diff --git a/[refs] b/[refs]
index 425b534039d9..c6e9164f83e9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 74a5ce20e6eeeb3751340b390e7ac1d1d07bbf55
+refs/heads/master: b654f7de41b0e3903ee2b51d3b8db77fe52ce728
diff --git a/trunk/kernel/sched/fair.c b/trunk/kernel/sched/fair.c
index f0380d4987b3..2b449a762074 100644
--- a/trunk/kernel/sched/fair.c
+++ b/trunk/kernel/sched/fair.c
@@ -3503,15 +3503,22 @@ unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
 unsigned long scale_rt_power(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
-	u64 total, available;
+	u64 total, available, age_stamp, avg;
 
-	total = sched_avg_period() + (rq->clock - rq->age_stamp);
+	/*
+	 * Since we're reading these variables without serialization make sure
+	 * we read them once before doing sanity checks on them.
+	 */
+	age_stamp = ACCESS_ONCE(rq->age_stamp);
+	avg = ACCESS_ONCE(rq->rt_avg);
+
+	total = sched_avg_period() + (rq->clock - age_stamp);
 
-	if (unlikely(total < rq->rt_avg)) {
+	if (unlikely(total < avg)) {
 		/* Ensures that power won't end up being negative */
 		available = 0;
 	} else {
-		available = total - rq->rt_avg;
+		available = total - avg;
 	}
 
 	if (unlikely((s64)total < SCHED_POWER_SCALE))