cpufrequi is a tool to display cpu clock averages over a chosen time window on a Raspberry Pi 4 Model B (https://www.raspberrypi.com/products/raspberry-pi-4-model-b/) running a modern linux kernel that exposes the relevant files in sysfs (developed and tested on 5.10.x)
The data is obtained from
/sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
see https://www.kernel.org/doc/Documentation/cpu-freq/cpufreq-stats.txt
It also displays the current clock according to
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq
current cpu temperature is read from
/sys/class/thermal/thermal_zone0/temp
I enjoy benchmarking and inspecting performance metrics of computers. Some tools i usually use (see "other platforms") are not available for the raspberry, and i couldnt really get a grip of how the CPU clocks behave under minor load. Specifically, I used cpufrequi to compare the behavior of cpufreq governors "schedutil" and "ondemand" with various settings.
# cpufrequi -h
Usage of cpufrequi:
-i int
interval in ms (default 1000)
-s int
size of history (default 1000)
-w int
size of avg window (default 5)
For now, the history switch isnt useful. The idea is to be able to change the interval and window size at runtime in the future. Right now you can only set it via flags when starting the program, so you would never need more history than the window size.
TL;DR: use
- https://linux.die.net/man/1/cpupower-monitor
- https://www.linux.org/docs/man8/turbostat.html
- https://github.com/lm-sensors/lm-sensors
In theory, cpufrequi could be used for any cpu platform supporting cpufreq-stats and hwmon. In reality though, there are some things to consider:
- boost technology on modern AMD/Intel CPUs is not reflected in cpufreq-stats
- AMD/Intel CPUs use seperate clocks for each logical core
On systems with different clocks for each core, the tool just doesnt make sense in its current state. You would really need an instance of the tool for each logical core, or have the tool build some kind of average over all cores.
For these systems i suggest to use cpupower-monitor, which displays averages for cpu clocks per core in the Mperf section and/or turbostat which displays a whole lot of stuff