From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] netfilter: per-cpu spin-lock with recursion (v0.8)
Date: Fri, 17 Apr 2009 19:08:15 +0200
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Cc: Stephen Hemminger <shemminger@vyatta.com>,
	paulmck@linux.vnet.ibm.com, David Miller <davem@davemloft.net>,
	kaber@trash.net, torvalds@linux-foundation.org,
	jeff.chua.linux@gmail.com, paulus@samba.org, mingo@elte.hu,
	laijs@cn.fujitsu.com, jengelh@medozas.de, r000n@r000n.net,
	linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org,
	netdev@vger.kernel.org, benh@kernel.crashing.org
To: Eric Dumazet <dada1@cosmosbay.com>
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On Fri, 2009-04-17 at 08:14 +0200, Eric Dumazet wrote:
> > Also, please dont call this a 'recursive lock', since it is not a general
> > recursive lock, as pointed by Linus and Paul.
> > 
> > Second question is about MAX_LOCK_DEPTH
> 
> I meant here the ~256 limit we have on preempt_count, not related to LOCKDEP

Very good point, so 256 nested spin_lock() instances will make the
kernel unhappy -- since we now (almost?) support up to 4096 cpus, this
seems like a no-no.