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References: <20240109094112.2871346-1-daniel.lezcano@linaro.org> <20240109094112.2871346-2-daniel.lezcano@linaro.org>
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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Tue, 9 Jan 2024 14:02:44 +0100
Message-ID: <CAJZ5v0iL9PhG5e8f9rAL05FHT6TnhSYx6=XOFdgnBtbC--ZZ9w@mail.gmail.com>
Subject: Re: [PATCH v6 2/2] thermal/debugfs: Add thermal debugfs information
 for mitigation episodes
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: rjw@rjwysocki.net, lukasz.luba@arm.com, rui.zhang@intel.com, 
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
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On Tue, Jan 9, 2024 at 10:41=E2=80=AFAM Daniel Lezcano
<daniel.lezcano@linaro.org> wrote:
>
> The mitigation episodes are recorded. A mitigation episode happens
> when the first trip point is crossed the way up and then the way
> down. During this episode other trip points can be crossed also and
> are accounted for this mitigation episode. The interesting information
> is the average temperature at the trip point, the undershot and the
> overshot. The standard deviation of the mitigated temperature will be
> added later.
>
> The thermal debugfs directory structure tries to stay consistent with
> the sysfs one but in a very simplified way:
>
> thermal/
>  `-- thermal_zones
>      |-- 0
>      |   `-- mitigations
>      `-- 1
>          `-- mitigations
>
> The content of the mitigations file has the following format:
>
> ,-Mitigation at 349988258us, duration=3D130136ms
> | trip |     type | temp(=C2=B0mC) | hyst(=C2=B0mC) |  duration  |  avg(=
=C2=B0mC) |  min(=C2=B0mC) |  max(=C2=B0mC) |
> |    0 |  passive |     65000 |      2000 |     130136 |     68227 |     =
62500 |     75625 |
> |    1 |  passive |     75000 |      2000 |     104209 |     74857 |     =
71666 |     77500 |
> ,-Mitigation at 272451637us, duration=3D75000ms
> | trip |     type | temp(=C2=B0mC) | hyst(=C2=B0mC) |  duration  |  avg(=
=C2=B0mC) |  min(=C2=B0mC) |  max(=C2=B0mC) |
> |    0 |  passive |     65000 |      2000 |      75000 |     68561 |     =
62500 |     75000 |
> |    1 |  passive |     75000 |      2000 |      60714 |     74820 |     =
70555 |     77500 |
> ,-Mitigation at 238184119us, duration=3D27316ms
> | trip |     type | temp(=C2=B0mC) | hyst(=C2=B0mC) |  duration  |  avg(=
=C2=B0mC) |  min(=C2=B0mC) |  max(=C2=B0mC) |
> |    0 |  passive |     65000 |      2000 |      27316 |     73377 |     =
62500 |     75000 |
> |    1 |  passive |     75000 |      2000 |      19468 |     75284 |     =
69444 |     77500 |
> ,-Mitigation at 39863713us, duration=3D136196ms
> | trip |     type | temp(=C2=B0mC) | hyst(=C2=B0mC) |  duration  |  avg(=
=C2=B0mC) |  min(=C2=B0mC) |  max(=C2=B0mC) |
> |    0 |  passive |     65000 |      2000 |     136196 |     73922 |     =
62500 |     75000 |
> |    1 |  passive |     75000 |      2000 |      91721 |     74386 |     =
69444 |     78125 |
>
> More information for a better understanding of the thermal behavior
> will be added after. The idea is to give detailed statistics
> information about the undershots and overshots, the temperature speed,
> etc... As all the information in a single file is too much, the idea
> would be to create a directory named with the mitigation timestamp
> where all data could be added.
>
> Please note this code is immune against trip ordering but not against
> a trip temperature change while a mitigation is happening. However,
> this situation should be extremely rare, perhaps not happening and we
> might question ourselves if something should be done in the core
> framework for other components first.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Both patches in the series look good to me now, so I'll queue them up
for 6.8-rc1.

Thanks!