From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262035AbUKDBjL (ORCPT ); Wed, 3 Nov 2004 20:39:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262041AbUKDBjE (ORCPT ); Wed, 3 Nov 2004 20:39:04 -0500 Received: from sp-260-1.net4.netcentrix.net ([4.21.254.118]:35486 "EHLO asmodeus.mcnaught.org") by vger.kernel.org with ESMTP id S262035AbUKDBjB (ORCPT ); Wed, 3 Nov 2004 20:39:01 -0500 To: Russell Miller Cc: Kurt Wall , linux-kernel@vger.kernel.org Subject: Re: is killing zombies possible w/o a reboot? References: <200411030751.39578.gene.heskett@verizon.net> <200411031540.03598.gene.heskett@verizon.net> <20041104004342.GD5283@kurtwerks.com> <200411031901.28977.rmiller@duskglow.com> From: Doug McNaught Date: Wed, 03 Nov 2004 20:38:48 -0500 In-Reply-To: <200411031901.28977.rmiller@duskglow.com> (Russell Miller's message of "Wed, 3 Nov 2004 20:01:28 -0500") Message-ID: <87654m4clz.fsf@asmodeus.mcnaught.org> User-Agent: Gnus/5.1002 (Gnus v5.10.2) Emacs/20.7 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Russell Miller writes: > This brings up another question I've had since reading the documentation on > later pentium-class chips: > > why are only rings 0 and 3 used in linux? Because the "traditional" Unix privilege model only has two levels, and Linux runs on many architectures, most of which have only two privilege levels (the 68000 called them "user" and "supervisor"). Special-casing x86 is possible but probably wouldn't be worth it. -Doug