From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: lockdep report from 2.6.20.5-rc1 Date: Wed, 4 Apr 2007 17:30:50 -0400 Message-ID: <20070404213050.GA19261@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([66.187.233.31]:36532 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894AbXDDVax (ORCPT ); Wed, 4 Apr 2007 17:30:53 -0400 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.1/8.13.1) with ESMTP id l34LUqFA030154 for ; Wed, 4 Apr 2007 17:30:52 -0400 Received: from gelk.kernelslacker.org (vpn-248-96.boston.redhat.com [10.13.248.96]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l34LUp9i023921 for ; Wed, 4 Apr 2007 17:30:52 -0400 Received: from gelk.kernelslacker.org (localhost.localdomain [127.0.0.1]) by gelk.kernelslacker.org (8.13.8/8.13.8) with ESMTP id l34LUpBq021103 for ; Wed, 4 Apr 2007 17:30:51 -0400 Received: (from davej@localhost) by gelk.kernelslacker.org (8.13.8/8.13.8/Submit) id l34LUoLU021102 for netdev@vger.kernel.org; Wed, 4 Apr 2007 17:30:50 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.20-1.2933.fc6debug #1 ------------------------------------------------------- swapper/0 is trying to acquire lock: (&tbl->lock){-+-+}, at: [] neigh_lookup+0x43/0xa2 but task is already holding lock: (&list->lock#4){-+..}, at: [] neigh_proxy_process+0x20/0xc2 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&list->lock#4){-+..}: [] __lock_acquire+0x913/0xa43 [] lock_acquire+0x56/0x6f [] _spin_lock_irqsave+0x34/0x44 [] skb_dequeue+0x12/0x43 [] skb_queue_purge+0x14/0x1b [] neigh_update+0x349/0x3a5 [] arp_process+0x4d1/0x50a [] arp_rcv+0xe3/0x100 [] netif_receive_skb+0x2db/0x35a [] process_backlog+0x95/0xf6 [] net_rx_action+0xa1/0x1a8 [] __do_softirq+0x6f/0xe2 [] do_softirq+0x61/0xd0 [] 0xffffffff -> #1 (&n->lock){-+-+}: [] __lock_acquire+0x913/0xa43 [] lock_acquire+0x56/0x6f [] _write_lock+0x2b/0x38 [] neigh_periodic_timer+0x99/0x138 [] run_timer_softirq+0x104/0x168 [] __do_softirq+0x6f/0xe2 [] do_softirq+0x61/0xd0 [] 0xffffffff -> #0 (&tbl->lock){-+-+}: [] __lock_acquire+0x814/0xa43 [] lock_acquire+0x56/0x6f [] _read_lock_bh+0x30/0x3d [] neigh_lookup+0x43/0xa2 [] neigh_event_ns+0x2c/0x7a [] arp_process+0x386/0x50a [] parp_redo+0x8/0xa [] neigh_proxy_process+0x66/0xc2 [] run_timer_softirq+0x104/0x168 [] __do_softirq+0x6f/0xe2 [] do_softirq+0x61/0xd0 [] 0xffffffff other info that might help us debug this: 1 lock held by swapper/0: #0: (&list->lock#4){-+..}, at: [] neigh_proxy_process+0x20/0xc2 stack backtrace: [] show_trace_log_lvl+0x1a/0x2f [] show_trace+0x12/0x14 [] dump_stack+0x16/0x18 [] print_circular_bug_tail+0x5f/0x68 [] __lock_acquire+0x814/0xa43 [] lock_acquire+0x56/0x6f [] _read_lock_bh+0x30/0x3d [] neigh_lookup+0x43/0xa2 [] neigh_event_ns+0x2c/0x7a [] arp_process+0x386/0x50a [] parp_redo+0x8/0xa [] neigh_proxy_process+0x66/0xc2 [] run_timer_softirq+0x104/0x168 [] __do_softirq+0x6f/0xe2 [] do_softirq+0x61/0xd0 ======================= -- http://www.codemonkey.org.uk