NOHZ: split tick_nohz_restart_sched_tick()
Thomas Gleixner [Fri, 17 Oct 2008 08:04:34 +0000 (10:04 +0200)]
Split out the clock event device reprogramming. Preparatory
patch.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/time/tick-sched.c

index fdcf3f9..7aedf43 100644 (file)
@@ -377,6 +377,32 @@ ktime_t tick_nohz_get_sleep_length(void)
        return ts->sleep_length;
 }
 
+static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
+{
+       hrtimer_cancel(&ts->sched_timer);
+       ts->sched_timer.expires = 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_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))
+                               break;
+               }
+               /* Update jiffies and reread time */
+               tick_do_update_jiffies64(now);
+               now = ktime_get();
+       }
+}
+
 /**
  * tick_nohz_restart_sched_tick - restart the idle tick from the idle task
  *
@@ -430,28 +456,7 @@ void tick_nohz_restart_sched_tick(void)
         */
        ts->tick_stopped  = 0;
        ts->idle_exittime = now;
-       hrtimer_cancel(&ts->sched_timer);
-       ts->sched_timer.expires = 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_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))
-                               break;
-               }
-               /* Update jiffies and reread time */
-               tick_do_update_jiffies64(now);
-               now = ktime_get();
-       }
+       tick_nohz_restart(ts, now);
        local_irq_enable();
 }