2 files changed, 14 insertions, 2 deletions

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 57a1f02e5ec0..67f80c261709 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -30,6 +30,7 @@
 struct tick_device tick_broadcast_device;
 static cpumask_t tick_broadcast_mask;
 static DEFINE_SPINLOCK(tick_broadcast_lock);
+static int tick_broadcast_force;
 
 #ifdef CONFIG_TICK_ONESHOT
 static void tick_broadcast_clear_oneshot(int cpu);
@@ -232,10 +233,11 @@ static void tick_do_broadcast_on_off(void *why)
                                                      CLOCK_EVT_MODE_SHUTDOWN);
                 }
                 if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
-                        dev->features |= CLOCK_EVT_FEAT_DUMMY;
+                        tick_broadcast_force = 1;
                 break;
         case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
-                if (cpu_isset(cpu, tick_broadcast_mask)) {
+                if (!tick_broadcast_force &&
+                    cpu_isset(cpu, tick_broadcast_mask)) {
                         cpu_clear(cpu, tick_broadcast_mask);
                         if (td->mode == TICKDEV_MODE_PERIODIC)
                                 tick_setup_periodic(dev, 0);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 28abad66fc8e..942fc7c85283 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -48,6 +48,13 @@ static void tick_do_update_jiffies64(ktime_t now)
         unsigned long ticks = 0;
         ktime_t delta;
 
+        /*
+         * Do a quick check without holding xtime_lock:
+         */
+        delta = ktime_sub(now, last_jiffies_update);
+        if (delta.tv64 < tick_period.tv64)
+                return;
+
         /* Reevalute with xtime_lock held */
         write_seqlock(&xtime_lock);
 
@@ -228,6 +235,7 @@ void tick_nohz_stop_sched_tick(void)
                                local_softirq_pending());
                         ratelimit++;
                 }
+                goto end;
         }
 
         ts->idle_calls++;
@@ -276,6 +284,7 @@ void tick_nohz_stop_sched_tick(void)
                         ts->tick_stopped = 1;
                         ts->idle_jiffies = last_jiffies;
                         rcu_enter_nohz();
+                        sched_clock_tick_stop(cpu);
                 }
 
                 /*
@@ -375,6 +384,7 @@ void tick_nohz_restart_sched_tick(void)
         select_nohz_load_balancer(0);
         now = ktime_get();
         tick_do_update_jiffies64(now);
+        sched_clock_tick_start(cpu);
         cpu_clear(cpu, nohz_cpu_mask);
 
         /*