how to know the amount of cpu utilized by each process
1 System time is the amount of time the CPU was busy executing code in kernel space. 2  If this value is reported for a thread or process, then it represents the amount of time the kernel was doing work on behalf of the executing context, for example, after a thread issued a system call. Idle time (for the whole system only) is the amount of time the CPU was not busy, or, otherwise, the amount of time it executed the System Idle process.