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Date: Wed, 23 Jan 2008 11:47:27 -0800 (PST)
From: Christoph Lameter <clameter@sgi.com>
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To: Andrea Arcangeli <andrea@qumranet.com>
cc: Robin Holt <holt@sgi.com>, Avi Kivity <avi@qumranet.com>,
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       linux-kernel@vger.kernel.org, linux-mm@kvack.org,
       daniel.blueman@quadrics.com, Hugh Dickins <hugh@veritas.com>
Subject: Re: [kvm-devel] [PATCH] export notifier #1
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On Wed, 23 Jan 2008, Robin Holt wrote:

> > That won't work for kvm.  If we have a hundred virtual machines, that means
> > 99 no-op notifications.
> 
> But 100 callouts holding spinlocks will not work for our implementation
> and even if the callouts are made with spinlocks released, we would very
> strongly prefer a single callout which messages the range to the other
> side.


Andrea wont have 99 no op notifications. You will have one notification to 
the kvm subsystem (since there needs to be only one register operation 
for a subsystem that wants to get notifications). What do you do there is 
up to kvm. If you want to call some function 99 times then you are free to 
do that.