sched: cleanup fair task selection

Impact: cleanup

Clean up task selection

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 22 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index ce514afd78ff..6167336a2372 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -347,17 +347,17 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
 }
 
-static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
-{
-        return cfs_rq->rb_leftmost;
-}
-
 static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
 {
-        return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node);
+        struct rb_node *left = cfs_rq->rb_leftmost;
+
+        if (!left)
+                return NULL;
+
+        return rb_entry(left, struct sched_entity, run_node);
 }
 
-static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
+static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
         struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
 
@@ -794,28 +794,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static int
 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
 
-static struct sched_entity *
-pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
 {
+        struct sched_entity *se = __pick_next_entity(cfs_rq);
+
         if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1)
                 return se;
 
         return cfs_rq->next;
 }
 
-static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
-{
-        struct sched_entity *se = NULL;
-
-        if (first_fair(cfs_rq)) {
-                se = __pick_next_entity(cfs_rq);
-                se = pick_next(cfs_rq, se);
-                set_next_entity(cfs_rq, se);
-        }
-
-        return se;
-}
-
 static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
 {
         /*
@@ -1396,6 +1384,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
 
         do {
                 se = pick_next_entity(cfs_rq);
+                set_next_entity(cfs_rq, se);
                 cfs_rq = group_cfs_rq(se);
         } while (cfs_rq);