RENICE(1) User Commands RENICE(1)
NAME
renice - alter priority of running processes
SYNOPSIS
renice [-n] priority [-gpu] identifier...
DESCRIPTION
renice alters the scheduling priority of one or more running processes.
The first argument is the priority value to be used. The other argu-
ments are interpreted as process IDs (by default), process group IDs,
user IDs, or user names. renice'ing a process group causes all pro-
cesses in the process group to have their scheduling priority altered.
renice'ing a user causes all processes owned by the user to have their
scheduling priority altered.
OPTIONS
-n, --priority priority
Specify the scheduling priority to be used for the process,
process group, or user. Use of the option -n or --priority is
optional, but when used it must be the first argument.
-g, --pgrp pgid...
Force the succeeding arguments to be interpreted as process
group IDs.
-u, --user name_or_uid...
Force the succeeding arguments to be interpreted as usernames or
UIDs.
-p, --pid pid...
Force the succeeding arguments to be interpreted as process IDs
(the default).
-h, --help
Display a help text.
-V, --version
Display version information.
EXAMPLES
The following command would change the priority of the processes with
PIDs 987 and 32, plus all processes owned by the users daemon and root:
renice +1 987 -u daemon root -p 32
NOTES
Users other than the super-user may only alter the priority of pro-
cesses they own, and can only monotonically increase their ``nice
value'' (for security reasons) within the range 0 to PRIO_MAX (20),
unless a nice resource limit is set (Linux 2.6.12 and higher). The
super-user may alter the priority of any process and set the priority
to any value in the range PRIO_MIN (-20) to PRIO_MAX. Useful priori-
ties are: 20 (the affected processes will run only when nothing else in
the system wants to), 0 (the ``base'' scheduling priority), anything
negative (to make things go very fast).
FILES
/etc/passwd
to map user names to user IDs
SEE ALSO
getpriority(2), setpriority(2)
BUGS
Non super-users can not increase scheduling priorities of their own
processes, even if they were the ones that decreased the priorities in
the first place.
The Linux kernel (at least version 2.0.0) and linux libc (at least ver-
sion 5.2.18) does not agree entirely on what the specifics of the sys-
temcall interface to set nice values is. Thus causes renice to report
bogus previous nice values.
HISTORY
The renice command appeared in 4.0BSD.
AVAILABILITY
The renice command is part of the util-linux package and is available
from Linux Kernel Archive <ftp://ftp.kernel.org/pub/linux/utils/util-
linux/>.
util-linux September 2011 RENICE(1)