Posted by
michael
on from the oh-christmas-tree dept.
BigFire writes "Professor Tanenbaum responds to the slashdot effect and a small critique of Ken Brown's forthcoming book in his followup. A small gem is where he disclosed that Ken Brown can't multiply simple positive integers."
Changed opinion
by
Dasein
·
· Score: 5, Insightful
You know, I think I had AST wrong. I'd seen the thread where he bashes Linus for not doing a microkernel design and thought that maybe it was sour grapes.
His exchanges on this subject have changed my opinion on that. He's been nothing but kind toward Linus, generous with his time, and well-spoken.
If anything good come out of this whole mess, maybe it's that AST really got to show us what he's really like instead of all of us just assuming that he was bitter about the MINIX/Linux history.
-- You are not a beautiful or unique snowflake -- but you could be if you got off your ass.
Re:Changed opinion
by
pankajsethi
·
· Score: 5, Insightful
I agree that a lot of people in academia have superinflated egos, but the ones who are at the top are because of their earnest desire to learn and explore new realms of their beloved fields. If Tannenbaum was narrow minded to get entangled in micro-kernel vs. macro-kernel, he wouldn't be where he is right now.
Remember that research is more about asking questions, engaging in discussions, acting as a devil's advocate to prove yourself wrong, and dealing paradoxes then it is about answering them. I'm sure nobody around here as any doubt about contribution Tannenbaum has made to computer sceience can be surpassed only by few.
He so totally rocks and has been my inspirtation since my undergrad days and has written a few books that I will never part with.
Re:Changed opinion
by
dan_sdot
·
· Score: 5, Insightful
You know, I think I had AST wrong. I'd seen the thread where he bashes Linus for not doing a microkernel design and thought that maybe it was sour grapes.
Well, its good that you made such an informed judgement on his character so early. I think that way to many/.ers are doing that. They read one thread that was linked to a couple days ago, and just because it was an argument with Linus, he must be the bad guy. Remember that, after all, he was being very polite in that discussion and in the end Linus had to apologize for being too hotheaded. He simply strongly believes that microkernels are the best approach.
So please,/.ers, stop thinking that you have to have an opinion on everything, even the things that you don't really know about.
Re:Changed opinion
by
Omnifarious
·
· Score: 4, Insightful
I sort of thought that way about him after I read the initial argument, though I still had a lot of respect for his books. But, after reading his first article about the Brown book, I didn't feel that way anymore. It was clear to me that his comments in the middle were him gleefully taking advantage of the fact that he (deservedly) had a wide audience to point out that he still considers monolithic kernels a poor design choice and to give reasons why.
I detected no note of bitterness or anger over Linux's success. Though I did find some of his comments about Minix licensing to be slightly revisionist. I found people's comments here to be more amusing.
I sometimes think that people who do not have a scientist mindset mistake heated debate among scientists for petty emotional rancor. The latter does happen, but heated debate is not a definitive indicator.
Re:Changed opinion
by
iabervon
·
· Score: 4, Insightful
Linus is an engineer, and is wants to make a system that works really well. Tanenbaum is an academic, and wants to make a system which is informative. Both have been wildly successful at their respective goals.
The microkernel argument was an academic argument, of the sort that which is not held for the purpose of winning it, but of coming to an agreement on the relative merits of different approaches. As for winners, Linux obviously continues to be a monolithic kernel. But it should not be ignored that you can now add filesystems to a running kernel as modules, and even build them outside of the kernel tree. At this point, Linux is essentially a microkernel design running as a monolithic kernel for performance reasons as an implementation detail. A future version could offer the option of running the filesystems in userspace if you want. (That is, running all of the filesystems in userspace with the kernel fs API; there's already support for having filesystems in userspace if you want.) I wouldn't be surprised if people having weird problems would be advised to try the "ext3.userspace" option, and if you could avoid tainting your kernel with "nvidia.userspace".
Re:Changed opinion
by
be-fan
·
· Score: 5, Insightful
Please, respond when you know what you are talking about.
Someone in an academic environment supposed to be open to idea's and non baised. Most though have ego's including Tanenbaum which blind them. Who said academics are supposed to be biased? Most are very biased towards their own ideas, and push them whenever possible. Its a natural part of the competitive system that allows academia to advance.
Funny, Linux, Solaris, FreeBSD, and As/400 have uptimes that measure in years if you do not include security patching. Even funnier is the fact that, with a microkernel OS, lots of downtime due to security-patching is unnecessary, because critical services run as easily restarted userspace tasks. There is no doubt that Linux, Solaris, *BSD, etc, are highly stable, but they are something you trust your server to --- a microkernel like QNX is what you trust your nuclear reactor to!
MacOSX is less stable than a macrokernels like Linux according to those who use it as a server. MacOS X has a monolithic kernel. Mach and BSD both run in kernel-space, with messaging replaced by direct function calls wherever possible. That was one of the chief changes between NeXTStep and OS X.
-- A deep unwavering belief is a sure sign you're missing something...
That's the point the professor was trying to make
by
StevenMaurer
·
· Score: 4, Insightful
This isn't being disingenious, that is a highbrow critique.
If the author was serious then he would have given his "target" - Linus - at least some chance to respond. He didn't. Therefore he isn't a serious author.
Professors generally don't go saying directly, 'that author is such a luuusor dude!' And authors who write trash books about Di aren't exactly people to take seriously either.
Re:Linux is Obsolete
by
dan_sdot
·
· Score: 5, Insightful
So I guess Prof. Tanenbaum can give higher grade than "F" to Linus now.:)
Actually, I still don't think that he would. He still affirms that the point of view from which he looks at OS design is academic. He emphasizes that he is a PROFESSOR, not someone trying to make a production grade operating system. As are many academics, he is a purist and thus believes in a conceptually optimized design (microkernel) rather than a practical design (monolithic kernel). So, if Linus was still in his class, the "F" would probably stand, because Linux does not follow all the conceptual guidelines that Tanenbaum feels so strongly about. This argument was never really a big deal in the first place, it was just a classic arguemnt between a realist and a purist.
Re:We should set up better Open Source Marketing
by
Clover_Kicker
·
· Score: 4, Insightful
>Therefore the only effect Tanenbaum (and Slashdot) gets from this >document is self-defence and mutual knob-polishery. Not that >Tanenbaum is entitled to have his say and defend his honor, but there >you go.
I don't think Tanenbaum loses sleep worrying about the commercial sucess of Linux:)
I think he was mostly trying to prevent looking like a dick for being associated with that book. Mission accomplished!
Perhaps today he's preaching to the choir, but look at it this way: One of the world's most respected computer scientists just TRASHED the integrity of the guy who interviewed him. I'm sure the whatchamacallit institute will be a long time living this down. And Tanembaum provides lots of nice quotes for the profesional marketers from Red Hat/IBM/Novell/whatever, computer columnists, etc.
Re:His comment on Slashdot:
by
kfg
·
· Score: 5, Insightful
I'm posting this as AC since I'll most likely be modded down for touching a "hero" of the Linux revolution:
I've always rather gotten the impression that he was something of the anti-christ of the Linux revolution, and that that's why he has to waste so much time explaining that he and Linus are not enemies.
. ..very very pleased with himself for having written Minix and fostered the development of Linux.
And says so in the very paper in question.
The trouble is that Minix, which was meant to be an academic OS to study. ..
And says so in the very paper in question.
. ..was never good performance-wise. ..
And says so in the very paper in question.
. ..and wasn't really good for learning the architecture of an OS either.
Here I'm sure he'd disagree with you, however, since you leave out why it "wasn't really good" you protect yourself from criticism.
Minix knew success because it was "this other, free Unix for i386" (and some other architectures like the Atari ST), and people could goof around with it for free.
And says so in both papers in question.
That's the extent of Tanenbaum's achievenemts.
And explains that such is not the case in the paper in question.
. ..but somehow Tanenbaum feels entitled to think of himself as a pillar of computer science and computer history, and act accordingly.
And not only says so in the paper in question, but points to references should one chose to follow them up. Not to mention the fact that if he were not popularly regarded as such among the computer science community said paper whould have no had raison d'etre in the first place.
Now I shall watch myself be modded down as a troll by Slashdotter who have never met, read about, or listened to him...
As a general rule I find it more responsive to posts such as yours to, well, respond, rather than mod down something just because I might find it unpalatable. An unpalatable point of view is not the same thing as a troll.
I have never met the man, nor listened to him, but I have both read him and read about him. He is a public figure in the computer science community, just as is Linus.
He impresses me, as he appears to impress the orginal poster, as just the sort of intelligently sarcastic "prick," in the Swift/Dickens/Twain/Leacock mode, that I rather enjoy dealing with.
Of course you have to consider the source of that last statement (as one might well consider the source of any), as I myself have been accused, on occasion, of being such a man, and may be merely feeling an affinity of kind.
KFG
Re:His comment on Slashdot:
by
mst76
·
· Score: 5, Insightful
> I'll most likely be modded down for touching a "hero" of the Linux revolution:
Tanenbaum is hardly seen as a "hero" in the Linux community, of those who know him at all, most only remember the infamous "Linux is obsolete" flameware on Usenet.
> It's quite well known that Proff Tanenbaum is somewhat of a prick, very very pleased with himself for having written Minix and fostered the development of Linux.
How is this well known? I've never read anything about him boasting about having fostered the development of Linux. He does point out areas where the early Linux was inspired by Minix, but I don't think anyone would dispute that.
> Minix knew success because it was "this other, free Unix for i386"
It was the "free Unix for XT". One of the reasons for Linus to develop Linux was that Minix didn't take advantage of any of the advanced features of the 80386. AST refused almost all suggested improvements, his motivation being that he wanted to teach it in a one semester course.
> That's the extent of Tanenbaum's achievenemts.
Tanenbaum is a university professor. His achievements are his publications in peer reviewed journals, and citations to these publications. Since he has lots of both, he's been pretty successful.
Battle of the Philosophies
by
puntloos
·
· Score: 3, Insightful
You're right, and indeed I said 'unix' not 'linux'. The whole thing that is both the strenght and the weakness of the 'alternative to windows' is its very nature, the design Philosophy. Open Source most notably. The problem is, everyone has the right and the possibility to make their custom version of an application or even core structure, tweaked to their needs, and this is a Marketing disaster.
Open Source fights itself
If I promote Linux I would have no time to promote OpenBSD, even though in principle I have no reason to dislike openBSD, Im just more familiar with Linux.
The key thing that makes these systems competition to Windows is the way they are designed. Open the source completely thereby both creating a greater likelyhood of dumb mistakes being caught but on the flipside removing the whole 'security by obscurity' concept.
One thing Id like to re-emphasize is that there is Too Much Preaching to the Choir in our circles. I know why I like Linux (etc), Slashdot likes Linux but there are plenty of ignorant (not necessarily because of stupidity) middle-management types that need to be convinced by less formal and more 'shouty' methods.
Linux has far too few scantily clad ladies at the booths in conventions, and too many people who look like Andrew Tanenbaum
Re: microkernels the best approach
by
Anonymous Coward
·
· Score: 4, Insightful
Actually, his argument is that a microkernel would make a better early-90s graduate-level compsci project than a conventional monolithic kernel.
He's basically bashing Linus for doing an academically uninteresting project. (Keep in mind that as a professor, he's got the complete UNIX source code at his fingertips - he didn't need a free unix.)
And he was right, but that hasn't stopped damp pantied fanboys from tarring-n-feathering him over the years for arguing with the Great Linus.
Re:Little Help?
by
nathanh
·
· Score: 5, Insightful
Who is Professor Tanenbaum? Who is Ken Brown?
Tanenbaum (AST) is a Professor who worked at AT&T and has written many textbooks aimed at university students. AST's most famous book - Operating Systems: Design and Implementation - includes a UNIX-alike operating system called Minix that he wrote himself. Minix includes binaries and source code for the kernel, C library, C compiler, and all the utilities. AST wrote Minix and the book to teach students how operating systems are written. Any computing science student who attended a decent university in the past decade has probably had at least one of AST's books as a required text.
Minix ran on an 8086 and didn't have modern virtual memory (VM) features. When the 80386 came out there were some unofficial patches to make Minix/386. These patches added virtual memory and paging and memory protection, turning Minix into an useful OS. AST refused to add these patches to Minix, rightly arguing that they would make Minix too complex for a student to understand. Minix was a teaching tool, not a general purpose OS, even though Minix/386 was a pretty good general purpose OS. Unfortunately the license back then didn't permit forking. Despite these limitations, Minix had a very large user community. .
When Linus came along and announced Linux a lot of people realised that GNU (basically all of UNIX except for the kernel) and Linux (basically none of UNIX except the kernel) when combined would produce a UNIX-alike operating system. Just like Minix but with VM and the more relaxed GPL for a license. There was no Linux news group so all the discussions were on the Minix news group.
AST put his two cents in on the Linux kernel. He correctly pointed out that the Linux design was a 30 year old monolithic design; not elegant or modern. Linus argued back that monolithic kernels are more practical. AST said Linus would fail his OS class, if Linus was his student. That's the infamous AST/Linus flamewar. It wasn't very hot, as far as flamewars went. AST was right, so was Linus. They just had different perspectives.
Ken Brown is an ignorant idiot who is selling a book claiming that Linus didn't write Linux. He argues that noone could write something so complex as a UNIX-like kernel without stealing code. Ken is under the delusion that writing a UNIX needs a huge team of people working for many years. He seems to be ignorant of the fact that the first UNIX was written by Ken Thompson on a computer so ancient that your wrist watch has more computing power. For "research", Ken Brown spoke to AST. Notably he did not speak to Linus Torvalds. AST is pointing out that Ken is lying in his book; AST has pointed to several examples of single authors who created a UNIX-like kernel, AST included.
The confusion might be that Ken Brown doesn't understand that Linux is just a kernel. The first "Linux" that you ran back in 1991 was actually GNU/Linux. Linux comprised less than 2% of that system. RMS and his team had been working on GNU for nearly a decade by that stage (longer if you count emacs). Linux The Kernel was a small piece of the puzzle. An essential piece, but certainly writable in 6 months by a bright and talented person. These days, Linux is an incredibly tiny piece of a "Linux distribution". Ken Brown might think that Linus is laying claim to the entire system. Of course, Linus has only ever claimed credit for the first kernel. Recent kernels have very little "Linus" in them. And the distro you have on the desktop is less than 1% Linux anyway.
The other theory is that Ken Brown is being paid by SCO/Microsoft/LatestPariah to create FUD over the legal origins of Linux.
I prefer my own theory. Ken wants attention. Saying something ridiculous gets easy attention and increases book sales. We're playing right into his hands by giving him the time of day. It gives him false credibility by creating a "controversy" when in reality there is no controversy. Just Ken saying ridiculous things with no evidence to back them up. It's like all those authors who write books on Noah's Ark, or the location of Atlantis. They must have a huge grin on their face when somebody pays attention to them.
The more I read of Tanenbaum and his work the more I admire him. The fact that he is a Fellow of two prestigious societies says alot about his contributions. Tanenbaum is a classic academic; he knows where to pick his fights - on the science. He attempts to stay above personalities, but doesn't flinch when it comes to calling bullshit on some dickhead (my words) who is out to smear someone for money.
-- "Rocky Rococo, at your cervix!"
Re:Multiply small integers
by
36-bitter
·
· Score: 4, Insightful
Careless spelling and careless arithmetic are often indicators of sloppy thinking. They're also impolite -- the rest of us have to think harder than should be necessary in order to take your meaning. Don't be surprised to find that some readers will not put forth the extra effort, when they see that a writer does not put forth even the minimum effort.
Linux is not an improvement on Minux
by
AHumbleOpinion
·
· Score: 4, Insightful
And, even if the OS itself was not so good, it doesn't matter, because people often learn the subject from the mistakes, shortcomings.
You may be suffering from the misconception that Minix tried to be, or should have been, a commercial grade Unix workalike. If so you are wrong. When you write software in an academic environment where the goal is to teach students the code should be written with clarity and easy of understanding being paramount. If efficiency or more advanced techniques conflicts with clarity or ease of understanding you should choose the later. The job of the University is to teach core concepts that are long lived and transcend the OS, language, or architecture of the day.
After all, Linus wrote the Linux to improve Minix on Minix.
No. Linux and Minix have different missions. Minix was a teaching tool, it's mission was not to become a full featured Unix workalike. Its goal was to remain small and comprehensible to further its teaching mission. Linux had a very different mission. It is silly to compare the two. Linux is no more of an improvement on Minix than a wrench is an improvement on a screwdriver. Different tools for different jobs, or missions in this case.
Re:I'm with Tannebaum about microkernels
by
0x0d0a
·
· Score: 3, Insightful
The only thing they accomplish is code memory savings.
Ironically enough, this is not really the case for Windows due to a pretty poor (in retrospect) design decision.
Windows supports pageable kernel memory, unlike Linux. This leads to vastly more complexity than Linux (since you *really* don't want kernel code like your paging code, say, to accidently cause a page fault). You also don't want anything that might be involved with paging (want to support a remote pagefile? Hope network support doesn't page! A pagefile on a USB keydrive? You'll need USB code and thus probably power-saving code and so forth to never cause pagefaults). Any *data* touched by any code that can be invoked by a page fault cannot ever be paged out, or else the risk of a hang again appears. Windows maintains different lists of "pageable" and "unpageable" memory.
Linux took a much simpler approach -- kernel memory isn't pageable, but kernel modules can be unloaded -- that increases the simplicity and reliability of kernel code.
Re:Little Help?
by
Typhon100
·
· Score: 3, Insightful
You may not agree with him, but you'd have a tough time arguing he's not a respected researcher. His books are standard texts at many universities...Modern Operating Systems is the one used in the undergrad OS class here at Harvard.
Re:His comment on Slashdot:
by
0x0d0a
·
· Score: 3, Insightful
To be honest, the only times I've read anything directly written by Tanenbaum (and been aware of the fact) was when reading the minor flames between him and Linus and this recent webpage. (My OS class used the "dinosaur book".)
From this tiny dataset, it doesn't really seem that AST is particularly arrogant. I've written much nastier flames than AST did on that infamous occasion. He backs up his claims -- "microkernels are better -- I can say this because I know better than you due to 20 years studying them" would be arrogant. "Microkernels take a relatively minor 20% performance hit or so and provide easier debugging" is a different story.
The flamefest is clearly over.....
by
tiger99
·
· Score: 3, Insightful
..... which must be a good thing for FOSS, Linux and the world at large. Brown may have, by accident, done everyone a big favour here, by forcing Prof. Tannenbaum to say what might otherwise have been left unsaid. We might otherwise imagine that animosity existed when in point of fact it did not.
All due respect to Linus and the Prof, none at all to Brown.
Slashdot Mirror
You know, I think I had AST wrong. I'd seen the thread where he bashes Linus for not doing a microkernel design and thought that maybe it was sour grapes.
His exchanges on this subject have changed my opinion on that. He's been nothing but kind toward Linus, generous with his time, and well-spoken.
If anything good come out of this whole mess, maybe it's that AST really got to show us what he's really like instead of all of us just assuming that he was bitter about the MINIX/Linux history.
You are not a beautiful or unique snowflake -- but you could be if you got off your ass.
This isn't being disingenious, that is a highbrow critique.
If the author was serious then he would have given his "target" - Linus - at least some chance to respond. He didn't. Therefore he isn't a serious author.
Professors generally don't go saying directly, 'that author is such a luuusor dude!' And authors who write trash books about Di aren't exactly people to take seriously either.
This argument was never really a big deal in the first place, it was just a classic arguemnt between a realist and a purist.
>Therefore the only effect Tanenbaum (and Slashdot) gets from this
:)
>document is self-defence and mutual knob-polishery. Not that
>Tanenbaum is entitled to have his say and defend his honor, but there
>you go.
I don't think Tanenbaum loses sleep worrying about the commercial sucess of Linux
I think he was mostly trying to prevent looking like a dick for being associated with that book. Mission accomplished!
Perhaps today he's preaching to the choir, but look at it this way: One of the world's most respected computer scientists just TRASHED the integrity of the guy who interviewed him. I'm sure the whatchamacallit institute will be a long time living this down. And Tanembaum provides lots of nice quotes for the profesional marketers from Red Hat/IBM/Novell/whatever, computer columnists, etc.
I'm posting this as AC since I'll most likely be modded down for touching a "hero" of the Linux revolution:
.very very pleased with himself for having written Minix and fostered the development of Linux.
.
.was never good performance-wise. . .
.and wasn't really good for learning the architecture of an OS either.
.but somehow Tanenbaum feels entitled to think of himself as a pillar of computer science and computer history, and act accordingly.
I've always rather gotten the impression that he was something of the anti-christ of the Linux revolution, and that that's why he has to waste so much time explaining that he and Linus are not enemies.
. .
And says so in the very paper in question.
The trouble is that Minix, which was meant to be an academic OS to study. .
And says so in the very paper in question.
. .
And says so in the very paper in question.
. .
Here I'm sure he'd disagree with you, however, since you leave out why it "wasn't really good" you protect yourself from criticism.
Minix knew success because it was "this other, free Unix for i386" (and some other architectures like the Atari ST), and people could goof around with it for free.
And says so in both papers in question.
That's the extent of Tanenbaum's achievenemts.
And explains that such is not the case in the paper in question.
. .
And not only says so in the paper in question, but points to references should one chose to follow them up. Not to mention the fact that if he were not popularly regarded as such among the computer science community said paper whould have no had raison d'etre in the first place.
Now I shall watch myself be modded down as a troll by Slashdotter who have never met, read about, or listened to him...
As a general rule I find it more responsive to posts such as yours to, well, respond, rather than mod down something just because I might find it unpalatable. An unpalatable point of view is not the same thing as a troll.
I have never met the man, nor listened to him, but I have both read him and read about him. He is a public figure in the computer science community, just as is Linus.
He impresses me, as he appears to impress the orginal poster, as just the sort of intelligently sarcastic "prick," in the Swift/Dickens/Twain/Leacock mode, that I rather enjoy dealing with.
Of course you have to consider the source of that last statement (as one might well consider the source of any), as I myself have been accused, on occasion, of being such a man, and may be merely feeling an affinity of kind.
KFG
> I'll most likely be modded down for touching a "hero" of the Linux revolution:
Tanenbaum is hardly seen as a "hero" in the Linux community, of those who know him at all, most only remember the infamous "Linux is obsolete" flameware on Usenet.
> It's quite well known that Proff Tanenbaum is somewhat of a prick, very very pleased with himself for having written Minix and fostered the development of Linux.
How is this well known? I've never read anything about him boasting about having fostered the development of Linux. He does point out areas where the early Linux was inspired by Minix, but I don't think anyone would dispute that.
> Minix knew success because it was "this other, free Unix for i386"
It was the "free Unix for XT". One of the reasons for Linus to develop Linux was that Minix didn't take advantage of any of the advanced features of the 80386. AST refused almost all suggested improvements, his motivation being that he wanted to teach it in a one semester course.
> That's the extent of Tanenbaum's achievenemts.
Tanenbaum is a university professor. His achievements are his publications in peer reviewed journals, and citations to these publications. Since he has lots of both, he's been pretty successful.
You're right, and indeed I said 'unix' not 'linux'. The whole thing that is both the strenght and the weakness of the 'alternative to windows' is its very nature, the design Philosophy. Open Source most notably. The problem is, everyone has the right and the possibility to make their custom version of an application or even core structure, tweaked to their needs, and this is a Marketing disaster.
Open Source fights itself
If I promote Linux I would have no time to promote OpenBSD, even though in principle I have no reason to dislike openBSD, Im just more familiar with Linux.
The key thing that makes these systems competition to Windows is the way they are designed. Open the source completely thereby both creating a greater likelyhood of dumb mistakes being caught but on the flipside removing the whole 'security by obscurity' concept.
One thing Id like to re-emphasize is that there is Too Much Preaching to the Choir in our circles. I know why I like Linux (etc), Slashdot likes Linux but there are plenty of ignorant (not necessarily because of stupidity) middle-management types that need to be convinced by less formal and more 'shouty' methods.
Linux has far too few scantily clad ladies at the booths in conventions, and too many people who look like Andrew Tanenbaum
Actually, his argument is that a microkernel would make a better early-90s graduate-level compsci project than a conventional monolithic kernel.
He's basically bashing Linus for doing an academically uninteresting project. (Keep in mind that as a professor, he's got the complete UNIX source code at his fingertips - he didn't need a free unix.)
And he was right, but that hasn't stopped damp pantied fanboys from tarring-n-feathering him over the years for arguing with the Great Linus.
Tanenbaum (AST) is a Professor who worked at AT&T and has written many textbooks aimed at university students. AST's most famous book - Operating Systems: Design and Implementation - includes a UNIX-alike operating system called Minix that he wrote himself. Minix includes binaries and source code for the kernel, C library, C compiler, and all the utilities. AST wrote Minix and the book to teach students how operating systems are written. Any computing science student who attended a decent university in the past decade has probably had at least one of AST's books as a required text.
Minix ran on an 8086 and didn't have modern virtual memory (VM) features. When the 80386 came out there were some unofficial patches to make Minix/386. These patches added virtual memory and paging and memory protection, turning Minix into an useful OS. AST refused to add these patches to Minix, rightly arguing that they would make Minix too complex for a student to understand. Minix was a teaching tool, not a general purpose OS, even though Minix/386 was a pretty good general purpose OS. Unfortunately the license back then didn't permit forking. Despite these limitations, Minix had a very large user community. .
When Linus came along and announced Linux a lot of people realised that GNU (basically all of UNIX except for the kernel) and Linux (basically none of UNIX except the kernel) when combined would produce a UNIX-alike operating system. Just like Minix but with VM and the more relaxed GPL for a license. There was no Linux news group so all the discussions were on the Minix news group.
AST put his two cents in on the Linux kernel. He correctly pointed out that the Linux design was a 30 year old monolithic design; not elegant or modern. Linus argued back that monolithic kernels are more practical. AST said Linus would fail his OS class, if Linus was his student. That's the infamous AST/Linus flamewar. It wasn't very hot, as far as flamewars went. AST was right, so was Linus. They just had different perspectives.
Ken Brown is an ignorant idiot who is selling a book claiming that Linus didn't write Linux. He argues that noone could write something so complex as a UNIX-like kernel without stealing code. Ken is under the delusion that writing a UNIX needs a huge team of people working for many years. He seems to be ignorant of the fact that the first UNIX was written by Ken Thompson on a computer so ancient that your wrist watch has more computing power. For "research", Ken Brown spoke to AST. Notably he did not speak to Linus Torvalds. AST is pointing out that Ken is lying in his book; AST has pointed to several examples of single authors who created a UNIX-like kernel, AST included.
The confusion might be that Ken Brown doesn't understand that Linux is just a kernel. The first "Linux" that you ran back in 1991 was actually GNU/Linux. Linux comprised less than 2% of that system. RMS and his team had been working on GNU for nearly a decade by that stage (longer if you count emacs). Linux The Kernel was a small piece of the puzzle. An essential piece, but certainly writable in 6 months by a bright and talented person. These days, Linux is an incredibly tiny piece of a "Linux distribution". Ken Brown might think that Linus is laying claim to the entire system. Of course, Linus has only ever claimed credit for the first kernel. Recent kernels have very little "Linus" in them. And the distro you have on the desktop is less than 1% Linux anyway.
The other theory is that Ken Brown is being paid by SCO/Microsoft/LatestPariah to create FUD over the legal origins of Linux.
I prefer my own theory. Ken wants attention. Saying something ridiculous gets easy attention and increases book sales. We're playing right into his hands by giving him the time of day. It gives him false credibility by creating a "controversy" when in reality there is no controversy. Just Ken saying ridiculous things with no evidence to back them up. It's like all those authors who write books on Noah's Ark, or the location of Atlantis. They must have a huge grin on their face when somebody pays attention to them.
The more I read of Tanenbaum and his work the more I admire him. The fact that he is a Fellow of two prestigious societies says alot about his contributions.
Tanenbaum is a classic academic; he knows where to pick his fights - on the science. He attempts to stay above personalities, but doesn't flinch when it comes to calling bullshit on some dickhead (my words) who is out to smear someone for money.
"Rocky Rococo, at your cervix!"
Careless spelling and careless arithmetic are often indicators of sloppy thinking. They're also impolite -- the rest of us have to think harder than should be necessary in order to take your meaning. Don't be surprised to find that some readers will not put forth the extra effort, when they see that a writer does not put forth even the minimum effort.
And, even if the OS itself was not so good, it doesn't matter, because people often learn the subject from the mistakes, shortcomings.
You may be suffering from the misconception that Minix tried to be, or should have been, a commercial grade Unix workalike. If so you are wrong. When you write software in an academic environment where the goal is to teach students the code should be written with clarity and easy of understanding being paramount. If efficiency or more advanced techniques conflicts with clarity or ease of understanding you should choose the later. The job of the University is to teach core concepts that are long lived and transcend the OS, language, or architecture of the day.
After all, Linus wrote the Linux to improve Minix on Minix.
No. Linux and Minix have different missions. Minix was a teaching tool, it's mission was not to become a full featured Unix workalike. Its goal was to remain small and comprehensible to further its teaching mission. Linux had a very different mission. It is silly to compare the two. Linux is no more of an improvement on Minix than a wrench is an improvement on a screwdriver. Different tools for different jobs, or missions in this case.
The only thing they accomplish is code memory savings.
Ironically enough, this is not really the case for Windows due to a pretty poor (in retrospect) design decision.
Windows supports pageable kernel memory, unlike Linux. This leads to vastly more complexity than Linux (since you *really* don't want kernel code like your paging code, say, to accidently cause a page fault). You also don't want anything that might be involved with paging (want to support a remote pagefile? Hope network support doesn't page! A pagefile on a USB keydrive? You'll need USB code and thus probably power-saving code and so forth to never cause pagefaults). Any *data* touched by any code that can be invoked by a page fault cannot ever be paged out, or else the risk of a hang again appears. Windows maintains different lists of "pageable" and "unpageable" memory.
Linux took a much simpler approach -- kernel memory isn't pageable, but kernel modules can be unloaded -- that increases the simplicity and reliability of kernel code.
May we never see th
You may not agree with him, but you'd have a tough time arguing he's not a respected researcher. His books are standard texts at many universities...Modern Operating Systems is the one used in the undergrad OS class here at Harvard.
To be honest, the only times I've read anything directly written by Tanenbaum (and been aware of the fact) was when reading the minor flames between him and Linus and this recent webpage. (My OS class used the "dinosaur book".)
From this tiny dataset, it doesn't really seem that AST is particularly arrogant. I've written much nastier flames than AST did on that infamous occasion. He backs up his claims -- "microkernels are better -- I can say this because I know better than you due to 20 years studying them" would be arrogant. "Microkernels take a relatively minor 20% performance hit or so and provide easier debugging" is a different story.
May we never see th
All due respect to Linus and the Prof, none at all to Brown.