1 files changed, 13 insertions, 0 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 573e1ca01102..944cb68420e9 100644
--- a/kernel/sched/rt.c
+++ b/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);