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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2015-02-12 15:00:25 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-18 14:10:54 +0100 |
| commit | 1bab6ee0b41e4fa4550693da82742aa50a94290c (patch) | |
| tree | 8a5b78944d062bc11c41f115bf0f5fedb17c0b5e /mm | |
| parent | 6f5468a717c8f18e721dc9bc7f8d7ce41f22eb1a (diff) | |
| download | lwn-1bab6ee0b41e4fa4550693da82742aa50a94290c.tar.gz lwn-1bab6ee0b41e4fa4550693da82742aa50a94290c.zip | |
mm: hwpoison: drop lru_add_drain_all() in __soft_offline_page()
commit 9ab3b598d2dfbdb0153ffa7e4b1456bbff59a25d upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 feb803bf3443..20c29ddff17b 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1654,8 +1654,6 @@ 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)) |