Date: Wed, 23 Feb 2011 12:15:34 -0800
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Lameter <cl@linux.com>, Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
        Frederic Weisbecker <fweisbec@gmail.com>, linux-kernel@vger.kernel.org,
        mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
        akpm@linux-foundation.org, josh@joshtriplett.org, niv@us.ibm.com,
        tglx@linutronix.de, Valdis.Kletnieks@vt.edu, dhowells@redhat.com,
        eric.dumazet@gmail.com, darren@dvhart.com,
        "Paul E. McKenney" <paul.mckenney@linaro.org>
Subject: Re: [PATCH RFC tip/core/rcu 11/11] rcu: move TREE_RCU from softirq
 to kthread
Message-ID: <20110223201534.GX2163@linux.vnet.ibm.com>
Reply-To: paulmck@linux.vnet.ibm.com
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On Wed, Feb 23, 2011 at 08:23:50PM +0100, Peter Zijlstra wrote:
> On Wed, 2011-02-23 at 13:19 -0600, Christoph Lameter wrote:
> 
> > this_cpu_inc is already percpu atomic. On x86 it is an instruction that
> > cannot be interrupted nor preempted while in progress.
> 
> On x86, yes, but is this true for all architectures? I guess the
> fallback is implemented with local_irq_disable() which might be good
> enough for some but not for NMI usage.

Good point!  Thankfully, no worries about NMI usage in this piece of
code.  ;-)

							Thanx, Paul
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