I'm searching the easiest way to monitor the cpu usage of a single process in linux. Use ps and change output is the way i have, but maybe a monitor tool is better. Also I want to plot the usage (nice look). graph and gnuplot are to ugly ;) But plot is optional.
The top command can take a PID as input:
top -p <pid>
No graphs available then though, but you will see the change in CPU usage for this process over time.