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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2015-05-05 16:23:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-05-05 17:10:10 -0700 |
| commit | 602498f9aa43d4951eece3fd6ad95a6d0a78d537 (patch) | |
| tree | 0cf960b93d33ac4f3d27c6dd5b5af3856f7eadae /mm/memory-failure.c | |
| parent | 4d61ff6b9960cb00cf2c12abd5769aa2dd475415 (diff) | |
| download | lwn-602498f9aa43d4951eece3fd6ad95a6d0a78d537.tar.gz lwn-602498f9aa43d4951eece3fd6ad95a6d0a78d537.zip | |
mm: soft-offline: fix num_poisoned_pages counting on concurrent events
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>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory-failure.c')
| -rw-r--r-- | mm/memory-failure.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 22e0f270e4f7..501820c815b3 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1777,12 +1777,12 @@ int soft_offline_page(struct page *page, int flags) } 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); |