diff --git a/init/Kconfig b/init/Kconfig
index 9afb971497f4c9972b0dcf14071edf9ef81320be..d3ee66a6990f7f7b974deb8238bb6ce779e84cac 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -668,9 +668,10 @@ config RCU_BOOST
 
 config RCU_KTHREAD_PRIO
 	int "Real-time priority to use for RCU worker threads"
-	range 1 99
-	depends on RCU_BOOST
-	default 1
+	range 1 99 if RCU_BOOST
+	range 0 99 if !RCU_BOOST
+	default 1 if RCU_BOOST
+	default 0 if !RCU_BOOST
 	help
 	  This option specifies the SCHED_FIFO priority value that will be
 	  assigned to the rcuc/n and rcub/n threads and is also the value
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5987fdc85fc4c5d29eb3b4f8c4329f93259764d3..75ce12316b4c5455f9d36f69cf1364ba0407df7d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -156,6 +156,10 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
 static void invoke_rcu_core(void);
 static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
 
+/* rcuc/rcub kthread realtime priority */
+static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;
+module_param(kthread_prio, int, 0644);
+
 /*
  * Track the rcutorture test sequence number and the update version
  * number within a given test.  The rcutorture_testseq is incremented
@@ -3597,17 +3601,35 @@ static int rcu_pm_notify(struct notifier_block *self,
 static int __init rcu_spawn_gp_kthread(void)
 {
 	unsigned long flags;
+	int kthread_prio_in = kthread_prio;
 	struct rcu_node *rnp;
 	struct rcu_state *rsp;
+	struct sched_param sp;
 	struct task_struct *t;
 
+	/* Force priority into range. */
+	if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
+		kthread_prio = 1;
+	else if (kthread_prio < 0)
+		kthread_prio = 0;
+	else if (kthread_prio > 99)
+		kthread_prio = 99;
+	if (kthread_prio != kthread_prio_in)
+		pr_alert("rcu_spawn_gp_kthread(): Limited prio to %d from %d\n",
+			 kthread_prio, kthread_prio_in);
+
 	rcu_scheduler_fully_active = 1;
 	for_each_rcu_flavor(rsp) {
-		t = kthread_run(rcu_gp_kthread, rsp, "%s", rsp->name);
+		t = kthread_create(rcu_gp_kthread, rsp, "%s", rsp->name);
 		BUG_ON(IS_ERR(t));
 		rnp = rcu_get_root(rsp);
 		raw_spin_lock_irqsave(&rnp->lock, flags);
 		rsp->gp_kthread = t;
+		if (kthread_prio) {
+			sp.sched_priority = kthread_prio;
+			sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+		}
+		wake_up_process(t);
 		raw_spin_unlock_irqrestore(&rnp->lock, flags);
 	}
 	rcu_spawn_nocb_kthreads();
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 81ff8b9a5a39138befde38d16ec3f04b03e4a02e..dcb32638f88bfb83da15f26ae281a519bf39e88d 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -34,10 +34,6 @@
 
 #include "../locking/rtmutex_common.h"
 
-/* rcuc/rcub kthread realtime priority */
-static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;
-module_param(kthread_prio, int, 0644);
-
 /*
  * Control variables for per-CPU and per-rcu_node kthreads.  These
  * handle all flavors of RCU.