I tried to calculate the % of CPU usage in linux via the /proc/stat kernel interface.
I read the first "cpu" line twice in /proc/stat with an interval of 0.5 seconds and then save the output into two ArrayLists (arrayStats = [user, nice, system, idle]).

I want to calculate CPU time consumption of a particular process in system mode and user mode using statistics present in /proc/

There are two fields utime and stime in /proc//stat file, whose documentation says

utime: Amount of time that this process has been scheduled in user mode
stime: Amount of time that this process has been scheduled in kernel(system) mode

I am calculating CPU time con

I am about to find out how a specific process, in C, loads the CPU over a certain time frame.
The process may switch processor core during runtime, therefore
I need to handle that too.

Hi.

For an homework, I have to simulate some part of the PS function.

I am bit confuse between cpu usage and cpu load, Can anyone please explain me the basic difference between them and what formula should we use to calculate them on Linux?
I am accessing /proc/stat file to calculate cpu usage.

I'm trying to write a script that gives back the CPU usage (in %) for a specific process
I need to use the /proc/pPID/stat because ps aux is not present on the embedded system.

I tried this:

#!/usr/bin/env bash

PID=$1

PREV_TIME=0
PREV_TOTAL=0
while true;do
TOTAL=$(grep '^cpu ' /proc/stat |awk '{sum=$2+$3+$4+$5+$6+$7+$8+$9+$10; print sum}')
echo $TOTAL
sfile=/proc/$PID/stat
PROC

My program samples /proc data in order to get statistic about the CPU usage of the system.
I sample both /proc/stat and calculate the statistics delta (in interval of 1 second),
and I also sample the process /proc/pid/stat user ticks and system ticks.
This is an exmaple of log from my system:

From /proc/stat(total System)- UserTicksDelta: 9, niceTicksDelta: 0, SystemTicksDelta: 3, IrqTicksDelta:

My program samples /proc data in order to get statistic about the CPU usage of the system. I sample both /proc/stat and calculate the statistics delta (in interval of 1 second), and I also sample the process /proc/pid/stat user ticks and system ticks.

Is there any C API to calculate per CPU load? /proc/loadavg gives the CPU average load for all available CPUs and /proc/stat doesn't mention anything about active processes per CPU.

How can I obtain the load per CPU?