On Tue, Dec 10, 2019 at 02:31:54PM +0100, Paolo Bonzini wrote: > On 10/12/19 14:25, Michael S. Tsirkin wrote: > >> There is no new infrastructure to track the dirty pages---it's just a > >> different way to pass them to userspace. > > Did you guys consider using one of the virtio ring formats? > > Maybe reusing vhost code? > > There are no used/available entries here, it's unidirectional > (kernel->user). Didn't look at the design yet, but flow control (to prevent overflow) goes the other way, doesn't it? That's what used is, essentially. > > If you did and it's not a good fit, this is something good to mention > > in the commit log. > > > > I also wonder about performance numbers - any data here? > > Yes some numbers would be useful. Note however that the improvement is > asymptotical, O(#dirtied pages) vs O(#total pages) so it may differ > depending on the workload. > > Paolo
