From: David Miller <davem@davemloft.net>
To: a.p.zijlstra@chello.nl
Cc: akpm@linux-foundation.org, jarkao2@gmail.com,
netdev@vger.kernel.org, bugme-daemon@bugzilla.kernel.org,
marcus@better.se, shemminger@linux-foundation.org, rjw@sisk.pl,
linux-kernel@vger.kernel.org, mingo@elte.hu
Subject: Re: [Bugme-new] [Bug 10326] New: inconsistent lock state in net_rx_action
Date: Thu, 27 Mar 2008 04:03:34 -0700 (PDT) [thread overview]
Message-ID: <20080327.040334.25440988.davem@davemloft.net> (raw)
In-Reply-To: <1206615379.8514.502.camel@twins>
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 27 Mar 2008 11:56:19 +0100
> How about this:
>
> <irqs disabled>
>
> netpoll_poll()
> poll_napi()
> spin_trylock(&napi->poll_lock)
> poll_one_napi()
> napi->poll() := sky2_poll()
> napi_complete()
> local_irq_disable()
> local_irq_enable() <--- *BUG*
>
> <irq>
> irq_exit()
> do_softirq()
> net_rx_action()
> spin_lock(&napi->poll_lock) <--- Deadlock!
>
> Because we still hold the lock....
Yep, that will deadlock.
Can some test if using local_irq_{save,restore}() in
napi_complete() cures this lockdep warning?
Thanks.
next prev parent reply other threads:[~2008-03-27 11:03 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-10326-10286@http.bugzilla.kernel.org/>
2008-03-25 20:43 ` [Bugme-new] [Bug 10326] New: inconsistent lock state in net_rx_action Andrew Morton
2008-03-26 23:13 ` Jarek Poplawski
2008-03-27 0:14 ` Andrew Morton
2008-03-27 8:55 ` Jarek Poplawski
2008-03-27 9:08 ` Jarek Poplawski
2008-03-27 9:18 ` Andrew Morton
2008-03-27 10:07 ` Jarek Poplawski
2008-03-27 10:56 ` Peter Zijlstra
2008-03-27 11:03 ` David Miller [this message]
2008-03-27 11:59 ` Marcus Better
2008-03-27 12:32 ` Jarek Poplawski
2008-03-27 21:44 ` David Miller
2008-03-27 12:22 ` Jarek Poplawski
2008-03-27 12:30 ` Peter Zijlstra
2008-03-27 12:49 ` Jarek Poplawski
2008-03-27 21:56 ` Rafael J. Wysocki
2008-03-27 22:22 ` Jarek Poplawski
2008-03-27 22:22 ` David Miller
2008-03-27 22:39 ` Jarek Poplawski
2008-03-28 0:59 ` David Miller
2008-03-28 10:12 ` Peter Zijlstra
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