On Thu, Mar 01, 2018 at 01:15:21PM -0800, Matthew Wilcox wrote: > From: Matthew Wilcox <[email protected]> > > We're already using a union of many fields here, so stop abusing the > _map_count and make page_type its own field. That implies renaming some
s/_map_count/_mapcount/ and in subject. > of the machinery that creates PageBuddy, PageBalloon and PageKmemcg; > bring back the PG_buddy, PG_balloon and PG_kmemcg names. > > As suggested by Kirill, make page_type a bitmask. Because it starts out > life as -1 (thanks to sharing the storage with _map_count), setting a > page flag means clearing the appropriate bit. This gives us space for > probably twenty or so extra bits (depending how paranoid we want to be > about _mapcount underflow). > > Signed-off-by: Matthew Wilcox <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> -- Kirill A. Shutemov
