schedctl(8) - NetBSD Manual Pages

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SCHEDCTL(8)             NetBSD System Manager's Manual             SCHEDCTL(8)


NAME

     schedctl -- control scheduling of processes and threads


SYNOPSIS

     schedctl [-A cpus] [-C class] [-P pri] [-t lid] -p pid | command


DESCRIPTION

     The schedctl command can be used to control the scheduling of processes
     and threads.  It also returns information about the current scheduling
     parameters of the process or thread.  Only the super-user may change the
     scheduling parameters.  schedctl can also be used to start a new command
     using the specified parameters.

     Available options:

     -A cpus    Set of the processors on which process or thread should run,
                that is, affinity.  Processors are defined as numbers (start-
                ing from zero) and separated by commas.  A value of -1 is used
                to unset the affinity.

     -C class   Scheduling class (policy), one of:

                SCHED_OTHER   Time-sharing (TS) scheduling policy.  The
                              default policy in NetBSD.

                SCHED_FIFO    First in, first out (FIFO) scheduling policy.

                SCHED_RR      Round-robin scheduling policy.

     -P pri     Priority for the process or thread.  Value should be in the
                range from SCHED_PRI_MIN (0) to SCHED_PRI_MAX (63).  Setting
                of priority for the process or thread running at SCHED_OTHER
                policy is not allowed.

     -p pid     The target process which will be affected.  If the process has
                more than one thread, all of them will be affected.

                If -p is not given, a command to execute must be given on the
                command line.

     -t lid     Thread in the specified process.  If specified, only this
                thread in the process will be affected.  May only be specified
                if -p is also given.


EXAMPLES

     Show scheduling information about the process whose ID is ``123'':

           # schedctl -p 123

     Set the affinity to CPU 0 and CPU 1, policy to SCHED_RR, and priority to
     63 for thread whose ID is ``1'' in process whose ID is ``123'':

           # schedctl -p 123 -t 1 -A 0,1 -C SCHED_RR -P 63

     Run the top(1) command with real-time priority:

           # schedctl -C SCHED_FIFO top


SEE ALSO

     nice(1), getpriority(2), setpriority(2), psrset(8), renice(8)


HISTORY

     The schedctl command first appeared in NetBSD 5.0.

NetBSD 6.0                      March 21, 2011                      NetBSD 6.0