tick: sched: Remove hrtimer_active() checks

hrtimer_start() enforces a timer interrupt if the timer is already
expired. Get rid of the checks and the forward loop.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203501.943658239@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 914259128145e2394e65bd36f18aaf9a81f78843..dc586c3716878f530c075ec9a1c9e99135828682 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -696,11 +696,9 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
                if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
                        hrtimer_start(&ts->sched_timer, expires,
                                      HRTIMER_MODE_ABS_PINNED);
-                       /* Check, if the timer was already in the past */
-                       if (hrtimer_active(&ts->sched_timer))
-                               goto out;
+                       goto out;
                } else if (!tick_program_event(expires, 0))
-                               goto out;
+                       goto out;
                /*
                 * We are past the event already. So we crossed a
                 * jiffie boundary. Update jiffies and raise the
@@ -888,8 +886,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
                if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
                        hrtimer_start_expires(&ts->sched_timer,
                                              HRTIMER_MODE_ABS_PINNED);
-                       /* Check, if the timer was already in the past */
-                       if (hrtimer_active(&ts->sched_timer))
                                break;
                } else {
                        if (!tick_program_event(
@@ -1167,15 +1163,8 @@ void tick_setup_sched_timer(void)
                hrtimer_add_expires_ns(&ts->sched_timer, offset);
        }
 
-       for (;;) {
-               hrtimer_forward(&ts->sched_timer, now, tick_period);
-               hrtimer_start_expires(&ts->sched_timer,
-                                     HRTIMER_MODE_ABS_PINNED);
-               /* Check, if the timer was already in the past */
-               if (hrtimer_active(&ts->sched_timer))
-                       break;
-               now = ktime_get();
-       }
+       hrtimer_forward(&ts->sched_timer, now, tick_period);
+       hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
 
 #ifdef CONFIG_NO_HZ_COMMON
        if (tick_nohz_enabled) {