Commit 4db0e950 authored Feb 22, 2013 by Naoya Horiguchi Committed by Linus Torvalds Feb 23, 2013

mm/memory-failure.c: fix wrong num_poisoned_pages in handling memory error on thp

num_poisoned_pages counts up the number of pages isolated by memory
errors.  But for thp, only one subpage is isolated because memory error
handler splits it, so it's wrong to add (1 << compound_trans_order).

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent af8fae7c

mm/memory-failure.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -1039,7 +1039,17 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
		return 0;
		}

		nr_pages = 1 << compound_trans_order(hpage);
		/*
		* Currently errors on hugetlbfs pages are measured in hugepage units,
		* so nr_pages should be 1 << compound_order. OTOH when errors are on
		* transparent hugepages, they are supposed to be split and error
		* measurement is done in normal page units. So nr_pages should be one
		* in this case.
		*/
		if (PageHuge(p))
		nr_pages = 1 << compound_order(hpage);
		else /* normal page or thp */
		nr_pages = 1;
		atomic_long_add(nr_pages, &num_poisoned_pages);

		/*