tracing: timer: Add deferrable flag to timer_start

The timer_start event now shows whether the timer is deferrable in case of a low-res timer. The debug_activate function now includes deferrable flag while calling trace_timer_start event.

Signed-off-by Badhri Jagan Sridharan <[email protected]>

---
Changelog since v2:
- changed deferrable flag to unsigned int

Changelog since v1:
- fixed indentation
- moved deferrable flag checking to tracing code

 include/trace/events/timer.h | 13 +++++++++----
 kernel/time/timer.c          |  3 ++-
 2 files changed, 11 insertions(+), 5 deletions(-)

include/trace/events/timer.h +9 -4

index 68c2c20..d7abef1 100644
@@ -43,15 +43,18 @@ DEFINE_EVENT(timer_class, timer_init,
  */
 TRACE_EVENT(timer_start,
 
-	TP_PROTO(struct timer_list *timer, unsigned long expires),
+	TP_PROTO(struct timer_list *timer,
+		unsigned long expires,
+		unsigned int deferrable),
 
-	TP_ARGS(timer, expires),
+	TP_ARGS(timer, expires, deferrable),
 
 	TP_STRUCT__entry(
 		__field( void *,	timer		)
 		__field( void *,	function	)
 		__field( unsigned long,	expires		)
 		__field( unsigned long,	now		)
+		__field( unsigned int,	deferrable	)
 	),
 
 	TP_fast_assign(

@@ -59,11 +62,13 @@ TRACE_EVENT(timer_start,
 		__entry->function	= timer->function;
 		__entry->expires	= expires;
 		__entry->now		= jiffies;
+		__entry->deferrable     = deferrable;
 	),
 
-	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld]",
+	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] defer=%c",
 		  __entry->timer, __entry->function, __entry->expires,
-		  (long)__entry->expires - __entry->now)
+		  (long)__entry->expires - __entry->now,
+		  __entry->deferrable > 0 ? 'y':'n')
 );
 
 /**

kernel/time/timer.c +2 -1

index 2ece3aa..e5588da 100644
@@ -648,7 +648,8 @@ static inline void
 debug_activate(struct timer_list *timer, unsigned long expires)
 {
 	debug_timer_activate(timer);
-	trace_timer_start(timer, expires);
+	trace_timer_start(timer, expires,
+		tbase_get_deferrable(timer->base));
 }
 
 static inline void debug_deactivate(struct timer_list *timer)

Quoted 5 lines · On Thu, 7 May 2015 16:20:34 -0700 Badhri Jagan Sridharan <[email protected]>…

The timer_start event now shows whether the timer is deferrable in case of a low-res timer. The debug_activate function now includes deferrable flag while calling trace_timer_start event.

Quoted 1 line

Signed-off-by Badhri Jagan Sridharan <[email protected]>

Acked-by Steven Rostedt <[email protected]>

John, Thomas, you want to pick this up?