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document kpreempt_disable, kpreempt_enable, and kpreempt_disabled.

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yamt 2008-05-06 08:34:35 +00:00
parent 82ae7f3c2b
commit 508d265a44
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6
share/man/man9/Makefile
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@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.262 2008/05/03 09:43:40 plunky Exp $
# $NetBSD: Makefile,v 1.263 2008/05/06 08:34:35 yamt Exp $
# Makefile for section 9 (kernel function and variable) manual pages.
@ -304,6 +304,10 @@ MLINKS+=isapnp.9 isapnp_devmatch.9 \
isapnp.9 isapnp_unconfig.9
MLINKS+=knote.9 KNOTE.9 \
kfilter_register.9 kfilter_unregister.9
MAN+= kpreempt.9
MLINKS+=kpreempt.9 kpreempt_disable.9 \
kpreempt.9 kpreempt_disabled.9 \
kpreempt.9 kpreempt_enable.9
MLINKS+=kprintf.9 printf.9 kprintf.9 printf_nolog.9 kprintf.9 sprintf.9 \
kprintf.9 snprintf.9 kprintf.9 vprintf.9 kprintf.9 vsprintf.9 \
kprintf.9 vsnprintf.9 kprintf.9 uprintf.9 kprintf.9 ttyprintf.9 \

79
share/man/man9/kpreempt.9 Normal file
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.\" $NetBSD: kpreempt.9,v 1.1 2008/05/06 08:34:35 yamt Exp $
.\"
.\" Copyright (c)2008 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
.\" 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 May 6, 2008
.Dt KPREEMPT 9
.Os
.\" ------------------------------------------------------------
.Sh NAME
.Nm kpreempt
.Nd control kernel preemption
.\" ------------------------------------------------------------
.Sh SYNOPSIS
.In sys/systm.h
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft void
.Fn kpreempt_disable \
"void"
.Ft void
.Fn kpreempt_enable \
"void"
.Ft bool
.Fn kpreempt_disabled \
"void"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
These functions are used to control kernel preemption of the calling LWP.
.Pp
Kernel preemption is currently disabled by default.
It can be enabled by tweaking kern.sched.kpreempt_pri sysctl.
.Pp
.Fn kpreempt_disable
disables kernel preemption of the calling LWP.
Note that disabling kernel preemption can prevent LWPs with higher priorities
from running.
.Pp
.Fn kpreempt_enable
enables kernel preemption of the calling LWP, which was previously disabled by
.Fn kpreempt_disable .
.Pp
.Fn kpreempt_disable
and
.Fn kpreempt_enable
can be nested.
.Pp
.Fn kpreempt_disabled
returns
.Dv true
if preemption of the calling LWP is disabled.
It's for diagnostic purpose.
.\" ------------------------------------------------------------
.\" .Sh RETURN VALUES
.\" ------------------------------------------------------------
.Sh SEE ALSO
.Xr intro 9 ,
.Xr spl 9