From owner-freebsd-fs@FreeBSD.ORG  Wed May 23 10:06:32 2007
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
X-Original-To: freebsd-fs@freebsd.org
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 6F87916A469;
	Wed, 23 May 2007 10:06:32 +0000 (UTC)
	(envelope-from kris@obsecurity.org)
Received: from elvis.mu.org (elvis.mu.org [192.203.228.196])
	by mx1.freebsd.org (Postfix) with ESMTP id 5916E13C448;
	Wed, 23 May 2007 10:06:32 +0000 (UTC)
	(envelope-from kris@obsecurity.org)
Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196])
	by elvis.mu.org (Postfix) with ESMTP id BC0051A4D80;
	Wed, 23 May 2007 03:07:32 -0700 (PDT)
Received: by obsecurity.dyndns.org (Postfix, from userid 1000)
	id 7AFE8513AD; Wed, 23 May 2007 06:06:31 -0400 (EDT)
Date: Wed, 23 May 2007 06:06:31 -0400
From: Kris Kennaway <kris@obsecurity.org>
To: Kris Kennaway <kris@obsecurity.org>
Message-ID: <20070523100631.GA30143@xor.obsecurity.org>
References: <20070410003505.GA8189@nowhere> <20070410003837.GB8189@nowhere>
	<20070410011125.GB38535@xor.obsecurity.org>
	<20070410013034.GC8189@nowhere> <20070410014233.GD8189@nowhere>
	<4651BD6F.5050301@unsane.co.uk>
	<20070522083112.GA5136@hub.freebsd.org>
	<4652B15D.5060505@unsane.co.uk>
	<20070523085532.GA27542@hub.freebsd.org>
	<20070523093231.GA29797@xor.obsecurity.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20070523093231.GA29797@xor.obsecurity.org>
User-Agent: Mutt/1.4.2.2i
Cc: Craig Boston <craig@xfoil.gank.org>, Pawel Jakub Dawidek <pjd@freebsd.org>,
	freebsd-fs@freebsd.org, freebsd-current@freebsd.org,
	Darren Reed <darrenr@freebsd.org>, Vince <jhary@unsane.co.uk>
Subject: Re: ZFS committed to the FreeBSD base.
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 23 May 2007 10:06:32 -0000

On Wed, May 23, 2007 at 05:32:31AM -0400, Kris Kennaway wrote:

> I would actually be interested to know how Solaris gets away with
> this.  It sounds like there must be less of a distinction between
> memory allocated to the kernel and to userland, and the ability for
> memory to flow between these two with some form of backpressure when
> userland wants memory that is currently gobbled by up solaris ZFS.
> 
> This kind of system probably makes good sense (although maybe there
> are trade-offs), but anyway it's not how FreeBSD does it.

After some further thought I guess the difference is just that on a
64-bit kernel you don't have KVA issues and can indeed map all of
physical RAM into the kernel for caching.

Kris