when the page (and the block) in the buddy, the mapcount equals PAGE_BUDDY_MAPCOUNT_VALUE
when the page is in pcp list, the page private records the migratetype
private field is sometimes used to store the order or the migrate type temporarily when the page is inside the buddy system.
event:
sometimes we do not have enough pages in a specified migratetype. to sometimes it helps if we can move some free pages around in a page block to the page list of corresponding migratetype.
when the page is in pcp list, the page private records the migratetype
private field is sometimes used to store the order or the migrate type temporarily when the page is inside the buddy system.
event:
sometimes we do not have enough pages in a specified migratetype. to sometimes it helps if we can move some free pages around in a page block to the page list of corresponding migratetype.
