Muli Ben-Yehuda's journal

Linus on specifications. All I can say is – amen. The rest of the thread is amusing in a horrifying way, an Adaptec guy ranting and raving and Just Not Getting It. If this is any indication of Adaptec engineers… I know which storage vendor I will not be buying from.

How we do the SW is indeed up to us, but I want to step in on your first point.

Again.

A “spec” is close to useless. I have _never_ seen a spec that was both big enough to be useful _and_ accurate.

And I have seen _lots_ of total crap work that was based on specs. It’s _the_ single worst way to write software, because it by definition means that the software was written to match theory, not reality.

So there’s two MAJOR reasons to avoid specs:

– they’re dangerously wrong. Reality is different, and anybody who thinks specs matter over reality should get out of kernel programming NOW. When reality and specs clash, the spec has zero meaning. Zilch. Nada. None.

It’s like real science: if you have a theory that doesn’t match experiments, it doesn’t matter _how_ much you like that theory. It’s wrong. You can use it as an approximation, but you MUST keep in mind that it’s an approximation.

– specs have an inevitably tendency to try to introduce abstractions levels and wording and documentation policies that make sense for a written spec. Trying to implement actual code off the spec leads to the code looking and working like CRAP.

The classic example of this is the OSI network model protocols. Classic spec-design, which had absolutely _zero_ relevance for the real world. We still talk about the seven layers model, because it’s a convenient model for _discussion_, but that has absolutely zero to do with any real-life software engineering. In other words, it’s a way to _talk_ about things, not to implement them.

And that’s important. Specs are a basis for _talking_about_ things. But they are _not_ a basis for implementing software.

So please don’t bother talking about specs. Real standards grow up _despite_ specs, not thanks to them.

Linus

Mission accomplished. I’m going home now 🙂

My McGuyver.

… and I’m off to the US. That is, unless Rita decides to interfere. See you on the other side!

LibraryThing is awesome. I’m ‘muli’, naturally.

Thanks, ijon!

Guess who’s going to be in town at the same time as the P=ac^2 conference?

So it looks like I’m heading for the US again next week. First a few days in Austin working on Xen related things, and then a week in the NY area working on … other Xen related things.

I don’t know yet how busy this trip will be. Options range from “laid back” to “lock me in the lab until it works”, and are mostly dependent on other people, so we’ll just have to wait and see.

The Haifa Symphony Orchestra will be performing in April my favorite classical work, Carl Orff’s Carmina Burana. I’m so there…

So a Microsoft vendor employee approached ESR, probably because he hasn’t done his homework, and ESR then reacted like a spoiled brat. Read the two emails – I think it’s obvious who’s the bigger fool in this story.

This and Shachar’s entry reminded me that MS tried to recruit me as well a few years ago, before I came to work for IBM at the Haifa Research Lab. I spent a pleasant three hours interviewing at MS for a position as a “full time consultant on the Linux system”, whatever that means (what it probably meant at the time was “how can we learn from Linux and make better products that compete with it?”) . I don’t remember much from the interview, except that I gave an off-the-cuff lecture on the design and implementation of syscalltrack. Hey, they asked 🙂

Eventually I decided that working for MS is not something that I could do with a clean conscience and told them so. Around the same time I accepted IBM’s offer. When MS heard about it, one of the guys who interviewed me, who previously used to work for the lab, called me and passionately tried to get me to change my mind. His main selling point was that IBM research plays, but only at MS do you get to write real software. Considering my usual opinion of MS’s software, I’d say this was an interesting, but less than persuasive, argument…

Is anyone using FitDay.com? I just signed up (too lazy for the alternative, writing my own tracking software), we’ll see how it works out.

The Open Graphics project seems like an interesting way to learn more about hardware design.