From: Dave Jones <davej@redhat.com>
To: netdev@vger.kernel.org
Subject: lockdep report from 2.6.20.5-rc1
Date: Wed, 4 Apr 2007 17:30:50 -0400 [thread overview]
Message-ID: <20070404213050.GA19261@redhat.com> (raw)
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.20-1.2933.fc6debug #1
-------------------------------------------------------
swapper/0 is trying to acquire lock:
(&tbl->lock){-+-+}, at: [<c05d5664>] neigh_lookup+0x43/0xa2
but task is already holding lock:
(&list->lock#4){-+..}, at: [<c05d65c8>] 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){-+..}:
[<c043f4f2>] __lock_acquire+0x913/0xa43
[<c043f933>] lock_acquire+0x56/0x6f
[<c06325df>] _spin_lock_irqsave+0x34/0x44
[<c05cbb87>] skb_dequeue+0x12/0x43
[<c05cc9d4>] skb_queue_purge+0x14/0x1b
[<c05d5b70>] neigh_update+0x349/0x3a5
[<c060cd37>] arp_process+0x4d1/0x50a
[<c060ce53>] arp_rcv+0xe3/0x100
[<c05d0e43>] netif_receive_skb+0x2db/0x35a
[<c05d2806>] process_backlog+0x95/0xf6
[<c05d29ed>] net_rx_action+0xa1/0x1a8
[<c042c1f6>] __do_softirq+0x6f/0xe2
[<c04063c6>] do_softirq+0x61/0xd0
[<ffffffff>] 0xffffffff
-> #1 (&n->lock){-+-+}:
[<c043f4f2>] __lock_acquire+0x913/0xa43
[<c043f933>] lock_acquire+0x56/0x6f
[<c063231e>] _write_lock+0x2b/0x38
[<c05d74b7>] neigh_periodic_timer+0x99/0x138
[<c042f053>] run_timer_softirq+0x104/0x168
[<c042c1f6>] __do_softirq+0x6f/0xe2
[<c04063c6>] do_softirq+0x61/0xd0
[<ffffffff>] 0xffffffff
-> #0 (&tbl->lock){-+-+}:
[<c043f3f3>] __lock_acquire+0x814/0xa43
[<c043f933>] lock_acquire+0x56/0x6f
[<c06323d6>] _read_lock_bh+0x30/0x3d
[<c05d5664>] neigh_lookup+0x43/0xa2
[<c05d6317>] neigh_event_ns+0x2c/0x7a
[<c060cbec>] arp_process+0x386/0x50a
[<c060ce78>] parp_redo+0x8/0xa
[<c05d660e>] neigh_proxy_process+0x66/0xc2
[<c042f053>] run_timer_softirq+0x104/0x168
[<c042c1f6>] __do_softirq+0x6f/0xe2
[<c04063c6>] do_softirq+0x61/0xd0
[<ffffffff>] 0xffffffff
other info that might help us debug this:
1 lock held by swapper/0:
#0: (&list->lock#4){-+..}, at: [<c05d65c8>] neigh_proxy_process+0x20/0xc2
stack backtrace:
[<c04051dd>] show_trace_log_lvl+0x1a/0x2f
[<c0405782>] show_trace+0x12/0x14
[<c0405806>] dump_stack+0x16/0x18
[<c043dcf5>] print_circular_bug_tail+0x5f/0x68
[<c043f3f3>] __lock_acquire+0x814/0xa43
[<c043f933>] lock_acquire+0x56/0x6f
[<c06323d6>] _read_lock_bh+0x30/0x3d
[<c05d5664>] neigh_lookup+0x43/0xa2
[<c05d6317>] neigh_event_ns+0x2c/0x7a
[<c060cbec>] arp_process+0x386/0x50a
[<c060ce78>] parp_redo+0x8/0xa
[<c05d660e>] neigh_proxy_process+0x66/0xc2
[<c042f053>] run_timer_softirq+0x104/0x168
[<c042c1f6>] __do_softirq+0x6f/0xe2
[<c04063c6>] do_softirq+0x61/0xd0
=======================
--
http://www.codemonkey.org.uk
next reply other threads:[~2007-04-04 21:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-04 21:30 Dave Jones [this message]
2007-04-04 22:26 ` [RFT] proxy arp deadlock possible Stephen Hemminger
2007-04-05 0:44 ` Herbert Xu
2007-04-05 1:10 ` Arjan van de Ven
2007-04-05 4:49 ` Dave Jones
2007-04-05 5:32 ` Herbert Xu
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