From 24dd08d3605098ad7640de276f5a8e484b4d67a7 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.cz>
Date: Wed, 24 Aug 2011 09:39:30 +0200
Subject: [PATCH] --- yaml --- r: 269191 b: refs/heads/master c:
 09a1d34f8535ecf9a347ea76f7597730c2bc0c8d h: refs/heads/master i:   269189:
 2b86ec26c261fe822dff255be11fcf3ca7a20500   269187:
 1dff2c3de749e1f85e33b0bfcd03c1a42163e61a   269183:
 cb6f994ae2e009b95b631fafb86d53f91bac784e v: v3

---
 [refs]                         |  2 +-
 trunk/kernel/time/tick-sched.c | 41 +++++++++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index 9a67537a7433..794ab16b5237 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6beea0cda8ce71c01354e688e5735c47e331e84f
+refs/heads/master: 09a1d34f8535ecf9a347ea76f7597730c2bc0c8d
diff --git a/trunk/kernel/time/tick-sched.c b/trunk/kernel/time/tick-sched.c
index 7ab44bca6546..664c4a365439 100644
--- a/trunk/kernel/time/tick-sched.c
+++ b/trunk/kernel/time/tick-sched.c
@@ -198,7 +198,8 @@ static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
 /**
  * get_cpu_idle_time_us - get the total idle time of a cpu
  * @cpu: CPU number to query
- * @last_update_time: variable to store update time in
+ * @last_update_time: variable to store update time in. Do not update
+ * counters if NULL.
  *
  * Return the cummulative idle time (since boot) for a given
  * CPU, in microseconds.
@@ -211,20 +212,35 @@ static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
 u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
 {
 	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+	ktime_t now, idle;
 
 	if (!tick_nohz_enabled)
 		return -1;
 
-	update_ts_time_stats(cpu, ts, ktime_get(), last_update_time);
+	now = ktime_get();
+	if (last_update_time) {
+		update_ts_time_stats(cpu, ts, now, last_update_time);
+		idle = ts->idle_sleeptime;
+	} else {
+		if (ts->idle_active && !nr_iowait_cpu(cpu)) {
+			ktime_t delta = ktime_sub(now, ts->idle_entrytime);
+
+			idle = ktime_add(ts->idle_sleeptime, delta);
+		} else {
+			idle = ts->idle_sleeptime;
+		}
+	}
+
+	return ktime_to_us(idle);
 
-	return ktime_to_us(ts->idle_sleeptime);
 }
 EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
 
 /**
  * get_cpu_iowait_time_us - get the total iowait time of a cpu
  * @cpu: CPU number to query
- * @last_update_time: variable to store update time in
+ * @last_update_time: variable to store update time in. Do not update
+ * counters if NULL.
  *
  * Return the cummulative iowait time (since boot) for a given
  * CPU, in microseconds.
@@ -237,13 +253,26 @@ EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
 u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
 {
 	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+	ktime_t now, iowait;
 
 	if (!tick_nohz_enabled)
 		return -1;
 
-	update_ts_time_stats(cpu, ts, ktime_get(), last_update_time);
+	now = ktime_get();
+	if (last_update_time) {
+		update_ts_time_stats(cpu, ts, now, last_update_time);
+		iowait = ts->iowait_sleeptime;
+	} else {
+		if (ts->idle_active && nr_iowait_cpu(cpu) > 0) {
+			ktime_t delta = ktime_sub(now, ts->idle_entrytime);
+
+			iowait = ktime_add(ts->iowait_sleeptime, delta);
+		} else {
+			iowait = ts->iowait_sleeptime;
+		}
+	}
 
-	return ktime_to_us(ts->iowait_sleeptime);
+	return ktime_to_us(iowait);
 }
 EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);