3 files changed, 21 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8cc863d66477..13efe7dac5fa 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -271,11 +271,17 @@ extern cpumask_var_t nohz_cpu_mask;
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
 extern int select_nohz_load_balancer(int cpu);
 extern int get_nohz_load_balancer(void);
+extern int nohz_ratelimit(int cpu);
 #else
 static inline int select_nohz_load_balancer(int cpu)
 {
         return 0;
 }
+
+static inline int nohz_ratelimit(int cpu)
+{
+        return 0;
+}
 #endif
 
 /*
diff --git a/kernel/sched.c b/kernel/sched.c
index a4aa071f08f3..60b1bbe2ad1b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -492,6 +492,7 @@ struct rq {
         #define CPU_LOAD_IDX_MAX 5
         unsigned long cpu_load[CPU_LOAD_IDX_MAX];
 #ifdef CONFIG_NO_HZ
+        u64 nohz_stamp;
         unsigned char in_nohz_recently;
 #endif
         /* capture load from *all* tasks on this cpu: */
@@ -1228,6 +1229,17 @@ void wake_up_idle_cpu(int cpu)
         if (!tsk_is_polling(rq->idle))
                 smp_send_reschedule(cpu);
 }
+
+int nohz_ratelimit(int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+        u64 diff = rq->clock - rq->nohz_stamp;
+
+        rq->nohz_stamp = rq->clock;
+
+        return diff < (NSEC_PER_SEC / HZ) >> 1;
+}
+
 #endif /* CONFIG_NO_HZ */
 
 static u64 sched_avg_period(void)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f992762d7f51..f25735a767af 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -262,6 +262,9 @@ void tick_nohz_stop_sched_tick(int inidle)
                 goto end;
         }
 
+        if (nohz_ratelimit(cpu))
+                goto end;
+
         ts->idle_calls++;
         /* Read jiffies and the time when jiffies were updated last */
         do {