From owner-freebsd-chat Mon Apr 9 16: 3:25 2001 Delivered-To: freebsd-chat@freebsd.org Received: from valiant.cnchost.com (valiant.concentric.net [207.155.252.9]) by hub.freebsd.org (Postfix) with ESMTP id 93EE237B423 for ; Mon, 9 Apr 2001 16:03:18 -0700 (PDT) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by valiant.cnchost.com id TAA20542; Mon, 9 Apr 2001 19:03:07 -0400 (EDT) [ConcentricHost SMTP Relay 1.10] Message-ID: <200104092303.TAA20542@valiant.cnchost.com> To: Terry Lambert Cc: jmallett@newgold.net (Joseph Mallett), dkelly@grumpy.dyndns.org (David Kelly), bzdik@yahoo.com (Bzdik BSD), freebsd-chat@FreeBSD.ORG Subject: Re: Clash of Titans - Tale of two Morons In-Reply-To: Your message of "Mon, 09 Apr 2001 21:55:28 -0000." <200104092155.OAA00840@usr08.primenet.com> Date: Mon, 09 Apr 2001 16:03:07 -0700 From: Bakul Shah Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > I'm not terribly impressed with L4. Their "no commercial use" > license doesn't help my opinion any. Are you saying you are not impressed with L4's technology or its licence? If the latter, you should look at Fiasco as it implements the same API and is under GPL. > At one time, I got pretty deep into the bowels of Chorus, > which I fond to be very impressive (I've seen it running on > a 1024 node multiprocessor). Yes indeed. I failed to mention it. I'd like to get my hands on a Usenix winter '91 paper by Chorus people about ukernels and unix. > Given my druthers, I think Inferno is better than Plan9, as an > example microkernel. I believe calling either os a microkernel will rile the Bell Labs guys mightily!:-) But plan9 does seem very nice, elegant, modular and quite simple. Inferno runs on top of Plan9 (whether it runs natively as well I do not know). `given my druthers'. Does it come from "I'd rather"? > I think that the licensing costs for both, as well as the yearly > subscription renewal requirement, are why neither are gaining > any real ground. Plan9 has been open-sourced for a while now. See plan9.bell-labs.com. Too bad it was not open sourced 10 years ago when it could've had the impact it deserves. Judging from reading comp.os.plan9 now and then I get the feeling plan9 is slowly winning converts. Inferno has been transferred lock, stock and barrel to Vitanuovo. > > Bringing this back to FreeBSD, it would be neat to see the > > BSD API implemented on top of a tiny ukernel even if that > > meant a few % slowdown. The FreeBSD kernel is grown quite a > > lot over the years and while I applaud and marvel at the > > amount of new stuff added and old stuff speeded up, every > > time someone adds a new feature I keep thinking does it have > > to be in the kernel? Perhaps -current has become so fragile > > partially because of the kernel size and interdependency of > > modules. Such rearchitecting would be fun but a big task.... > > That's what the Lites project was all about. Unfortunately, > the only really good microkernel implementations out there are > very expensive closed source products. Fiasco is open. If you don't like it, L4 interface is simple enough to reengineer from scratch relatively straight forwardly. QNX is not free but can also serve as a good model for what to factor out in a ukernel. But just porting FreeBSD on top of such a kernel wouldn't be worth it. One would have to tear apart intertwined modules and reduce their interdependencies, simplify and thereby generalize various subsystems and so on. Probably better to start from scratch, build a framework and start implementing syscalls and reintroduce code (treat FreeBSD as a collection of very borrowable code fragments). I know, a lot of handwaving! On the other hand plan9 seems like an eminently usable system. Just imagine, you can mount tarfiles, zipfiles, mailbox, dump tapes and so on as filesystems and (from what I hear) it is easy to create a fs server for any such collection of objects. I'll have to find out for myself.... -- bakul To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message