renice

Alters the scheduling priority/niceness of one or more running processes. Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process). More information: https://manned.org/renice.

• Change priority of a running process:
  renice -n {{niceness_value}} -p {{pid}}
• Change priority of all processes owned by a user:
  renice -n {{niceness_value}} -u {{user}}
• Change priority of all processes that belong to a process group:
  renice -n {{niceness_value}} --pgrp {{process_group}}