From LQWiki

You have to be root or the owner of a process to change its priority.

Contents 1 Reasons to Change a Process's Priority 2 Files 3 utilities 4 See also

Reasons to Change a Process's Priority

If a high priority task has a flaw in it, a brute force attack will have more cycles to work with. Because of this, a low priority task is marginally more secure. However, the difference is so slight as to be not worth mentioning.

More importantly, a background task, like updatedb or emerge, can bring your system to a complete crawl. You'll want to make unimportant background tasks be of very low priority, or niced very high.

Files

Administrators can use /etc/security/limits.conf to make a certain user's default prioity be higher or lower. however, priority is completely ambiguous.. and .. is 0 highest, or lowest priority? and can there be negative priorities.. like nice?

utilities

nice  -20 is highest priority, 19 is lowest priority.
renice
top   r or n is the renice command,

See also

pid process id