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) 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.

       -v   This activates verbose mode.  Error messages, some statistics and all renice actions
            are printed to stdout.

       -o format
            Set the ps(1) output format to filter on.  The default format is "comm".  See the -o
            parameter in the ps(1) 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) 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.

       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 <http://www.cpan.org>.

PROGRAMS NEEDED

        ps
        ionice

       ionice is only needed if you want to change io priority.  It can be obtained from
       <http://rlove.org/schedutils/>.

       You also need a suitable kernel and scheduler, e.g. Linux 2.6 with CFQ.

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) 2005,2007 by Christian Garbs.  It is licensed under the GNU GPL.

AVAILABILITY

       Look for updates at <http://www.cgarbs.de/stuff.en.html>.

SEE ALSO

       ionice(1), renice(1), ps(1)