Re: [PATCH v2 03/10] cgroup: net_cls: Protect access to task_cls_classid() when built as module
From: Tejun Heo <hidden>
Date: 2012-08-24 23:26:21
Also in:
cgroups
On Fri, Aug 24, 2012 at 04:01:37PM +0200, Daniel Wagner wrote:
quoted hunk
@@ -306,6 +312,11 @@ static void __exit exit_cgroup_cls(void) synchronize_rcu(); #endif +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) + static_key_slow_dec(&cgroup_cls_enabled); + rcu_barrier();
Why is this rcu_barrier() necessary? In general, please explain what synchronization is going on when using sync constructs which aren't obvious - e.g. memory barriers, rcu barriers. Thanks. -- tejun