---

yaml
---
r: 64347
b: refs/heads/master
c: f549da8
h: refs/heads/master
i:
  64345: af4b445
  64343: 2f588c8
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f8700df7c419781efb34696de7e7f49717f8ede7
+refs/heads/master: f549da848eca595abca14ebc5e1bf00fd72aa53d

trunk/kernel/sched.c

@@ -3043,6 +3043,7 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
 	struct sched_domain *sd;
 	/* Earliest time when we have to do rebalance again */
 	unsigned long next_balance = jiffies + 60*HZ;
+	int update_next_balance = 0;
 
 	for_each_domain(cpu, sd) {
 		if (!(sd->flags & SD_LOAD_BALANCE))
@@ -3079,8 +3080,10 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
 		if (sd->flags & SD_SERIALIZE)
 			spin_unlock(&balancing);
 out:
-		if (time_after(next_balance, sd->last_balance + interval))
+		if (time_after(next_balance, sd->last_balance + interval)) {
 			next_balance = sd->last_balance + interval;
+			update_next_balance = 1;
+		}
 
 		/*
 		 * Stop the load balance at this level. There is another
@@ -3090,7 +3093,14 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
 		if (!balance)
 			break;
 	}
-	rq->next_balance = next_balance;
+
+	/*
+	 * next_balance will be updated only when there is a need.
+	 * When the cpu is attached to null domain for ex, it will not be
+	 * updated.
+	 */
+	if (likely(update_next_balance))
+		rq->next_balance = next_balance;
 }
 
 /*