On (Thu) 10 Mar 2016 [12:31:32], Jitendra Kolhe wrote: > On 3/8/2016 4:44 PM, Amit Shah wrote: > >>>> Hi, > >>>> An interesting solution; I know a few different people have been looking at > >>>> how to speed up ballooned VM migration. > >>>> > >>> > >>> Ooh, different solutions for the same purpose, and both based on the balloon. > >> > >> We were also tying to address similar problem, without actually needing to modify > >> the guest driver. Please find patch details under mail with subject. > >> migration: skip sending ram pages released by virtio-balloon driver > > > > The scope of this patch series seems to be wider: don't send free > > pages to a dest at all, vs. don't send pages that are ballooned out. > > Hi, > > Thanks for your response. The scope of this patch series doesn’t seem to take care > of ballooned out pages. To balloon out a guest ram page the guest balloon driver does > a alloc_page() and then return the guest pfn to Qemu, so ballooned out pages will not > be seen as free ram pages by the guest. > Thus we will still end up scanning (for zero page) for ballooned out pages during > migration. It would be ideal if we could have both solutions. Yes, of course it would be nice to have both solutions. My response was to the line: > >>> Ooh, different solutions for the same purpose, and both based on the balloon. which sounded misleading to me for a couple of reasons: 1, as you describe, pages being considered by this patchset and yours are different; and 2, as I mentioned in the other mail, this patchset doesn't really depend on the balloon, and I believe it should not. Amit -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
