From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932070AbXBNAAU (ORCPT ); Tue, 13 Feb 2007 19:00:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932072AbXBNAAT (ORCPT ); Tue, 13 Feb 2007 19:00:19 -0500 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:43672 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932070AbXBNAAS (ORCPT ); Tue, 13 Feb 2007 19:00:18 -0500 Message-ID: <45D250BA.7010104@vmware.com> Date: Tue, 13 Feb 2007 15:58:50 -0800 From: Dan Hecht User-Agent: Thunderbird 1.5.0.2 (X11/20060420) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Andi Kleen , Andrew Morton , virtualization@lists.osdl.org, xen-devel@lists.xensource.com, Chris Wright , Ian Pratt , linux-kernel@vger.kernel.org Subject: Re: [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options. References: <20070213221729.772002682@goop.org> <20070213221830.542511707@goop.org> <45D24172.9020800@vmware.com> <45D249D9.80407@goop.org> In-Reply-To: <45D249D9.80407@goop.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 13 Feb 2007 23:59:21.0725 (UTC) FILETIME=[FB0CB2D0:01C74FCA] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 02/13/2007 03:29 PM, Jeremy Fitzhardinge wrote: > Dan Hecht wrote: >> I assume you plan to eventually get all this stuff working but just >> want to prevent configurations that the Xen paravirt-ops isn't ready >> for at the moment? >> >> Instead can you do it this way: >> >> config XEN >> depends on PARAVIRT && !PREEMPT && HZ_100 && !DOUBLEFAULT && !KEXEC > > That's a bit simpler code-wise, but it does make it pretty complex to > get everything just-so to even see the CONFIG_XEN option. > Not only is it simpler code-wise, but it is more to the point... it is CONFIG_XEN that needs to be fixed to handle PREEMPT, KEXEC, different HZ values, etc. Not the other way around. Enabling the compile of any paravirt-ops backend shouldn't cripple the kernel in any way... instead, the burden should be on the xen paravirt-ops backend to be completed. CONFIG_PREEMPT shouldn't care about which paravirt-ops are compiled in. Instead, CONFIG_XEN is the one that needs !PREEMPT. Dan