1 files changed, 17 insertions, 20 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 3eedd5260907..6b02276baaa6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -232,10 +232,10 @@ static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
 static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
 static struct rt_rq *init_rt_rq_p[NR_CPUS];
 
-/* task_group_mutex serializes add/remove of task groups and also changes to
+/* task_group_lock serializes add/remove of task groups and also changes to
  * a task group's cpu shares.
  */
-static DEFINE_MUTEX(task_group_mutex);
+static DEFINE_SPINLOCK(task_group_lock);
 
 /* doms_cur_mutex serializes access to doms_cur[] array */
 static DEFINE_MUTEX(doms_cur_mutex);
@@ -295,16 +295,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
         p->rt.parent = task_group(p)->rt_se[cpu];
 }
 
-static inline void lock_task_group_list(void)
-{
-        mutex_lock(&task_group_mutex);
-}
-
-static inline void unlock_task_group_list(void)
-{
-        mutex_unlock(&task_group_mutex);
-}
-
 static inline void lock_doms_cur(void)
 {
         mutex_lock(&doms_cur_mutex);
@@ -318,8 +308,6 @@ static inline void unlock_doms_cur(void)
 #else
 
 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
-static inline void lock_task_group_list(void) { }
-static inline void unlock_task_group_list(void) { }
 static inline void lock_doms_cur(void) { }
 static inline void unlock_doms_cur(void) { }
 
@@ -7571,6 +7559,7 @@ struct task_group *sched_create_group(void)
         struct rt_rq *rt_rq;
         struct sched_rt_entity *rt_se;
         struct rq *rq;
+        unsigned long flags;
         int i;
 
         tg = kzalloc(sizeof(*tg), GFP_KERNEL);
@@ -7620,7 +7609,7 @@ struct task_group *sched_create_group(void)
                 init_tg_rt_entry(rq, tg, rt_rq, rt_se, i, 0);
         }
 
-        lock_task_group_list();
+        spin_lock_irqsave(&task_group_lock, flags);
         for_each_possible_cpu(i) {
                 rq = cpu_rq(i);
                 cfs_rq = tg->cfs_rq[i];
@@ -7629,7 +7618,7 @@ struct task_group *sched_create_group(void)
                 list_add_rcu(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list);
         }
         list_add_rcu(&tg->list, &task_groups);
-        unlock_task_group_list();
+        spin_unlock_irqrestore(&task_group_lock, flags);
 
         return tg;
 
@@ -7650,9 +7639,10 @@ void sched_destroy_group(struct task_group *tg)
 {
         struct cfs_rq *cfs_rq = NULL;
         struct rt_rq *rt_rq = NULL;
+        unsigned long flags;
         int i;
 
-        lock_task_group_list();
+        spin_lock_irqsave(&task_group_lock, flags);
         for_each_possible_cpu(i) {
                 cfs_rq = tg->cfs_rq[i];
                 list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
@@ -7660,7 +7650,7 @@ void sched_destroy_group(struct task_group *tg)
                 list_del_rcu(&rt_rq->leaf_rt_rq_list);
         }
         list_del_rcu(&tg->list);
-        unlock_task_group_list();
+        spin_unlock_irqrestore(&task_group_lock, flags);
 
         BUG_ON(!cfs_rq);
 
@@ -7728,13 +7718,16 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
         }
 }
 
+static DEFINE_MUTEX(shares_mutex);
+
 int sched_group_set_shares(struct task_group *tg, unsigned long shares)
 {
         int i;
         struct cfs_rq *cfs_rq;
         struct rq *rq;
+        unsigned long flags;
 
-        lock_task_group_list();
+        mutex_lock(&shares_mutex);
         if (tg->shares == shares)
                 goto done;
 
@@ -7746,10 +7739,12 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
          * load_balance_fair) from referring to this group first,
          * by taking it off the rq->leaf_cfs_rq_list on each cpu.
          */
+        spin_lock_irqsave(&task_group_lock, flags);
         for_each_possible_cpu(i) {
                 cfs_rq = tg->cfs_rq[i];
                 list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
         }
+        spin_unlock_irqrestore(&task_group_lock, flags);
 
         /* wait for any ongoing reference to this group to finish */
         synchronize_sched();
@@ -7769,13 +7764,15 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
          * Enable load balance activity on this group, by inserting it back on
          * each cpu's rq->leaf_cfs_rq_list.
          */
+        spin_lock_irqsave(&task_group_lock, flags);
         for_each_possible_cpu(i) {
                 rq = cpu_rq(i);
                 cfs_rq = tg->cfs_rq[i];
                 list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
         }
+        spin_unlock_irqrestore(&task_group_lock, flags);
 done:
-        unlock_task_group_list();
+        mutex_unlock(&shares_mutex);
         return 0;
 }