---
 kernel/cgroup.c |    3 +--
 mm/memcontrol.c |   11 ++++++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7981850..01c67f4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c

@@ -4151,7 +4151,6 @@ again:
 		mutex_unlock(&cgroup_mutex);
 		return -EBUSY;
 	}
-	mutex_unlock(&cgroup_mutex);
 
 	/*
 	 * In general, subsystem has no css->refcnt after pre_destroy(). But

@@ -4171,10 +4170,10 @@ again:
 	ret = cgroup_call_pre_destroy(cgrp);
 	if (ret) {
 		clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags);
+		mutex_unlock(&cgroup_mutex);
 		return ret;
 	}
 
-	mutex_lock(&cgroup_mutex);
 	parent = cgrp->parent;
 	if (atomic_read(&cgrp->count) || !list_empty(&cgrp->children)) {
 		clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e8ddc00..9bd56ee 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -4993,9 +4993,18 @@ free_out:
 
 static int mem_cgroup_pre_destroy(struct cgroup *cont)
 {
+	int ret;
 	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-	return mem_cgroup_force_empty(memcg, false);
+	cgroup_unlock();
+	/*
+	 * we call lru_add_drain_all, which end up taking
+	 * mutex_lock(&cpu_hotplug.lock), But cpuset have
+	 * the reverse order. So drop the cgroup lock
+	 */
+	ret = mem_cgroup_force_empty(memcg, false);
+	cgroup_lock();
+	return ret;
 }
 
 static void mem_cgroup_destroy(struct cgroup *cont)

-- 
1.7.10