cpulimit

Limit process by PID to 25% CPU

$ cpulimit -p 1234 -l 25

$ cpulimit -e program -l 25

$ cpulimit -l 50 -- program arg1 arg2

$ cpulimit -l 50 -b -- program

$ cpulimit -l 50 -k -- program

$ cpulimit -l 25 -m -- program

cpulimit [TARGET] [OPTIONS...] [-- PROGRAM]

cpulimit limits the CPU usage of a process by sending SIGSTOP and SIGCONT signals to throttle CPU consumption. It can target running processes or launch new ones with CPU limits applied.

-p, --pid=N

Target process by PID

Target process by executable name

Target process by absolute path to executable

CPU percentage limit (1-100 per core, mandatory)

Run cpulimit as a background process

Run in foreground while waiting for launched process

Specify number of CPU cores (for percentage calculation)

Kill process instead of throttling if over limit

Also watch and throttle child processes

Restore a process previously killed with -k

Suppress output messages

Display control statistics

Exit if target process is absent or terminates

Uses SIGSTOP and SIGCONT signals, which may cause misleading job control messages in shells. When using -e or -P, targets the first matching process; use -p with PID for specific instances. The -m flag can cause issues with shell scripts that spawn many processes.

cpulimit was created to provide CPU usage limiting functionality for Linux processes, useful for preventing runaway processes from consuming all CPU resources.

nice(1), renice(1), cgroups(7), kill(1)