Posted Nov 17, 2011 21:57 UTC (Thu) by khim
In reply to: Interview with Andrew Tanenbaum (LinuxFr.org)
Parent article: Interview with Andrew Tanenbaum (LinuxFr.org)
On what planet does he spend most of his time?
Ivory tower^Wplanet, apparently.
You see: AT has this insanely great answer (it's not 42 but MINIX for a change). Now he just need to find the question.
Some strange suggestions:
There are a lot of applications in the world that would love to run 24/7/365 and never go down, not even to upgrade to a new version of the operating system.
This is valid concern but all these application are legacy code which was written in time when hardware was large, expensive and reliable. Today you achieve the same thing with redundancy and distributed computing. And legacy code can not use MINIX anyway so... what's the point?
What most ordinary users want is that it ALWAYS works. In engineering terms I would say this could be expressed as mean time to failure of 50 years.
Well, this is big problem, true. When activity manager in Android or Compiz on desktop decide to wreak havoc - this is big issue. Ah, you mean you are trying to fix problems in kernel which brings about 1% of problems to "ordinary users"? Well... this is novel idea, I'll grant you that - but how wise it is?
If you want to change the memory manager, only one module is affected. Changing it in Linux is far more complicated because it is all spaghetti down there.
And this is really, really, REALLY important. People want to change memory manager every five minutes. But they never plug USB handsets, never play 3D games, never run heavy SMP databases on these 24/7/365 systems, you know. These things are trivial in comparison.
L4 is very successful. Gernot Heiser in Australia managed to sell it to Qualcomm, so it is now running on 300 million phones in the world. Not bad for a microkernel. The biggest difference is that we run the entire operating system as a collection of servers in userland. They mostly run Linux as a whole unit in userland. This means that a single bug in Linux can crash Linux.
In other words: we've created enormous buzz around the microkernels and managed to shove useless piece of software in millions of mobile phones and desktops (see MacOS X). Now we have this great success which combines worst qualities of microkernel and monolithic kernel.
One thing I would like is that when microkernels take over the world, which I fully expect, is that we at least get a footnote.
Yeah, because it sure will be a pity to admit that we spent last 20 years on dead end.
Being ahead of your time is never good. I published a paper in 1978 on something very close to the Java Virtual Machine, but we never got much credit for it although we were years ahead of Sun.
I like this one the best: when AT tries to explain why his current ideas will take over he uses another, earlier idea, which failed to take the world over as well. Just like L4 in example above JVM was oversold and pushed around where it was not really needed till Sun just simply run out of money.
to post comments)