diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/tick-sched.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f25735a767af..358822ee32d5 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -179,6 +179,20 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts) return now; } +/** + * 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 + * + * Return the cummulative idle time (since boot) for a given + * CPU, in microseconds. The idle time returned includes + * the iowait time (unlike what "top" and co report). + * + * This time is measured via accounting rather than sampling, + * and is as accurate as ktime_get() is. + * + * This function returns -1 if NOHZ is not enabled. + */ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); |