| From 602498f9aa43d4951eece3fd6ad95a6d0a78d537 Mon Sep 17 00:00:00 2001 |
| From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> |
| Date: Tue, 5 May 2015 16:23:46 -0700 |
| Subject: mm: soft-offline: fix num_poisoned_pages counting on concurrent events |
| |
| 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 |
| @@ -1721,12 +1721,12 @@ 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); |
