Q:

How to change process priority

I want to change the priority of a process on my Ubuntu 12.04 Desktop, but I can't. I go into an app called "System Monitor", right click the process, and change the priority to "high". I then get this message: "Cannot change the priority of process with PID 4364 to -5. Permission denied." I have tried to give myself root. What does this mean, and is there a more acute way to change the priority?

A:

The way to change the default priority of system processes is through the renice command. From a terminal window, use renice to change your own processes' priority. Use sudo renice to change system process priorities. Read the manual page about renice first:
man renice.

