On Sun, 3 Nov 2019, John Hubbard wrote: > Introduce pin_user_pages*() variations of get_user_pages*() calls, > and also pin_longterm_pages*() variations. > > These variants all set FOLL_PIN, which is also introduced, and > thoroughly documented. > > The pin_longterm*() variants also set FOLL_LONGTERM, in addition > to FOLL_PIN: > > pin_user_pages() > pin_user_pages_remote() > pin_user_pages_fast() > > pin_longterm_pages() > pin_longterm_pages_remote() > pin_longterm_pages_fast() > > All pages that are pinned via the above calls, must be unpinned via > put_user_page(). > Hi John, I'm curious what consideration is given to what pageblock migrate types that FOLL_PIN and FOLL_LONGTERM pages originate from, assuming that longterm would want to originate from MIGRATE_UNMOVABLE pageblocks for the purposes of anti-fragmentation?
