Hi Oliver,

On Thu, Jul 26, 2018 at 4:05 PM Oliver Effland s5770874@msx.tu-dresden.de wrote:

Hi,

First of all: thanks for all the valuable input! @(Russell, Dietmar & Steven)

On 07/23/2018 08:51 AM, Steven Miao wrote:

...

Hi Oliver,

Generally these dynamic co-efficiency and static leakage power comes from hardware design team by running power estimation tool, however you can tun these co-efficiency and parameters for better performance.

How did you get A7 or A15 power? Get Soc power or there's separate sensor for A7/A15?

Yes indeed, there are 2 seperate sensors for the A7 and A15.

...

If you want to create cpu busy power model manually, you can: 1 leave 1 A7 + 1 A15 core online, keep other cores offline, disable thermal zone, disable idle state for all cores 2 set A7 frequency to 200Mhz, move all the task to A15, run cpu intensive task on A7(dhrystone, sysbench cpu test), read sensor to get 1 A7 power P1(read from A7 cluster sensor) 3 online 2 A7 core, run dhrystone on each core, and get power P2

we can get 1 A7 core power@200Mhz ~= P2 - P1 (A7 power X 2 + static power - A7 power X 1 - static power

I followed your manual steps (using a busy loop for 10s, instead of a benchmark) and corrected my calculations (with the static power in mind):

A7: freq(MHz) voltage(mV) Power(mW) A7_Power(mW) Stat_Power(mW) DPC 200 918.750 34.768 12.203 10.362 72.283955 400 920.000 60.805 21.25 18.305 62.765831 600 968.750 98.046 35.084 27.878 62.306652 800 1042.500 148.095 52.285 43.525 60.136063 1000 1116.250 212.214 76.112 59.99 61.084382 1200 1190.000 288.958 99.993 88.972 58.842948 1400 1288.750 411.936 144.807 122.322 62.276495

                                                    mean: 62

A15: freq(MHz) voltage(mV) Power(mW) A15_Power(mW) Stat_Power(mW) DPC 200 916250 122.584 31.139 60.306 185.458477 500 916250 225.101 68.774 87.553 163.842401 800 942500 349.158 112.432 124.294 158.211202 1100 1016250 540.78 169.556 201.668 149.251725 1400 1078750 779.19 258.214 262.762 158.493016 1700 1180000 1179.344 392.107 395.13 165.650083 2000 1320000 1969.764 648.768 672.228 186.170798

                                                    mean: 164

The ratio between A15 and A7 is now 164/62 = 2.645

I hope the dynamic-power-coefficient's are more accurate now?

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dynamic-power-coefficient ~= 400 - 500 is reasonable for big core dynamic-power-coefficient ~= 100 is reasonable for LITTLE core. For IPA it can work effectively with a poor power model(not so accurate), for EAS it just need power model of LITTLE core and big core is proportional.

I'm guessing my values differ from your suggested values, because it's 32bit ARM?

Yes, the ratio bit and LITTLE ~= 400/100 ~= 4.x is from A73 and A53 @ 16nm process, it could vary from 32bit core or different process.

Best regards, Oliver

Cheers, Steven