From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC] Unify KVM kernel-space and user-space code into a single project Date: Mon, 22 Mar 2010 19:44:11 +0200 Message-ID: <4BA7AC6B.3050103@redhat.com> References: <20100318172805.GB26067@elte.hu> <4BA32E1A.2060703@redhat.com> <20100319085346.GG12576@elte.hu> <4BA3747F.60401@codemonkey.ws> <20100321191742.GD25922@elte.hu> <4BA67B2F.4030101@redhat.com> <20100321203121.GA30194@elte.hu> <20100322111040.GL13108@8bytes.org> <20100322122228.GH3483@elte.hu> <20100322134633.GD1940@8bytes.org> <20100322163215.GC18796@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Joerg Roedel , Anthony Liguori , Pekka Enberg , "Zhang, Yanmin" , Peter Zijlstra , Sheng Yang , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Marcelo Tosatti , Jes Sorensen , Gleb Natapov , Zachary Amsden , ziteng.huang@intel.com, Arnaldo Carvalho de Melo , Fr?d?ric Weisbecker To: Ingo Molnar Return-path: In-Reply-To: <20100322163215.GC18796@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 03/22/2010 06:32 PM, Ingo Molnar wrote: > > So, what do you think creates code communities and keeps them alive? > Developers and code. And the wellbeing of developers are primarily influenced > by the repository structure and by the development/maintenance process - i.e. > by the 'fun' aspect. (i'm simplifying things there but that's the crux of it.) > There is nothing fun about having one repository or two. Who cares about this anyway? tools/kvm/ probably will draw developers, simply because of the glory associated with kernel work. That's a bug, not a feature. It means that effort is not distributed according to how it's needed, but because of irrelevant considerations. > I simply do not want to see KVM face the same fate, and yes i do see similar > warnings signs. > The number of kvm and qemu developers keeps increasing. We're having a kvm forum in August where we all meet. Come and see for yourself. >> We actually have lguest which is small. But it lacks functionality and the >> developer community KVM has attracted. >> > I suggested long ago to merge lguest into KVM to cover non-VMX/non-SVM > execution. > Rusty posted some initial patches for pv-only kvm but he lost interest before they were completed. No one followed up. btw, lguest has a single repository, userspace and kernel in the same repository, yet is practically dead. >>> I think you are rationalizing the status quo. >>> >> I see that there are issues with KVM today in some areas. You pointed out >> the desktop usability already. I personally have trouble with the >> qem-kvm.git because it is unbisectable. But repository unification doesn't >> solve the problem here. >> > Why doesnt it solve the bisectability problem? The kernel repo is supposed to > be bisectable so that problem would be solved. > These days qemu-kvm.git is bisectable (though not always trivially). qemu.git doesn't have this problem. >> The point for a single repository is that it simplifies the development >> process. I agree with you here. But the current process of KVM is not too >> difficult after all. I don't have to touch qemu sources for most of my work >> on KVM. >> > In my judgement you'd have to do that more frequently, if KVM was properly > weighting its priorities. For example regarding this recent KVM commit of > yours: > > | commit ec1ff79084fccdae0dca9b04b89dcdf3235bbfa1 > | Author: Joerg Roedel > | Date: Fri Oct 9 16:08:31 2009 +0200 > | > | KVM: SVM: Add tracepoint for invlpga instruction > | > | This patch adds a tracepoint for the event that the guest > | executed the INVLPGA instruction. > > With integrated KVM tooling i might have insisted for that new tracepoint to > be available to users as well via some more meaningful tooling than just a > pure tracepoint. > Something I've wanted for a long time is to port kvm_stat to use tracepoints instead of the home-grown instrumentation. But that is unrelated to this new tracepoint. Other than that we're satisfied with ftrace. > You should realize that naturally developers will gravitate towards the most > 'fun' aspects of a project. It is the task of the maintainer to keep the > balance between fun and utility, bugs and features, quality and code-rot. > There are plenty of un-fun tasks (like fixing bugs and providing RAS features) that we're doing. We don't do this for fun but to satisfy our users. -- error compiling committee.c: too many arguments to function