From 0bb2c7637ef0db4f44528698fa725179fb4917ad Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Tue, 18 Dec 2012 14:21:32 -0800 Subject: [PATCH] mm/page_alloc.c: remove duplicate check While allocating pages using buddy allocator, the compound page is probably split up to free pages. Under these circumstances, the compound page should be destroyed by destroy_compound_page(). However, there is a duplicate check to judge if the page is compound. Remove the duplicate check since the compound_order() returns 0 when the page doesn't have PG_head set in destroy_compound_page(). That is to say, destroy_compound_page() needn't check PageHead(). Signed-off-by: Gavin Shan Acked-by: Johannes Weiner Acked-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d037c8b..62496ed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -371,8 +371,7 @@ static int destroy_compound_page(struct page *page, unsigned long order) int nr_pages = 1 << order; int bad = 0; - if (unlikely(compound_order(page) != order) || - unlikely(!PageHead(page))) { + if (unlikely(compound_order(page) != order)) { bad_page(page); bad++; } -- 2.7.4