tick-sched: add more debug information

To allow better diagnosis of tick-sched related, especially NOHZ
related problems, we need to know when the last wakeup via an irq
happened and when the CPU left the idle state.

Add two fields (idle_waketime, idle_exittime) to the tick_sched
structure and add them to the timer_list output.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2008-02-01 17:45:14 +01:00 committed by Ingo Molnar
parent 1001d0a9ee
commit 5df7fa1c62
3 changed files with 8 additions and 0 deletions

View File

@ -39,6 +39,8 @@ enum tick_nohz_mode {
* @idle_calls: Total number of idle calls
* @idle_sleeps: Number of idle calls, where the sched tick was stopped
* @idle_entrytime: Time when the idle call was entered
* @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
* @sleep_length: Duration of the current idle sleep
*/
@ -53,6 +55,8 @@ struct tick_sched {
unsigned long idle_sleeps;
int idle_active;
ktime_t idle_entrytime;
ktime_t idle_waketime;
ktime_t idle_exittime;
ktime_t idle_sleeptime;
ktime_t idle_lastupdate;
ktime_t sleep_length;

View File

@ -137,6 +137,7 @@ void tick_nohz_update_jiffies(void)
cpu_clear(cpu, nohz_cpu_mask);
now = ktime_get();
ts->idle_waketime = now;
local_irq_save(flags);
tick_do_update_jiffies64(now);
@ -400,6 +401,7 @@ void tick_nohz_restart_sched_tick(void)
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
ts->idle_exittime = now;
hrtimer_cancel(&ts->sched_timer);
ts->sched_timer.expires = ts->idle_tick;

View File

@ -166,6 +166,8 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now)
P(idle_calls);
P(idle_sleeps);
P_ns(idle_entrytime);
P_ns(idle_waketime);
P_ns(idle_exittime);
P_ns(idle_sleeptime);
P(last_jiffies);
P(next_jiffies);