[PATCH v14 08/20] mm/memcg: add debug checking in lock_page_memcg

[Alex Shi]

Add a debug checking in lock_page_memcg, then we could get alarm
if anything wrong here.

Suggested-by: Johannes Weiner <han...@cmpxchg.org>
Signed-off-by: Alex Shi <alex....@linux.alibaba.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Michal Hocko <mho...@kernel.org>
Cc: Vladimir Davydov <vdavydov....@gmail.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: cgro...@vger.kernel.org
Cc: linux...@kvack.org
Cc: linux-kernel@vger.kernel.org
---
 mm/memcontrol.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 19622328e4b5..fde47272b13c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1983,6 +1983,12 @@ struct mem_cgroup *lock_page_memcg(struct page *page)
        if (unlikely(!memcg))
                return NULL;
 
+#ifdef CONFIG_PROVE_LOCKING
+       local_irq_save(flags);
+       might_lock(&memcg->move_lock);
+       local_irq_restore(flags);
+#endif
+
        if (atomic_read(&memcg->moving_account) <= 0)
                return memcg;
 
-- 
1.8.3.1