Linus Torvalds Will Answer Your Questions

Linus Torvalds was (and still is) the primary force behind the development of the Linux kernel, and since you are reading Slashdot, you already knew that. Mr. Torvalds has agreed to answer any questions you may have about the direction of software, his thoughts on politics, winning the Millenial Technology Prize, or anything else. Ask as many questions as you'd like, but please keep them to one per post. We'll send the best to Linus, and post his answers when we get them back. Remember to keep an eye out for the rest of our upcoming special interviews this month.

Comments

Your 2007 Comments on C++

[eldavojohn]

In 2007 you made some rather polarizing remarks about C++. Coincidentally, Slashdot absolutely loves language wars and I seem to only find evidence that you use C based on the lack of malice and contempt I can find you publicizing on it. Do you find anything terrible about C? Conversely, do you have anything nice to say bout C++, Java, Ruby, Perl, JavaScript, Lisp, Prolog, Microsoft's languages or any other language you feel particularly vehement about at the moment?

Re:Your 2007 Comments on C++

[i_ate_god]

what about PHP?

Re:Your 2007 Comments on C++

[Anonymous Coward]

This site you link to is mostly gibberish. Linus is more concise and a much better writer.

This author views it as a logical fallacy for Linus to say that C++ is terrible because terrible programmers use it. I think to call that a "logical fallacy" misses the point - the point that in practice, it's actually true.

The idea that criticism of common practice in the C++ community comes from ignorance is also kind of amusing. I'm no stranger to C++ personally, there are things that are great about it. I dig that templates can generate good machine code while still allowing generics at the source code level (much better performance than doing generics with function pointers and void*, like libc's qsort for example). I think RAII is great and it's interesting that the technique replicates some of the practices I already do in my C code, but with less room for programmer error. That's all good. I'm a fan of some of what C++11 brings to the table, lambdas are nice, it's good to have the whole "move semantics" to fix those annoying issues with copy constructors getting called more than they ought to.

At the same time in my career I haven't worked with any programmers who understand these points and what they mean. I mean, I know that the "good" C++ programmers are somewhere, I see them occasionally make intelligent points on forums or hear them give talks about C++11. But I never seem to work with these people. Instead what I get are either (1) people writing C++ with a Java accent, or (2) people writing C++ with a C accent. In both cases they tend to do this poorly. The results are pretty crap to work with.

Yes there is bad C code out there, like there is bad code in every language. The mplayer example is fair. But I don't think that's as fundamental to the language as inefficient use of STL is. How many times have you seen a programmer introduce tons of heap allocations or copies without realizing it, due to un-careful use of STL? That's a problem that C has a lot less of. Sticking to a simple language to avoid those issues doesn't seem that unreasonable to me, especially in a development model where people contribute from all over, and being able to quickly audit for bad practices is important.

A Helsinki Finn in King Dubya's Court

[eldavojohn]

Despite your accomplishments and some of your public comments about the dire state of American politics, you remain a resident of the United States of America. Clearly you have the clout to live where you please, why do you continue to reside in the United States? Assuming your answer is simply "work", if there was one thing you could change in the United States what would it be and are you doing anything to move toward that accomplishment (aside from procreating and trying to help us out that way)?

When I'm designing a processor for Linux....

[Art Popp]

I spend some time designing things in Verilog and trying to read other people's source code at opencores.org, and I recall you did some work at Transmeta. For some time I've had a list of instructions that could be added to processsors that would be drastically speed up common functions, and SSE 4.2 includes some of my favorites, the dqword string comparision instructions. So...

What are your ideas for instrructions that you've always thought should be handled by the processor, but never seen implemented?

Books, Books, Books

[eldavojohn]

As a software developer, I have a coveted collection of books. A few of said tomes -- both fiction and non -- have fundamentally altered the course of my life. Assuming yours aren't just man pages and .txt files, what are they?

Aging and low-level programming...

[jasno]

Hi Linus! Thanks for everything!

How has getting older and raising a family changed the way you look at kernel work and programming in general? Do you see yourself still being involved in the kernel in 20 years? Do you ever just want to take a break for a few years, or do you feel like your time working on the kernel is a rest from the real world?

Avoiding the Unix Wars

[dkleinsc]

Why do you think Linux has been able to (mostly) avoid the fragmentation that plagued the competing Unixes of the 1980's? What would you say helps keep Linux a unified project rather than more forked system like BSD?

general-purpose computing

[Type44Q]

Linus, what are your thoughts re: the coming war on general-purpose computing?

PS: Thank you for everything you've done, and continue to do (the world is actually full of heroes but the vast majority of them - at least in this day and age - have limited spheres of influence. You on the other hand...) ;)

Any wisdom for students and early-career techies?

[davidwr]

If you could give one piece of technical advice and one piece of non-technical advice to students seeking a technical career and/or early-career tech professionals, what would it be?

Cooles

[needs2bfree]

What is the coolest thing that you have heard of people doing with Linux recently?

Monolithic vs. Micro-kernel architecture

[NoNeeeed]

Has there ever been a time in the development of the Linux Kernel where you've wished you'd gone the Hurd-style micro-kernel route espoused by the like of Tannenbaum, or do you feel that from an architectural standpoint Linux has benefitted from having a monolithic design?

Linux has been massively more successful than Hurd, but I wonder how much of that is down to intrinsic technical superiority of its approach, and how much to the lack of a central driving force supported by a community of committed developers? It always seemed like the Hurd model should have allowed more people to be involved, but that has never seemed to be the case.

GIT

[vlm]

If you had to do GIT over again, what, if anything, would you change?
VERY closely related question, do you like the git-flow project and would you think about pulling that into mainline or not?

Android

[Jacek Poplawski]

What is your current opinion on Android? Do you consider Android as a "Linux", "Linux type" or "Linux child"? Are you connected somehow with Android development?

favorite hack

[vlm]

I asked a bunch of hard architecture questions, now for a softball Q. Your favorite hack WRT kernel internals and kernel programming in general. drivers, innards, I don't care which. The kind of thing where you took a look at the code and go 'holy cow thats cool' or whatever. You define favorite, hack, and kernel. Just wanting to kick back and hear a story about cool code.

Simple: Microsoft

[ThatsNotPudding]

Tell me how can we defeat UEFI and 'Windows Only' ARM devices?

Re:The End

[Narnie]

Speaking of ends, one day you'll pass on your duties. How do you envision the kernel and the Linux ecosystem after passing your reigns?

How do you deal with burn-out?

[kallisti5]

You must of been burned out on Linux kernel development multiple-times over by now... how do you deal with it?

Re:The Absolute Death of Software Copyright?

[hairyfeet]

That sounds like a question more for Perens than for Torvalds.

My question for Torvalds would be thus: Now that all mainstream OSes other than yours, BSD, Solaris, OSX, Windows, have a stable ABI to help make sure that drivers continue to work why do you think your way is better than all those other OSes? How can the kernel devs do QA and QC for tens of thousands of drivers when there are so few of you, so many drivers, and such a hectic release schedule? Why is an ABI such a bad thing when it seems to work for everybody else? If it is because you hope to use lack of an ABI to force drivers to be open what do you say to the fact that the most stable graphics driver in Linux is Nvidia, who is closed?

If you are gonna ask the man questions don't play pattycake and throw softballs, give him the hard ones. While I'm sure to be modded down for asking the hard questions and I doubt anybody would have had the guts to ask him I for one would have liked to have seen if he had a truly legitimate answer or if it would have boiled down to dogma or "If things are stable then i can't tweak all I want" instead of having a legitimate programming reason why he thinks his design is better than everyone else on the planet.