3 files changed, 29 insertions, 17 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 1a20715bfd6e..8ff15e5d486b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -142,8 +142,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
                 time_state = TIME_OOP;
                 printk(KERN_NOTICE "Clock: "
                        "inserting leap second 23:59:60 UTC\n");
-                leap_timer.expires = ktime_add_ns(leap_timer.expires,
-                                                  NSEC_PER_SEC);
+                hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
                 res = HRTIMER_RESTART;
                 break;
         case TIME_DEL:
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 0581c11fe6c6..5bbb1044f847 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -300,7 +300,7 @@ void tick_nohz_stop_sched_tick(int inidle)
                                 goto out;
                         }
 
-                        ts->idle_tick = ts->sched_timer.expires;
+                        ts->idle_tick = hrtimer_get_expires(&ts->sched_timer);
                         ts->tick_stopped = 1;
                         ts->idle_jiffies = last_jiffies;
                         rcu_enter_nohz();
@@ -380,21 +380,21 @@ ktime_t tick_nohz_get_sleep_length(void)
 static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
 {
         hrtimer_cancel(&ts->sched_timer);
-        ts->sched_timer.expires = ts->idle_tick;
+        hrtimer_set_expires(&ts->sched_timer, ts->idle_tick);
 
         while (1) {
                 /* Forward the time to expire in the future */
                 hrtimer_forward(&ts->sched_timer, now, tick_period);
 
                 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-                        hrtimer_start(&ts->sched_timer,
-                                      ts->sched_timer.expires,
+                        hrtimer_start_expires(&ts->sched_timer,
                                       HRTIMER_MODE_ABS);
                         /* Check, if the timer was already in the past */
                         if (hrtimer_active(&ts->sched_timer))
                                 break;
                 } else {
-                        if (!tick_program_event(ts->sched_timer.expires, 0))
+                        if (!tick_program_event(
+                                hrtimer_get_expires(&ts->sched_timer), 0))
                                 break;
                 }
                 /* Update jiffies and reread time */
@@ -456,14 +456,16 @@ void tick_nohz_restart_sched_tick(void)
          */
         ts->tick_stopped  = 0;
         ts->idle_exittime = now;
+
         tick_nohz_restart(ts, now);
+
         local_irq_enable();
 }
 
 static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
 {
         hrtimer_forward(&ts->sched_timer, now, tick_period);
-        return tick_program_event(ts->sched_timer.expires, 0);
+        return tick_program_event(hrtimer_get_expires(&ts->sched_timer), 0);
 }
 
 /*
@@ -542,7 +544,7 @@ static void tick_nohz_switch_to_nohz(void)
         next = tick_init_jiffy_update();
 
         for (;;) {
-                ts->sched_timer.expires = next;
+                hrtimer_set_expires(&ts->sched_timer, next);
                 if (!tick_program_event(next, 0))
                         break;
                 next = ktime_add(next, tick_period);
@@ -567,11 +569,21 @@ 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(hrtimer_get_expires(&ts->sched_timer), now);
+        if (delta.tv64 <= tick_period.tv64)
+                return;
+
+        tick_nohz_restart(ts, now);
 }
 
 #else
@@ -668,16 +680,15 @@ void tick_setup_sched_timer(void)
         ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
 
         /* Get the next period (per cpu) */
-        ts->sched_timer.expires = tick_init_jiffy_update();
+        hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
         offset = ktime_to_ns(tick_period) >> 1;
         do_div(offset, num_possible_cpus());
         offset *= smp_processor_id();
-        ts->sched_timer.expires = ktime_add_ns(ts->sched_timer.expires, offset);
+        hrtimer_add_expires_ns(&ts->sched_timer, offset);
 
         for (;;) {
                 hrtimer_forward(&ts->sched_timer, now, tick_period);
-                hrtimer_start(&ts->sched_timer, ts->sched_timer.expires,
-                              HRTIMER_MODE_ABS);
+                hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS);
                 /* Check, if the timer was already in the past */
                 if (hrtimer_active(&ts->sched_timer))
                         break;
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index f6426911e35a..a999b92a1277 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -66,9 +66,11 @@ print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
         SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
 #endif
         SEQ_printf(m, "\n");
-        SEQ_printf(m, " # expires at %Lu nsecs [in %Ld nsecs]\n",
-                (unsigned long long)ktime_to_ns(timer->expires),
-                (long long)(ktime_to_ns(timer->expires) - now));
+        SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
+                (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
+                (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
+                (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
+                (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
 }
 
 static void