"Linus Torvalds...is a terrible engineer" - Alan Cox

[Agathon]

Yes, but I've yet to find someone with credentials who would disagree with the assertion that monolithic kernels are frowned upon, and the Linux kernel is anything but well-designed.

Credentials aren't all they are cracked up to be, especially in things like tech, where there are a lot of talented amateurs who tinker.

You may well be right, though.

[Ari Rahikkala]

Originally posted by Asher
I agree with the statement that he's not a good engineer, in that the software is not well-designed. He may be a good software developer, as in a programmer, but I don't think he's even very good with that, either.

I don't really care much about Linus's programming ability, to be honest. If he really was too bad for the job and somebody else was better, I trust the kernel *would* be forked.

As for his management abilities, I again very much disagree. What evidence do we have for his abilities? The incredibly-delayed 2.4 kernel? The buggy, delayed release of the 2.6 kernel? The "secret" undocumented security fixes? The fact that he's a megalomaniac with a "what I say goes" attitude?

You're one to talk about delays, aren't you ?

On the secret security fixes: Go ahead and work them out, the diffs are public . It's just a case of sanity: They don't want to scream to every script kiddie out there "Hey! This bug here is a security bug! Go exploit it before sysadmins upgrade their machines!"

On the megalomania: He can afford it. Again, if people thought there was something wrong with it, the project would be forked.

Ironically, it was Windows NT that started with the perspective of 20+ years or research and OS development, where the designers (who happened to be far more qualified than Linus) rethought a lot of the OS design and threw out what didn't work, and tried some new things.

You'll be hard-pressed to find someone who studies Operating System design at a high academic level to say the Linux kernel is a better design than the NT kernel.

I'd love to discuss operating system design, but I simply don't know enough about it to put up a fight . I'll get back to you when I see a working production-quality free software microkernel that I can study and compare to the monolithic kernels... I hear The Hurd can now run on L4 well enough to execute Banner, so in a few dozen years they might be far enough to be worth looking at .

[Asher]

Originally posted by Ari Rahikkala
On the secret security fixes: Go ahead and work them out, the diffs are public . It's just a case of sanity: They don't want to scream to every script kiddie out there "Hey! This bug here is a security bug! Go exploit it before sysadmins upgrade their machines!"

But the Linux geeks (including Linus himself IIRC) flamed MS for not making vulnerabilities public until they have a fix...

On the megalomania: He can afford it. Again, if people thought there was something wrong with it, the project would be forked.

If the problem is the fundamental design, why would you both forking it? There are better open source alternatives to develop, like BSD. No point in forking and hacking an already hacky mess to be better...

I'd love to discuss operating system design, but I simply don't know enough about it to put up a fight . I'll get back to you when I see a working production-quality free software microkernel that I can study and compare to the monolithic kernels...

See Darwin.

[Ari Rahikkala]

Thanks about that last note, I just remembered it and I was coming back to edit my post to include it, but you were too fast . I'll see what I can do about the rest of your points later..

[LDiCesare]

As the maintainer of the development kernel Torvalds needs make sure the kernel code is easy to maintain, while Cox is more interested in kernel stability and is not so worried about "hacking" the code to get it to work.

"One of the hard problems to fix are design errors," said Cox. "These are a pain because they need a lot of refactoring. Linus' approach is to re-write it to a better design. But to get a stable kernel you tend to do small horrible fixes. Linus is very keen to have maintainable code, while to have a stable kernel I'm keen to have code that works."

Reading this, to me, Linus codes better than Cox. At least his approach is safer in the long run. If Cox advocates makings small dirty hacks so you have something stable versus keeping the code maintainable, well, he's gonna run into a wall someday. You can fix with a kludge (hotfixes/service packs in the commercial world) but in the long run, you must refactor and rewrite. So to me, Cox is essentially saying he's a worse programmer than Torvalds here.

[Whaleboy]

Firstly, who really gives a ****?

Secondly, Linux

Thirdly, BSD

And I'm a happy windows user

[Urban Ranger]

Originally posted by Asher
I agree with the statement that he's not a good engineer, in that the software is not well-designed.

That's not what Cox actually said, if you RTFA.

"One of the hard problems to fix are design errors," said Cox. "These are a pain because they need a lot of refactoring. Linus' approach is to re-write it to a better design. But to get a stable kernel you tend to do small horrible fixes. Linus is very keen to have maintainable code, while to have a stable kernel I'm keen to have code that works."

[empahsis mine]

Originally posted by Asher
I very much disagree with Ingo Molnar's quote, mainly because it doesn't make any sense. The purpose of Linux was a free Minix clone

What are you talking about? Minix is already free. Trovalds wanted to write his own Unix clone, so he started with Minix code.

Originally posted by Asher
It's not because of 20 years of OS research that was studied

That's okay. None of the mainstream operating systems are.

Originally posted by Asher
If Linus actually knew about making maintainble code, the last thing he would've done was opt for a monolithic kernel.

Go ahead, display your "awesome" knowledge.

The Linux kernel is monolithic in the sense that a lot of device support, etc. goes into the kernel (although if you are careful you can take them out as modules). But, you can highly optimise GNU/Linux for your system, completely unlike another (in)famous operating system.

It is not monolithic in the sense that thousands of lines of code are in one big blob, with functions from various parts mixed together. Again unlike the same other operating system.

Originally posted by Asher
Ironically, it was Windows NT that started with the perspective of 20+ years or research and OS development, where the designers (who happened to be far more qualified than Linus) rethought a lot of the OS design and threw out what didn't work, and tried some new things.

Is that why a bad device driver can bring down an entire NT system?

Originally posted by Asher
The incredibly-delayed 2.4 kernel? The buggy, delayed release of the 2.6 kernel? The "secret" undocumented security fixes?

My sides.

This wouldn't be nearly as funny if Windows aren't as bad.

Incredibly delayed - first Windows 2000, then "Longhorn."

Buggy - Microsoft software is notorious for bugs. Everybody knows that.

Originally posted by Asher
You'll be hard-pressed to find someone who studies Operating System design at a high academic level to say the Linux kernel is a better design than the NT kernel.

That's fallacious, since the source code for NT is not open for public viewing.

[Asher]

Originally posted by Urban Ranger
What are you talking about? Minix is already free. Trovalds wanted to write his own Unix clone, so he started with Minix code.

Brush up on your history old man, Minix 1.0 was $169, which spurred Linus to create Linux.

Minix 2.0 and beyond were free.

That's okay. None of the mainstream operating systems are.

NT and OS/2 were...if you knew your history and who designed them, at least.

Go ahead, display your "awesome" knowledge.

The Linux kernel is monolithic in the sense that a lot of device support, etc. goes into the kernel (although if you are careful you can take them out as modules). But, you can highly optimise GNU/Linux for your system, completely unlike another (in)famous operating system.

It is not monolithic in the sense that thousands of lines of code are in one big blob, with functions from various parts mixed together. Again unlike the same other operating system.

It is monolithic by definition. Period. Linus admits it. I have no idea why you're arguing this.

The linux kernel is monolithic...straight-up, undeniable fact from the creator and maintainer himself. The fact that you don't entirely agree is just saying a lot about what you think you know, but don't.

Is that why a bad device driver can bring down an entire NT system?

I said pseudo-microkernel for a reason. Hell, NT 3.0 still kept the device driver in userland. It was moved into kernelspace for performance reasons in NT 4.0 and beyond.

That's fallacious, since the source code for NT is not open for public viewing.

You don't need the source code to talk about its design -- its design is well documented.

Even then, pretty much any University professor and researcher is given access to the NT source code, once they ask and sign some agreements not to distribute it.

It's only fallacious to you because the people who actually know their sh*t disagree with the fundamentals behind the Linux kernel.

There's some fundamental reasons why the Linux kernel has far more security vulnerabilities than the NT kernel, and the main reason is the entire kernel shares the same memory space -- while Darwin/MachBSD and NT do not.

It's easier and more "oldschool" to do it like Linux did, it's considered proper to do it like NT and Darwin did.

[Asher]

Read this before you talk anymore, UR. It'll help you understand just what you're talking about.

http://www.bellevuelinux.org/obsolete.html

Some excerpts:

1. MICROKERNEL VS MONOLITHIC SYSTEM
Most older operating systems are monolithic, that is, the whole operating
system is a single a.out file that runs in 'kernel mode.' This binary
contains the process management, memory management, file system and the
rest. Examples of such systems are UNIX, MS-DOS, VMS, MVS, OS/360,
MULTICS, and many more.

The alternative is a microkernel-based system, in which most of the OS
runs as separate processes, mostly outside the kernel. They communicate
by message passing. The kernel's job is to handle the message passing,
interrupt handling, low-level process management, and possibly the I/O.
Examples of this design are the RC4000, Amoeba, Chorus, Mach, and the
not-yet-released Windows/NT.

While I could go into a long story here about the relative merits of the
two designs, suffice it to say that among the people who actually design
operating systems, the debate is essentially over. Microkernels have won.
The only real argument for monolithic systems was performance, and there
is now enough evidence showing that microkernel systems can be just as
fast as monolithic systems (e.g., Rick Rashid has published papers
comparing Mach 3.0 to monolithic systems) that it is now all over but
the shoutin`.

[Ari Rahikkala]

Originally posted by Asher
But the Linux geeks (including Linus himself IIRC) flamed MS for not making vulnerabilities public until they have a fix...

They'd flame MS for introducing world peace if that occurred, but anyway.. as far as I understand, the logic goes like this: "A company that writes non-free software can't be trusted to spend its resources on fixing security bugs instead of, say, adding new features, since you can't actually see what changes have been made between versions. Therefore, it's better in the long run that their vulnerabilities are made public since that pressures the company to fix them". Free software is different here since you can read the diffs...

If the problem is the fundamental design, why would you both forking it? There are better open source alternatives to develop, like BSD. No point in forking and hacking an already hacky mess to be better...

I thought Linux and at least FreeBSD actually were rather similar architecturally, but again, I didn't claim to know much about OS design in the beginning of this thread and I don't claim to know much about it now.

[Geronimo]

Re: "Linus Torvalds...is a terrible engineer" - Alan Cox

Originally posted by Asher

http://news.zdnet.co.uk/software/linuxunix/0,39020390,39189593,00.htm

I've always been of the opinion that the Linux kernel design is both antiquated and a kludgey mess. Then again, that opinion may have been influenced by my OS Design prof who had only bad things to say about it...

It's nice to see that Alan Cox seems to agree. Not everyone involved in the development process lacks good judgement...

is it possible to compare it to non open source codes to see how kludgey it is in a relative sense?

Something makes me think the windows kernal design would turn out to be appallingly kludgey as well.

[Pekka]

I'm sure your near prodigal mad skills will take over Linus' any day. You do realize, that there are kazillion other PhD's that disagrees with your lecturer. There are many legit beefs about Linux and Linus himself as well, and you have brought up many of them with valid arguments. However, sometimes it seems to me, that the bias is into the hardcore of sides, so it strikes odd to me that such intelligent guy like you would totally get sucked into it, with very little pragmatism. VERY little.

It also seems to me we read two different articles. Then again, I often make mistakes reading and interpreting foreign languages so it's a possibility I keep open, the other possibility I keep open is... your never ending bias.

Ta-ta!

[Asher]

Of course Alan Cox is on the "same side" as Linus, so it wouldn't be all negative. The article showed him just illustrating the difference between their two approaches.

In terms of the article, I would be more with the Linus side of the camp than the Alan Cox "hack it til it works" camp. But I don't think Linus is a good engineer in general, because there are lots of design issues with the Linux kernel.

How many MachBSD/Darwin and Windows NT kernel vulnerabilities have we had recently compared to the linux kernel? The numbers are not even close.

For the people like Urban Ranger who constantly deride Windows for having poor design choices w.r.t. security (which is certainly true in many cases), in terms of the kernel the roles are totally reversed.

The Linux kernel has an amazing array of vulnerabilities compared to WinNT/Mach, and this is either because (a) the code is of very poor quality, (b) the design is of very poor quality.

[Pekka]

Now now, those are good fighting words .

Yes, everyone knows Linux is less vunerable only because less crackers try to beat it down, and multiple amount of them try to search MS products and bring them down. Nothing new here.