On Mon, Sep 18, 2023 at 09:55:22AM +0000, Shameerali Kolothum Thodi wrote: [...] > > Sorry, this was rather nonspecific. I was describing the pre-copy > > strategies we're using at Google (out of tree). We're carrying patches > > to use EPT D-bit for exitless dirty tracking. > > Just curious, how does it handle the overheads associated with scanning for > dirty pages and the convergence w.r.t high rate of dirtying in exitless mode? A pool of kthreads, which really isn't a good solution at all. The 'better' way to do it would be to add some back pressure to the guest such that your pre-copy transfer can converge with the guest and use the freed up CPU time to manage the dirty state. But hopefully we can make that a userspace issue. -- Thanks, Oliver
