renice - alter priority of running processes
renice [--priority|--relative] 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.
If no -n, --priority or --relative option is used, then the priority is set as absolute.
Users other than the superuser may only alter the priority of processes they own. Furthermore, an unprivileged user can only increase the "nice value" (i.e., choose a lower priority) and such changes are irreversible unless (since Linux 2.6.12) the user has a suitable "nice" resource limit (see ulimit(1p) and getrlimit(2)).
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).
For historical reasons in this implementation, the -n option did not follow the POSIX specification. Therefore, instead of setting a relative priority, it sets an absolute priority by default. As this may not be desirable, this behavior can be controlled by setting the environment variable POSIXLY_CORRECT to be fully POSIX compliant. See the -n option for details. See --relative and --priority for options that do not change behavior depending on environment variables.
The renice command appeared in 4.0BSD.
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
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
The renice command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.