Determining CPU utilization

Question

Is there a command or any other way to get the current or average CPU utilization (for a multi-processor environment) in Linux?

I am using embedded Linux in a small system. Basically, I need to determine the CPU utilization, so that if it is high, I can instead divert a new process to another controller in the system, rather than executing on the main processor, which could be busy doing a more important process.

This question is not about merely prioritizing processes, the other controller can sufficiently handle the new process, just that when the main processor is not busy, I would prefer it to do the execution.

Answer 1

The answer to the question after much searching and tinkering:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    long double a[4], b[4], loadavg;
    FILE *fp;
    char dump[50];

    for(;;)
    {
        fp = fopen("/proc/stat","r");
        fscanf(fp,"%*s %Lf %Lf %Lf %Lf",&a[0],&a[1],&a[2],&a[3]);
        fclose(fp);
        sleep(1);

        fp = fopen("/proc/stat","r");
        fscanf(fp,"%*s %Lf %Lf %Lf %Lf",&b[0],&b[1],&b[2],&b[3]);
        fclose(fp);

        loadavg = ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) / ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3]));
        printf("The current CPU utilization is : %Lf\n",loadavg);
    }

    return(0);
}

I am getting the same values as those reported by the System Monitor.