.\"	$NetBSD: schedctl.8,v 1.10 2011/03/21 15:35:21 jruoho Exp $
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.Dd March 21, 2011
.Dt SCHEDCTL 8
.Os
.Sh NAME
.Nm schedctl
.Nd control scheduling of processes and threads
.Sh SYNOPSIS
.Nm
.Op Fl A Ar cpus
.Op Fl C Ar class
.Op Fl P Ar pri
.Op Fl t Ar lid
.Fl p Ar pid | Ar command
.Sh DESCRIPTION
The
.Nm
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.
.Nm
can also be used to start a new command using the specified parameters.
.Pp
Available options:
.Bl -tag -width "-C class "
.It Fl A Ar cpus
Set of the processors on which process or thread should run, that
is, affinity.
Processors are defined as numbers (starting from zero) and separated
by commas.
A value of \-1 is used to unset the affinity.
.It Fl C Ar class
Scheduling class (policy), one of:
.Bl -tag -width SCHEDOTHERXX
.It Dv SCHED_OTHER
Time-sharing (TS) scheduling policy.
The default policy in
.Nx .
.It Dv SCHED_FIFO
First in, first out (FIFO) scheduling policy.
.It Dv SCHED_RR
Round-robin scheduling policy.
.El
.It Fl P Ar pri
Priority for the process or thread.
Value should be in the range from
.Dv SCHED_PRI_MIN
(0) to
.Dv SCHED_PRI_MAX
(63).
Setting of priority for the process or thread running at
.Dv SCHED_OTHER
policy is not allowed.
.It Fl p Ar pid
The target process which will be affected.
If the process has more than one thread, all of them will be affected.
.Pp
If
.Fl p
is not given, a command to execute must be given on the command line.
.It Fl t Ar lid
Thread in the specified process.
If specified, only this thread in the process will be affected.
May only be specified if
.Fl p
is also given.
.El
.Sh EXAMPLES
Show scheduling information about the process whose ID is
.Dq 123 :
.Bd -literal -offset indent
# schedctl -p 123
.Ed
.Pp
Set the affinity to CPU 0 and CPU 1, policy to
.Dv SCHED_RR ,
and priority to 63
for thread whose ID is
.Dq 1
in process whose ID is
.Dq 123 :
.Bd -literal -offset indent
# schedctl -p 123 -t 1 -A 0,1 -C SCHED_RR -P 63
.Ed
.Pp
Run the
.Xr top 1
command with real-time priority:
.Bd -literal -offset indent
# schedctl -C SCHED_FIFO top
.Ed
.Sh SEE ALSO
.Xr nice 1 ,
.Xr getpriority 2 ,
.Xr setpriority 2 ,
.Xr psrset 8 ,
.Xr renice 8
.Sh HISTORY
The
.Nm
command first appeared in
.Nx 5.0 .