sched/deadline: Fix the earliest_dl.next logic

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

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 8b0a15e..cd64c97 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -176,8 +176,10 @@ static void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p)
                }
        }
 
-       if (leftmost)
+       if (leftmost) {
                dl_rq->pushable_dl_tasks_leftmost = &p->pushable_dl_tasks;
+               dl_rq->earliest_dl.next = p->dl.deadline;
+       }
 
        rb_link_node(&p->pushable_dl_tasks, parent, link);
        rb_insert_color(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root);
@@ -195,6 +197,10 @@ static void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p)
 
                next_node = rb_next(&p->pushable_dl_tasks);
                dl_rq->pushable_dl_tasks_leftmost = next_node;
+               if (next_node) {
+                       dl_rq->earliest_dl.next = rb_entry(next_node,
+                               struct task_struct, pushable_dl_tasks)->dl.deadline;
+               }
        }
 
        rb_erase(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root);
@@ -782,42 +788,14 @@ static void update_curr_dl(struct rq *rq)
 
 #ifdef CONFIG_SMP
 
-static struct task_struct *pick_next_earliest_dl_task(struct rq *rq, int cpu);
-
-static inline u64 next_deadline(struct rq *rq)
-{
-       struct task_struct *next = pick_next_earliest_dl_task(rq, rq->cpu);
-
-       if (next && dl_prio(next->prio))
-               return next->dl.deadline;
-       else
-               return 0;
-}
-
 static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
 {
        struct rq *rq = rq_of_dl_rq(dl_rq);
 
        if (dl_rq->earliest_dl.curr == 0 ||
            dl_time_before(deadline, dl_rq->earliest_dl.curr)) {
-               /*
-                * If the dl_rq had no -deadline tasks, or if the new task
-                * has shorter deadline than the current one on dl_rq, we
-                * know that the previous earliest becomes our next earliest,
-                * as the new task becomes the earliest itself.
-                */
-               dl_rq->earliest_dl.next = dl_rq->earliest_dl.curr;
                dl_rq->earliest_dl.curr = deadline;
                cpudl_set(&rq->rd->cpudl, rq->cpu, deadline, 1);
-       } else if (dl_rq->earliest_dl.next == 0 ||
-                  dl_time_before(deadline, dl_rq->earliest_dl.next)) {
-               /*
-                * On the other hand, if the new -deadline task has a
-                * a later deadline than the earliest one on dl_rq, but
-                * it is earlier than the next (if any), we must
-                * recompute the next-earliest.
-                */
-               dl_rq->earliest_dl.next = next_deadline(rq);
        }
 }
 
@@ -839,7 +817,6 @@ static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
 
                entry = rb_entry(leftmost, struct sched_dl_entity, rb_node);
                dl_rq->earliest_dl.curr = entry->deadline;
-               dl_rq->earliest_dl.next = next_deadline(rq);
                cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline, 1);
        }
 }
@@ -1274,28 +1251,6 @@ static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu)
        return 0;
 }
 
-/* Returns the second earliest -deadline task, NULL otherwise */
-static struct task_struct *pick_next_earliest_dl_task(struct rq *rq, int cpu)
-{
-       struct rb_node *next_node = rq->dl.rb_leftmost;
-       struct sched_dl_entity *dl_se;
-       struct task_struct *p = NULL;
-
-next_node:
-       next_node = rb_next(next_node);
-       if (next_node) {
-               dl_se = rb_entry(next_node, struct sched_dl_entity, rb_node);
-               p = dl_task_of(dl_se);
-
-               if (pick_dl_task(rq, p, cpu))
-                       return p;
-
-               goto next_node;
-       }
-
-       return NULL;
-}
-
 /*
  * Return the earliest pushable rq's task, which is suitable to be executed
  * on the CPU, NULL otherwise: