1 files changed, 19 insertions, 0 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 6a3a5b9ff561..da70c6db496c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -576,6 +576,7 @@ void tick_nohz_idle_exit(void)
         /* Update jiffies first */
         select_nohz_load_balancer(0);
         tick_do_update_jiffies64(now);
+        update_cpu_load_nohz();
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
         /*
@@ -814,6 +815,16 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
         return HRTIMER_RESTART;
 }
 
+static int sched_skew_tick;
+
+static int __init skew_tick(char *str)
+{
+        get_option(&str, &sched_skew_tick);
+
+        return 0;
+}
+early_param("skew_tick", skew_tick);
+
 /**
  * tick_setup_sched_timer - setup the tick emulation timer
  */
@@ -831,6 +842,14 @@ void tick_setup_sched_timer(void)
         /* Get the next period (per cpu) */
         hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
 
+        /* Offset the tick to avert xtime_lock contention. */
+        if (sched_skew_tick) {
+                u64 offset = ktime_to_ns(tick_period) >> 1;
+                do_div(offset, num_possible_cpus());
+                offset *= smp_processor_id();
+                hrtimer_add_expires_ns(&ts->sched_timer, offset);
+        }
+
         for (;;) {
                 hrtimer_forward(&ts->sched_timer, now, tick_period);
                 hrtimer_start_expires(&ts->sched_timer,