— alter priority of running
alters the scheduling priority of one or more running
processes. The following who
parameters are interpreted
as process ID's, process group ID's, or user names.
'ing a process group causes all processes in the
process group to have their scheduling priority altered.
'ing a user causes all processes owned by the user to
have their scheduling priority altered. By default, the processes to be
affected are specified by their process ID's.
Options supported by renice
- The scheduling priority of the
process, process group, or user.
- Force who parameters to be
interpreted as process group ID's.
- Force the who parameters to be
interpreted as user names.
- Resets the who interpretation to be
(the default) process ID's.
- Print version.
- Print help.
renice +1 987 -u daemon root -p 32
would change the priority of process ID's 987 and 32, and all processes owned by
users daemon and root.
Users other than the super-user 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
(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
Useful priorities 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).
- to map user names to user ID's
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 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