1 files changed, 66 insertions, 11 deletions

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 3fa8fa6d9403..5e95145088fd 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -69,7 +69,7 @@ void init_dl_bw(struct dl_bw *dl_b)
         dl_b->total_bw = 0;
 }
 
-void init_dl_rq(struct dl_rq *dl_rq, struct rq *rq)
+void init_dl_rq(struct dl_rq *dl_rq)
 {
         dl_rq->rb_root = RB_ROOT;
 
@@ -218,6 +218,52 @@ static inline void set_post_schedule(struct rq *rq)
         rq->post_schedule = has_pushable_dl_tasks(rq);
 }
 
+static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq);
+
+static void dl_task_offline_migration(struct rq *rq, struct task_struct *p)
+{
+        struct rq *later_rq = NULL;
+        bool fallback = false;
+
+        later_rq = find_lock_later_rq(p, rq);
+
+        if (!later_rq) {
+                int cpu;
+
+                /*
+                 * If we cannot preempt any rq, fall back to pick any
+                 * online cpu.
+                 */
+                fallback = true;
+                cpu = cpumask_any_and(cpu_active_mask, tsk_cpus_allowed(p));
+                if (cpu >= nr_cpu_ids) {
+                        /*
+                         * Fail to find any suitable cpu.
+                         * The task will never come back!
+                         */
+                        BUG_ON(dl_bandwidth_enabled());
+
+                        /*
+                         * If admission control is disabled we
+                         * try a little harder to let the task
+                         * run.
+                         */
+                        cpu = cpumask_any(cpu_active_mask);
+                }
+                later_rq = cpu_rq(cpu);
+                double_lock_balance(rq, later_rq);
+        }
+
+        deactivate_task(rq, p, 0);
+        set_task_cpu(p, later_rq->cpu);
+        activate_task(later_rq, p, ENQUEUE_REPLENISH);
+
+        if (!fallback)
+                resched_curr(later_rq);
+
+        double_unlock_balance(rq, later_rq);
+}
+
 #else
 
 static inline
@@ -514,7 +560,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
         unsigned long flags;
         struct rq *rq;
 
-        rq = task_rq_lock(current, &flags);
+        rq = task_rq_lock(p, &flags);
 
         /*
          * We need to take care of several possible races here:
@@ -536,6 +582,17 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
         sched_clock_tick();
         update_rq_clock(rq);
 
+#ifdef CONFIG_SMP
+        /*
+         * If we find that the rq the task was on is no longer
+         * available, we need to select a new rq.
+         */
+        if (unlikely(!rq->online)) {
+                dl_task_offline_migration(rq, p);
+                goto unlock;
+        }
+#endif
+
         /*
          * If the throttle happened during sched-out; like:
          *
@@ -569,7 +626,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
                 push_dl_task(rq);
 #endif
 unlock:
-        task_rq_unlock(rq, current, &flags);
+        task_rq_unlock(rq, p, &flags);
 
         return HRTIMER_NORESTART;
 }
@@ -914,6 +971,12 @@ static void yield_task_dl(struct rq *rq)
         }
         update_rq_clock(rq);
         update_curr_dl(rq);
+        /*
+         * Tell update_rq_clock() that we've just updated,
+         * so we don't do microscopic update in schedule()
+         * and double the fastpath cost.
+         */
+        rq_clock_skip_update(rq, true);
 }
 
 #ifdef CONFIG_SMP
@@ -1659,14 +1722,6 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
 {
         int check_resched = 1;
 
-        /*
-         * If p is throttled, don't consider the possibility
-         * of preempting rq->curr, the check will be done right
-         * after its runtime will get replenished.
-         */
-        if (unlikely(p->dl.dl_throttled))
-                return;
-
         if (task_on_rq_queued(p) && rq->curr != p) {
 #ifdef CONFIG_SMP
                 if (p->nr_cpus_allowed > 1 && rq->dl.overloaded &&