X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=kernel%2Fsched_fair.c;h=5cc1c162044fc4f40b15c351cd170ce2c58703f7;hb=6272d68cc6a5f90c6b1a2228cf0f67b895305d17;hp=e0c0b4bc3f08e822d976fe2d6c222300a61c6352;hpb=57c44c5f6fb0a8002feb258c1af58e1a744b1fcb;p=deliverable%2Flinux.git

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e0c0b4bc3f08..5cc1c162044f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -283,7 +283,7 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
 						   struct sched_entity,
 						   run_node);
 
-		if (vruntime == cfs_rq->min_vruntime)
+		if (!cfs_rq->curr)
 			vruntime = se->vruntime;
 		else
 			vruntime = min_vruntime(vruntime, se->vruntime);
@@ -429,7 +429,10 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
 
 	for_each_sched_entity(se) {
-		struct load_weight *load = &cfs_rq->load;
+		struct load_weight *load;
+
+		cfs_rq = cfs_rq_of(se);
+		load = &cfs_rq->load;
 
 		if (unlikely(!se->on_rq)) {
 			struct load_weight lw = cfs_rq->load;
@@ -677,9 +680,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 			unsigned long thresh = sysctl_sched_latency;
 
 			/*
-			 * convert the sleeper threshold into virtual time
+			 * Convert the sleeper threshold into virtual time.
+			 * SCHED_IDLE is a special sub-class.  We care about
+			 * fairness only relative to other SCHED_IDLE tasks,
+			 * all of which have the same weight.
 			 */
-			if (sched_feat(NORMALIZED_SLEEPER))
+			if (sched_feat(NORMALIZED_SLEEPER) &&
+					task_of(se)->policy != SCHED_IDLE)
 				thresh = calc_delta_fair(thresh, se);
 
 			vruntime -= thresh;
@@ -1340,14 +1347,18 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
 
 static void set_last_buddy(struct sched_entity *se)
 {
-	for_each_sched_entity(se)
-		cfs_rq_of(se)->last = se;
+	if (likely(task_of(se)->policy != SCHED_IDLE)) {
+		for_each_sched_entity(se)
+			cfs_rq_of(se)->last = se;
+	}
 }
 
 static void set_next_buddy(struct sched_entity *se)
 {
-	for_each_sched_entity(se)
-		cfs_rq_of(se)->next = se;
+	if (likely(task_of(se)->policy != SCHED_IDLE)) {
+		for_each_sched_entity(se)
+			cfs_rq_of(se)->next = se;
+	}
 }
 
 /*
@@ -1393,12 +1404,18 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
 		return;
 
 	/*
-	 * Batch tasks do not preempt (their preemption is driven by
+	 * Batch and idle tasks do not preempt (their preemption is driven by
 	 * the tick):
 	 */
-	if (unlikely(p->policy == SCHED_BATCH))
+	if (unlikely(p->policy != SCHED_NORMAL))
 		return;
 
+	/* Idle tasks are by definition preempted by everybody. */
+	if (unlikely(curr->policy == SCHED_IDLE)) {
+		resched_task(curr);
+		return;
+	}
+
 	if (!sched_feat(WAKEUP_PREEMPT))
 		return;
 
@@ -1617,8 +1634,6 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 	}
 }
 
-#define swap(a, b) do { typeof(a) tmp = (a); (a) = (b); (b) = tmp; } while (0)
-
 /*
  * Share the fairness runtime between parent and child, thus the
  * total amount of pressure for CPU stays equal - new tasks