From 2186bb4e794d284012e9af6bf592e5375279439d Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Mon, 10 Feb 2014 14:25:50 -0800 Subject: mm/memory-failure.c: move refcount only in !MF_COUNT_INCREASED commit 8d547ff4ac5927245e0833ac18528f939da0ee0e upstream. mce-test detected a test failure when injecting error to a thp tail page. This is because we take page refcount of the tail page in madvise_hwpoison() while the fix in commit a3e0f9e47d5e ("mm/memory-failure.c: transfer page count from head page to tail page after split thp") assumes that we always take refcount on the head page. When a real memory error happens we take refcount on the head page where memory_failure() is called without MF_COUNT_INCREASED set, so it seems to me that testing memory error on thp tail page using madvise makes little sense. This patch cancels moving refcount in !MF_COUNT_INCREASED for valid testing. [akpm@linux-foundation.org: s/&&/&/] Signed-off-by: Naoya Horiguchi Cc: Andi Kleen Cc: Wanpeng Li Cc: Chen Gong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memory-failure.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f2a591d87d00..e386beefc994 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -943,8 +943,10 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * to it. Similarly, page lock is shifted. */ if (hpage != p) { - put_page(hpage); - get_page(p); + if (!(flags & MF_COUNT_INCREASED)) { + put_page(hpage); + get_page(p); + } lock_page(p); unlock_page(hpage); *hpagep = p; -- cgit v1.2.3