mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-29 12:03:03 +00:00
168 lines
4.8 KiB
Groff
168 lines
4.8 KiB
Groff
.\" $Id: sched_setscheduler.2,v 1.1 1998/03/28 11:48:55 dufault Exp $
|
|
.\" Copyright (c) 1998 HD Associates, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd Mar 12, 1998
|
|
.Dt SCHED_SETSCHEDULER 2
|
|
.Os BSD 4
|
|
.Sh NAME
|
|
.Nm sched_setscheduler ,
|
|
.Nm sched_getscheduler
|
|
.Nd set/get scheduling policy and scheduler parameters
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sched.h>
|
|
.Ft int
|
|
.Fn sched_setscheduler "pid_t pid" "int policy" "const struct sched_param *param"
|
|
.Ft int
|
|
.Fn sched_getscheduler "pid_t pid"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn sched_setscheduler
|
|
function sets the scheduling policy and scheduling parameters
|
|
of the process specified by
|
|
.Fa pid
|
|
to
|
|
.Fa policy
|
|
and the parameters specified in the
|
|
.Fa sched_param
|
|
structure pointed to by
|
|
.Fa param ,
|
|
respectively.
|
|
The value of the
|
|
.Fa sched_priority
|
|
member in the
|
|
.Fa param
|
|
structure must be any integer within the inclusive priority range for
|
|
the scheduling policy specified by
|
|
.Fa policy .
|
|
.Pp
|
|
In this implementation, if the value of
|
|
.Fa pid
|
|
is negative the function will fail.
|
|
.Pp
|
|
If a process specified by
|
|
.Fa pid
|
|
exists and if the calling process has permission, the scheduling
|
|
policy and scheduling parameters will be set for the process
|
|
whose process ID is equal to
|
|
.Fa pid .
|
|
.Pp
|
|
If
|
|
.Fa pid
|
|
is zero, the scheduling policy and scheduling
|
|
parameters are set for the calling process.
|
|
.Pp
|
|
In this implementation, the policy of when a process can affect
|
|
the scheduling parameters of another process is specified in
|
|
.Xr p1003_1b
|
|
as a write-style operation.
|
|
.Pp
|
|
The scheduling policies are in
|
|
.Fa <sched.h> :
|
|
.Bl -tag -width [SCHED_OTHER]
|
|
.It Bq Er SCHED_FIFO
|
|
First-in-first-out fixed priority scheduling with no round robin scheduling;
|
|
.It Bq Er SCHED_OTHER
|
|
The standard time sharing scheduler;
|
|
.It Bq Er SCHED_RR
|
|
Round-robin scheduling across same priority processes.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fa sched_param
|
|
structure is defined in
|
|
.Fa <sched.h> :
|
|
|
|
.Bd -literal -offset indent
|
|
struct sched_param {
|
|
int sched_priority; /* scheduling priority */
|
|
};
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn sched_getscheduler
|
|
function returns the scheduling policy of the process specified
|
|
by
|
|
.Fa pid .
|
|
.Pp
|
|
If a process specified by
|
|
.Fa pid
|
|
exists and if the calling process has permission,
|
|
the scheduling parameters for the process whose process ID is equal to
|
|
.Fa pid
|
|
are returned.
|
|
.Pp
|
|
In this implementation, the policy of when a process can obtain the
|
|
scheduling parameters of another process are detailed in
|
|
.Xr p1003_1b
|
|
as a read-style operation.
|
|
.Pp
|
|
If
|
|
.Fa pid
|
|
is zero, the scheduling parameters for the calling process will be
|
|
returned. In this implementation, the
|
|
.Fa sched_getscheduler
|
|
function will fail if
|
|
.Fa pid
|
|
is negative.
|
|
.Sh RETURN
|
|
The function will return zero if it completes successfully, or it
|
|
will return a value of -1 and set
|
|
.Va errno
|
|
to indicate the error.
|
|
.Sh ERRORS
|
|
On failure
|
|
.Va errno
|
|
will be set to the corresponding value:
|
|
.Bl -tag -width [EFAULT]
|
|
.It Bq Er ENOSYS
|
|
The system is not configured to support this functionality.
|
|
.It Bq Er EPERM
|
|
The requesting process doesn not have permission as detailed in
|
|
.Xr p1003_1b .
|
|
.It Bq Er ESRCH
|
|
No process can be found corresponding to that specified by
|
|
.Fa pid .
|
|
.It Bq Er EINVAL
|
|
The value of the
|
|
.Fa policy
|
|
parameter is invalid, or one or more of the parameters contained in
|
|
.Fa param
|
|
is outside the valid range for the specified scheduling policy.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr sched_get_priority_max 2 ,
|
|
.Xr sched_get_priority_min 2 ,
|
|
.Xr sched_getparam 2 ,
|
|
.Xr sched_rr_get_interval 2 ,
|
|
.Xr sched_setparam 2 ,
|
|
.Xr sched_yield 2
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn sched_setscheduler
|
|
and
|
|
.Fn sched_getscheduler
|
|
functions conform to
|
|
.St -p1003.1b-93 .
|