2 files changed, 27 insertions, 1 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 6b06f23261c0..d1ad69b270ca 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -301,7 +301,7 @@ struct cfs_rq {
         /* 'curr' points to currently running entity on this cfs_rq.
          * It is set to NULL otherwise (i.e when none are currently running).
          */
-        struct sched_entity *curr;
+        struct sched_entity *curr, *next;
 
         unsigned long nr_spread_over;
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9d003c9d2a48..31c4a2988b64 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -207,6 +207,9 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
                 }
         }
 
+        if (cfs_rq->next == se)
+                cfs_rq->next = NULL;
+
         rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
 }
 
@@ -626,12 +629,32 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
         se->prev_sum_exec_runtime = se->sum_exec_runtime;
 }
 
+static struct sched_entity *
+pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+        s64 diff, gran;
+
+        if (!cfs_rq->next)
+                return se;
+
+        diff = cfs_rq->next->vruntime - se->vruntime;
+        if (diff < 0)
+                return se;
+
+        gran = calc_delta_fair(sysctl_sched_wakeup_granularity, &cfs_rq->load);
+        if (diff > gran)
+                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);
         }
 
@@ -1070,6 +1093,9 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
                 resched_task(curr);
                 return;
         }
+
+        cfs_rq_of(pse)->next = pse;
+
         /*
          * Batch tasks do not preempt (their preemption is driven by
          * the tick):