folio_xchg_last_cpupid
int folio_xchg_last_cpupid(struct folio *folio, int cpupid);
last_time = folio_xchg_last_cpupid(folio,
last_cpupid = folio_xchg_last_cpupid(folio, this_cpupid);
folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
folio_xchg_last_cpupid(folio, (1 << LAST_CPUPID_SHIFT) - 1);
cpupid = folio_xchg_last_cpupid(folio, -1);
folio_xchg_last_cpupid(newfolio, cpupid);