From mboxrd@z Thu Jan  1 00:00:00 1970
From: John Levon <levon@movementarian.org>
Subject: Re: Live migration fails under heavy network use
Date: Thu, 22 Feb 2007 21:11:21 +0000
Message-ID: <20070222211121.GA19511@totally.trollied.org.uk>
References: <20070222195547.GA17823@totally.trollied.org.uk>
	<C203B3CB.27B9%Keir.Fraser@cl.cam.ac.uk>
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To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
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On Thu, Feb 22, 2007 at 08:55:39PM +0000, Keir Fraser wrote:

> Yes, it's because of the extra dom0 mapping. The count is 2 because one
> reference is held at this point by the freeing function in Xen.
> 
> The comment above that warning in the Xen source is a bit strong. I don't
> think we can change the semantics of the existing command but we may add a
> new one to let the caller know whether the page(s) could immediately be
> freed.

Hmm. This debug message has caught one real bug in our balloon code
recently. I presume it's not trivial to distinguish between that case
(where the domain really did have its own mapping) and the
live-migration one though.

regards
john