Re: Question on lockdep and sysrq - d

[Ming Lei <tom.leiming@gmail.com>]

See http://marc.info/?l=linux-kernel&m=124211522525625&w=2.

thanks.

2009/5/23 Ben Greear <greearb@candelatech.com>:
> Hello!
>
> I'm trying to debug an apparent deadlock in some code I'm
> writing.
>
> When I do a sysrq 'd', I get a nice dump of locks (I have lockdep enabled).
>
> However, the output appears to show multiple processes holding the
> same locks (rtnl_mutex, for example):
>
> Showing all locks held in the system:
> 3 locks held by events/11/63:
>  #0:  (events){--..}, at: [<ffffffff8104f71e>] run_workqueue+0xb1/0x216
>  #1:  ((linkwatch_work).work){--..}, at: [<ffffffff8104f71e>]
> run_workqueue+0xb1/0x216
>  #2:  (rtnl_mutex){--..}, at: [<ffffffff8125def1>] rtnl_lock+0x12/0x14
> 1 lock held by irqbalance/3360:
>  #0:  (rtnl_mutex){--..}, at: [<ffffffff8125def1>] rtnl_lock+0x12/0x14
> 1 lock held by hald/3605:
>  #0:  (rtnl_mutex){--..}, at: [<ffffffff8125def1>] rtnl_lock+0x12/0x14
> ...
>
> Is this merely showing processes that are blocked on trying to acquire these
> locks?
>
> If so, is there any way to tell which processes have fully acquired locks
> v/s
> just waiting to acquire them?
>
> Thanks,
> Ben
>
> --
> Ben Greear <greearb@candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
>
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-- 
Lei Ming