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 a deferrable flag while calling
the trace_timer_start event.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
[jstultz: Fixed minor whitespace and grammer tweaks
 pointed out by Ingo]
Signed-off-by: John Stultz <john.stultz@linaro.org>

2 files changed, 10 insertions, 5 deletions

diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index 68c2c2000f02..d7abef1fe6e0 100644
--- a/include/trace/events/timer.h
+++ b/include/trace/events/timer.h
@@ -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')
 );
 
 /**
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index d4af7c56c95d..7775d454a204 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -650,7 +650,7 @@ 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)