diff options
| -rw-r--r-- | include/linux/tick.h | 4 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 28 | ||||
| -rw-r--r-- | kernel/time/timer_list.c | 1 |
3 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h index 0343eed40619..b232ccc0ee29 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -42,6 +42,7 @@ enum tick_nohz_mode { * @idle_waketime: Time when the idle was interrupted * @idle_exittime: Time when the idle state was left * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped + * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding * @sleep_length: Duration of the current idle sleep * @do_timer_lst: CPU was the last one doing do_timer before going idle */ @@ -60,6 +61,7 @@ struct tick_sched { ktime_t idle_waketime; ktime_t idle_exittime; ktime_t idle_sleeptime; + ktime_t iowait_sleeptime; ktime_t sleep_length; unsigned long last_jiffies; unsigned long next_jiffies; @@ -123,6 +125,7 @@ extern void tick_nohz_stop_sched_tick(int inidle); extern void tick_nohz_restart_sched_tick(void); extern ktime_t tick_nohz_get_sleep_length(void); extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); +extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); # else static inline void tick_nohz_stop_sched_tick(int inidle) { } static inline void tick_nohz_restart_sched_tick(void) { } @@ -133,6 +136,7 @@ static inline ktime_t tick_nohz_get_sleep_length(void) return len; } static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } +static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } # endif /* !NO_HZ */ #endif diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 50953f4c42b2..1d7b9bc1c034 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -161,6 +161,8 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time) if (ts->idle_active) { delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + if (nr_iowait_cpu() > 0) + ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta); ts->idle_entrytime = now; } @@ -220,6 +222,32 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) } 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 + * + * Return the cummulative iowait time (since boot) for a given + * CPU, in microseconds. + * + * 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_iowait_time_us(int cpu, u64 *last_update_time) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + + if (!tick_nohz_enabled) + return -1; + + update_ts_time_stats(ts, ktime_get(), last_update_time); + + return ktime_to_us(ts->iowait_sleeptime); +} +EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us); + /** * tick_nohz_stop_sched_tick - stop the idle tick from the idle task * diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 1a4a7dd78777..ab8f5e33fa92 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -176,6 +176,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) P_ns(idle_waketime); P_ns(idle_exittime); P_ns(idle_sleeptime); + P_ns(iowait_sleeptime); P(last_jiffies); P(next_jiffies); P_ns(idle_expires); |