On Mon, Nov 23, 2020 at 11:06:21AM -0500, Pavel Tatashin wrote: > What I mean here is allowing users to guarantee that the page's PA is > going to stay the same. Sort of a stronger mlock. Mlock only > guarantees that the page is not swapped, but something like You've just described get/pin_user_pages(), that is exactly what it is for. I agree with the other emails, ZONE_MOVABLE needs to be reconciled with FOLL_LONGTERM - most likely by preventing ZONE_MOVABLE pages from being returned. This will need migration like CMA does and the point about faulting is only an optimization to prevent fault then immediate migration. Jason
