Slashdot Mirror
First Program Executed on L4 Port of GNU/HURD
wikinerd writes "The GNU Project was working on a new OS kernel called HURD from 1990, using the GNU Mach microkernel. However, when HURD-Mach was able to run a GUI and a browser, the developers decided to start from scratch and port the project to the high-performance L4 microkernel. As a result development was slowed by years, but now HURD developer Marcus Brinkmann made a historic step and finished the process initialization code, which enabled him to execute the first software on HURD-L4. He says: 'We can now easily explore and develop the system in any way we want. The dinner is prepared!'"
How fast is GNU/HURD compared to GNU/Linux? How about non-GNU/Linux?
Microkernel systems are always slightly slower because of the message passing overhead but they can be much more secure and stable because all of the device drivers are run in user space. Contrast it with systems such as Windows and Linux where drivers are in kernel space and it is impossible to have a stable or secure system with poor drivers, and in fact most of the problems with Windows and Linux crashing is caused by buggy drivers running in kernel space. When the drivers are just user processes like in HURD then a faulty driver can't crash the system and if it goes berserk it'll just get terminated just like a buggy browser or text editor without affecting the stability of th entire system.
Palm OS is on its 4th kernel. Did anyone notice? I didn't. I've been a full-time Palm developer for two years, and I couldn't even tell you which version has which kernel (except that I'm pretty sure they switched kernels when they ditched 68k processors for ARM). Did they have to "completely rewrite it down to the kernel level"? Nope, that's just the point: they did the opposite. They left it the same all the way down to the kernel level; it's just the stuff below the kernel level (and a few minor piece above it) that they changed.
The point is, switching out kernels is not necessarily that tough a thing. Sure, it can't be done overnight, but it doesn't force you to rewrite your entire OS.
Much more to the point, if you research it a little, you'll find that Linux has already been ported to L4Ka. And the version of Linux that was ported still runs exactly the same software as regular Linux. If some small team of researchers can port Linux to L4Ka just to give themselves a convenient development platform, then I guess Apple could do the same thing to OS X if they had any interest in doing so.
I think his point is that:
1. Yes - if your filesystem code crashes, you could end up with a dirty filesystem.
2. Yes - if your hard drive code crashes, you could end up with a dirty hard drive.
But:
3. No - if your webcam driver crashes, you won't end up with a dirty hard drive.
Right now with linux, if a kernel-level driver of any kind panics, the whole thing goes down the tubes.
Certainly a little compartmentalization can't possibly hurt. It won't fix every problem, but it does prevent a small problem in a non-essential driver from taking down the whole system.
As you point out, it will still be critical for some pieces of code to just work without bugs at all. However, the amount of that code can be reduced in a microkernel design.
Also - I don't think TWAIN is windows-specific. I seem to recall using TWAIN on a Mac many a year ago...
Um, Dilbert is a comic strip. It is meant to be funny and it attacks some areas of interest to a specific niche of readers. If you think you can address other issues in a funny way, by all means write another comic strip!
Now, to pick apart his list of things he says are never addressed in Dilbert...
Is this guy serious? Hello, Elbonia???? He has clearly not read much of the strip.
Oh yeah, those are really funny topics that the average geek encounters on a day-to-day basis.... HELLLO, Dilbert takes place in a cube-farm! There is no union in the average cube-farm environment, and when there is interaction it usually leads to a feeling that I would describe as PRO union-busting.
Again, he must not read the strip. Alice's character is there, I think, to humorously depict a woman's experience in a male bastion. Also, I think that they address planned obsolescence sufficently.
Jeese... again, just not funny material here. Also, not something that most cube-dwellers will run into except in the newspaper.
Man, alive, this is not a "blue-collar" strip. Again, if this guy wants to make a new strip that targets a different audience, he is welcome to. I don't feel that it is a valid criticism to blame a comic strip, or even any other piece of literary or artistic work, for targeting the wrong audience. Try to restrict yourself to commenting on the content provided. Man, he only has three frames a day! I imagine this guy gets his panties in a bunch over Garfield because none of the characters has ever developed feline AIDS.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.