[PATCH v13 08/18] mm/memcg: add debug checking in lock_page_memcg

From: Alex Shi <alex.shi@linux.alibaba.com>
To: akpm@linux-foundation.org, mgorman@techsingularity.net,
	tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru,
	daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com,
	willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	cgroups@vger.kernel.org, shakeelb@google.com,
	iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com
Cc: Michal Hocko <mhocko@kernel.org>,
	Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: [PATCH v13 08/18] mm/memcg: add debug checking in lock_page_memcg
Date: Fri, 19 Jun 2020 16:33:46 +0800	[thread overview]
Message-ID: <1592555636-115095-9-git-send-email-alex.shi@linux.alibaba.com> (raw)
In-Reply-To: <1592555636-115095-1-git-send-email-alex.shi@linux.alibaba.com>

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

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: cgroups@vger.kernel.org
Cc: linux-mm@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 0b38b6ad547d..78c16ac1473d 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

