Braindead safety checks for cgroups stubs.

-ck

---
 kernel/sched/bfs.c |   21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

Index: linux-4.7-ck4/kernel/sched/bfs.c
===================================================================
--- linux-4.7-ck4.orig/kernel/sched/bfs.c	2016-09-13 17:21:53.284225917 +1000
+++ linux-4.7-ck4/kernel/sched/bfs.c	2016-09-13 17:21:53.282225963 +1000
@@ -7339,8 +7339,6 @@ LIST_HEAD(task_groups);
 
 /* Cacheline aligned slab cache for task_group */
 static struct kmem_cache *task_group_cache __read_mostly;
-/* task_group_lock serializes the addition/removal of task groups */
-static DEFINE_SPINLOCK(task_group_lock);
 #endif /* CONFIG_CGROUP_SCHED */
 
 void __init sched_init(void)
@@ -7827,17 +7825,6 @@ struct task_group *sched_create_group(st
 
 void sched_online_group(struct task_group *tg, struct task_group *parent)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&task_group_lock, flags);
-	list_add_rcu(&tg->list, &task_groups);
-
-	WARN_ON(!parent); /* root should already exist */
-
-	tg->parent = parent;
-	INIT_LIST_HEAD(&tg->children);
-	list_add_rcu(&tg->siblings, &parent->children);
-	spin_unlock_irqrestore(&task_group_lock, flags);
 }
 
 /* rcu callback to free various structures associated with a task group */
@@ -7855,12 +7842,6 @@ void sched_destroy_group(struct task_gro
 
 void sched_offline_group(struct task_group *tg)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&task_group_lock, flags);
-	list_del_rcu(&tg->list);
-	list_del_rcu(&tg->siblings);
-	spin_unlock_irqrestore(&task_group_lock, flags);
 }
 
 static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
@@ -7908,7 +7889,7 @@ static void cpu_cgroup_fork(struct task_
 
 static int cpu_cgroup_can_attach(struct cgroup_taskset *tset)
 {
-		return 0;
+	return 0;
 }
 
 static void cpu_cgroup_attach(struct cgroup_taskset *tset)