Hi David, > > >> - Add a new API to the backing store/allocator to longterm-pin the page. > >> For example, something along the lines of > shmem_pin_mapping_page_longterm() > >> for shmem as suggested by Daniel. A similar one needs to be added for > >> hugetlbfs as well. > > > > This may also be reasonable. > > Sounds reasonable to keep the old API (that we unfortunately have) working. I agree; I'd like to avoid adding new APIs unless absolutely necessary. Given this, and considering the options I have mentioned earlier, what would be your recommendation for how page migration needs to be done in udmabuf driver? Thanks, Vivek > > -- > Cheers, > > David / dhildenb