From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933081AbWFXMoO (ORCPT ); Sat, 24 Jun 2006 08:44:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933085AbWFXMoO (ORCPT ); Sat, 24 Jun 2006 08:44:14 -0400 Received: from thunk.org ([69.25.196.29]:44747 "EHLO thunker.thunk.org") by vger.kernel.org with ESMTP id S933081AbWFXMoN (ORCPT ); Sat, 24 Jun 2006 08:44:13 -0400 Date: Sat, 24 Jun 2006 08:43:54 -0400 From: Theodore Tso To: Jeff Dike Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.17-mm1: UML failing w/o SKAS enabled Message-ID: <20060624124354.GA7290@thunk.org> Mail-Followup-To: Theodore Tso , Jeff Dike , Andrew Morton , linux-kernel@vger.kernel.org References: <20060621034857.35cfe36f.akpm@osdl.org> <20060622213443.GA22303@thunk.org> <20060623024222.GA8316@ccure.user-mode-linux.org> <20060623210714.GA16661@thunk.org> <20060623214623.GA7319@ccure.user-mode-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060623214623.GA7319@ccure.user-mode-linux.org> User-Agent: Mutt/1.5.11 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 23, 2006 at 05:46:23PM -0400, Jeff Dike wrote: > On Fri, Jun 23, 2006 at 05:07:14PM -0400, Theodore Tso wrote: > > Well, because my host kernel is running a completely stock 2.6.17 > > kernel and so I don't have the SKAS patch applied. If the goal is to > > abandon tt mode, it would be really nice if the SKAS patch gets > > integrated into mainline first.... > > UML has a form of skas which runs on stock hosts. defconfig will give > you a CONFIG_MODE_SKAS, !CONFIG_MODE_TT UML which will run on an > unmodified host. It might be good to explicitly state that in the Kconfig documentation, in particular in the documentation for CONFIG_MODE_TT. Note that the entry for CONFIG_MODE_SKAS still mentions the need for an external patch, and I tried searching 2.6.17-mm1's x86 config options to see if the SKAS patch had been applied, and I couldn't find anything, so I assumed that SKAS still required the out-of-tree patch. If the situation is changed, config MODE_SKAS bool "Separate Kernel Address Space support" if MODE_TT default y help This option controls whether skas (separate kernel address space) support is compiled in. If you have applied the skas patch to the host, then you certainly want to say Y here (and consider saying N to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this option will shrink the UML binary slightly. Also, just as a suggestion, it might be a good idea to update the UML HOWTO in Documentation/uml/UserModeLinux-HOWTO.txt (or at least the November 18, 2002 date), and also the SKAS page at: http://user-mode-linux.sourceforge.net/skas.html Regards, - Ted