SYNOPSIS

OVERVIEW

DESCRIPTION

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

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/$PID/oom_adj" to the given number. (Internally, "/proc/$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 <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.

LIMITATIONS

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.

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