sched/fair: Push down check for high priority class task into idle_balance()

We close idle_exit_fair() bracket in case of we've pulled something or we've received
task of high priority class.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/1394098315.19290.10.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d8482e1c575e..b956e70fc503 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4787,17 +4787,16 @@ simple:
         return p;
 
 idle:
+        new_tasks = idle_balance(rq);
         /*
          * Because idle_balance() releases (and re-acquires) rq->lock, it is
          * possible for any higher priority task to appear. In that case we
          * must re-start the pick_next_entity() loop.
          */
-        new_tasks = idle_balance(rq);
-
-        if (rq->nr_running != rq->cfs.h_nr_running)
+        if (new_tasks < 0)
                 return RETRY_TASK;
 
-        if (new_tasks)
+        if (new_tasks > 0)
                 goto again;
 
         return NULL;
@@ -6728,8 +6727,14 @@ static int idle_balance(struct rq *this_rq)
                 this_rq->max_idle_balance_cost = curr_cost;
 
 out:
-        if (pulled_task)
+        /* Is there a task of a high priority class? */
+        if (this_rq->nr_running != this_rq->cfs.h_nr_running)
+                pulled_task = -1;
+
+        if (pulled_task) {
+                idle_exit_fair(this_rq);
                 this_rq->idle_stamp = 0;
+        }
 
         return pulled_task;
 }