linux-kernel - Re: [PATCH 0/5] thermal: multi-sensor aggregation support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAGXv+5H0ocBWxGseoRXWyBo48+5-F-FRLZZcywcM-_vwu4=jVg@mail.gmail.com>
Date: Mon, 2 Dec 2024 11:41:20 +0800
From: Chen-Yu Tsai <wenst@...omium.org>
To: Daniel Lezcano <daniel.lezcano@...aro.org>
Cc: Nicolas Pitre <nico@...xnic.net>, "Rafael J . Wysocki" <rafael@...nel.org>, linux-pm@...r.kernel.org, 
	linux-mediatek@...ts.infradead.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, Nicolas Pitre <npitre@...libre.com>, 
	Alexandre Bailon <abailon@...libre.com>
Subject: Re: [PATCH 0/5] thermal: multi-sensor aggregation support

On Sat, Nov 30, 2024 at 4:00 AM Daniel Lezcano
<daniel.lezcano@...aro.org> wrote:
>
> On 12/11/2024 06:19, Nicolas Pitre wrote:
> > This series provides support for thermal aggregation of multiple sensors.
> > The "one sensor per zone" model is preserved for all its advantages.
> > Aggregation is performed via the creation of a special zone whose purpose
> > consists in aggregating its associated primary zones using a weighted
> > average.
> >
> > Motivation for this work stems from use cases where multiple sensors are
> > contained within the same performance domain. In such case it is preferable
> > to apply thermal mitigation while considering all such sensors as a whole.
>
> Do we have a real use case where we can compare the per sensor vs
> aggregated sensors approach ?

The MediaTek platforms have one sensor per CPU core, but the cores are
grouped into two clusters, and DVFS is tied together for all the cores
in each cluster, as is commonly seen on ARM systems.

Furthermore, there is a hardware block that does minute OPP voltage
tweaking based on thermal readings, and AFAIK that block wants the
per-cluster aggregate temperature.

ChenYu

> > Previous incarnation by Alexandre Bailon can be found here:
> > https://patchwork.kernel.org/project/linux-pm/cover/20240613132410.161663-1-abailon@baylibre.com/
> >
> > diffstat:
> >   .../bindings/thermal/thermal-zones.yaml       |   5 +-
> >   arch/arm64/boot/dts/mediatek/mt8195.dtsi      | 210 +-----
> >   drivers/thermal/Kconfig                       |  27 +
> >   drivers/thermal/thermal_core.c                | 643 ++++++++++++++++++
> >   drivers/thermal/thermal_core.h                |  14 +
> >   drivers/thermal/thermal_of.c                  |  86 ++-
> >   6 files changed, 780 insertions(+), 205 deletions(-)
>
>
> --
> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
>