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>
This commit is contained in:
Naoya Horiguchi 2013-02-22 16:34:05 -08:00 committed by Linus Torvalds
parent af8fae7c08
commit 4db0e950c5

View File

@ -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);
/*