NAME¶

cputool - CPU usage management utility

SYNOPSIS¶

cputool [OPTION] [-- COMMAND]

DESCRIPTION¶

CPUTool is a utility which manages CPU usage and system load using SIGSTOP and SIGCONT. CPUTool is able to "slow down" process CPU usage and manage load levels caused by processes utilizing CPU and/or IO resources.

A common use for CPUTool is decreasing the CPU load caused by compression software or backup software where there is no limit on CPU or IO resources normally imposed, but it can be used to manage almost any process.

OPTIONS¶

-h, --help

Display command line usage then exit.

-p, --pid PID

Manage the CPU usage of a specific PID. This is the most efficient use of CPUTool as it does not have to walk the process tree to look for forks of children.

-P, --pid-pgrp PID

Manage the CPU usage of a specific PID's entire process group. The same can be achieved by specifying a COMMAND which CPUTool will then execute and manage the process group created by that command.

-c, --cpu-limit PERCENT

Specify the maximum CPU the process / process group can use. Expressed as percentage of total CPU. Eg. 200 is two full CPUs in a multi processor system. Specify an integer value.

-l, --load-limit LOAD

Specify the maximum load the system may experience for the process process group to continue running. Specifyng a fractional value is possible (e.g. 3.5).

-v, --verbose

Increase the amount of messages printed to stderr.

-vv will additionally show statistical information.

-vvv will addditionally show signals being sent to processes.

-V, --version

Output version information and exit.

EXAMPLES¶

Limit the PID 4711 to 75% use of one CPU core:

cputool -p 4711 -c 75

Run rsync for a local backup only when the system load does not exceed 7.5. See the note for -l when using program that relies on TCP network connections:

cputool -l 7.5 -- rsync -av /home /backup/`date +%Y-%m-%d`

NOTES¶

CPUTool should run on all Linux systems. It depends on the /proc pseudo-filesystem to detect PIDs and their resource usage.

TCP network connections could time out if process execution is suspended for extended periods of time (while the load is too high). Not all programs handle this case well.

BUGS¶

Please report all bugs you discover. This should be done via:

Alternatively, you may report bugs to your software distributor / vendor.

AUTHORS¶

Please refer to the AUTHORS file distributed with CPUTool.

COPYRIGHT¶

Copyright (c) 2012-2021, AllWorldIT., and the authors listed in the CPUTool AUTHORS file.

LICENSE¶

cputool is distributed under the terms of the GNU v3+. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE