On Mon, Aug 16, 2021 at 03:00:49PM -0400, Felix Kuehling wrote: > > Am 2021-08-15 um 11:40 a.m. schrieb Christoph Hellwig: > > On Fri, Aug 13, 2021 at 01:31:45AM -0500, Alex Sierra wrote: > >> Add MEMORY_DEVICE_GENERIC case to free_zone_device_page callback. > >> Device generic type memory case is now able to free its pages properly. > > How is this going to work for the two existing MEMORY_DEVICE_GENERIC > > that now change behavior? And which don't have a ->page_free callback > > at all? > > That's a good catch. Existing drivers shouldn't need a page_free > callback if they didn't have one before. That means we need to add a > NULL-pointer check in free_device_page. Also the other state clearing (__ClearPageWaiters/mem_cgroup_uncharge/ ->mapping = NULL). In many ways this seems like you want to bring back the DEVICE_PUBLIC pgmap type that was removed a while ago due to the lack of users instead of overloading the generic type.