Updated: April 19, 2023

Adjust the priorities of running processes (POSIX)


renice prioritylevel [-g pgrp...] 
       [-p pid...] [-u user...]

Runs on:

QNX Neutrino


-g pgrp
Renice processes in this process group.
-p pid
Renice this process.
-u user
Renice processes owned by this user.
The amount to adjust the priority by. Positive numbers lower the priority by that many full priority levels, while negative numbers raise the priority.


The renice utility adjusts the priority of all the threads in one or more running processes. The specified prioritylevel is subtracted from the current priority of each selected process.

If you enter a: renice:
Positive value (e.g., 2 or +2) Lowers the priority of a process, making it “nicer” to other processes
Negative value (e.g., -2) Raises the priority of a process, making it “meaner” to other processes

You can adjust the priority as follows:

If you're: You can change to any priority:
A non-root user From 1 to 63
root From 1 to 255

If you don't have the appropriate privileges, you can renice only the processes you own. You can change the range of privileged priorities with the -P option for procnto.


Lower the priority of process 768 by 2:

renice 2 -p 768

Exit status:

Successful completion.
> 0
An error occurred.