Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-s…

…ched

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: default to more agressive yield for SCHED_BATCH tasks
  sched: fix crash in sys_sched_rr_get_interval()

kernel/sched.c

@@ -4850,17 +4850,21 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
 	if (retval)
 		goto out_unlock;
 
-	if (p->policy == SCHED_FIFO)
-		time_slice = 0;
-	else if (p->policy == SCHED_RR)
+	/*
+	 * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
+	 * tasks that are on an otherwise idle runqueue:
+	 */
+	time_slice = 0;
+	if (p->policy == SCHED_RR) {
 		time_slice = DEF_TIMESLICE;
-	else {
+	} else {
 		struct sched_entity *se = &p->se;
 		unsigned long flags;
 		struct rq *rq;
 
 		rq = task_rq_lock(p, &flags);
-		time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
+		if (rq->cfs.load.weight)
+			time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
 		task_rq_unlock(rq, &flags);
 	}
 	read_unlock(&tasklist_lock);

kernel/sched_fair.c

@@ -799,16 +799,17 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
  */
 static void yield_task_fair(struct rq *rq)
 {
-	struct cfs_rq *cfs_rq = task_cfs_rq(rq->curr);
-	struct sched_entity *rightmost, *se = &rq->curr->se;
+	struct task_struct *curr = rq->curr;
+	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+	struct sched_entity *rightmost, *se = &curr->se;
 
 	/*
 	 * Are we the only task in the tree?
 	 */
 	if (unlikely(cfs_rq->nr_running == 1))
 		return;
 
-	if (likely(!sysctl_sched_compat_yield)) {
+	if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
 		__update_rq_clock(rq);
 		/*
 		 * Update run-time statistics of the 'current'.