1 files changed, 39 insertions, 10 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 257002c13bb0..106167243d68 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7159,7 +7159,6 @@ static void free_sched_group(struct task_group *tg)
 struct task_group *sched_create_group(struct task_group *parent)
 {
         struct task_group *tg;
-        unsigned long flags;
 
         tg = kzalloc(sizeof(*tg), GFP_KERNEL);
         if (!tg)
@@ -7171,6 +7170,17 @@ struct task_group *sched_create_group(struct task_group *parent)
         if (!alloc_rt_sched_group(tg, parent))
                 goto err;
 
+        return tg;
+
+err:
+        free_sched_group(tg);
+        return ERR_PTR(-ENOMEM);
+}
+
+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);
 
@@ -7180,12 +7190,6 @@ struct task_group *sched_create_group(struct task_group *parent)
         INIT_LIST_HEAD(&tg->children);
         list_add_rcu(&tg->siblings, &parent->children);
         spin_unlock_irqrestore(&task_group_lock, flags);
-
-        return tg;
-
-err:
-        free_sched_group(tg);
-        return ERR_PTR(-ENOMEM);
 }
 
 /* rcu callback to free various structures associated with a task group */
@@ -7198,6 +7202,12 @@ static void free_sched_group_rcu(struct rcu_head *rhp)
 /* Destroy runqueue etc associated with a task group */
 void sched_destroy_group(struct task_group *tg)
 {
+        /* wait for possible concurrent references to cfs_rqs complete */
+        call_rcu(&tg->rcu, free_sched_group_rcu);
+}
+
+void sched_offline_group(struct task_group *tg)
+{
         unsigned long flags;
         int i;
 
@@ -7209,9 +7219,6 @@ void sched_destroy_group(struct task_group *tg)
         list_del_rcu(&tg->list);
         list_del_rcu(&tg->siblings);
         spin_unlock_irqrestore(&task_group_lock, flags);
-
-        /* wait for possible concurrent references to cfs_rqs complete */
-        call_rcu(&tg->rcu, free_sched_group_rcu);
 }
 
 /* change task's runqueue when it moves between groups.
@@ -7563,6 +7570,19 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
         return &tg->css;
 }
 
+static int cpu_cgroup_css_online(struct cgroup *cgrp)
+{
+        struct task_group *tg = cgroup_tg(cgrp);
+        struct task_group *parent;
+
+        if (!cgrp->parent)
+                return 0;
+
+        parent = cgroup_tg(cgrp->parent);
+        sched_online_group(tg, parent);
+        return 0;
+}
+
 static void cpu_cgroup_css_free(struct cgroup *cgrp)
 {
         struct task_group *tg = cgroup_tg(cgrp);
@@ -7570,6 +7590,13 @@ static void cpu_cgroup_css_free(struct cgroup *cgrp)
         sched_destroy_group(tg);
 }
 
+static void cpu_cgroup_css_offline(struct cgroup *cgrp)
+{
+        struct task_group *tg = cgroup_tg(cgrp);
+
+        sched_offline_group(tg);
+}
+
 static int cpu_cgroup_can_attach(struct cgroup *cgrp,
                                  struct cgroup_taskset *tset)
 {
@@ -7925,6 +7952,8 @@ struct cgroup_subsys cpu_cgroup_subsys = {
         .name           = "cpu",
         .css_alloc      = cpu_cgroup_css_alloc,
         .css_free       = cpu_cgroup_css_free,
+        .css_online     = cpu_cgroup_css_online,
+        .css_offline    = cpu_cgroup_css_offline,
         .can_attach     = cpu_cgroup_can_attach,
         .attach         = cpu_cgroup_attach,
         .exit           = cpu_cgroup_exit,