Hi Jason, David, > > > Sure, we can simply always fail when we detect ZONE_MOVABLE or > MIGRATE_CMA. > > Maybe that keeps at least some use cases working. > > That seems fairly reasonable AFAICS, failing udmabuf_create() if we detect one or more pages are in ZONE_MOVABLE or MIGRATE_CMA would not be a recoverable failure -- as it would result in the failure of Guest GUI (or compositor). I think it makes sense to have a generic version of And, since check_and_migrate_movable_pages() is GUP-specific, would it be ok to create a generic version of that (in mm/migrate.c) which can be used by udmabuf and/or other drivers in the future? Thanks, Vivek > > Jason
