Section: User Commands (1)
Updated: July 2014Index
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renice - alter priority of running processes
alters the scheduling priority of one or more running processes. The
first argument is the priority
value to be used.
The other arguments are interpreted as process IDs (by default),
process group IDs, user IDs, or user names.
a process group causes all processes in the process group to have their
scheduling priority altered.
a user causes all processes owned by the user to have their scheduling
- -n, --priority priority
Specify the scheduling
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
Interpret the succeeding arguments as process group IDs.
- -p, --pid
Interpret the succeeding arguments as process IDs
- -u, --user
Interpret the succeeding arguments as usernames or UIDs.
- -h, --help
Display help text and exit.
- -V, --version
Display version information and exit.
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
Users other than the superuser may only alter the priority of processes they
own, and can only monotonically increase their ``nice value'' (for security
reasons) within the range 0 to 19,
unless a nice resource limit is set (Linux 2.6.12 and higher). The
superuser may alter the priority of any process and set the priority to any
value in the range -20 to 19.
Useful priorities are: 19 (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).
to map user names to user IDs
Non-superusers cannot 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 version
5.2.18) does not agree entirely on what the specifics of the systemcall
interface to set nice values is. Thus causes renice to report bogus previous
command appeared in 4.0BSD.
The renice command is part of the util-linux package and is available from
Linux Kernel Archive
- SEE ALSO