Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755510Ab1DFKOM (ORCPT ); Wed, 6 Apr 2011 06:14:12 -0400 Received: from dspnet.fr ([188.165.44.67]:32145 "EHLO dspnet.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755101Ab1DFKOL (ORCPT ); Wed, 6 Apr 2011 06:14:11 -0400 Date: Wed, 6 Apr 2011 12:14:05 +0200 From: Olivier Galibert To: Ingo Molnar Cc: Avi Kivity , Anthony Liguori , Pekka Enberg , linux-kernel@vger.kernel.org, aarcange@redhat.com, mtosatti@redhat.com, kvm@vger.kernel.org, joro@8bytes.org, penberg@cs.helsinki.fi, asias.hejun@gmail.com, gorcunov@gmail.com Subject: Re: [ANNOUNCE] Native Linux KVM tool Message-ID: <20110406101405.GA65838@dspnet.fr> References: <1301592656.586.15.camel@jaguar> <4D982E89.8070502@redhat.com> <4D9847BC.9060906@redhat.com> <4D98716D.9040307@codemonkey.ws> <4D9873CD.3080207@redhat.com> <20110406093333.GB6465@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110406093333.GB6465@elte.hu> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1797 Lines: 49 On Wed, Apr 06, 2011 at 11:33:33AM +0200, Ingo Molnar wrote: > Examples: X11 and GCC - both were struggling for years to break through magic > invisible barriers of growth and IMHO a lot of it had to do with the lack of > code (and development model) cleanliness. A large part of what's killing X11 and qemu is the decomposition in multiple trees and the requirement that every version must work with every other version. For X11 you have: - the server - the protocol headers - the individual 2D drivers - libdrm - the kernel - mesa - the video decoding driver/libs For qemu you have: - qemu - qemu-kvm - the kernel - libvirt - seabios Any reaching change ends up hitting most of the trees, with all to coordination that means. And in any case you're supposed to handle any version of the other components. Virtualbox works in part because they provide everything, from the dhcp server to the kernel modules. The NVidia closed-source drivers works in part because they provide everything, from the glx interface to the kernel modules. And both of them refuse to start if everything is not in lockstep. Meanwhile the open source idealists are a way smaller number and expect to support every combination of everything with everything as long as it appeared one day in a release, no matter how buggy or badly designed it was. So less people, additional hurdles that experience has shown not to be a necessity (people cope with lockstep updates, vbox and nvidia prove it), and one wonders why the "open" solutions end up way inferior? OG. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/