Date: Tue, 22 Aug 2000 16:00:52 -0400 From: "Eric S. Raymond" <esr@thyrsus.com> To: Linus Torvalds <torvalds@transmeta.com> Subject: Re: [PATCH] Re: Move of input drivers, some word needed from you Linus Torvalds <torvalds@transmeta.com>: > > > On Tue, 22 Aug 2000, Eric S. Raymond wrote: > > > > Linus Torvalds <torvalds@transmeta.com>: > > > But the "common code helps" thing is WRONG. Face it. It can hurt. A lot. > > > And people shouldn't think it is the God of CS. > > > > I think you're mistaken about this. > > I'll give you a rule of thumb, and I can back it up with historical fact. > You can back up yours with nada. Yes, if twenty-seven years of engineering experience with complex software in over fourteen languages and across a dozen operating systems at every level from kernel out to applications is nada :-). Now you listen to grandpa for a few minutes. He may be an old fart, but he was programming when you were in diapers and he's learned a few tricks... > Face it. Every once in a while, you have to start afresh. Tell people that > "Ok, we can't share this code any more, it's getting to be a major > disaster". I'm not arguing that splitting a driver is always wrong -- I can easily imagine making that call myself in your shoes, and for the exact reasons you give. I'm arguing that the perspective from which you approach this issue causes you to underweight the benefits of sharing code, and to not look for ways to do it as carefully and systematically as you ought. When you were in college, did you ever meet bright kids who graduated top of their class in high-school and then floundered freshman year in college because they had never learned how to study? It's a common trap. A friend of mine calls it "the curse of the gifted" -- a tendency to lean on your native ability too much, because you've always been rewarded for doing that and self-discipline would take actual work. You are a brilliant implementor, more able than me and possibly (I say this after consideration, and in all seriousness) the best one in the Unix tradition since Ken Thompson himself. As a consequence, you suffer the curse of the gifted programmer -- you lean on your ability so much that you've never learned to value certain kinds of coding self-discipline and design craftsmanship that lesser mortals *must* develop in order to handle the kind of problem complexity you eat for breakfast. Your tendency to undervalue modularization and code-sharing is one symptom. Another is your refusal to use systematic version-control or release-engineering practices. To you, these things seem mostly like overhead and a way of needlessly complicating your life. And so far, your strategy has worked; your natural if relatively undisciplined ability has proved more than equal to the problems you have set it. That success predisposes you to relatively sloppy tactics like splitting drivers before you ought to and using your inbox as a patch queue. But you make some of your more senior colleagues nervous. See, we've seen the curse of the gifted before. Some of us were those kids in college. We learned the hard way that the bill always comes due -- the scale of the problems always increases to a point where your native talent alone doesn't cut it any more. The smarter you are, the longer it takes to hit that crunch point -- and the harder the adjustment when you finally do. And we can see that *you*, poor damn genius that you are, are cruising for a serious bruising. As Linux grows, there will come a time when your raw talent is not enough. What happens then will depend on how much discipline about coding and release practices and fastidiousness about clean design you developed *before* you needed it, back when your talent was sufficient to let you get away without. The code-sharing issue -- more specifically, your tendency to abandon modularization and re-use before you probably ought to -- is part of this. Andy Tanenbaum's charge against you was not entirely without justice. The larger problem is a chronic topic of face-to-face conversation whenever two or more senior lkml people get together and you aren't around. You're our chosen benevolent dictator and maybe the second coming of Ken, and we respect you and like you, but that doesn't mean we're willing to close our eyes. And when you react to cogent and well-founded arguments like Rogier Wolff's as you have -- well, it makes us more nervous. I used to worry about what would happen if Linus got hit by a truck. With all respect, I still worry about what will happen if the complexity of the kernel exceeds the scope of your astonishing native talent before you grow up. -- <a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a> "...The Bill of Rights is a literal and absolute document. The First Amendment doesn't say you have a right to speak out unless the government has a 'compelling interest' in censoring the Internet. The Second Amendment doesn't say you have the right to keep and bear arms until some madman plants a bomb. The Fourth Amendment doesn't say you have the right to be secure from search and seizure unless some FBI agent thinks you fit the profile of a terrorist. The government has no right to interfere with any of these freedoms under any circumstances." -- Harry Browne, 1996 USA presidential candidate, Libertarian Party - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/