diff --git a/kernel/softirq.c b/kernel/softirq.c
index 19668d614f4738d511df3289d650e55ca3bb7c8d..4196b9f84690066a75f6e67bdefbe4ff79eb0336 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -350,7 +350,8 @@ asmlinkage __visible void do_softirq(void)
  */
 void irq_enter_rcu(void)
 {
-	if (is_idle_task(current) && !in_interrupt()) {
+	if (tick_nohz_full_cpu(smp_processor_id()) ||
+		(is_idle_task(current) && !in_interrupt())) {
 		/*
 		 * Prevent raise_softirq from needlessly waking up ksoftirqd
 		 * here, as softirq will be serviced on return from interrupt.
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 33750db5b56469e9cd770a0f0a4bfe75cdd7f747..aed5d6b6ca718f90a3509d97295e413ca5419a83 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1347,6 +1347,13 @@ static inline void tick_nohz_irq_enter(void)
 	now = ktime_get();
 	if (ts->idle_active)
 		tick_nohz_stop_idle(ts, now);
+	/*
+	 * If all CPUs are idle. We may need to update a stale jiffies value.
+	 * Note nohz_full is a special case: a timekeeper is guaranteed to stay
+	 * alive but it might be busy looping with interrupts disabled in some
+	 * rare case (typically stop machine). So we must make sure we have a
+	 * last resort.
+	 */
 	if (ts->tick_stopped)
 		tick_nohz_update_jiffies(now);
 }