HOWTO: Change a Running Processes’ Priority with Renice

You can change the default priority that an application runs with by starting it with the nice command, but if you want to change the priority of a process that is already running, the command to use is renice.

Renice can be used to change the priority of a single process, or of all the processes owned by a specified user. As with the nice command, the priority values range from -20 to +19 and negative numbers raise the priority of a task while positive numbers lower it. Only the superuser can specify negative numbers (thus raising the priority of a process).

renice 5 some_process

This command will change the priority of some_process to 5.

renice -5 -u jon

will change the priority of all processes owned by user jon to -5.

renice -5 -u jon -p 588

will chance the priority of all processes owned by jon and process with PID 588 to -5.