Re: [v2 PATCH] mm: vmscan: correct nr_reclaimed for THP

[Yang Shi]

> [ check_move_unevictable_pages() seems weird. It gets a pagevec from
>    find_get_entries(), which, if I understand the THP page cache code
>    correctly, might contain the same compound page over and over. It'll
>    be !unevictable after the first iteration, so will only run once. So
>    it produces incorrect numbers now, but it is probably best to ignore
>    it until we figure out THP cache. Maybe add an XXX comment. ]

The commit 5fd4ca2d84b2 ("mm: page cache: store only head pages in 
i_pages") changed how THP is stored in page cache, but 
find_get_entries() would return base page by calling find_subpage(), so 
check_move_unevictable_pages() should just returns the number of base pages.