Getting precise per process CPU usage on MACOS

[jasonwitty]

I am having difficulty finding a way to get precise per process CPU% usage when comparing to activity monitor and BTOP on macos. i have tried normalizing against the number of cores (using sys.cpus().len()) and clamping at 100% before and after dividing by cores. I do realize this can be very tricky because my sample rates and iterations will always be different than the tools mentioned above, but even considering this I dont think my results are precise. Has anyone dealt with this and if so can you provide any advice ?