1 files changed, 35 insertions, 6 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 7ab44bca6546..664c4a365439 100644
--- a/kernel/time/tick-sched.c
+++ b/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);