From owner-freebsd-hackers@FreeBSD.ORG Tue Mar 18 22:32:37 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 58B48106564A for ; Tue, 18 Mar 2008 22:32:37 +0000 (UTC) (envelope-from fbsd-hackers@mawer.org) Received: from outbound.icp-qv1-irony-out1.iinet.net.au (outbound.icp-qv1-irony-out1.iinet.net.au [203.59.1.108]) by mx1.freebsd.org (Postfix) with ESMTP id E3F748FC1F for ; Tue, 18 Mar 2008 22:32:36 +0000 (UTC) (envelope-from fbsd-hackers@mawer.org) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnIBAD7Y30fLzq3r/2dsb2JhbAAIqSg X-IronPort-AV: E=Sophos;i="4.25,519,1199631600"; d="scan'208";a="299759680" Received: from unknown (HELO [10.24.1.1]) ([203.206.173.235]) by outbound.icp-qv1-irony-out1.iinet.net.au with ESMTP; 19 Mar 2008 07:02:43 +0900 Message-ID: <47E03BDB.40406@mawer.org> Date: Wed, 19 Mar 2008 09:02:03 +1100 From: Antony Mawer User-Agent: Thunderbird 2.0.0.12 (Windows/20080213) MIME-Version: 1.0 To: Jordan Gordeev References: <200803172158.m2HLwPSI021438@apollo.backplane.com> <200803181806.m2II6OMc031236@apollo.backplane.com> <47E0182F.3060606@dir.bg> In-Reply-To: <47E0182F.3060606@dir.bg> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org Subject: Re: vkernel & GSoC, some questions X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Mar 2008 22:32:37 -0000 Jordan Gordeev wrote: > Matthew Dillon wrote: >> We use vkernel's for development and debugging. >> ... >> One interesting side-effect of having a vkernel so easily accessible >> is that it opens up kernel development to normal programmers. More >> DragonFly developers have been dipping their fingers into the kernel >> code in the last 6 months then in all the time before then. That >> alone >> justifies the time spent doing it. Except for hardware device driver >> development, the agonizing engineering cycle for kernel development >> is completely gone now. >> > I have thought of the vkernel primarily as an aid to kernel development > (where performance is not a prime concern), not as a virtualisation > solution that will compete with Xen and VMWare. It's difficult to > compete with thousands of men-hours paid by corporate funding. > > So far nobody has expressed interest in vkernels as a tool for kernel > development. And I got the general impression that I've proposed > something stupid and useless. I can see this would be advantageous for lowering the barrier for kernel development. The easier this is made, the better chance we have of people having a go at fixing issues in some of the unmaintained bits and pieces out there. I recall trying to take the leap into kernel development some years back to fix some issues in NWFS and SMBFS; even though I was using VMware for testing, I still found the whole compile/install/reboot test cycle a bit tedious. If it were a matter of just Ctrl-C'ing a kernel and then waiting 5 seconds or a new one to boot up, while still having the rest of the machine available "outside" to view/edit source at the same time, it would be much simpler... -- Antony