? __lock_acquire+0x3fa/0x1c30 >> [ 3014.524118] [] lock_acquire+0xb0/0x150 >> [ 3014.524118] [] ? ovs_flow_stats_update+0x4f/0xd0 [openvswitch] >> [ 3014.524118] [] _raw_spin_lock+0x39/0x50 >> [ 3014.524118] [] ? ovs_flow_stats_update+0x4f/0xd0 [openvswitch] >> [ 3014.524118] [] ovs_flow_stats_update+0x4f/0xd0 [openvswitch] >> [ 3014.524118] [] ovs_dp_process_received_packet+0x75/0x100 [openvswitch] >> [ 3014.524118] [] ovs_vport_receive+0x2a/0x30 [openvswitch] >> [ 3014.524118] [] internal_dev_xmit+0x56/0x90 [openvswitch] >> [ 3014.524118] [] ? internal_dev_xmit+0x5/0x90 [openvswitch] >> [ 3014.524118] [] dev_hard_start_xmit+0x316/0x620 >> [ 3014.524118] [] __dev_queue_xmit+0x37f/0x6a0 >> [ 3014.524118] [] ? __dev_queue_xmit+0x5/0x6a0 >> [ 3014.524118] [] ? ip6_finish_output2+0x380/0x670 >> [ 3014.524118] [] dev_queue_xmit+0x10/0x20 >> [ 3014.524118] [] ip6_finish_output2+0x3e0/0x670 >> [ 3014.524118] [] ? ip6_finish_output+0x9a/0x200 >> [ 3014.524118] [] ip6_finish_output+0x9a/0x200 >> [ 3014.524118] [] ip6_output+0x4f/0x1d0 >> [ 3014.524118] [] mld_sendpack+0x196/0x330 >> [ 3014.524118] [] ? mld_sendpack+0x5/0x330 >> [ 3014.524118] [] mld_ifc_timer_expire+0x19d/0x2d0 >> [ 3014.524118] [] ? mld_dad_timer_expire+0x70/0x70 >> [ 3014.524118] [] call_timer_fn+0x7a/0x180 >> [ 3014.524118] [] ? call_timer_fn+0x5/0x180 >> [ 3014.524118] [] ? mld_dad_timer_expire+0x70/0x70 >> [ 3014.524118] [] run_timer_softirq+0x20c/0x2c0 >> [ 3014.524118] [] __do_softirq+0x12d/0x310 >> [ 3014.524118] [] irq_exit+0xc5/0xd0 >> [ 3014.524118] [] smp_apic_timer_interrupt+0x45/0x60 >> [ 3014.524118] [] apic_timer_interrupt+0x72/0x80 >> [ 3014.524118] [] ? native_safe_halt+0x6/0x10 >> [ 3014.524118] [] default_idle+0x24/0xe0 >> [ 3014.524118] [] arch_cpu_idle+0x2e/0x40 >> [ 3014.524118] [] cpu_startup_entry+0x9e/0x280 >> [ 3014.524118] [] start_secondary+0x1d9/0x280 >> -- > >Since ovs disable bh while reading stats from local cpu, deadlock can >not occur. This is false positive. I fail to see where bh is disabled. ovs_dp_process_received_packet() is called with rcu_read_lock... > >> To unsubscribe from this list: send the line "unsubscribe netdev" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html