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; }