Take the 2-minute tour ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.

I am curious where gnome-system-monitor and top (the command line tool) get their information about the CPU usage in %. Could you please explain it to me?

share|improve this question

1 Answer 1

up vote 4 down vote accepted

From /proc.

At /proc/[PID]/stat you have kernel statistics about a given process.

You can find more information on about what to look for on the stat file on this previous SO question.

I'm not sure if it's a reasonable assumption but probably the current CPU usage is (100% - [the cpu usage for the idle process]).

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.