Messages in this thread | | | Date | Wed, 16 Feb 2022 16:26:51 -0800 | From | Matthias Kaehlcke <> | Subject | Re: [PATCH 1/2] thermal: cooling: Check Energy Model type in cpufreq_cooling and devfreq_cooling |
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On Wed, Feb 16, 2022 at 10:43:34PM +0000, Lukasz Luba wrote: > > > On 2/16/22 10:13 PM, Matthias Kaehlcke wrote: > > On Wed, Feb 16, 2022 at 09:33:50AM -0800, Doug Anderson wrote: > > > Hi, > > > > > > On Wed, Feb 16, 2022 at 7:35 AM Lukasz Luba <lukasz.luba@arm.com> wrote: > > > > > > > > Hi Matthias, > > > > > > > > On 2/9/22 10:17 PM, Matthias Kaehlcke wrote: > > > > > On Wed, Feb 09, 2022 at 11:16:36AM +0000, Lukasz Luba wrote: > > > > > > > > > > > > > > > > > > On 2/8/22 5:25 PM, Matthias Kaehlcke wrote: > > > > > > > On Tue, Feb 08, 2022 at 09:32:28AM +0000, Lukasz Luba wrote: > > > > > > > > > > > > > > > > > > > > > > > > [snip] > > > > > > > > > > > > Could you point me to those devices please? > > > > > > > > > > > > > > arch/arm64/boot/dts/qcom/sc7180-trogdor-* > > > > > > > > > > > > > > Though as per above they shouldn't be impacted by your change, since the > > > > > > > CPUs always pretend to use milli-Watts. > > > > > > > > > > > > > > [skipped some questions/answers since sc7180 isn't actually impacted by > > > > > > > the change] > > > > > > > > > > > > Thank you Matthias. I will investigate your setup to get better > > > > > > understanding. > > > > > > > > > > Thanks! > > > > > > > > > > > > > I've checked those DT files and related code. > > > > As you already said, this patch is safe for them. > > > > So we can apply it IMO. > > > > > > > > > > > > -------------Off-topic------------------ > > > > Not in $subject comments: > > > > > > > > AFAICS based on two files which define thermal zones: > > > > sc7180-trogdor-homestar.dtsi > > > > sc7180-trogdor-coachz.dtsi > > > > > > > > only the 'big' cores are used as cooling devices in the > > > > 'skin_temp_thermal' - the CPU6 and CPU7. > > > > > > > > I assume you don't want to model at all the power usage > > > > from the Little cluster (which is quite big: 6 CPUs), do you? > > > > I can see that the Little CPUs have small dyn-power-coeff > > > > ~30% of the big and lower max freq, but still might be worth > > > > to add them to IPA. You might give them more 'weight', to > > > > make sure they receive more power during power split. > > > > In experiments we saw that including the little cores as cooling > > devices for 'skin_temp_thermal' didn't have a significant impact on > > thermals, so we left them out. > > > > > > You also don't have GPU cooling device in that thermal zone. > > > > Based on my experience if your GPU is a power hungry one, > > > > e.g. 2-4Watts, you might get better results when you model > > > > this 'hot' device (which impacts your temp sensor reported value). > > > > > > I think the two boards you point at (homestar and coachz) are just the > > > two that override the default defined in the SoC dtsi file. If you > > > look in sc7180.dtsi you'll see 'gpuss1-thermal' which has a cooling > > > map. You can also see the cooling maps for the littles. > > > > Yep, plus thermal zones with cooling maps for the big cores. > > > > > I guess we don't have a `dynamic-power-coefficient` for the GPU, > > > though? Seems like we should, but I haven't dug through all the code > > > here... > > > > To my knowledge the SC7x80 GPU doesn't register an energy model, which is > > one of the reasons the GPU wasn't included as cooling device for > > 'skin_temp_thermal'. > > > > You can give it a try by editing the DT and adding in the > GPU node the 'dynamic-power-coefficient' + probably > small modification in the driver code. > > If the GPU driver registers the cooling device in the new way, you > would also get EM registered thanks to the devfreq cooling new code > (commit: 84e0d87c9944eb36ae6037a). > > You can check an example from Panfrost GPU driver [1].
Ah, I missed that, thanks for the pointer!
> I can see some upstream MSM GPU driver, but I don't know if that is > your GPU driver. It registers the 'old' way the devfreq cooling [2] > but it would be easy to change to use the new function. > The GPU driver would use the same dev_pm_opp_of_register_em() as > your CPUs do, so EM would be in 'milli-Watts' (so should be fine).
Yep, that's whay we are using.
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