[PATCH] sched: ->task_new cleanup

make sched_class.task_new == NULL a 'default method', this
allows the removal of task_rt_new.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/sched.h

@@ -874,7 +874,7 @@ struct sched_class {
 
 	void (*set_curr_task) (struct rq *rq);
 	void (*task_tick) (struct rq *rq, struct task_struct *p);
-	void (*task_new) (struct rq *rq, struct task_struct *p);
+	void (*task_new) (struct rq *rq, struct task_struct *p, u64 now);
 };
 
 struct load_weight {

kernel/sched.c

@@ -1641,22 +1641,27 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 	unsigned long flags;
 	struct rq *rq;
 	int this_cpu;
+	u64 now;
 
 	rq = task_rq_lock(p, &flags);
 	BUG_ON(p->state != TASK_RUNNING);
 	this_cpu = smp_processor_id(); /* parent's CPU */
+	now = rq_clock(rq);
 
 	p->prio = effective_prio(p);
 
-	if (!sysctl_sched_child_runs_first || (clone_flags & CLONE_VM) ||
-			task_cpu(p) != this_cpu || !current->se.on_rq) {
+	if (!p->sched_class->task_new || !sysctl_sched_child_runs_first ||
+			(clone_flags & CLONE_VM) || task_cpu(p) != this_cpu ||
+			!current->se.on_rq) {
+
 		activate_task(rq, p, 0);
 	} else {
 		/*
 		 * Let the scheduling class do new task startup
 		 * management (if any):
 		 */
-		p->sched_class->task_new(rq, p);
+		p->sched_class->task_new(rq, p, now);
+		inc_nr_running(p, rq, now);
 	}
 	check_preempt_curr(rq, p);
 	task_rq_unlock(rq, &flags);

kernel/sched_fair.c

@@ -1041,11 +1041,10 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr)
  * monopolize the CPU. Note: the parent runqueue is locked,
  * the child is not running yet.
  */
-static void task_new_fair(struct rq *rq, struct task_struct *p)
+static void task_new_fair(struct rq *rq, struct task_struct *p, u64 now)
 {
 	struct cfs_rq *cfs_rq = task_cfs_rq(p);
 	struct sched_entity *se = &p->se;
-	u64 now = rq_clock(rq);
 
 	sched_info_queued(p);
 
@@ -1072,7 +1071,6 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
 		p->se.wait_runtime = -(sysctl_sched_granularity / 2);
 
 	__enqueue_entity(cfs_rq, se);
-	inc_nr_running(p, rq, now);
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED

kernel/sched_rt.c

@@ -229,15 +229,6 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p)
 	requeue_task_rt(rq, p);
 }
 
-/*
- * No parent/child timeslice management necessary for RT tasks,
- * just activate them:
- */
-static void task_new_rt(struct rq *rq, struct task_struct *p)
-{
-	activate_task(rq, p, 1);
-}
-
 static struct sched_class rt_sched_class __read_mostly = {
 	.enqueue_task		= enqueue_task_rt,
 	.dequeue_task		= dequeue_task_rt,
@@ -251,5 +242,4 @@ static struct sched_class rt_sched_class __read_mostly = {
 	.load_balance		= load_balance_rt,
 
 	.task_tick		= task_tick_rt,
-	.task_new		= task_new_rt,
 };