From owner-freebsd-hackers  Tue Feb  5  7:53:10 2002
Delivered-To: freebsd-hackers@freebsd.org
Received: from patrocles.silby.com (d179.as0.nwbl0.wi.voyager.net [169.207.130.181])
	by hub.freebsd.org (Postfix) with ESMTP
	id 840B937B41A; Tue,  5 Feb 2002 07:53:02 -0800 (PST)
Received: from localhost (silby@localhost)
	by patrocles.silby.com (8.11.6/8.11.6) with ESMTP id g159t8C01650;
	Tue, 5 Feb 2002 09:55:19 GMT
	(envelope-from silby@silby.com)
X-Authentication-Warning: patrocles.silby.com: silby owned process doing -bs
Date: Tue, 5 Feb 2002 09:55:08 +0000 (GMT)
From: Mike Silbersack <silby@silby.com>
To: Daniel Lang <dl@leo.org>, <freebsd-stable@freebsd.org>
Cc: freebsd-hackers@freebsd.org
Subject: Re: autotuning kernel vars
In-Reply-To: <20020205131312.GA58643@atrbg11.informatik.tu-muenchen.de>
Message-ID: <20020205094939.A1617-100000@patrocles.silby.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG


On Tue, 5 Feb 2002, Daniel Lang wrote:

> Hi,
>
> (sorry for posting this to two lists, Reply-To: is set.)
>
> I've just built a new kernel for a just upgraded box to
> 4.5-STABLE. I've included
>
> NMBCLUSTERS=0 and
> NBUF=0
>
> to try the auto-sizing feature as documented in LINT
>
> Any advice, even "don't set NMBCLUSTERS to 0", preferred with
> "because in your setup XXXX happens", but greatly appreciated
> in any way.
>
> TIA,
>  Daniel

LINT says, and I quote:

#
# The `maxusers' parameter controls the static sizing of a number of
# internal system tables by a formula defined in subr_param.c.  Setting
# maxusers to 0 will cause the system to auto-size based on physical
# memory.
#

Hence, you should set maxusers to 0, not nmbclusters, not nbuf.  In fact,
for autosizing to work, you should not specify nmbclusters or nbuf
whatsoever.

The autotuning simply sets maxusers to megs of memory / 2.  While this is
a huge improvement from having maxusers default to 32 for everyone running
GENERIC, it's not some magic feature that will turbocharge your machine.
If you have been comfortable with manually setting up your configuration,
you do not need to worry about autosizing.

Mike "Silby" Silbersack



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message