From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [RFC] Notifier for Externally Mapped Memory (EMM)
Date: Tue, 04 Mar 2008 23:42:09 +0100
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Cc: Andrea Arcangeli <andrea@qumranet.com>,
	Jack Steiner <steiner@sgi.com>, Nick Piggin <npiggin@suse.de>,
	akpm@linux-foundation.org, Robin Holt <holt@sgi.com>,
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To: Christoph Lameter <clameter@sgi.com>
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On Tue, 2008-03-04 at 14:35 -0800, Christoph Lameter wrote:

> RCU means that the callbacks occur in an atomic context.

Not really, if it requires moving the VM locks to sleepable locks under
a .config option, I think its also fair to require PREEMPT_RCU.

OTOH, if you want to unconditionally move the VM locks to sleepable
locks you have a point.