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

Rafael J. Wysocki
2023-06-23T16:41:17Z

On Wed, Jun 21, 2023 at 6:45 AM Eduardo Valentin <evalenti@kernel.org> wrote:
>
> 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.

But there's no guarantee that they will be ordered, so it looks like
those other things are already broken.