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>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/tick.h b/include/linux/tick.h
index 0fadf95debe1..a881c652f7e9 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -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;