renice — Change the Priority of a Running Process

The renice command changes the nice value of a process that is already running. It can be useful when a process is using too much CPU or when you want to give a task lower priority.

Find the process ID

ps aux | grep process-name

Lower priority of a running process

renice 10 -p 1234

A higher nice value means lower scheduling priority. Raising priority usually needs elevated privileges and should be done carefully on shared systems.