NAME

       cputool — CPUTool is a utility which manages CPU usage and system load

SYNOPSIS

       cputool [--cpu-limit PCNT]  [--load-limit LOAD]  [ [--pid PID  | --pid-pgrp PID ]  |  [--]
       COMMAND ...  ]

DESCRIPTION

       Limit the CPU usage of a process or a process  group  to  a  given  limit  and/or  suspend
       processes  if  the  system  load exceeds a threshold. CPUTool works by sending SIGSTOP and
       SIGCONT signals to processes depending on the system load.

OPTIONS

       These programs follow the usual GNU command line syntax, with long options  starting  with
       two dashes (`-').  A summary of options is included below.

       -c, --cpu-limit PCNT
                 Specify  the  maxium  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 maxium load the system may experience for the process process group
                 to continue running. Specifyng a fractional value is possible (e.g. 3.5).

       -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.

       -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.

       -h, --help
                 Display a help page and exit.

NOTES

       CPUTool will run on 32-bit and 64-bit Linux systems.  It  depends  on  the  /proc  pseudo-
       filesystem to detect PIDs and their resource usage.

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

EXAMPLES

       cputool -p 4711 -c 75
                 Limit the PID 4711 to 75% use of one CPU core.

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

SEE ALSO

       signals (7), kill(1), uptime(1).

AUTHOR

       This  manual  page  was  written  by  Daniel  Lange  and converted to SGML by Nigel Kukard
       <nkukard@lbsd.net>. Permission is granted to copy, distribute and/or modify this  document
       under  the  terms of the GNU General Public License, Version 3 any later version published
       by the Free Software Foundation.

       On Debian systems, the complete text of the GNU General Public License  can  be  found  in
       /usr/share/common-licenses/GPL-3.

                                                                                       CPUTOOL(8)