diff --git a/kernel/sched.c b/kernel/sched.c index 9dd8d121eea6..6185fa080ec8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -343,6 +343,8 @@ struct rt_rq { int rt_load_balance_idx; struct list_head *rt_load_balance_head, *rt_load_balance_curr; unsigned long rt_nr_running; + /* highest queued rt task prio */ + int highest_prio; }; /* @@ -6864,6 +6866,7 @@ void __init sched_init(void) rq->cpu = i; rq->migration_thread = NULL; INIT_LIST_HEAD(&rq->migration_queue); + rq->rt.highest_prio = MAX_RT_PRIO; #endif atomic_set(&rq->nr_iowait, 0); diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index e3d2ca8832af..136c2857a049 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -30,6 +30,10 @@ static inline void inc_rt_tasks(struct task_struct *p, struct rq *rq) { WARN_ON(!rt_task(p)); rq->rt.rt_nr_running++; +#ifdef CONFIG_SMP + if (p->prio < rq->rt.highest_prio) + rq->rt.highest_prio = p->prio; +#endif /* CONFIG_SMP */ } static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq) @@ -37,6 +41,20 @@ static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq) WARN_ON(!rt_task(p)); WARN_ON(!rq->rt.rt_nr_running); rq->rt.rt_nr_running--; +#ifdef CONFIG_SMP + if (rq->rt.rt_nr_running) { + struct rt_prio_array *array; + + WARN_ON(p->prio < rq->rt.highest_prio); + if (p->prio == rq->rt.highest_prio) { + /* recalculate */ + array = &rq->rt.active; + rq->rt.highest_prio = + sched_find_first_bit(array->bitmap); + } /* otherwise leave rq->highest prio alone */ + } else + rq->rt.highest_prio = MAX_RT_PRIO; +#endif /* CONFIG_SMP */ } static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)