From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Hecht Subject: Re: [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options. Date: Tue, 13 Feb 2007 15:58:50 -0800 Message-ID: <45D250BA.7010104@vmware.com> References: <20070213221729.772002682@goop.org> <20070213221830.542511707@goop.org> <45D24172.9020800@vmware.com> <45D249D9.80407@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <45D249D9.80407@goop.org> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: virtualization@lists.linuxfoundation.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