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From: David Miller <davem@davemloft.net>
To: a.p.zijlstra@chello.nl
Cc: laurent.riffard@free.fr, netdev@vger.kernel.org
Subject: Re: [BUG] netconsole broken by scheduler updates
Date: Thu, 26 May 2011 16:18:21 -0400 (EDT)	[thread overview]
Message-ID: <20110526.161821.1324179861744722209.davem@davemloft.net> (raw)
In-Reply-To: <1306403308.1200.44.camel@twins>

From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 26 May 2011 11:48:28 +0200

> Also, are you very _very_ sure that lockdep message is a false positive?

I suspect these warnings are entirely specific to using netconsole
with the forcedeth driver.

There is some really scary stuff in there, to say the least.

Just have a look at nv_do_nic_poll().  That's the first time I've
seen a networking driver use the {disable,enable}_irq_lockdep()
interfaces.

It's also using netif_tx_unlock_bh() in the "recovery" case which
in netpoll will cause a local_bh_enable() with cpu interrupts
disabled.  Which is not allowed.

Much of the forcedeth driver's locking seems suspect to me.

      parent reply	other threads:[~2011-05-26 20:18 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-26  9:21 [BUG] netconsole broken by scheduler updates Laurent Riffard
2011-05-26  9:48 ` Peter Zijlstra
2011-05-26 10:35   ` Laurent Riffard
2011-05-26 16:12     ` Laurent Riffard
2011-05-26 16:17       ` Peter Zijlstra
2011-06-03 21:15         ` Laurent Riffard
2011-05-26 20:18   ` David Miller [this message]

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