[PATCH 5/7] thermal: stats: introduce tz time in trip

Eduardo Valentin
2023-06-21T04:45:30Z

On Tue, Jun 20, 2023 at 07:27:57PM +0200, Rafael J. Wysocki wrote:
>
>
>
> On Fri, May 19, 2023 at 5:27 AM Eduardo Valentin <evalenti@kernel.org> wrote:
> >
> > From: Eduardo Valentin <eduval@amazon.com>
> >
> > This patch adds a statistic to report how long
> > the thermal zone spent on temperature intervals
> > created by each trip point. The first interval
> > is the range below the first trip point. All
> > subsequent intervals are accounted when temperature
> > is above the trip point temperature value.
> >
> > Samples:
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
>
> The above line is confusing.
>
> > trip0 -10000 35188
> > trip1 25000 0
>
> And the format violates the "one value per attribute" sysfs rule.
>
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
> > trip0 -10000 36901
> > trip1 25000 0
> > $ echo 25001 > /sys//class/thermal/thermal_zone0/emul_temp
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
> > trip0 -10000 47810
> > trip1 25000 2259
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
> > trip0 -10000 47810
> > trip1 25000 3224
> > $ echo 24001 > /sys//class/thermal/thermal_zone0/emul_temp
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
> > trip0 -10000 48960
> > trip1 25000 10080
> > $ cat /sys//class/thermal/thermal_zone0/stats/time_in_trip_ms
> > trip-1 0 0
> > trip0 -10000 49844
> > trip1 25000 10080
> >
> > Cc: "Rafael J. Wysocki" <rafael@kernel.org> (supporter:THERMAL)
> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> (supporter:THERMAL)
> > Cc: Amit Kucheria <amitk@kernel.org> (reviewer:THERMAL)
> > Cc: Zhang Rui <rui.zhang@intel.com> (reviewer:THERMAL)
> > Cc: Jonathan Corbet <corbet@lwn.net> (maintainer:DOCUMENTATION)
> > Cc: linux-pm@vger.kernel.org (open list:THERMAL)
> > Cc: linux-doc@vger.kernel.org (open list:DOCUMENTATION)
> > Cc: linux-kernel@vger.kernel.org (open list)
> >
> > Signed-off-by: Eduardo Valentin <eduval@amazon.com>
> > ---
> > .../driver-api/thermal/sysfs-api.rst | 2 +
> > drivers/thermal/thermal_sysfs.c | 86 +++++++++++++++++++
> > 2 files changed, 88 insertions(+)
> >
> > diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
> > index ed5e6ba4e0d7..4a2b92a7488c 100644
> > --- a/Documentation/driver-api/thermal/sysfs-api.rst
> > +++ b/Documentation/driver-api/thermal/sysfs-api.rst
> > @@ -359,6 +359,8 @@ Thermal zone device sys I/F, created once it's registered::
> > |---stats/reset_tz_stats: Writes to this file resets the statistics.
> > |---stats/max_gradient: The maximum recorded dT/dt in uC/ms.
> > |---stats/min_gradient: The minimum recorded dT/dt in uC/ms.
> > + |---stats/time_in_trip_ms: Time spent on each temperature interval of
> > + trip points.
>
> I would write "in each temperature interval between consecutive trip points".

Ok

>
> Doesn't this assume a specific temperature ordering of trip points?
> And so what if they are not ordered?

It does. I believe other things will break if they are not ordered. Like the temperature update
against the governor throttle callback invocation in the thermal core.

--
All the best,
Eduardo Valentin