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Subject: Re: [PATCH] lockdep: Make lockstats counting per cpu
From: Peter Zijlstra <peterz@infradead.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
       Steven Rostedt <rostedt@goodmis.org>
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Date: Fri, 26 Mar 2010 07:52:38 +0100
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On Fri, 2010-03-26 at 03:22 +0100, Frederic Weisbecker wrote:
> We can't use irqsafe per cpu counters for that as
> these stats might be also written from NMI path, and irqsafe per
> cpu counters are not NMI safe, but local_t operations are.
> 
lockdep shouldn't do NMI, nmi_enter() has an explicit lockdep_off().