Linux/AM5728: Setting OPP and Dhrystone test

Hallo Pavel,

Thank you for the material provided, I can now change the opp_mode and running frequency then run some application like a while(1){},  but the power exhausted by SoC still stays low.

Here I want to push the SoC to exhaust power as high as possible, like the Dhrystone tests in TI thermal documention, which says the function had been included into SDK.

Could you help advising how to get the SoC into Dhrystone mode?

Thanks,

MG

12072017

Thanks to Pavel's help, I collect comands to adjust opp_mode here:

代码kill_cpu.c

#include <stdlib.h>
int main()
{
while(1);

return 0;
}


运行：

# gcc -o out kill_cpu.c
# ./out &

for i in `seq 1 $(cat /proc/cpuinfo | grep "processor" | wc -l)`; do ./out & done




Driver Usage

All of the standard governors are built-in to the kernel, and by default the ondemand governor is selected.

To view available governors,
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
conservative userspace powersave ondemand performance


To view current governor,
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
ondemand


To set a governor, roo
$ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor


To view current OPP (frequency in kHz)
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
720000


To view supported OPP's (frequency in kHz),
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
275000 500000 600000 720000


To change OPP (can be done only for userspace governor. If governors like ondemand is used, OPP change happens automatically based on the system load)
$ echo 1500000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed




mycount=0; while (( $mycount < 10000 )); do cat /sys/devices/virtual/thermal/thermal_zone0/temp; ((mycount=$mycount+1)); done;

while (( 1 )); do cat /sys/devices/virtual/thermal/thermal_zone0/temp; done;

cat /sys/devices/virtual/thermal/thermal_zone0/temp

cat /sys/class/thermal/thermal_zone0/temp


cat /proc/cpuinfo

mpstat

dhrystone excutable can be found from the sdk:)