Re: [patch] lockdep, annotate slocks: turn lockdep off for them

["Miles Lane" <miles.lane@gmail.com>]

Okay, I rebuilt my kernel with your combo patch applied.
Then, I inserted my US Robotics USR2210 PCMCIA wifi card,
ran "pccardutil eject", popped out the card and then inserted
a Compaq iPaq wifi card.  This triggered the following.

[ INFO: possible circular locking dependency detected ]
-------------------------------------------------------
syslogd/1886 is trying to acquire lock:
(&dev->queue_lock){-+..}, at: [<c11a50b5>] dev_queue_xmit+0x120/0x24b

but task is already holding lock:
(&dev->_xmit_lock){-+..}, at: [<c11a5118>] dev_queue_xmit+0x183/0x24b

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dev->_xmit_lock){-+..}:
      [<c102d1b6>] lock_acquire+0x60/0x80
      [<c12013ed>] _spin_lock_bh+0x28/0x37
      [<c11b0045>] dev_activate+0xce/0x100
      [<c11a42e7>] dev_open+0x4c/0x64
      [<c11a2e44>] dev_change_flags+0x51/0xf1
      [<c11ab07d>] do_setlink+0x73/0x312
      [<c11aadcc>] rtnetlink_rcv_msg+0x1ae/0x1d1
      [<c11b5c91>] netlink_run_queue+0x69/0x100
      [<c11aabd4>] rtnetlink_rcv+0x29/0x42
      [<c11b6104>] netlink_data_ready+0x12/0x4f
      [<c11b4f51>] netlink_sendskb+0x1f/0x50
      [<c11b5a42>] netlink_unicast+0x1b4/0x1ce
      [<c11b60e5>] netlink_sendmsg+0x259/0x266
      [<c1199c7a>] sock_sendmsg+0xe8/0x103
      [<c119a2a5>] sys_sendmsg+0x14f/0x1aa
      [<c119b5e3>] sys_socketcall+0x16b/0x186
      [<c1002d6d>] sysenter_past_esp+0x56/0x8d

-> #0 (&dev->queue_lock){-+..}:
      [<c102d1b6>] lock_acquire+0x60/0x80
      [<c12013b6>] _spin_lock+0x23/0x32
      [<c11a50b5>] dev_queue_xmit+0x120/0x24b
      [<f948379e>] hostap_data_start_xmit+0x610/0x61a [hostap]
      [<c11a371d>] dev_hard_start_xmit+0x206/0x212
      [<c11a5134>] dev_queue_xmit+0x19f/0x24b
      [<f939c7c9>] mld_sendpack+0x1a0/0x26a [ipv6]
      [<f939d3a3>] mld_ifc_timer_expire+0x1d6/0x1fd [ipv6]
      [<c101db26>] run_timer_softirq+0xf2/0x14a
      [<c101a709>] __do_softirq+0x55/0xb0
      [<c1004a64>] do_softirq+0x58/0xbd

other info that might help us debug this:

4 locks held by syslogd/1886:
#0:  (&inode->i_mutex){--..}, at: [<c120028e>] mutex_lock+0x1c/0x1f
#1:  (&journal->j_state_lock){--..}, at: [<c10aee62>]
journal_stop+0x109/0x1f8 #2:  (&transaction->t_handle_lock){--..}, at:
[<c10aee6c>] journal_stop+0x113/0x1f8
#3:  (&dev->_xmit_lock){-+..}, at: [<c11a5118>] dev_queue_xmit+0x183/0x24b

stack backtrace:
[<c1003502>] show_trace_log_lvl+0x54/0xfd
[<c1003b6a>] show_trace+0xd/0x10
[<c1003c0e>] dump_stack+0x19/0x1b
[<c102c576>] print_circular_bug_tail+0x59/0x64
[<c102cd5c>] __lock_acquire+0x7db/0x970
[<c102d1b6>] lock_acquire+0x60/0x80
[<c12013b6>] _spin_lock+0x23/0x32
[<c11a50b5>] dev_queue_xmit+0x120/0x24b
[<f948379e>] hostap_data_start_xmit+0x610/0x61a [hostap]
[<c11a371d>] dev_hard_start_xmit+0x206/0x212
[<c11a5134>] dev_queue_xmit+0x19f/0x24b
[<f939c7c9>] mld_sendpack+0x1a0/0x26a [ipv6]
[<f939d3a3>] mld_ifc_timer_expire+0x1d6/0x1fd [ipv6]
[<c101db26>] run_timer_softirq+0xf2/0x14a
[<c101a709>] __do_softirq+0x55/0xb0
[<c1004a64>] do_softirq+0x58/0xbd
[<c101a6a8>] irq_exit+0x3f/0x4b
[<c1004b89>] do_IRQ+0xc0/0xcf
[<c1002fd9>] common_interrupt+0x25/0x2c


On 6/30/06, Ingo Molnar <mingo@elte.hu> wrote:
> * Miles Lane <miles.lane@gmail.com> wrote:
>
> > I cannot get this patch to apply cleanly to 2.6.17-mm4. Since the
> > patch listed in this message covers the same files as your previous
> > lockdep-annotate-slock.patch, I am assuming this is supposed to
> > replace it.  I should also still apply
> > lockdep-core-add-set-class-and-name.patch, correct?
>
> correct. My latest combo patch has it all included, it's at:
>
>   http://redhat.com/~mingo/lockdep-patches/lockdep-combo-2.6.17-mm4.patch
>
> could you try that one?
>
>         Ingo
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