chrt(1) - Linux man page
Name
chrt - manipulate real-time attributes of a processSynopsis
chrt [options] prio command [arg]...chrt [options] -p [prio] pid
Description
chrt(1) sets or retrieves the real-time scheduling attributes of an existing PID or runs COMMAND with the given attributes. Both policy (one of SCHED_OTHER, SCHED_FIFO, SCHED_RR, SCHED_BATCH, or SCHED_IDLE) and priority can be set and retrieved.
The SCHED_BATCH policy is supported since Linux 2.6.16. The SCHED_IDLE policy is supported since Linux 2.6.23.
Options
- -p, --pid
- operate on an existing PID and do not launch a new task
- -b, --batch
- set scheduling policy to SCHED_BATCH (Linux specific)
- -f, --fifo
- set scheduling policy to SCHED_FIFO
- -i, --idle
- set schedulng policy to SCHED_IDLE (Linux specific)
- -m, --max
- show minimum and maximum valid priorities, then exit
- -o, --other
- set policy scheduling policy to SCHED_OTHER
- -r, --rr
- set scheduling policy to SCHED_RR (the default)
- -h, --help
- display usage information and exit
- -v, --version
- output version information and exit
Usage
- The default behavior is to run a new command::
- chrt prio command [arguments]
- You can also retrieve the real-time attributes of an existing task:
- chrt -p pid
- Or set them:
- chrt -p prio pid
Permissions
A user must possess CAP_SYS_NICE to change the scheduling attributes of a process. Any user can retrieve the scheduling information.Notes
Only SCHED_FIFO, SCHED_OTHER and SCHED_RR are part of POSIX 1003.1b Process Scheduling. The other scheduling attributes may be ignored on some systems.Author
Written by Robert M. Love.Copyright
Copyright © 2004 Robert M. LoveThis is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See Also
taskset(1), nice(1), renice(1)See sched_setscheduler(2) for a description of the Linux scheduling scheme.