mm: thp: turn compound_head() into BUG_ON(!PageTail) in get_huge_page_tail()

get_huge_page_tail()->compound_head() looks confusing.  Every caller
must check PageTail(page), otherwise atomic_inc(&page->_mapcount) is
simply wrong if this page is compound-trans-head.

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Dave Jones <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mel Gorman <[email protected]>
Acked-by: Andrea Arcangeli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions