diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0692c8ff6ff6..ac6b52d8c79e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9601,8 +9601,13 @@ static void nohz_balancer_kick(struct rq *rq)
 	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
 	if (sds) {
 		/*
-		 * XXX: write a coherent comment on why we do this.
-		 * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com
+		 * If there is an imbalance between LLC domains (IOW we could
+		 * increase the overall cache use), we need some less-loaded LLC
+		 * domain to pull some load. Likewise, we may need to spread
+		 * load within the current LLC domain (e.g. packed SMT cores but
+		 * other CPUs are idle). We can't really know from here how busy
+		 * the others are - so just get a nohz balance going if it looks
+		 * like this LLC domain has tasks we could move.
 		 */
 		nr_busy = atomic_read(&sds->nr_busy_cpus);
 		if (nr_busy > 1) {