Andy Tanenbaum on 'Who Wrote Linux'

Andy Tanenbaum writes "Ken Brown has just released a book on open source code. In it, he claims (1) to have interviewed me, and (2) that Linus Torvalds didn't write Linux. I think Brown is batting .500, which is not bad for an amateur (for people other than Americans, Japanese, and Cubans, this is an obscure reference to baseball). Since I am one of the principals in this matter, I thought it might be useful for me to put my 2 eurocents' worth into the hopper. If you were weren't hacking much code in the 1980s, you might learn something." Tanenbaum's description of the interview process with Brown is classic. See also Slashdot's original story and Linus' reply.

Comments

Re:I like the last bit

[gowen]

Well, there are certainly benefits to a modular micro-kernel design. I wouldn't deny it (and haven't). But there are also drawbacks (message passing is terribly hard to make secure in a multi-tasking context, and is frequently slower than dirt. Add to that some of the braindead design decisions of the x386 w.r.t. privileged processes...) Yuck.

Treating the micro v. monolithic debate as a solved problem ("microkernels win!") is as idiotic as suggesting that object orientation is the ideal solution to all programming problems.

Re:I like the last bit

[gowen]

And you disagree with this? Why?

Because if you want any kind of decent performance out of a server system you need both those things. Otherwise you've got a couple of designed-in bottlenecks to throughput. Now *that's* a braindead design decision. Of course, its completely understandable in the context of MINIX's design as a teaching system, but to deride those features in other OS's as "a hack" is just pure prejudice.

In conclusion ..

[Macka]

My conclusion is the Ken Brown doesn't have a clue what he is talking about. I also have grave questions about his methodology. After he talked to me, he prowled the university halls buttonholing random students and asking them questions. Not exactly primary sources

What more needs to be said !

Re:How can Linux be a copy of Minix

[Tarantolato]

I don't think Tanenbaum is bitter. He just wants to point this out.

Since I don't think anyone here has RTFA'd (/. effect and all) it's not worth judging right now. I think it's pretty classy of Tanenbaum to step up and offer some perspective on the AdTI FUD. If he does that as someone who still doesn't buy into Linux, that makes it all the more credible. Do we really want every response to this to be written by a Linux fanboy?

The Important Point

[Dark Paladin]

Whatever anyone does - do not read Brown's book when it comes out.

Thanks to Mr. Tanenbaum, we have the proof here:

People can create operating systems on their own. Even UNIX-like operating systems. Linus learned from Mr. Tanenbaum. Linus wrote the first kernel, published it and asked for input, which the rest of the world provided.

Linus then acted as a proper project manager, and the rest is history.

So again, whatever people do - do not buy the book.

Now, here's the problem: if we talk about this upcoming book, people will want to buy it. It's the Gibson Effect - the more its denounced, the more people will want to read it, and next thing you know there will be lines of people at the bookstores claiming they can see Jesus's face on this book.

So instead, I recommend to all intelligent folks in the programming community: ignore it. From here on out, don't even refer to the book by name, or its foundation, or the author. The more we pretend it doesn't exist and it's not important, the less interest people will have in it. If someone asks (such as a Pointy Haired Boss guy), shrug and lie as you say "No idea. I heard it was some book, but that it wasn't that good." And then shut up and leave it at that.

Don't give these guys free advertising. Don't even give them an ounce of respect, they don't deserve it.

Re:I like the last bit

[arkanes]

I've re-read that old flameware a few times over the years. It's kinda interesting how one reason he derides the performance hack is that "you don't need them", because normal PCs only have one job running. Certainly nobody envisioned the kind of systems we'd be running today (note the comment about 10 years from now when we're all on 200mips 64MB sparcs. That'd barely qualify as a toaster today....), but Linux rose to the challenge, Minix pretty much didn't. I think the freedom of Linux had alot to do with that (and he misses the point during the flamewar on that, too).

12 years ago, who would have imagined that it is normal and in fact essential for a desktop OS to be able to smoothly handle many IO intensive processes at the same time?

Level-headed and interesting

[Junks Jerzey]

I know many in the Linux community like to paint Mr. Tanenbaum as a bitter lunatic, but this is a great article, one that every Linux user/zealot should read.

First, he goes into the history of why people were souring on UNIX and the various independently-written UNIXalikes. These were mostly individual projects, which really sets the record straight for the people who seem to think that Linus was the first person to do this, and that Linus was somehow the only person intelligent and manly enough to write his own kernel.

At the same time, he lays out the history of UNIX clones, of which Linux was definitely one. It's surprising to me how many people seem to think of Linux as a great, independent OS, and fight so hard to deny that it has roots in UNIX. Of course these people are mostly young and don't know much about computer history. In that respect, this is an educational article.

And, yes, he does talk about the micro vs. monolithic kernel issue, but he does so without fanaticism, and, you know, what he says is generally correct. He's all for small and reliable software, which is something that UNIX was originally but rapidly became the antithesis of. Performance issues, back when people were using 4.77 and 8 MHz desktop processors, well, let's just say that things were different then. Now you have people writing big applications in Python. The real reason Linux ended up with a monolithic kernel is because that's what Linus understood and it was easier for him to write that way.

Writing a kernel is easy!

[Anonymous Coward]

Writing a simple OS kernel is easy. I wrote one, and believe me, it wasn't that hard. At the university where I am a grad student, we require the undergrads to write most of an OS kernel (including virtual memory and a filesystem) in a one-semester course. I read alt.os.development regularly, and there are high school students who are writing OS kernels. (I'm often depressed by the fact that they are much better programmers than I am :-)

Writing a scalable, production-quality OS kernel is another matter entirely. That takes hundreds or thousands of person-years by talented programmers.

Ken Brown is obviously a complete shithead if he doesn't understand this distinction. AST's rebuttal made the facts of the matter abundantly clear, and I'm sure any competent OS developer he asked would have told him the same thing.

Re:I like the last bit

[Profane MuthaFucka]

Thirteen years ago, I didn't give a flying FUCK about how outdatated Linus' monolithic kernel was. Remember, we were all running DOS, and desperate to break out of real mode hell.

Arguing about monolithic versus microkernel was like arguing about whether a starving man's meal should be vegetarian or not.

Re:QNX

[Tony-A]

A 20% performance hit really doesn't matter. Look at the rate of speed increases in hardware. When new systems come out doubling performance at such a regular pace, a one-time 20% slowdown to switch to an otherwise superior architecture with other benefits is an easy pill to swallow.

Good theory. Practice seems to work out differently.

Speed comparisons between products. Seems like 5% difference is enough to declare a clear winner. Unless you look behind the curtain.

Speed increases in hardware? At work I have two computers. I am typing this on NT4 on a 400MHz Gateway. My "other" computer is XP on a 2.4GHz Dell. Other than some legacy dBase for DOS applications the "faster" computer isn't any faster. It does boot faster which means that the XP machine is booted a lot more often than the NT. A 20% performance hit would be the same 20% on both machines.

The quoted improved performance doesn't quite translate into reality. A legitimate 10-times performance (IBM 1410 to IBM 370/135) transated into a 2-times difference in actual throughput. By the way, going the other direction won't work. As a rule of thumb, you will feel 90% of all slowdowns and only 10% of all speedups. This works both directions, like the "uphill both ways" quip.

Re:How can Linux be a copy of Minix

[Tarantolato]

I really have to figure out how to do this scam. Get money from big corporations

They started off taking money from the Swiss. The process seems to go something like this:

1. Get some hack-journalist experience (overfunded and obscure policy journals publish damn near anything; ditto for the Washington Times, as long as it purports to be conservative).
2. Get to know rich people
--a. get cushy internships in college
--b. marry a lawyer at a Big Firm
3. Convince the rich people you know to pay you for hack journalism.
4. Use hack journalism to push dubious foreign-investment schemes
5. PROFIT!!!

The key is that business, academia, law, journalism and government don't really know how to function with one another. They want to, for both good and bad reasons, so a lot of the time they're willing to throw big money conferences, fellowships, publications and "research institutions" that are supposed to grease the wheels.

Added to this, washed-up bigwigs usually want some place to go, and their former friends often set up make-work jobs for them. Lose an election? Why don't you give a lecture once a month at my public policy school. Get shitcanned from your CEO job? Why don't you sit on my government advisory committee. Newspaper column dried up? How bout you be a fellow at my think-tank. And of course, all of these people need gophers, personal assistants, research aides, etc. - a whole industry of suckups scurrying around washups.

The pay is peanuts for the honorees, sometimes even nonexistent. But they like the honorary titles. In exchange, the institution that hands out the titles gets more prestige from having Big Names attached to it. Look at the name-dropping on AdTI website: Jack Kemp, Newt Gingrich (Republicans), John Norquist (Democrat). In turn, the aura of Big Names clustered around an institution makes it easier to sucker donors.

That's basically the scam: laundering prestige for money. All you have to do is Know People(tm).