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

From: Javi Merino
Date: Fri Jun 20 2014 - 13:24:53 EST


Hi Punit,

On Wed, Jun 11, 2014 at 12:31:44PM +0100, Punit Agrawal 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@xxxxxxxxx>
> Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
> ---
> 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?
>
> 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);

This should be outside the if condition. You want to report when trip
points have been hit, like in the step_wise code below.

> 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);
>

Cheers,
Javi

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