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authorThomas Gleixner <tglx@linutronix.de>2008-02-01 17:45:14 +0100
committerIngo Molnar <mingo@elte.hu>2008-02-01 17:45:14 +0100
commit5df7fa1c62146a0933767d040d400013310dbcc7 (patch)
treebfd108f0d33a91d4f2476df7f5a7f562b640eb97
parent1001d0a9ee74a468077dfd4da0565174e88de26b (diff)
downloadblackbird-op-linux-5df7fa1c62146a0933767d040d400013310dbcc7.tar.gz
blackbird-op-linux-5df7fa1c62146a0933767d040d400013310dbcc7.zip
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>
-rw-r--r--include/linux/tick.h4
-rw-r--r--kernel/time/tick-sched.c2
-rw-r--r--kernel/time/timer_list.c2
3 files changed, 8 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;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 63f24b550695..88267f0a8471 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -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;
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 12c5f4cb6b8c..d3d94c1a0fd2 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -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);
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