1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 54d67b94f1a9..2a43a581ead3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9917,6 +9917,13 @@ static int sched_rt_global_constraints(void)
         if (sysctl_sched_rt_period <= 0)
                 return -EINVAL;
 
+        /*
+         * There's always some RT tasks in the root group
+         * -- migration, kstopmachine etc..
+         */
+        if (sysctl_sched_rt_runtime == 0)
+                return -EBUSY;
+
         spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
         for_each_possible_cpu(i) {
                 struct rt_rq *rt_rq = &cpu_rq(i)->rt;