sched: Clean up SCHED_RESET_ON_FORK

Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Lennart Poettering <mzxreary@0pointer.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1245228361.18329.6.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -2613,27 +2613,29 @@ void sched_fork(struct task_struct *p, int clone_flags)
 	set_task_cpu(p, cpu);
 
 	/*
-	 * Revert to default priority/policy on fork if requested. Make sure we
-	 * do not leak PI boosting priority to the child.
+	 * Make sure we do not leak PI boosting priority to the child.
 	 */
-	if (current->sched_reset_on_fork &&
-			(p->policy == SCHED_FIFO || p->policy == SCHED_RR))
+	p->prio = current->normal_prio;
+
+	/*
+	 * Revert to default priority/policy on fork if requested.
+	 */
+	if (unlikely(p->sched_reset_on_fork)) {
+		if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
 			p->policy = SCHED_NORMAL;
 
-	if (current->sched_reset_on_fork &&
-			(current->normal_prio < DEFAULT_PRIO))
+		if (p->normal_prio < DEFAULT_PRIO)
 			p->prio = DEFAULT_PRIO;
-	else
-		p->prio = current->normal_prio;
-
-	if (!rt_prio(p->prio))
-		p->sched_class = &fair_sched_class;
 
 		/*
 		 * We don't need the reset flag anymore after the fork. It has
 		 * fulfilled its duty:
 		 */
 		p->sched_reset_on_fork = 0;
+	}
+
+	if (!rt_prio(p->prio))
+		p->sched_class = &fair_sched_class;
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 	if (likely(sched_info_on()))