CHRT(1) 							Linux User's Manual							   CHRT(1)

NAME

       chrt - manipulate real-time attributes of a process

SYNOPSIS

       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 (C) 2004 Robert M. Love
       This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
       LAR PURPOSE.

SEE ALSO

       taskset(1), nice(1), renice(1)

       See sched_setscheduler(2) for a description of the Linux scheduling scheme.

AVAILABILITY

       The chrt command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.

schedutils							     Apr 2003								   CHRT(1)