From owner-freebsd-current@FreeBSD.ORG  Tue Jul 21 20:17:48 2009
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@FreeBSD.org
Received: from [127.0.0.1] (freefall.freebsd.org [IPv6:2001:4f8:fff6::28])
	by hub.freebsd.org (Postfix) with ESMTP id 0907E1065672;
	Tue, 21 Jul 2009 20:17:48 +0000 (UTC)
	(envelope-from jkim@FreeBSD.org)
From: Jung-uk Kim <jkim@FreeBSD.org>
To: freebsd-current@FreeBSD.org
Date: Tue, 21 Jul 2009 16:17:37 -0400
User-Agent: KMail/1.6.2
References: <4A660E83.6080004@cs.duke.edu>
	<200907211605.40390.jkim@FreeBSD.org>
In-Reply-To: <200907211605.40390.jkim@FreeBSD.org>
MIME-Version: 1.0
Content-Disposition: inline
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-Id: <200907211617.40842.jkim@FreeBSD.org>
Cc: Andrew Gallatin <gallatin@cs.duke.edu>
Subject: Re: loader.conf ignores setting variable ending in _type
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 21 Jul 2009 20:17:48 -0000

On Tuesday 21 July 2009 04:05 pm, Jung-uk Kim wrote:
> On Tuesday 21 July 2009 02:52 pm, Andrew Gallatin wrote:
> > Hi,
> >
> > I maintain the mxge (10GbE) driver.  A user complained to me
> > that one of my driver's tunables was ignored when he set it
> > in /boot/loader.conf.   I reproduced his problem both on -current
> > and 7.2.  I think there may be some quirk which is causing the
> > loader to ignore this variable, but my 4th skills are
> > non-existent, and I'm looking for some help.
> >
> > To reproduce this bug, I used a loader.conf which
> > looks like this:
> >
> > console=comconsole
> > if_mxge_load="YES"
> > mxge_eth_z8e_load="YES"
> > mxge_rss_eth_z8e_load="YES"
> > hw.mxge.rss_hash_type="2"
> > hw.mxge.max_slices="2"
> >
> >
> >
> > After interrupting the boot, I could confirm that rss_hash_type
> > was not set:
> >
> > .................................................................
> >. Hit [Enter] to boot immediately, or any other key for command
> > prompt. Booting [/boot/kernel/kernel] in 8 seconds...
> >
> > Type '?' for a list of commands, 'help' for more detailed help.
> > OK show hw.mxge.max_slices
> > 2
> > OK show hw.mxge.rss_hash_type
> > variable 'hw.mxge.rss_hash_type' not found
> > .................................................................
> >..
> >
> > I have no problem setting hw.mxge.rss_hash_type while the machine
> > is up via kenv.  Also, it seems to stick when set manually from
> > the loader.
> >
> >
> > After poking around for quite a while, I noticed that the loader
> > refuses to honor any variable ending in _type loaded from
> > loader.conf.
> >
> > Is this because the suffix "_type" (for module_type) is somehow
> > reserved and I should not be using a tunable ending in _type
> > Or is this a bug in the loader?
>
> Yes, it is reserved.
>
> loader.conf(5):
>
>      *_type	Defines the module's type.  If none is given, it
> defaults to a kld module.

Actually, I wanted to quote this:

loader.conf(5):

    WARNING:	developers should never use these suffixes for any
		kernel environment variables (tunables) or conflicts
		will result.

Jung-uk Kim