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. Both the policy (one of SCHED_OTHER
, SCHED_FIFO
, SCHED_RR
, SCHED_BATCH
, or SCHED_IDLE
) and the 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.
The SCHED_RESET_ON_FORK
flag
for policies SCHED_RR and SCHED_FIFO is supported since Linux
2.6.31.
−a,
−−all−tasks
Set or retrieve the scheduling attributes of all the tasks (threads) for a given PID.
−b,
−−batch
Set scheduling policy to SCHED_BATCH
(Linux-specific). The
priority argument has to be set to zero.
−f,
−−fifo
Set scheduling policy to SCHED_FIFO
.
−i,
−−idle
Set scheduling policy to SCHED_IDLE
(Linux-specific). The
priority argument has to be set to zero.
−m,
−−max
Show minimum and maximum valid priorities, then exit.
−o,
−−other
Set policy scheduling policy to SCHED_OTHER
.
−p,
−−pid
Operate on an existing PID and do not launch a new task.
−R,
−−reset−on−fork
Add SCHED_RESET_ON_FORK
flag to the
SCHED_FIFO
or
SCHED_RR
scheduling
policy (Linux-specific).
−r,
−−rr
Set scheduling policy to SCHED_RR
. When policy is not defined
the SCHED_RR
is used as
default.
−v,
−−verbose
Show status information.
−V,
−−version
Display version information and exit.
−h,
−−help
Display help text and exit.
chrt
priority
command
[arguments]
chrt −p
pid
chrt −r −p priority pid
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
.
taskset(1), nice(1), renice(1)
See sched_setscheduler(2) for a description of the Linux scheduling scheme.
Copyright © 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 PARTICULAR PURPOSE.
The chrt command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
chrt(1) manpage Copyright (C) 2004 Robert Love This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2, as published by the Free Software Foundation. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or typesetting system, including intermediate and printed output. This manual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |