Task groups can in a many-core system run on any CPU core, but to facilitate this, creating only one scheduling entity will not suffice. Groups thus must create a scheduling entity for every CPU core on the system. Scheduling entities across CPUs are represented by struct task_group:

/* task group related information */
struct task_group {
       struct cgroup_subsys_state css;

#ifdef CONFIG_FAIR_GROUP_SCHED
 /* schedulable entities of this group on each cpu */
      struct sched_entity **se;
 /* runqueue "owned" by this group on each cpu */
  struct cfs_rq **cfs_rq;
   unsigned long shares;

#ifdef CONFIG_SMP
        /*
         * load_avg can be heavily contended at clock tick time, so put
    * it in its own cacheline separated from the fields above which
   * will also be accessed at each tick.
     */
       atomic_long_t load_avg ____cacheline_aligned;
#endif
#endif

#ifdef CONFIG_RT_GROUP_SCHED
     struct sched_rt_entity **rt_se;
   struct rt_rq **rt_rq;

       struct rt_bandwidth rt_bandwidth;
#endif

       struct rcu_head rcu;
      struct list_head list;

      struct task_group *parent;
        struct list_head siblings;
        struct list_head children;

#ifdef CONFIG_SCHED_AUTOGROUP
       struct autogroup *autogroup;
#endif

    struct cfs_bandwidth cfs_bandwidth;
};

Now every task group has a scheduling entity for every CPU core along with a CFS runqueue associated with it. When a task from one task group migrates from one CPU core (x) to another CPU core (y), the task is dequeued from the CFS runqueue of CPU x and enqueued to the CFS runqueue of CPU y.