chrt - manipulate the real-time attributes of a process
chrt [options]
priority command [argument...]
chrt [options] -p [priority] pid
chrt sets or retrieves the real-time scheduling attributes
of an existing pid, or runs command with the given
attributes.
- -o, --other
- Set scheduling policy to SCHED_OTHER. This is the default Linux
scheduling policy.
- -f, --fifo
- Set scheduling policy to SCHED_FIFO.
- -r, --rr
- Set scheduling policy to SCHED_RR. When no policy is defined, the
SCHED_RR is used as the default.
- -b, --batch
- Set scheduling policy to SCHED_BATCH (Linux-specific, supported
since 2.6.16). The priority argument has to be set to zero.
- -i, --idle
- Set scheduling policy to SCHED_IDLE (Linux-specific, supported
since 2.6.23). The priority argument has to be set to zero.
- -d, --deadline
- Set scheduling policy to SCHED_DEADLINE (Linux-specific, supported
since 3.14). The priority argument has to be set to zero. See also
--sched-runtime, --sched-deadline and --sched-period.
The relation between the options required by the kernel is runtime <=
deadline <= period. chrt copies period to deadline
if --sched-deadline is not specified and deadline to
runtime if --sched-runtime is not specified. It means that
at least --sched-period has to be specified. See sched(7)
for more details.
- -a, --all-tasks
- Set or retrieve the scheduling attributes of all the tasks (threads) for a
given PID.
- -m, --max
- Show minimum and maximum valid priorities, then exit.
- -p, --pid
- Operate on an existing PID and do not launch a new task.
- -v, --verbose
- Show status information.
- -V, --version
- Display version information and exit.
- -h, --help
- Display help text and exit.
A user must possess CAP_SYS_NICE to change the scheduling
attributes of a process. Any user can retrieve the scheduling
information.
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.
Linux' default scheduling policy is SCHED_OTHER.
The chrt command is part of the util-linux package and is
available from https://www.kernel.org/pub/linux/utils/util-linux/.