--- l/net/sched/sch_fq_pie.c
+++ n/net/sched/sch_fq_pie.c
@@ -372,13 +372,16 @@ static void fq_pie_timer(struct timer_li
 	struct Qdisc *sch = q->sch;
 	spinlock_t *root_lock; /* to lock qdisc for probability calculations */
 	u32 idx;
+	unsigned long ts = jiffies + 2;
 
 	root_lock = qdisc_lock(qdisc_root_sleeping(sch));
 	spin_lock(root_lock);
 
-	for (idx = 0; idx < q->flows_cnt; idx++)
+	for (idx = 0; idx < q->flows_cnt; idx++) {
 		pie_calculate_probability(&q->p_params, &q->flows[idx].vars,
 					  q->flows[idx].backlog);
+		WARN_ON_ONCE(time_after(jiffies, ts));
+	}
 
 	/* reset the timer to fire after 'tupdate' jiffies. */
 	if (q->p_params.tupdate)