renice - alter priority of running processes
renice [-n] priority [-g|-p|-u] identifier...
renice 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. 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.
-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.
Interpret the succeeding arguments as process group IDs.
Interpret the succeeding arguments as process IDs (the default).
Interpret the succeeding arguments as usernames or UIDs.
Display help text and exit.
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 nice values.
The renice command appeared in 4.0BSD.
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-