Re: [RFC PATCH 0/7] Introduce thermal pressure

From: Daniel Lezcano
Date: Thu Oct 11 2018 - 04:23:22 EST


On 11/10/2018 09:35, Lukasz Luba wrote:
> Hi Daniel,
>
> On 10/10/2018 06:54 PM, Daniel Lezcano wrote:
>> On 10/10/2018 17:35, Lukasz Luba wrote:
>>> Hi Thara,
>>>
>>> I have run it on Exynos5433 mainline.
>>> When it is enabled with step_wise thermal governor,
>>> some of my tests are showing ~30-50% regression (i.e. hackbench),
>>> dhrystone ~10%.
>>>
>>> Could you tell me which thermal governor was used in your case?
>>> Please also share the name of that benchmark, i will give it a try.
>>> Is it single threaded compute-intensive?
>>
>> aobench AFAICT
>>
>> It would be interesting if you can share the thermal profile of your board.
>>
> Thanks for the benchmark name.
> It was tested on Samsung TM2 device with Exynos 5433 with debian.
> Thermal stuff you can find in mainline:
> arch/arm64/boot/dts/exynos/exynos5433-tmu.dtsi

By thermal profile, I was meaning a figure with the temperature
regulation (temperature idle, then workload, then temperature increase,
mitigated temperature, end of workload, temperature decrease).

The thermal description looks wrong in the DT. I suggest to experiment
the series with the DT fixed.

eg. from hi6220.dtsi


thermal-zones {

cls0: cls0 {
polling-delay = <1000>;
polling-delay-passive = <100>;
sustainable-power = <3326>;

/* sensor ID */
thermal-sensors = <&tsensor 2>;

trips {
threshold: trip-point@0 {
temperature = <65000>;
hysteresis = <0>;
type = "passive";
};

target: trip-point@1 {
temperature = <75000>;
hysteresis = <0>;
type = "passive";
};
};

cooling-maps {
map0 {
trip = <&target>;
cooling-device = <&cpu0
THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
};
};
};
};

Note the cooling devices are *passive*


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