From owner-freebsd-hackers@FreeBSD.ORG  Fri Aug  5 15:54:30 2005
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: freebsd-hackers@freebsd.org
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 567DB16A41F
	for <freebsd-hackers@freebsd.org>; Fri,  5 Aug 2005 15:54:30 +0000 (GMT)
	(envelope-from jhb@FreeBSD.org)
Received: from mv.twc.weather.com (mv.twc.weather.com [65.212.71.225])
	by mx1.FreeBSD.org (Postfix) with ESMTP id B619A43D72
	for <freebsd-hackers@freebsd.org>; Fri,  5 Aug 2005 15:54:25 +0000 (GMT)
	(envelope-from jhb@FreeBSD.org)
Received: from [10.50.40.201] (Not Verified[65.202.103.25]) by
	mv.twc.weather.com with NetIQ MailMarshal (v6, 0, 3, 8)
	id <B42f38f1d0000>; Fri, 05 Aug 2005 12:09:01 -0400
From: John Baldwin <jhb@FreeBSD.org>
To: freebsd-hackers@freebsd.org
Date: Fri, 5 Aug 2005 11:01:32 -0400
User-Agent: KMail/1.8
References: <20050805005543.5bd947f2.thib@mi.is>
	<20050805145046.GB78669@dan.emsphone.com>
In-Reply-To: <20050805145046.GB78669@dan.emsphone.com>
MIME-Version: 1.0
Content-Disposition: inline
Message-Id: <200508051101.33927.jhb@FreeBSD.org>
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Cc: Dan Nelson <dnelson@allantgroup.com>
Subject: Re: Checking sysctl values from within the kernel.
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 05 Aug 2005 15:54:30 -0000

On Friday 05 August 2005 10:50 am, Dan Nelson wrote:
> In the last episode (Aug 05), Thordur I. Bjornsson said:
> > If I want to check a sysctl value from within the kernel (e.g. an
> > KLD), should I use the system calls described in sysctl(3) ?
> >
> > If not, what is the propper way to do so ?
>
> Since most sysctls are direct mappings onto integer variables in the
> kernel, just check the variable directly.

There's also a kernel_sysctl() function available in the kernel for in-kernel 
access to sysctls.  You might have to lookup the OID for a given name 
yourself though.  Actually, there's a kernel_sysctlbyname() as well.

-- 
John Baldwin <jhb@FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org