Merge tag 'dts-subdirs-for-arm-soc-v3.19' of git://git.kernel.org/pub/scm/linux/kerne...

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

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index abfaf3d..5285332 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -518,12 +518,20 @@ again:
        }
 
        /*
-        * We need to take care of a possible races here. In fact, the
-        * task might have changed its scheduling policy to something
-        * different from SCHED_DEADLINE or changed its reservation
-        * parameters (through sched_setattr()).
+        * We need to take care of several possible races here:
+        *
+        *   - the task might have changed its scheduling policy
+        *     to something different than SCHED_DEADLINE
+        *   - the task might have changed its reservation parameters
+        *     (through sched_setattr())
+        *   - the task might have been boosted by someone else and
+        *     might be in the boosting/deboosting path
+        *
+        * In all this cases we bail out, as the task is already
+        * in the runqueue or is going to be enqueued back anyway.
         */
-       if (!dl_task(p) || dl_se->dl_new)
+       if (!dl_task(p) || dl_se->dl_new ||
+           dl_se->dl_boosted || !dl_se->dl_throttled)
                goto unlock;
 
        sched_clock_tick();
@@ -532,7 +540,7 @@ again:
        dl_se->dl_yielded = 0;
        if (task_on_rq_queued(p)) {
                enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
-               if (task_has_dl_policy(rq->curr))
+               if (dl_task(rq->curr))
                        check_preempt_curr_dl(rq, p, 0);
                else
                        resched_curr(rq);
@@ -847,8 +855,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
         * smaller than our one... OTW we keep our runtime and
         * deadline.
         */
-       if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio))
+       if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) {
                pi_se = &pi_task->dl;
+       } else if (!dl_prio(p->normal_prio)) {
+               /*
+                * Special case in which we have a !SCHED_DEADLINE task
+                * that is going to be deboosted, but exceedes its
+                * runtime while doing so. No point in replenishing
+                * it, as it's going to return back to its original
+                * scheduling class after this.
+                */
+               BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
+               return;
+       }
 
        /*
         * If p is throttled, we do nothing. In fact, if it exhausted
@@ -1153,7 +1172,7 @@ static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask_dl);
 static int find_later_rq(struct task_struct *task)
 {
        struct sched_domain *sd;
-       struct cpumask *later_mask = __get_cpu_var(local_cpu_mask_dl);
+       struct cpumask *later_mask = this_cpu_cpumask_var_ptr(local_cpu_mask_dl);
        int this_cpu = smp_processor_id();
        int best_cpu, cpu = task_cpu(task);
 
@@ -1607,8 +1626,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
                        /* Only reschedule if pushing failed */
                        check_resched = 0;
 #endif /* CONFIG_SMP */
-               if (check_resched && task_has_dl_policy(rq->curr))
-                       check_preempt_curr_dl(rq, p, 0);
+               if (check_resched) {
+                       if (dl_task(rq->curr))
+                               check_preempt_curr_dl(rq, p, 0);
+                       else
+                               resched_curr(rq);
+               }
        }
 }