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 <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8be81422d4bd..6e62d5f9d40b 100644
--- 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;