Messages in this thread | | | Date | Tue, 10 Nov 2009 16:43:38 +0200 | From | Avi Kivity <> | Subject | Re: [Qemu-devel] Re: virtio: Add memory statistics reporting to the balloon driver |
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On 11/10/2009 04:36 PM, Anthony Liguori wrote: > >> A stats vq might solve this more cleanly? > > actual and target are both really just stats. Had we implemented > those with a vq, I'd be inclined to agree with you but since they're > implemented in the config space, it seems natural to extend the config > space with other stats. >
There is in fact a difference; actual and target are very rarely updated, while the stats are updated very often. Using a vq means a constant number of exits per batch instead of one exit per statistic. If the vq is host-driven, it also allows the host to control the update frequency dynamically (i.e. stop polling when there is no memory pressure).
-- error compiling committee.c: too many arguments to function
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