1 files changed, 34 insertions, 9 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index f42ae7fb5ec5..b60dad720173 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -778,12 +778,9 @@ static inline int balance_runtime(struct rt_rq *rt_rq)
 
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
 {
-        int i, idle = 1;
+        int i, idle = 1, throttled = 0;
         const struct cpumask *span;
 
-        if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
-                return 1;
-
         span = sched_rt_period_mask();
         for_each_cpu(i, span) {
                 int enqueue = 0;
@@ -818,12 +815,17 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
                         if (!rt_rq_throttled(rt_rq))
                                 enqueue = 1;
                 }
+                if (rt_rq->rt_throttled)
+                        throttled = 1;
 
                 if (enqueue)
                         sched_rt_rq_enqueue(rt_rq);
                 raw_spin_unlock(&rq->lock);
         }
 
+        if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))
+                return 1;
+
         return idle;
 }
 
@@ -855,8 +857,30 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
                 return 0;
 
         if (rt_rq->rt_time > runtime) {
-                rt_rq->rt_throttled = 1;
-                printk_once(KERN_WARNING "sched: RT throttling activated\n");
+                struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+
+                /*
+                 * Don't actually throttle groups that have no runtime assigned
+                 * but accrue some time due to boosting.
+                 */
+                if (likely(rt_b->rt_runtime)) {
+                        static bool once = false;
+
+                        rt_rq->rt_throttled = 1;
+
+                        if (!once) {
+                                once = true;
+                                printk_sched("sched: RT throttling activated\n");
+                        }
+                } else {
+                        /*
+                         * In case we did anyway, make it go away,
+                         * replenishment is a joke, since it will replenish us
+                         * with exactly 0 ns.
+                         */
+                        rt_rq->rt_time = 0;
+                }
+
                 if (rt_rq_throttled(rt_rq)) {
                         sched_rt_rq_dequeue(rt_rq);
                         return 1;
@@ -884,7 +908,8 @@ static void update_curr_rt(struct rq *rq)
         if (unlikely((s64)delta_exec < 0))
                 delta_exec = 0;
 
-        schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));
+        schedstat_set(curr->se.statistics.exec_max,
+                      max(curr->se.statistics.exec_max, delta_exec));
 
         curr->se.sum_exec_runtime += delta_exec;
         account_group_exec_runtime(curr, delta_exec);
@@ -1972,7 +1997,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
         if (--p->rt.time_slice)
                 return;
 
-        p->rt.time_slice = DEF_TIMESLICE;
+        p->rt.time_slice = RR_TIMESLICE;
 
         /*
          * Requeue to the end of queue if we are not the only element
@@ -2000,7 +2025,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
          * Time slice is 0 for SCHED_FIFO tasks
          */
         if (task->policy == SCHED_RR)
-                return DEF_TIMESLICE;
+                return RR_TIMESLICE;
         else
                 return 0;
 }