Merge branch 'v28-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'v28-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  NOHZ: fix thinko in the timer restart code path

1 files changed, 11 insertions, 1 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 0581c11fe6c6..727c1ae0517a 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -567,11 +567,21 @@ static void tick_nohz_switch_to_nohz(void)
 static void tick_nohz_kick_tick(int cpu)
 {
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+        ktime_t delta, now;
 
         if (!ts->tick_stopped)
                 return;
 
-        tick_nohz_restart(ts, ktime_get());
+        /*
+         * Do not touch the tick device, when the next expiry is either
+         * already reached or less/equal than the tick period.
+         */
+        now = ktime_get();
+        delta = ktime_sub(ts->sched_timer.expires, now);
+        if (delta.tv64 <= tick_period.tv64)
+                return;
+
+        tick_nohz_restart(ts, now);
 }
 
 #else