Re: [PATCH V5 3/8] memcg: check for proper lock held in mem_cgroup_update_page_stat
From: Michal Hocko <hidden>
Date: 2013-08-01 14:35:03
Also in:
linux-mm
On Thu 01-08-13 19:52:26, Sha Zhengju wrote:
From: Sha Zhengju <redacted> We should call mem_cgroup_begin_update_page_stat() before mem_cgroup_update_page_stat() to get proper locks, however the latter doesn't do any checking that we use proper locking, which would be hard. Suggested by Michal Hock we could at least test for rcu_read_lock_held() because RCU is held if !mem_cgroup_disabled(). Signed-off-by: Sha Zhengju <redacted>
Acked-by: Michal Hocko <redacted>
quoted hunk ↗ jump to hunk
--- mm/memcontrol.c | 1 + 1 file changed, 1 insertion(+)diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7691cef..4a55d46 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -2301,6 +2301,7 @@ void mem_cgroup_update_page_stat(struct page *page, if (mem_cgroup_disabled()) return; + VM_BUG_ON(!rcu_read_lock_held()); memcg = pc->mem_cgroup; if (unlikely(!memcg || !PageCgroupUsed(pc))) return;-- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo-Bw31MaZKKs0EbZ0PF+XxCw@public.gmane.org For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org"> email-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org </a>
-- Michal Hocko SUSE Labs