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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2015-02-12 15:00:25 -0800 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-04-28 10:48:53 -0400 |
| commit | ad931555388824fb12bc8f555e6fb6ee57ad4352 (patch) | |
| tree | 51b4722b890ac57a0848b0de85a0ee02488c212e /mm | |
| parent | 3e16c7f2f05592c9dc7c337623786d875035dcdf (diff) | |
| download | lwn-ad931555388824fb12bc8f555e6fb6ee57ad4352.tar.gz lwn-ad931555388824fb12bc8f555e6fb6ee57ad4352.zip | |
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory-failure.c | 2 |
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)) drain_all_pages(); SetPageHWPoison(page); if (!is_free_buddy_page(page)) |