From b4fb8f66f1ae2e167d06c12d018025a8d4d3ba7e Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 8 Mar 2017 09:35:39 -0800 Subject: [PATCH] mm, page_alloc: Add missing check for memory holes Commit 13ad59df67f1 ("mm, page_alloc: avoid page_to_pfn() when merging buddies") moved the check for memory holes out of page_is_buddy() and had the callers do the check. But this wasn't done correctly in one place which caused ia64 to crash very early in boot. Update to fix that and make ia64 boot again. [ v2: Vlastimil pointed out we don't need to call page_to_pfn() since we already have the result of that in "buddy_pfn" ] Fixes: 13ad59df67f1 ("avoid page_to_pfn() when merging buddies") Cc: Mel Gorman Cc: Joonsoo Kim Cc: Michal Hocko Cc: "Kirill A. Shutemov" Cc: Johannes Weiner Cc: Andrew Morton Signed-off-by: Tony Luck Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index eaa64d2ffdc5..6cbde310abed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -873,7 +873,8 @@ done_merging: higher_page = page + (combined_pfn - pfn); buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); higher_buddy = higher_page + (buddy_pfn - combined_pfn); - if (page_is_buddy(higher_page, higher_buddy, order + 1)) { + if (pfn_valid_within(buddy_pfn) && + page_is_buddy(higher_page, higher_buddy, order + 1)) { list_add_tail(&page->lru, &zone->free_area[order].free_list[migratetype]); goto out; -- 2.20.1