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

[Glauber Costa]

On Mon, 2011-01-24 at 20:26 -0500, Rik van Riel wrote:
> On 01/24/2011 08:25 PM, Glauber Costa wrote:
> > 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.
> 
> In that case, does the per-cpu steal area need to be
> reinitialized at hotplug time?
Probably.

I have to look closely at all unregistration scenarios, like
reboot.
It's part of my todo list

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/