Re: [PATCH 14/16] KVM-GST: KVM Steal time registration

From: Glauber Costa
Date: Mon Jan 24 2011 - 20:25:33 EST


On Mon, 2011-01-24 at 18:31 -0500, Rik van Riel wrote:
> On 01/24/2011 01:06 PM, Glauber Costa wrote:
> > Register steal time within KVM. Everytime we sample the steal time
> > information, we update a local variable that tells what was the
> > last time read. We then account the difference.
> >
> > Signed-off-by: Glauber Costa<glommer@xxxxxxxxxx>
> > CC: Rik van Riel<riel@xxxxxxxxxx>
> > CC: Jeremy Fitzhardinge<jeremy.fitzhardinge@xxxxxxxxxx>
> > CC: Peter Zijlstra<peterz@xxxxxxxxxxxxx>
> > CC: Avi Kivity<avi@xxxxxxxxxx>
>
> On second thought - how does this deal with cpu hotplug and
> hot unplug?
>
> Do you allocate a new one of these structs every time a cpu
> is hot unplugged and then hotplugged, leaking the old one?
>
> Will leaving the old value around confuse the steal time
> calculation?

If you look closely, there are no allocations happening at all,
it's all static.

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