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path: root/recipes/linux/linux-omap-pm-2.6.28/timer-suppression.patch
blob: 04362c96e3e03c016e8dc5ab4ed490a2ae80a2e5 (plain)
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diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index b854a89..26f5569 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -253,6 +253,16 @@ void tick_nohz_stop_sched_tick(void)
 
 	/* Schedule the tick, if we are at least one jiffie off */
 	if ((long)delta_jiffies >= 1) {
+		/*
+		 * calculate the expiry time for the next timer wheel
+		 * timer
+		 */
+		expires = ktime_add_ns(last_update, tick_period.tv64 *
+					delta_jiffies);
+
+		/* Skip reprogram of event if its not changed */
+		if(ts->tick_stopped && ktime_equal(expires, dev->next_event))
+		goto out2;
 
 		if (delta_jiffies > 1)
 			cpu_set(cpu, nohz_cpu_mask);
@@ -304,12 +314,7 @@ void tick_nohz_stop_sched_tick(void)
 			goto out;
 		}
 
-		/*
-		 * calculate the expiry time for the next timer wheel
-		 * timer
-		 */
-		expires = ktime_add_ns(last_update, tick_period.tv64 *
-				       delta_jiffies);
+		/* Mark expiries */
 		ts->idle_expires = expires;
 
 		if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
@@ -328,6 +333,7 @@ void tick_nohz_stop_sched_tick(void)
 		tick_do_update_jiffies64(ktime_get());
 		cpu_clear(cpu, nohz_cpu_mask);
 	}
+out2:	
 	raise_softirq_irqoff(TIMER_SOFTIRQ);
 out:
 	ts->next_jiffies = next_jiffies;