minix/lib/libc/sys/sa_setconcurrency.2

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.\" $NetBSD: sa_setconcurrency.2,v 1.4 2005/09/05 21:57:35 yamt Exp $
.\"
.\" Copyright (c)2004 YAMAMOTO Takashi,
.\" 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
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.\"
.\" ------------------------------------------------------------
.Dd September 6, 2005
.Dt SA_CONCURRENCY 2
.Os
.Sh NAME
.Nm sa_setconcurrency
.Nd increase the number of virtual processors
.\" ------------------------------------------------------------
.Sh LIBRARY
.Lb libc
.\" ------------------------------------------------------------
.Sh SYNOPSIS
.In sa.h
.Ft int
.Fn sa_setconcurrency \
"int concurrency"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
.Fn sa_setconcurrency
is used to increase the number of scheduler activation virtual processors
used by the process.
.Fn sa_setconcurrency
increases the number of virtual processors, i.e., execution concurrency,
up to
.Fa concurrency .
However,
.Fn sa_setconcurrency
won't try to allocate more virtual processors than there are physical
processors on the system.
.Pp
Scheduler activation should be enabled by
.Fn sa_enable
beforehand.
.\" ------------------------------------------------------------
.Sh RETURN VALUES
On success,
.Fn sa_setconcurrency
returns the number of newly added virtual processors.
Otherwise, a value of \-1 is returned and
.Va errno
is set to indicate the error.
.\" ------------------------------------------------------------
.Sh SEE ALSO
.Xr pthread 3