Hi Robin, On 19/03/2021 13:17, Robin Murphy wrote: > On 2021-03-19 11:05, Daniel Lezcano wrote: >> The DTPM framework is looking for upstream SoC candidates to share the >> power numbers. >> >> We can see around different numbers but the one which seems to be >> consistent with the initial post for the values on the CPUs can be >> found in the patch https://lore.kernel.org/patchwork/patch/810159/ > > The kernel hacker in me would be more inclined to trust the BSP that the > vendor actively supports than a 5-year-old patch that was never pursued > upstream. Apparently that was last updated more recently: > > https://github.com/rockchip-linux/kernel/commit/98d4505e1bd62ff028bd79fbd8284d64b6f468f8 Yes, I've seen this value also. > The ex-mathematician in me can't even comment either way without > evidence that whatever model expects to consume this value is even > comparable to whatever "arm,mali-simple-power-model" is. > > The way the > latter apparently needs an explicit "static" coefficient as well as a > "dynamic" one, and the value here being nearly 3 times that of a > similarly-named one in active use downstream (ChromeOS appears to still > be using the values from before the above commit), certainly incline me > to think they may not be... Sorry, I'm missing the point :/ We dropped in the kernel any static power computation because as there was no value, the resulting code was considered dead. So we rely on the dynamic power only. >> I don't know the precision of this value but it is better than >> nothing. > > But is it? If it leads to some throttling mechanism kicking in and > crippling GPU performance because it's massively overestimating power > consumption, that would be objectively worse for most users, no? No because there is no sustainable power specified for the thermal zones related to the GPU. -- <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
