Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 09/51] mm: soft-offline: fix num_poisoned_pages counting on concurrent events | Date | Fri, 15 May 2015 16:10:11 -0700 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
commit 602498f9aa43d4951eece3fd6ad95a6d0a78d537 upstream.
If multiple soft offline events hit one free page/hugepage concurrently, soft_offline_page() can handle the free page/hugepage multiple times, which makes num_poisoned_pages counter increased more than once. This patch fixes this wrong counting by checking TestSetPageHWPoison for normal papes and by checking the return value of dequeue_hwpoisoned_huge_page() for hugepages.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> 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>
--- mm/memory-failure.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1723,12 +1723,12 @@ int soft_offline_page(struct page *page, } else if (ret == 0) { /* for free pages */ if (PageHuge(page)) { set_page_hwpoison_huge_page(hpage); - dequeue_hwpoisoned_huge_page(hpage); - atomic_long_add(1 << compound_order(hpage), + if (!dequeue_hwpoisoned_huge_page(hpage)) + atomic_long_add(1 << compound_order(hpage), &num_poisoned_pages); } else { - SetPageHWPoison(page); - atomic_long_inc(&num_poisoned_pages); + if (!TestSetPageHWPoison(page)) + atomic_long_inc(&num_poisoned_pages); } } unset_migratetype_isolate(page, MIGRATE_MOVABLE);
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