Linux Pocket Guide, 2nd Edition

Name

renice — stdin  stdout  - file  -- opt  --help  --version

Synopsis

renice [+-N] [options] PID

While the nice command can invoke a program at a given nice level, renice changes the nice level of an already-running process. Here we increase the nice level (decrease the priority) of process 28734 by five:

$ renice +5 -p 28734

Ordinary users can increase the nice level of their own processes, while the superuser can also decrease it (increasing the priority) and can operate on any process. The valid range is −20 to +20, but avoid high negative numbers or you might interfere with vital system processes.

Useful options

-p pid	Affect the given process ID. You can omit the -p and just provide a PID (renice +5 28734).
-u username	Affect all processes owned by the given user.