--- m/net/core/dev.c
+++ n/net/core/dev.c
@@ -5041,7 +5041,10 @@ static __latent_entropy void net_tx_acti
 
 			if (!(q->flags & TCQ_F_NOLOCK)) {
 				root_lock = qdisc_lock(q);
-				spin_lock(root_lock);
+				if (!spin_trylock(root_lock)) {
+					__netif_reschedule(q);
+					continue;
+				}
 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
 						     &q->state))) {
 				/* There is a synchronize_net() between
--- m/kernel/rcu/tree_stall.h
+++ n/kernel/rcu/tree_stall.h
@@ -267,8 +267,10 @@ static int rcu_print_task_stall(struct r
 	struct task_struct *ts[8];
 
 	lockdep_assert_irqs_disabled();
-	if (!rcu_preempt_blocked_readers_cgp(rnp))
+	if (!rcu_preempt_blocked_readers_cgp(rnp)) {
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return 0;
+	}
 	pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
 	       rnp->level, rnp->grplo, rnp->grphi);
 	t = list_entry(rnp->gp_tasks->prev,
--- m/kernel/time/hrtimer.c
+++ n/kernel/time/hrtimer.c
@@ -1030,12 +1030,13 @@ static void __remove_hrtimer(struct hrti
  * remove hrtimer, called with base lock held
  */
 static inline int
-remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool restart)
+remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base,
+	       bool restart, bool keep_local)
 {
 	u8 state = timer->state;
 
 	if (state & HRTIMER_STATE_ENQUEUED) {
-		int reprogram;
+		bool reprogram;
 
 		/*
 		 * Remove the timer and force reprogramming when high
@@ -1048,8 +1049,16 @@ remove_hrtimer(struct hrtimer *timer, st
 		debug_deactivate(timer);
 		reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
 
+		/*
+		 * If the timer is not restarted then reprogramming is
+		 * required if the timer is local. If it is local and about
+		 * to be restarted, avoid programming it twice (on removal
+		 * and a moment later when it's requeued).
+		 */
 		if (!restart)
 			state = HRTIMER_STATE_INACTIVE;
+		else
+			reprogram &= !keep_local;
 
 		__remove_hrtimer(timer, base, state, reprogram);
 		return 1;
@@ -1103,9 +1112,31 @@ static int __hrtimer_start_range_ns(stru
 				    struct hrtimer_clock_base *base)
 {
 	struct hrtimer_clock_base *new_base;
+	bool force_local, first;
 
-	/* Remove an active timer from the queue: */
-	remove_hrtimer(timer, base, true);
+	/*
+	 * If the timer is on the local cpu base and is the first expiring
+	 * timer then this might end up reprogramming the hardware twice
+	 * (on removal and on enqueue). To avoid that by prevent the
+	 * reprogram on removal, keep the timer local to the current CPU
+	 * and enforce reprogramming after it is queued no matter whether
+	 * it is the new first expiring timer again or not.
+	 */
+	force_local = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
+	force_local &= base->cpu_base->next_timer == timer;
+
+	/*
+	 * Remove an active timer from the queue. In case it is not queued
+	 * on the current CPU, make sure that remove_hrtimer() updates the
+	 * remote data correctly.
+	 *
+	 * If it's on the current CPU and the first expiring timer, then
+	 * skip reprogramming, keep the timer local and enforce
+	 * reprogramming later if it was the first expiring timer.  This
+	 * avoids programming the underlying clock event twice (once at
+	 * removal and once after enqueue).
+	 */
+	remove_hrtimer(timer, base, true, force_local);
 
 	if (mode & HRTIMER_MODE_REL)
 		tim = ktime_add_safe(tim, base->get_time());
@@ -1115,9 +1146,24 @@ static int __hrtimer_start_range_ns(stru
 	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
 
 	/* Switch the timer base, if necessary: */
-	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+	if (!force_local) {
+		new_base = switch_hrtimer_base(timer, base,
+					       mode & HRTIMER_MODE_PINNED);
+	} else {
+		new_base = base;
+	}
 
-	return enqueue_hrtimer(timer, new_base, mode);
+	first = enqueue_hrtimer(timer, new_base, mode);
+	if (!force_local)
+		return first;
+
+	/*
+	 * Timer was forced to stay on the current CPU to avoid
+	 * reprogramming on removal and enqueue. Force reprogram the
+	 * hardware by evaluating the new first expiring timer.
+	 */
+	hrtimer_force_reprogram(new_base->cpu_base, 1);
+	return 0;
 }
 
 /**
@@ -1183,7 +1229,7 @@ int hrtimer_try_to_cancel(struct hrtimer
 	base = lock_hrtimer_base(timer, &flags);
 
 	if (!hrtimer_callback_running(timer))
-		ret = remove_hrtimer(timer, base, false);
+		ret = remove_hrtimer(timer, base, false, false);
 
 	unlock_hrtimer_base(timer, &flags);