From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753982AbZB1Igv (ORCPT ); Sat, 28 Feb 2009 03:36:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751708AbZB1Ign (ORCPT ); Sat, 28 Feb 2009 03:36:43 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:34076 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751571AbZB1Igm (ORCPT ); Sat, 28 Feb 2009 03:36:42 -0500 Date: Sat, 28 Feb 2009 09:36:21 +0100 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: Andrew Morton , "H. Peter Anvin" , the arch/x86 maintainers , Linux Kernel Mailing List , Xen-devel Subject: Re: [PATCH] xen: core dom0 support Message-ID: <20090228083621.GC11425@elte.hu> References: <1235786365-17744-1-git-send-email-jeremy@goop.org> <20090227212812.26d02f34.akpm@linux-foundation.org> <49A8DF28.4050301@goop.org> <20090228072055.GC9351@elte.hu> <49A8F04D.4090409@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49A8F04D.4090409@goop.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jeremy Fitzhardinge wrote: > Ingo Molnar wrote: >> Hm, how can the same code that you call "massive out-of-tree patches >> which doesn't make anyone happy" in an out of tree context suddenly >> become non-intrusive "minor amount of extra stuff" in an upstream >> context? >> >> I wish the upstream kernel was able to do such magic, but i'm afraid it >> is not. > > No, but I am ;) The current out of tree Xen patches are very > intrusive because there hasn't been much incentive to reduce > their impact. I've going through it all and very carefully > rewriting it 1) be cleaner, 2) enable/disable itself at > runtime, 3) have clean interfaces and interactions with the > rest of the kernel, and 4) address any concerns that others > have. In other words, make Xen a first-class kernel citizen. > > Most of the intrusive stuff has already been merged (and > merged for some time now), but without dom0 support its only > half done; as it stands people are using mainline Linux for > their domUs, but are still limited to patched up (old) kernels > for dom0. This is a real problem because all the drivers for > interesting new devices are in the new kernels, so there's an > additional burden of backporting device support into old > kernels. This means that the "massive out-of-tree patches which doesn't make anyone happy" argument above is really ... a hiperbole and should be replaced with: "small, unintrusive out-of-tree patch"? Ingo