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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Murali raja Muniraju <murali.rajam@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: Query on a lockdep issue in neigh_lookup
Date: Wed, 14 Sep 2011 01:59:08 +0200	[thread overview]
Message-ID: <1315958348.2565.22.camel@edumazet-laptop> (raw)
In-Reply-To: <CAByGWUHkt=6AjW_GFsGd1EnbMC=pjhtxRu8ez0sw6rZNvA_nxg@mail.gmail.com>

Le mardi 13 septembre 2011 à 16:11 -0700, Murali raja Muniraju a écrit :
> Hi,
>    I see a potential deadlock situation on the kernel 2.6.34. Has this
> been fixed in the later version of the kernel.
> 
> I see that one after holding the neigh_lookup, one can acquire the
> lock for rt_hash_locks
> 
> But there is a situation while freed skb's in dst_release while
> holding the rt_hash_locks, neigh_lookup can be called which tries to
> acquire its lock.
> 
> This seems to be a deadlock candidate.
> 
> Thanks,
> Murali
> 
> Below if the scenario found by lockdep on a debug kernel during the
> kernel bootup.
> 

All this code changed in 2.6.37 with commit
d6bf781712a1d25cc8987036b3a48535b331eb91
(net neigh: RCU conversion of neigh hash table)

  reply	other threads:[~2011-09-13 23:59 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-13 23:11 Query on a lockdep issue in neigh_lookup Murali raja Muniraju
2011-09-13 23:59 ` Eric Dumazet [this message]
2011-09-14  9:36 ` Eric Dumazet

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