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

6       chrt - manipulate real-time attributes of a process
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SYNOPSIS

9       chrt [options] prio command [arg]...
10       chrt [options] -p [prio] pid
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DESCRIPTION

13       chrt(1)  sets  or  retrieves  the real-time scheduling attributes of an
14       existing PID, or runs COMMAND with the given attributes.   Both  policy
15       (one  of SCHED_OTHER, SCHED_FIFO, SCHED_RR, SCHED_BATCH, or SCHED_IDLE)
16       and priority can be set and retrieved.
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18       The SCHED_BATCH policy is supported since Linux 2.6.16. The  SCHED_IDLE
19       policy is supported since Linux 2.6.23.
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21       The  SCHED_RESET_ON_FORK  flag  for policies SCHED_RR and SCHED_FIFO is
22       supported since Linux 2.6.31.
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OPTIONS

25       -p, --pid
26              operate on an existing PID and do not launch a new task
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28       -b, --batch
29              set scheduling policy to SCHED_BATCH (Linux specific)
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31       -f, --fifo
32              set scheduling policy to SCHED_FIFO
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34       -i, --idle
35              set schedulng policy to SCHED_IDLE (Linux specific)
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37       -m, --max
38              show minimum and maximum valid priorities, then exit
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40       -o, --other
41              set policy scheduling policy to SCHED_OTHER
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43       -r, --rr
44              set scheduling policy to SCHED_RR (the default)
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46       -R, --reset-on-fork
47              add SCHED_RESET_ON_FORK  flag  to  the  SCHED_FIFO  or  SCHED_RR
48              scheduling policy (Linux specific)
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50       -v, --verbose
51              show status information
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53       -h, --help
54              display usage information and exit
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56       -V, --version
57              display version information and exit
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USAGE

60       The default behavior is to run a new command::
61              chrt prio command [arguments]
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63       You can also retrieve the real-time attributes of an existing task:
64              chrt -p pid
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66       Or set them:
67              chrt -p prio pid
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PERMISSIONS

70       A user must possess CAP_SYS_NICE to change the scheduling attributes of
71       a process.  Any user can retrieve the scheduling information.
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NOTES

74       Only SCHED_FIFO, SCHED_OTHER and SCHED_RR are  part  of  POSIX  1003.1b
75       Process  Scheduling.  The other scheduling attributes may be ignored on
76       some systems.
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AUTHOR

79       Written by Robert M. Love.
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82       Copyright © 2004 Robert M. Love
83       This is free software; see the source for copying conditions.  There is
84       NO  warranty;  not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
85       PURPOSE.
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SEE ALSO

88       taskset(1), nice(1), renice(1)
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90       See sched_setscheduler(2) for a description  of  the  Linux  scheduling
91       scheme.
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AVAILABILITY

94       The  chrt command is part of the util-linux-ng package and is available
95       from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
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99schedutils                         June 2010                           CHRT(1)
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