Understanding OS X Kernel Internals

jglidell writes "The OS X kernel has been in the news alot this past year, whether it's why its slow, Mach/micro-kernel makes it bad, it's going closed source and what not. Amit Singh has put up a new presentation on the innards of OS X. It does a pretty good job of summing up the OS X kernel architecture, and has some pretty detailed diagrams... for instance they show that there are so many process/threads layers in OS X. So if you are in the mood for doing some OS studying then head over."

Comments

Re:Spelling

[mangu]

"alot" isn't a word! It's "a lot."

I also get kinda pissed off because lotsa people write it that way.

Re:Needs more editor.

[gowen]

I think the problem is that they're not as skilled in writing english as they are in writing PERL.

I've seen slashcode.

I think the problem is that they're exactly as skilled in writing english as they are in writing PERL.

Re:huh?

[M. Baranczak]

Nope, it's still gibberish.

whether it's why it's slow

Well... why is it slow?

Mach/micro-kernel makes it bad

Debating the pros and cons of Mach is a valid topic, but a phrase like this is so vague that it's meaningless.

it's going closed source

OK, that one's intelligible. But then we come across gems like this:

for instance they show that there are so many process/threads layers in OS X.

A small request for submitters: Take a minute to actually proof-read your summary. I'm not even talking about simple typos, or the correct use of "you're/your" - those look ugly, but most of the time people can still figure out what you meant. Just ask yourself: will these words make sense to a moderately intelligent English speaker who's not on a meth bender?

Re:Closed?

[squiggleslash]

Uh, you don't appear to be presenting an argument, you seem to have an unsupported opinion. By the way, your position (not argument) makes sense to you. Yet you have at least two people who appear to disagree with the "logic" which lead you to your position, not that that really matters.

An unsupported opinion is one where facts are not presented that back up the opinion. Disagree with me all you like, but the facts do actually agree with my position, which is why I used them in my argument.

The two people disagreeing with me haven't really given me a reason to change my mind. JCR initially reponded to my argument with responses to a completely different argument (namely that I was expecting Apple to release details about a future product), and then simply implied I was wrong without explaining why. You're doing much the same thing, even accusing me of creating "straw men" in an argument that didn't actually have anything of the sort.

He doesn't need one. He's merely presenting what he sees as relevant facts to the seemingly unreasonable.

If you want to convince someone that their argument is incorrect, then yes, you need a counter argument to it. If I say "1+1=2", then a counter argument "No it isn't" isn't going to convince me otherwise. If you, however, explain your reasoning, I might agree with you if the argument makes sense. Right now, we have a discussion that goes something like this:

Me: 1+1=2
JCR: No, you can't use an assignment operator like that
Me: Erm, I wasn't using it as an assignment operator, if you add one and one, you get two.
JCR: You may get two, that doesn't mean it's the right answer
You: One and one becomes two? I don't think that can possibly work
Me (exasperated to JCR): Can you explain your reasoning?
JCR: I've got 20 years of being a know-it-all. How dare you challenge my foolproof knowledge!
You: Why should he have to explain anything, it's you who's in the wrong, look, two of us disagree with you!

All I've said so far is that:

1. The claim that Apple has said that the source for XNU for Intel is merely delayed is false. The evidence doesn't back that up at all. Apple has made no comment. That's a fact, and the idiot OP who posted otherwise should have been modded to the floor.

2. The fact that Apple has made no comment suggests that the future release of the source code is open to question. There are multiple explanations as to why they'd not have released the source code yet, but right now the most probable are to do with Apple being in a position where they may never release it. If there was no change of policy, if they still expected to release the source code, they'd have no problems saying that. They have no problems confirming they still sell MacBooks. They have no problems confirming iTunes will continue to support iPods.

Now, you and JCR seem to think otherwise, or else you're responding to an entirely different argument (as JCR initially did.) As I've clarified that point to JCR, there's not much excuse for that.

But, whatever, here's the central point: If you disagree with me, explain why. Because I can't change my mind unless you do. If you're just masturbating, posting "No you're wrong" because it turns you on, by all means continue, but there's little point.