Re: [Qemu-devel] [PATCH kernel 1/2] mm: add the related functions to build the free page bitmap

[Rik van Riel]

On Tue, 2016-04-19 at 15:02 +0000, Li, Liang Z wrote:
> > 
> > On Tue, 2016-04-19 at 22:34 +0800, Liang Li wrote:
> > > 
> > > The free page bitmap will be sent to QEMU through virtio
> > > interface and
> > > used for live migration optimization.
> > > Drop the cache before building the free page bitmap can get more
> > > free
> > > pages. Whether dropping the cache is decided by user.
> > > 
> > How do you prevent the guest from using those recently-freed pages
> > for
> > something else, between when you build the bitmap and the live
> > migration
> > completes?
> Because the dirty page logging is enabled before building the bitmap,
> there is no need
> to prevent the guest from using the recently-freed pages ...

Fair enough.

It would be good to have that mentioned in the
changelog.