sched: remove prio preference from balance decisions

Priority looses much of its meaning in a hierarchical context. So don't
use it in balance decisions.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -2896,7 +2896,7 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 	      enum cpu_idle_type idle, int *all_pinned,
 	      int *this_best_prio, struct rq_iterator *iterator)
 {
-	int loops = 0, pulled = 0, pinned = 0, skip_for_load;
+	int loops = 0, pulled = 0, pinned = 0;
 	struct task_struct *p;
 	long rem_load_move = max_load_move;
 
@@ -2912,14 +2912,8 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 next:
 	if (!p || loops++ > sysctl_sched_nr_migrate)
 		goto out;
-	/*
-	 * To help distribute high priority tasks across CPUs we don't
-	 * skip a task if it will be the highest priority task (i.e. smallest
-	 * prio value) on its new queue regardless of its load weight
-	 */
-	skip_for_load = (p->se.load.weight >> 1) > rem_load_move +
-							 SCHED_LOAD_SCALE_FUZZ;
-	if ((skip_for_load && p->prio >= *this_best_prio) ||
+
+	if ((p->se.load.weight >> 1) > rem_load_move ||
 	    !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
 		p = iterator->next(iterator->arg);
 		goto next;