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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2015-02-13 02:00:25 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-13 05:54:11 +0300 |
| commit | 9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d (patch) | |
| tree | 5eea7682b59e69f24c91b0606f7b4760fb6621a9 /mm/memory-failure.c | |
| parent | 84109e15ddc8fe00c832d5228ca2aedf95d13b97 (diff) | |
| download | linux-9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d.tar.xz | |
mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page()
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>
Diffstat (limited to 'mm/memory-failure.c')
| -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 1a735fad2a13..d487f8dc6d39 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1647,8 +1647,6 @@ 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(page_zone(page)); SetPageHWPoison(page); if (!is_free_buddy_page(page)) |