Re: [RFC PATCH 3/3] thermal: trace: Trace when temperature is above a trip point

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 11 Jun 2014 12:31:44 +0100
Punit Agrawal <punit.agrawal@arm.com> wrote:

> Create a new event to trace when the temperature is above a trip
> point. Use the trace-point when handling non-critical and critical
> trip pionts.
> 
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
> ---
> Hi Steven,
> 
> I am facing an issue with partial trace being emitted when using
> __print_symbolic in this patch. 
> 
> When the trip_type is THERMAL_TRIP_ACTIVE (i.e., the first value in
> the symbol map), the emitted trace contains the corresponding string
> ("active"). But for other values of trip_type an empty string is
> emitted in the trace.
> 
> I've looked at other uses of __print_symbolic in the kernel and don't
> see any difference in usage. Do you know what could be causing this or
> alternately have any pointers on how to debug this behaviour?
> 

If you can use trace-cmd to record your events then we can look at the
raw data too.

trace-cmd record -e thermal_zone_trip <some-command>

where <some-command> would trigger your tracepoint.

Then do: trace-cmd report -R

You should see the raw value of trip_type.

Make sure that it matches the enum values that you have listed.

-- Steve


> Thanks.
> Punit
> 
>  drivers/thermal/fair_share.c   |    7 ++++++-
>  drivers/thermal/step_wise.c    |    5 ++++-
>  drivers/thermal/thermal_core.c |    2 ++
>  include/trace/events/thermal.h |   30 ++++++++++++++++++++++++++++++
>  4 files changed, 42 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c
> index 944ba2f..2cddd68 100644
> --- a/drivers/thermal/fair_share.c
> +++ b/drivers/thermal/fair_share.c
> @@ -23,6 +23,7 @@
>   */
>  
>  #include <linux/thermal.h>
> +#include <trace/events/thermal.h>
>  
>  #include "thermal_core.h"
>  
> @@ -34,14 +35,18 @@ static int get_trip_level(struct thermal_zone_device *tz)
>  {
>  	int count = 0;
>  	unsigned long trip_temp;
> +	enum thermal_trip_type trip_type;
>  
>  	if (tz->trips == 0 || !tz->ops->get_trip_temp)
>  		return 0;
>  
>  	for (count = 0; count < tz->trips; count++) {
>  		tz->ops->get_trip_temp(tz, count, &trip_temp);
> -		if (tz->temperature < trip_temp)
> +		if (tz->temperature < trip_temp) {
> +			tz->ops->get_trip_type(tz, count, &trip_type);
> +			trace_thermal_zone_trip(tz, count, trip_type);
>  			break;
> +		}
>  	}
>  	return count;
>  }
> diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c
> index f251521..3b54c2c 100644
> --- a/drivers/thermal/step_wise.c
> +++ b/drivers/thermal/step_wise.c
> @@ -23,6 +23,7 @@
>   */
>  
>  #include <linux/thermal.h>
> +#include <trace/events/thermal.h>
>  
>  #include "thermal_core.h"
>  
> @@ -129,8 +130,10 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
>  
>  	trend = get_tz_trend(tz, trip);
>  
> -	if (tz->temperature >= trip_temp)
> +	if (tz->temperature >= trip_temp) {
>  		throttle = true;
> +		trace_thermal_zone_trip(tz, trip, trip_type);
> +	}
>  
>  	dev_dbg(&tz->device, "Trip%d[type=%d,temp=%ld]:trend=%d,throttle=%d\n",
>  				trip, trip_type, trip_temp, trend, throttle);
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index c74c78d..454884a 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -371,6 +371,8 @@ static void handle_critical_trips(struct thermal_zone_device *tz,
>  	if (tz->temperature < trip_temp)
>  		return;
>  
> +	trace_thermal_zone_trip(tz, trip, trip_type);
> +
>  	if (tz->ops->notify)
>  		tz->ops->notify(tz, trip, trip_type);
>  
> diff --git a/include/trace/events/thermal.h b/include/trace/events/thermal.h
> index 894a79e..5eeb1e7 100644
> --- a/include/trace/events/thermal.h
> +++ b/include/trace/events/thermal.h
> @@ -51,6 +51,36 @@ TRACE_EVENT(cdev_update,
>  	TP_printk("type=%s target=%lu", __get_str(type), __entry->target)
>  );
>  
> +TRACE_EVENT(,
> +
> +	TP_PROTO(struct thermal_zone_device *tz, int trip,
> +		enum thermal_trip_type trip_type),
> +
> +	TP_ARGS(tz, trip, trip_type),
> +
> +	TP_STRUCT__entry(
> +		__string(thermal_zone, tz->type)
> +		__field(int, id)
> +		__field(int, trip)
> +		__field(enum thermal_trip_type, trip_type)
> +	),
> +
> +	TP_fast_assign(
> +		__assign_str(thermal_zone, tz->type);
> +		__entry->id = tz->id;
> +		__entry->trip = trip;
> +		__entry->trip_type = trip_type;
> +	),
> +
> +	TP_printk("thermal_zone=%s id=%d trip=%d trip_type=%s",
> +		__get_str(thermal_zone), __entry->id, __entry->trip,
> +		__print_symbolic(__entry->trip_type,
> +				{ THERMAL_TRIP_ACTIVE, "active" },
> +				{ THERMAL_TRIP_PASSIVE, "passive" },
> +				{ THERMAL_TRIP_HOT, "hot" },
> +				{ THERMAL_TRIP_CRITICAL, "critical" }))
> +);
> +
>  #endif /* _TRACE_THERMAL_H */
>  
>  /* This part must be outside protection */