thp: comment reminder in destroy_compound_page

Warn destroy_compound_page that __split_huge_page_refcount is heavily
dependent on its internal behavior.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8be81422d4bd8de1d81d522884f159fa54e25f97..6e62d5f9d40b7260d9f933a3570f4e622f62b9dd 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -357,6 +357,7 @@ void prep_compound_page(struct page *page, unsigned long order)
        }
 }
 
+/* update __split_huge_page_refcount if you change this function */
 static int destroy_compound_page(struct page *page, unsigned long order)
 {
        int i;