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Date: Fri, 10 Apr 2009 02:18:54 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: ebiederm@xmission.com (Eric W. Biederman)
Cc: Ingo Molnar <mingo@elte.hu>, Jan Beulich <jbeulich@novell.com>,
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       Peter Zijlstra <peterz@infradead.org>,
       Alexey Dobriyan <adobriyan@gmail.com>, <netdev@vger.kernel.org>
Subject: Re: [PATCH 2/2] sysctl:  lockdep support for sysctl reference
 counting.
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On Sat, 21 Mar 2009 00:42:19 -0700 ebiederm@xmission.com (Eric W. Biederman) wrote:

> It is possible for get lock ordering deadlocks between locks
> and waiting for the sysctl used count to drop to zero.  We have
> recently observed one of these in the networking code.
> 
> So teach the sysctl code how to speak lockdep so the kernel
> can warn about these kinds of rare issues proactively.

`make headers_check':

/usr/src/25/usr/include/linux/sysctl.h:31: included file 'linux/lockdep.h' is not exported
make[2]: *** [/usr/src/25/usr/include/linux/.check] Error 1

It looks like we'll need version 2 on these patches..