nohz: Make idle/iowait counter update conditional

[pandora-kernel.git] / kernel / time / tick-sched.c

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 7ab44bc..664c4a3 100644 (file)
--- 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);