Merge tag 'v4.0.8' into xlnx_4.0.8-rt6

[zynq/linux.git] / kernel / sched / deadline.c

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a027799ae130d3623ff4351f08c3cf456979bfbc..f670cbb17f5d973740540ab85b739f491c6009fb 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -511,16 +511,10 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
                                                     struct sched_dl_entity,
                                                     dl_timer);
        struct task_struct *p = dl_task_of(dl_se);
+       unsigned long flags;
        struct rq *rq;
-again:
-       rq = task_rq(p);
-       raw_spin_lock(&rq->lock);
 
-       if (rq != task_rq(p)) {
-               /* Task was moved, retrying. */
-               raw_spin_unlock(&rq->lock);
-               goto again;
-       }
+       rq = task_rq_lock(p, &flags);
 
        /*
         * We need to take care of several possible races here:
@@ -541,6 +535,26 @@ again:
 
        sched_clock_tick();
        update_rq_clock(rq);
+
+       /*
+        * If the throttle happened during sched-out; like:
+        *
+        *   schedule()
+        *     deactivate_task()
+        *       dequeue_task_dl()
+        *         update_curr_dl()
+        *           start_dl_timer()
+        *         __dequeue_task_dl()
+        *     prev->on_rq = 0;
+        *
+        * We can be both throttled and !queued. Replenish the counter
+        * but do not enqueue -- wait for our wakeup to do that.
+        */
+       if (!task_on_rq_queued(p)) {
+               replenish_dl_entity(dl_se, dl_se);
+               goto unlock;
+       }
+
        enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
        if (dl_task(rq->curr))
                check_preempt_curr_dl(rq, p, 0);
@@ -555,7 +569,7 @@ again:
                push_dl_task(rq);
 #endif
 unlock:
-       raw_spin_unlock(&rq->lock);
+       task_rq_unlock(rq, p, &flags);
 
        return HRTIMER_NORESTART;
 }
@@ -898,6 +912,7 @@ static void yield_task_dl(struct rq *rq)
                rq->curr->dl.dl_yielded = 1;
                p->dl.runtime = 0;
        }
+       update_rq_clock(rq);
        update_curr_dl(rq);
 }