NAME
chrt - manipulate the real-time attributes of a processSYNOPSIS
chrt [options] priority command argument ...DESCRIPTION
chrt sets or retrieves the real-time scheduling attributes of an existing PID, or runs command with the given attributes.POLICIES
-o, --otherSet scheduling policy to SCHED_OTHER
(time-sharing scheduling). This is the default Linux scheduling policy.
Set scheduling policy to SCHED_FIFO
(first in-first out).
Set scheduling policy to SCHED_RR
(round-robin scheduling). When no policy is defined, the SCHED_RR is
used as the default.
Set scheduling policy to SCHED_BATCH
(scheduling batch processes). Linux-specific, supported since 2.6.16. The
priority argument has to be set to zero.
Set scheduling policy to SCHED_IDLE
(scheduling very low priority jobs). Linux-specific, supported since 2.6.23.
The priority argument has to be set to zero.
Set scheduling policy to SCHED_DEADLINE
(sporadic task model deadline scheduling). 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.
SCHEDULING OPTIONS
-T, --sched-runtime nanosecondsSpecifies runtime parameter for
SCHED_DEADLINE policy (Linux-specific).
Specifies period parameter for
SCHED_DEADLINE policy (Linux-specific).
Specifies deadline parameter for
SCHED_DEADLINE policy (Linux-specific).
Use SCHED_RESET_ON_FORK or
SCHED_FLAG_RESET_ON_FORK flag. Linux-specific, supported since
2.6.31.
•If the calling thread has a scheduling
policy of SCHED_FIFO or SCHED_RR, the policy is reset to
SCHED_OTHER in child processes.
•If the calling process has a negative
nice value, the nice value is reset to zero in child processes.
OPTIONS
-a, --all-tasksSet or retrieve the scheduling attributes of
all the tasks (threads) for a given PID.
Show minimum and maximum valid priorities,
then exit.
Operate on an existing PID and do not launch a
new task.
Show status information.
Display help text and exit.
Print version and exit.
USAGE
The default behavior is to run a new command:
chrt priority command
[arguments]
chrt -p PID
chrt -r -p priority 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.AUTHORS
Robert <[email protected]>Love Karel <[email protected]>ZakSEE ALSO
nice(1), renice(1), taskset(1), sched(7)REPORTING BUGS
For bug reports, use the issue tracker at <https://github.com/util-linux/util-linux/issues>.AVAILABILITY
The chrt 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/>.| 2022-05-11 | util-linux 2.38.1 |