path: root/mm
diff options
authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-02-12 15:00:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 18:54:11 -0800
commit9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d (patch)
tree5eea7682b59e69f24c91b0606f7b4760fb6621a9 /mm
parent84109e15ddc8fe00c832d5228ca2aedf95d13b97 (diff)
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')
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))
if (!is_free_buddy_page(page))

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