From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: 2.6.34-rc1: rcu lockdep bug?
Date: Mon, 15 Mar 2010 11:04:20 +0100
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Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	David Miller <davem@davemloft.net>, peterz@infradead.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org
To: =?ISO-8859-1?Q?Am=E9rico?= Wang <xiyou.wangcong@gmail.com>
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Le lundi 15 mars 2010 =C3=A0 17:39 +0800, Am=C3=A9rico Wang a =C3=A9cri=
t :

>=20
> Ok, I think I found what lockdep really complains about, it is that w=
e took
> spin_lock in netpoll_poll_lock() which is in hardirq-enabled environm=
ent,
> later, we took another spin_lock with spin_lock_irqsave() in netpoll_=
rx(),
> so lockdep thought we broke the locking rule.
>=20
> I don't know why netpoll_rx() needs irq disabled, it looks like that =
no one
> takes rx_lock in hardirq context. So can we use spin_lock(&rx_lock)
> instead? Or am I missing something here? Eric? David?

I am a bit lost.

Could you give the complete picture, because I cannot find it in my
netdev archives.