NAME
renice —
alter priority of running
processes
SYNOPSIS
renice |
[priority | [-n
increment]] [[-p]
pid ...] [[-g]
pgrp ...] [[-u]
user ...] |
DESCRIPTION
Renice alters the scheduling priority of one or more
running processes. The following who parameters are
interpreted as process ID's, process group ID's, user ID's or user names.
Renice'ing a process group causes all processes 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. By default, the processes to
be affected are specified by their process ID's.
Options supported by renice:
-g- Force who parameters to be interpreted as process group ID's.
-n- Instead of changing the specified processes to the given priority, interpret the following argument as an increment to be applied to the current priority of each process.
-u- Force the who parameters to be interpreted as user names or user ID's.
-p- Resets the who interpretation to be (the default) process ID's.
For example,
renice +1 987 -u daemon root -p
32would 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''
within the range 0 to PRIO_MAX (20). (This prevents
overriding administrative fiats.) 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 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).
FILES
- /etc/passwd
- to map user names to user ID's
SEE ALSO
STANDARDS
The renice utility conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).
HISTORY
The renice command appeared in
4.0BSD.
BUGS
Non super-users cannot increase scheduling priorities of their own processes, even if they were the ones that decreased the priorities in the first place.