Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld) [LWN.net]

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 22, 2009 18:20 UTC (Fri) by shmget (guest, #58347)
In reply to: Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld) by tdz
Parent article: Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

one of my favorite quote is:

"it wouldn't surprise me if most of the kernel's code which is not written in an assembly language is written in a GC language one day."

Bear in mind that in context, GC is a place holder for C#

But there are plenty of other gems in that book:

"If Microsoft were to move its important code to C# and the free
software world were to fail to move their code away from C/C++,
Microsoft could leave them in the dust."

"the mainstream media is mostly filled with liberals who push an agenda, and it has been that way for many decades. The bias of the media is one of the great ongoing scandals of our age, in my opinion."

"And while Fox News has higher ratings than CNN and MSNBC
combined, many of the rest of the media have colluded to discredit it
as a mere propaganda arm of the Republican party"

"Barack Obama [...] won
the presidency because journalists fomented anger towards Bush
over the last 8 years"

to post comments

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 23, 2009 13:38 UTC (Sat) by KevinSB (guest, #58750) [Link] (8 responses)

What we think of as Linux will never be written in anything but C? Not even 20 or 50 years from now? Do you have a time machine?

There are a number of OSes that are written entirely in virtual machines, like JavaOS. Sometimes what starts as a research project eventually becomes mainstream.

There are many GC languages other than C#.

If you think the media tell you the truth, you are naive. The bias towards Obama was obvious to anyone with two eyes.

Do you think fox is a propaganda arm of the republicans but MSNBC is accurate?

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 24, 2009 6:42 UTC (Sun) by shmget (guest, #58347) [Link] (5 responses)

"What we think of as Linux will never be written in anything but C?"
No not only C, but assembler too.

"Not even 20 or 50 years from now?"
Well that hold true for almost 40 years now (that OS are mostly written in C or/and in assembler)... pretty sure it will stand for another 20... At the very least - as far as Linux is concerned - for as long as Linus is alive and kicking.

"There are a number of OSes that are written entirely in virtual machines..."
And the virtual machines are written in what ? running on top of what ?

"...like JavaOS. Sometimes what starts as a research project eventually becomes mainstream."

from Wikipedia: "Sun now officially considers JavaOS a legacy system and recommends migration to Java ME.[1] This by itself however is not a full replacement, as Java ME is an API specification, which runs on top of an operating system, and is not an operating system in itself."

So sometimes what start as a research project fail and get abandonned.

"There are many GC languages other than C#."
Read again: "Bear in mind that in context [of the said book] GC is a place holder for C#".
The author clearly establish over the book that 1/ he is confused about the scope of the meaning of GC, and 2/ he clearly meant C# in the context of that quote.

"If you think the media tell you the truth, you are naive. The bias towards Obama was obvious to anyone with two eyes."
8 years ago, Obama was not even on the national political map yet...
beside the ridiculous part of the quote was : "journalists fomented anger towards Bush over the last __8 years__". Please explain where were all these 'anger fomenting journalists' prior to August 2005 ?
I supposed by the same logic, we should blame these pesky journalists at the Washington Post for Nixon unpopularity....

"Do you think fox is a propaganda arm of the republicans"
Yes
"but MSNBC is accurate?"
No

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 24, 2009 11:45 UTC (Sun) by nix (subscriber, #2304) [Link] (4 responses)

"There are a number of OSes that are written entirely in virtual machines..."
And the virtual machines are written in what ? running on top of what ?

Just because an OS is written in a language that usually runs a virtual machine does not necessarily imply that that machine must have any real existence. If you can compile the language down to native code and provide the runtime it expects, you can do away with the VM entirely. (This is exactly what GCJ can do for Java code: SBCL and CMUCL do it for Lisp. Hell, even C has an 'abstract machine' specified by the C Standard: that doesn't mean you need to run it in a VM.)

The hard part is writing the runtime. C#, like Java, has a huge runtime: in practice I'd expect a kernel written in those languages to specify a restricted subset of it that was available in kernelspace, because you'll probably have to reimplement a lot of it in that environment, and it's best to minimize that.

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 24, 2009 19:42 UTC (Sun) by shmget (guest, #58347) [Link] (3 responses)

"The hard part is writing the runtime."
Yes it is.
As a reader of LWN, you surely are aware of the occasional 'dispute' between kernel and gcc, mostly about what is generated by gcc and when.
Kernel programming has some very specific need that are quite irrelevant for user-space programming, but the runtime of C# or Java is rightfully designed with user-space in mind....
So essentially, the only way I could see that working, would be to have a extreme micro-kernel design, whith most of the kernel pushed in user-space. in which case you could envision that only the fundamental core of the micro-kernel is in C/assembler, and the rest in ... something else.
But at that point that would not be 'what we think of linux' anymore.

Maybe, one day, micro-kernel will get out of the research labs, and become practical in real-life... But again, Tanenbaum famously claimed that Linux design was obsolete... in January 1992. 17 years later and the obsolete Linux is alive and kicking, while micro-kernels are still PhDs' pet projects.

Another argument against GC is that someone that is too lazy or too stupid to be bothered with what a pointer is, should stay away from the kernel.

In user-space I've seen modules, in C, that were operating in O(n), being re-implemented in Java and ending-up in O(n^2) because the Java developer had no idea of the consequences of his disregard for memory management issues. (note: I believe that Java bad performance reputation is not so much an inherent problem with Java itself, but mostly due to brain-dead programmer. Java's fault is to make it so easy to hide the crap under the GC carpet.)

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 25, 2009 15:42 UTC (Mon) by nix (subscriber, #2304) [Link]

Another argument against GC is that someone that is too lazy or too stupid to be bothered with what a pointer is, should stay away from the kernel.

That's a bad argument. The real benefit of GC isn't when the programmer doesn't know what a pointer is: it's when the data structures are elaborate enough that doing C-style owner-frees is difficult to impossible because it is not clear enough who the 'owner' is. I'm not sure if the kernel's data structures are that complex: I guess not. GCC's definitely are: a huge number of bugs and leaks vanished when the (handrolled) garbage collector went in in GCC 3.0. (Unfortunately locality of reference suffered compared to obstacks, damaging performance: so some of the subsets of the compiler's data structures which *do* have simple ownership patterns have been moving back into obstacks again.)

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 26, 2009 19:14 UTC (Tue) by Wol (subscriber, #4433) [Link] (1 responses)

Linux will *always* kick ass over microkernels on x86. I've used Primes, which had a very fast ring-switching architecture. That WAS a micro-kernel (of sorts) - a lot of the OS that was user support ran in ring 2.

x86 can't ring-switch to save its life. They were planning to implement Primos on x86, but that's what killed it :-( the lack of fast switching.

Linux is a macrokernel that thinks it's a mcirokernel (linux is modular, that's a microkernel design). Everything is compiled into one "monolithic" lump that runs in ring 0 - that's a macrokernel.

Ring switching would cripple x86 performance if all the modules were pushed out of ring 0. The Prime 50-series could ring-switch at the same speed as a non-switch call. Unix only uses two rings (by design, and linux is the same because it would be a nightmare to change). Primos ran the microkernel in ring 0, a lot of user-support in ring 2, and left ring 3 to user-space code (can't remember what it did with ring 1 :-)

Oh, and like Unix, Primos was a Multics derivative :-)

Cheers,
Wol

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 26, 2009 22:30 UTC (Tue) by dlang (guest, #313) [Link]

linux is modular (i.e. you can add in or remove features), but the different components do _not_ communicate with each other via messages, they do so by sharing the same address space. it's not just running in the same ring.

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 24, 2009 10:32 UTC (Sun) by tdz (subscriber, #58733) [Link] (1 responses)

Before commenting, I think you should really look into the book, if you havn't done so. Quoting from page 170:

> In addition to knowing what memory is in use, a GC system knows
> the size of every buffer, and so can validate all reads and writes to
> memory.

Wrong, but the book is full of such statements. This concrete chapter is about reliability, but even for systems which do the described boundary checking, Mr. Curtis doesn't say how this helps building more reliable applications (not to speak of operating systems).

The author demonstrates that he has only a vague understanding of what garbage collection means, what it can do, and what it can _not_ do.

Regarding politics he writes on page 266:

> This book is about free software, but I'd like to end with a few
> words on a free press, free markets and a few other issues.
> [...]
> Reviewers told me that this material belongs in another book, but
> the problem is that everything here has already been written it
> just hasn't been read and accepted yet! If we knowledge technolo-
> gists are to become the dominant political force, then there are a
> few things I think we should understand.

For the rest of the chapter he pushes his hardcore-conservative opinions.

Whatever you think of his opinion, I hope you agree with me that the Free-Software movement is not primarily a political one. Given that, I hope you also agree that politics do not belong into such a book, as long as they do not relate to Free Software directly.

Regards

Ex-Microsoftie: Free Software Will Kill Redmond (ComputerWorld)

Posted May 24, 2009 11:48 UTC (Sun) by nix (subscriber, #2304) [Link]

"If we knowledge technologists are to become the dominant political
force", wow. I thought I knew some egotists but that is just stunning. Of
*course* computing is more important than everything else humanity does so
it deserves to be 'dominant', except for the water and power grids oh and
I suppose we need food and transport would be nice and the communications
infrastructure isn't 'knowledge' either and so on...

This guy has definitely been drinking the Kurzweil kool-aid.