diff --git a/[refs] b/[refs]
index ffed0c097233..839b11da7d38 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 35cf4e50b16331def6cfcbee11e49270b6db07f5
+refs/heads/master: e221d028bb08b47e624c5f0a31732c642db9d19a
diff --git a/trunk/kernel/sched/rt.c b/trunk/kernel/sched/rt.c
index 573e1ca01102..944cb68420e9 100644
--- a/trunk/kernel/sched/rt.c
+++ b/trunk/kernel/sched/rt.c
@@ -788,6 +788,19 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
 	const struct cpumask *span;
 
 	span = sched_rt_period_mask();
+#ifdef CONFIG_RT_GROUP_SCHED
+	/*
+	 * FIXME: isolated CPUs should really leave the root task group,
+	 * whether they are isolcpus or were isolated via cpusets, lest
+	 * the timer run on a CPU which does not service all runqueues,
+	 * potentially leaving other CPUs indefinitely throttled.  If
+	 * isolation is really required, the user will turn the throttle
+	 * off to kill the perturbations it causes anyway.  Meanwhile,
+	 * this maintains functionality for boot and/or troubleshooting.
+	 */
+	if (rt_b == &root_task_group.rt_bandwidth)
+		span = cpu_online_mask;
+#endif
 	for_each_cpu(i, span) {
 		int enqueue = 0;
 		struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);