--- name: "reniced" section: "1" platform: "linux" package: "reniced" version: "1.23-1" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/reniced" --- # reniced(1) renice running processes based on regular expressions ## NAME reniced - renice running processes based on regular expressions ## SYNOPSIS **reniced** \[**-h**\] \[**-v**\] \[**-o** *format*\] \[*configfile*\] ## OVERVIEW reniced takes a list of regular expressions, looks for processes (and threads) matching them and renices the processes to given values. reniced can also change io priorities. ## DESCRIPTION On start, reniced reads a configuration file. It consists of nice values and regular expressions. It then scans the process table using the [**ps**(1)](/ps/1.md) command. Whenever a process name from the CMD column matches a regular expression, that process is reniced to the given value. If a process matches multiple regular expressions, all rule matches are executed in order and the last match wins. When run as root, reniced will scan all processes (``"`ps H -e`"``). When run as a user, renice only scans the user's processes (``"`ps H --user`"``). ### Switches - **-h** This prints the version number, a short help text and exits without doing anything. - **-n** This activates no-op mode. No actions are taken but everything that would be done is written to stdout. - **-v** This activates verbose mode. Error messages, some statistics and all renice actions are printed to stdout. - **-o** *format* Set the [**ps**(1)](/ps/1.md) output format to filter on. The default format is `"comm"`. See the **-o** parameter in the [**ps**(1)](/ps/1.md) manpage for details. - *configfile* This reads the regular expressions from an alternate configfile. The default location of the configfile is `"/etc/reniced.conf"` if reniced is run as root, `"~/.reniced"` otherwise. ### Configuration file format The configuration file is composed of single lines. Empty lines and lines starting with a **#** are ignored. Every line must consist of a command followed by a whitespace and a Perl regular expression. The regular expression is matched against the [**ps**(1)](/ps/1.md) output. For every matched process the command is executed. A command generally takes the form of a character followed by a number. Multiple commands can be given simultaneously with no spaces inbetween. Sometimes the number is optional. *Command characters* - **n** Sets the nice value of a process. Must be followed by a number, usually within the range of -20 to 19. For backwards compatibility a **n** at the beginning of the command can be left out (if the command starts with a number it is treated as a nice value). - **r** Sets the io priority to the realtime scheduling class. The optional number is treated as class data (typically 0-7, lower being higher priority). - **b** Sets the io priority to the best-effort scheduling class. The optional number is treated as class data (typically 0-7, lower being higher priority). - **i** Sets the io priority to the idle scheduling class. No number needs to be given as the idle scheduling class ignores the class data value. - **o** Sets the OOM killer adjustment in `"/proc/$PID/oom_adj"` to the given number. (Internally, `"/proc/$PID/oom_score_adj"` will be used when available, but for backwards compatibility this value is still expected the in old `"oom_adj"` format and will be converted automatically.) *Examples* - "5 ^bash" gives currently running bash shells a nice value of 5 - "b2 ^tar" sets currently running tar-processes to io priority best-effort within class 2 - "i torrent" sets currently running torrent-like applications to io priority idle - "n-10r4 seti" gives currently running seti-processes a nice value of -10 and sets them to realtime io priority in class 4 ## MODULES NEEDED ``` use BSD::Resource; ``` This module can be obtained from \. ## PROGRAMS NEEDED ``` ps ionice ``` ionice is only needed if you want to change io priority. It can be obtained from \. You also need a suitable kernel and scheduler, e.g. Linux 2.6 with CFQ. ## LIMITATIONS The purpose of reniced is to renice long running server processes (hence the **d** for daemon in it's name). Selecting and renicing processes it not atomic: There is a small gap between scanning the process list and renicing the processes. If you target short-lived processes with your regular expressions, reniced might try to act on a process that is already gone. In the worst case it might renice a new process that got the same process id as the already ended process that was matched. ## BUGS reniced can run without the BSD::Resource module. In this case, the PRIO\_PROCESS is set to 0. This works on Linux 2.6.11 i686 but it could break on other systems. Installing BSD::Resource is the safer way. Be careful using realtime priorities, don't starve other tasks. Please report bugs to \<*mitch@cgarbs.de*\>. ## AUTHOR reniced was written by Christian Garbs \<*mitch@cgarbs.de*\>. ## COPYRIGHT reniced is Copyright (C) 2005, 2020 by Christian Garbs. It is licensed under the GNU GPL v2 or later. ## AVAILABILITY Look for updates at \. ## SEE ALSO [**ionice**(1)](/ionice/1.md), [**renice**(1)](/renice/1.md), [**ps**(1)](/ps/1.md)