From 08fb5e0d43434a56b35e3ef436c15ae9b3835fae 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 d8128c74d2ca ("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: d8128c74d2ca ("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 eaa64d2ffdc55..6cbde310abed8 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; -- 2.39.5