Slashdot Mirror
Java 2 For BSD
We've covered the movement to get Java 1.2 ported to the BSDs for a while now. After Linux got in on the act a couple of months ago, keepper was the first to write in with a link to this BSDi press release announcing the availability of Java 2 for BSD. Looks like BSD/OS will get it first (they're beta-ing it now). Then FreeBSD gets it, at which point (I assume) it'll be open to the other BSDs to take as they want.
Subject: Re: FreeBSD and SMP :
:-)). However, Linux supports SMP only marginally better than FreeBSD in the grand scheme of things.
From: "John S. Dyson"
Date: 2000/06/01
Newsgroups: comp.unix.bsd.freebsd.misc
Bruce Burden wrote:
>
> XuYifeng wrote:
>
> : I am newbie of FreeBSD, I heard rumor that Linux 2.2 has better SMP support
> : than FreeBSD 4.0?
>
> I understand the latest Linux kernels have a multi-threaded
> SMP kernel, while FreeBSD still uses the big lock model for SMP.
>
> From what little I have seen on the
-current mailing list,
> this is something the developers are going to have to "bite the
> bullet" on, it seems, because the change isn't going to be easy
> or compatible.
>
About the time that I left FreeBSD, my biggest TECHNICAL argument was that FreeBSD needed an official project to re-design the kernel so as to support multi-processors correctly. In NO WAY does FreeBSD do multi-processing correctly (and that isn't an insult, but is a result of the monolithic kernel legacy -- FreeBSD is an excellent kernel otherwise!!!
A significant and well thought out redesign is in order. This is NOT an easy project and would require a serious committment on the part of the kernel developers. Hack solutions shouldn't even be considered for the shortest amount of time (the time involved in looking at expedient work-around type efforts is totally wasted.)
IMO, the Linux approach so far appears to be an iterative improvement on the same basic design: TRADITIONAL monolithic kernel. Given a traditional monolithic design, once the kernel is fine grained enough, and provides correct internal structure, the kernel maintenance people will have to be MUCH more intelligent than the original developers themselves. The complications in an adequate monolithic design are enormous.
The reason for my work being aborted on the FreeBSD SMP MONOLITHIC kernel wasn't that I couldn't make a FreeBSD SMP monolithic kernel work very, very well. The resulting kernel design would have been unmaintainable. I decided (when it was my place to decide a LONG time ago) that a monolthic SMP kernel (other than the current stopgap) didn't provide the quality that the FreeBSD name demands.
I am currently making really good and effective progress on my video compression (data reduction) software, and I might be able to do kernel hacking (actually redesign) in the near future. I have no need for employment anymore to make money, so my time is fully my own.
The last few years has been frustrating, but at least I worked with some tremendously nice people. I now have a situation that is very close to what it used to be when I first started working on FreeBSD!!! (I doubt that I'll be directly involved in the project because of disagreements that I had about the technical direction of the kernel, and marketing disagreements (with the associated burnt bridges :-(()).
I am going to be lurking much more than I have in the last 2yrs anyway :-). I just looked that the FreeBSD mailing lists a couple of weeks ago for the first time in a few years!!!
--
John | Never try to teach a pig to sing,
dyson@iquest.net | it makes one look stupid
| and it irritates the pig.
If you read Dyson's explanation for leaving, you'll see he is quite the pessimist with regard to basically any project he's not working on. He's an extremely intelligent man, but he isn't criticizing a lot of the time on merit.
It also shows that his viewpoint hasn't changed in the few years since he's left. There are several very key architectural changes that make FreeBSD much less like a traditional monolithic kernel. One of the biggest is the changes, planned for a long time, that are now to be implemented with help from the BSDi people and the BSD/OS SMPng (5.0) kernel. Priority levels (splhigh(), splx(), etc.) are disappearing and will be replaced by very mutexes allowing much better SMP. Along with this, the interrupt model will be changing to interrupt threads, where each interrupt gets its own lightweight kernel thread.
In addition, pthreads are to be reimplimented using scheduler activations and (probably) a hybrid kernel/user thread model where the ratio of actual "processes" to threads will not be 1:1 like LinuxThreads or 1:many like the current pthreads implementation; the ratio will most likely be many:many which would allow for much nicer scaling than either of the other.
Don't look at things as short-sightedly as John Dyson likes to. There's a lot going on at a very fundamental level to improve what he thinks wouldn't be improved.
--
Brian Fundakowski Feldman
Not just that Java2 is coming out for BSD, but that the better stuff is coming out right at the start for BSD. The more recognition that BSD gets, the better. Any Operating System effort that can take hold now will be competing for the market share from the Microsoft breakup, so it's great to see Open Source efforts besides Linux (not to say that Linux isn't great, but most techies have heard of it) getting more media, as opposed to closed source efforts taking over. I see this as representative of the increasing popularity of the *BSDs, and open source in general, as companies begin to turn from the giant Microsoft to the stronger, more reliable Open Source operating systems. Support like this is critical is we want to attract more good developers to the Open Source platforms.
Technically isn't the first BSD based OS with Java 2 support Apple's Mac OS X? I believe Sun's Chairman and CEO Scott McNealy brought Steve Jobs up during the keynote at JavaOne to tout OS X's support for Java 2. According to Jobs, Apple has gone even further, mapping the "swing UI stuff" on to the graphics subsystem, Quartz and the new Aqua look and feel.