3.18-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 3aaa76e125c1dd58c9b599baa8c6021896874c12 ]
Since commit bcc54222309c ("mm: hugetlb: introduce page_huge_active")
each hugetlb page maintains its active flag to avoid a race condition
betwe= en multiple calls of isolate_huge_page(), but current kernel
doesn't set the f= lag on a hugepage allocated by migration because the
proper putback routine isn= 't called. This means that users could
still encounter the race referred to by bcc54222309c in this special
case, so this patch fixes it.
Fixes: bcc54222309c ("mm: hugetlb: introduce page_huge_active")
Signed-off-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Michal Hocko <mho...@suse.cz>
Cc: Andi Kleen <a...@firstfloor.org>
Cc: Hugh Dickins <hu...@google.com>
Cc: <sta...@vger.kernel.org> [4.1.x]
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 4d743bce5a23..57559f9295f9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1077,7 +1077,7 @@ out:
if (rc != MIGRATEPAGE_SUCCESS && put_new_page)
put_new_page(new_hpage, private);
else
- put_page(new_hpage);
+ putback_active_hugepage(new_hpage);
if (result) {
if (rc)
--
2.17.1
