sched: kill unused parameter of pick_next_task()

Impact: micro-optimization

Parameter "prev" is not used really.
Signed-off-by: NWang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -4603,7 +4603,7 @@ static inline void schedule_debug(struct task_struct *prev)
  * Pick up the highest-prio task:
  */
 static inline struct task_struct *
-pick_next_task(struct rq *rq, struct task_struct *prev)
+pick_next_task(struct rq *rq)
 {
 	const struct sched_class *class;
 	struct task_struct *p;
@@ -4678,7 +4678,7 @@ asmlinkage void __sched schedule(void)
 		idle_balance(cpu, rq);
 
 	prev->sched_class->put_prev_task(rq, prev);
-	next = pick_next_task(rq, prev);
+	next = pick_next_task(rq);
 
 	if (likely(prev != next)) {
 		sched_info_switch(prev, next);
@@ -6514,7 +6514,7 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
 		if (!rq->nr_running)
 			break;
 		update_rq_clock(rq);
-		next = pick_next_task(rq, rq->curr);
+		next = pick_next_task(rq);
 		if (!next)
 			break;
 		next->sched_class->put_prev_task(rq, next);