1 files changed, 30 insertions, 4 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4e305d174b55..36774e5dab01 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7647,8 +7647,22 @@ out:
 	 * When the cpu is attached to null domain for ex, it will not be
 	 * updated.
 	 */
-	if (likely(update_next_balance))
+	if (likely(update_next_balance)) {
 		rq->next_balance = next_balance;
+
+#ifdef CONFIG_NO_HZ_COMMON
+		/*
+		 * If this CPU has been elected to perform the nohz idle
+		 * balance. Other idle CPUs have already rebalanced with
+		 * nohz_idle_balance() and nohz.next_balance has been
+		 * updated accordingly. This CPU is now running the idle load
+		 * balance for itself and we need to update the
+		 * nohz.next_balance accordingly.
+		 */
+		if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance))
+			nohz.next_balance = rq->next_balance;
+#endif
+	}
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -7661,6 +7675,9 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 	int this_cpu = this_rq->cpu;
 	struct rq *rq;
 	int balance_cpu;
+	/* Earliest time when we have to do rebalance again */
+	unsigned long next_balance = jiffies + 60*HZ;
+	int update_next_balance = 0;
 
 	if (idle != CPU_IDLE ||
 	    !test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)))
@@ -7692,10 +7709,19 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 			rebalance_domains(rq, CPU_IDLE);
 		}
 
-		if (time_after(this_rq->next_balance, rq->next_balance))
-			this_rq->next_balance = rq->next_balance;
+		if (time_after(next_balance, rq->next_balance)) {
+			next_balance = rq->next_balance;
+			update_next_balance = 1;
+		}
 	}
-	nohz.next_balance = this_rq->next_balance;
+
+	/*
+	 * next_balance will be updated only when there is a need.
+	 * When the CPU is attached to null domain for ex, it will not be
+	 * updated.
+	 */
+	if (likely(update_next_balance))
+		nohz.next_balance = next_balance;
 end:
 	clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu));
 }