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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2014-02-10 14:25:50 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-22 12:41:26 -0800
commit2186bb4e794d284012e9af6bf592e5375279439d (patch)
treee4dd5404a3597aa6c66410447e38a40a7f75ea0a
parent434672c0c50a3ef988c9d582c0148c9067e6961c (diff)
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 <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/memory-failure.c6
1 files changed, 4 insertions, 2 deletions
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;