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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-02-12 15:00:25 -0800
committerSasha Levin <sasha.levin@oracle.com>2015-04-28 10:48:53 -0400
commitad931555388824fb12bc8f555e6fb6ee57ad4352 (patch)
parent3e16c7f2f05592c9dc7c337623786d875035dcdf (diff)
mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page()
[ Upstream commit 9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d ] A race condition starts to be visible in recent mmotm, where a PG_hwpoison flag is set on a migration source page *before* it's back in buddy page poo= l. This is problematic because no page flag is supposed to be set when freeing (see __free_one_page().) So the user-visible effect of this race is that it could trigger the BUG_ON() when soft-offlining is called. The root cause is that we call lru_add_drain_all() to make sure that the page is in buddy, but that doesn't work because this function just schedule= s a work item and doesn't wait its completion. drain_all_pages() does drainin= g directly, so simply dropping lru_add_drain_all() solves this problem. Fixes: f15bdfa802bf ("mm/memory-failure.c: fix memory leak in successful soft offlining") 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: Chen Gong <gong.chen@linux.intel.com> Cc: <stable@vger.kernel.org> [3.11+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
1 files changed, 0 insertions, 2 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 8639f6b28746..3415e7ad3973 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1659,8 +1659,6 @@ static int __soft_offline_page(struct page *page, int flags)
* setting PG_hwpoison.
if (!is_free_buddy_page(page))
- lru_add_drain_all();
- if (!is_free_buddy_page(page))
if (!is_free_buddy_page(page))