Re: [PATCH v3] tracing: timer: Add deferrable flag to timer_start

[Steven Rostedt <rostedt@goodmis.org>]

On Thu,  7 May 2015 16:20:34 -0700
Badhri Jagan Sridharan <badhri@google.com> wrote:

> 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 <Badhri@google.com>

Acked-by: Steven Rostedt <rostedt@goodmis.org>

John, Thomas, you want to pick this up?

-- Steve

> ---
> 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(-)
> 
> diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
> index 68c2c20..d7abef1 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 2ece3aa..e5588da 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -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)