To see how Linux CPU utilization, one command is enough.
top
The top command monitors CPU utilization, process statistics, and memory utilization. The top section contains information related to overall system status – uptime, load average, process counts, CPU status, and utilization statistics for both memory and swap space.
I use a Centos OS, no swap space now.
To quit from the real time screen, press button q.
If you find a process is always have many memory or running so long, you can kill it to free resource.