Re: [Qemu-devel] [RFC qemu 0/4] A PV solution for live migration optimization

[Michael S. Tsirkin]

On Fri, Mar 04, 2016 at 09:12:12AM +0000, Li, Liang Z wrote:
> > Although I wonder which is cheaper; that would be fairly expensive for the
> > guest wouldn't it? And you'd somehow have to kick the guest before
> > migration to do the ballooning - and how long would you wait for it to 
> > finish?
> 
> About 5 seconds for an 8G guest, balloon to 1G. Get the free pages bitmap 
> take about 20ms
> for an 8G idle guest.
> 
> Liang

Where is the time spent though? allocating within guest?
Or passing the info to host?
If the former, we can use existing inflate/deflate vqs:
Have guest put each free page on inflate vq, then on deflate vq.

-- 
MST