Linus Torvalds Speaks on the the divide between Rust and C Linux developers an the future Linux. Will things like fragmentation among the open source community hurt the Linux Kernel? We’ll listen to the Creator of Linux.
For the full key note, checkout: Keynote: Linus Torvalds in Conversation with Dirk Hohndel
The Register’s summary: Torvalds weighs in on ‘nasty’ Rust vs C for Linux debate
This video is full of jarring edits which initially made me wonder if someone had cut out words or phrases to create an abbreviated version. But, then I realized there are way too many of them to have been done manually. I checked the full original video and from the few edits i manually checked it seems like it is just inconsequential pauses etc that were removed: for instance, when Linus says “the other side of that picture” in the original there is an extra “p” sound which is removed here.
Yet another irritating and unnecessary application of neural networks, I guess.
Spoken like a wise elder!
If you believe in ADTs, limiting mutation, & a type system that goes beyond Rust’s affine types + lack of refinements (including a interleaved proof system), you could be writing kernel code in ATS which compiles to C.
there have been attempts at writing kernels using stuff like Coq https://www.cs.columbia.edu/~rgu/publications/cacm19-gu.pdf
Correct me if I am wrong, but my understanding is that you use Coq to prove your theroem, then need to rewrite it in something else. I think there is some OCaml integration, but OCaml—while having create performance for a high level language & fairly predictable output—isn’t well-suited for very low-level kernel code. The difference in the ATS case (with the ML syntax similarity 🤘) is you can a) write it all in a single language & b) you can interweave proof, type, & value-level code thru the language instead of separating them; which means your functions need to make the proof-level asserts inside their bodies to satisfy the compiler if written with these requirements, or the type level asserting the linear type usage with value-level requirements to if allocating memory, must deallocate memory as well as compeletly prevent double free & use after free.
For those in the back: Rust can’t do this with its affine types only preventing using a resource multiple times (at most once), where linear types say you must use once & can only use once.
You’r right that only OCaml and Haskell can be used as extraction target for Coq programs. However, it is possible to use Coq to write verified C software. On example is the Verified Software Toolchain that lets you translate C programs to a format that Coq understands and can prove theorems regarding their behavior.
You can’t improve and break silence without discussing and making changes. The existing maintainers won’t live forever, having Rust in the Kernel is a bet on the future. Linus wouldn’t have adopted and accepted Rust, if he wasn’t thinking its worth it. And looks like it was already worth it.
I think you’re correct except for “having Rust in the Kernel is a bet on the future”. That’s something the techbro’s would say.
Do you have something against it? People hate on it like it’s a fad or whatever. But, the people who like it, LOVE it.
Rust is the most admired language, more than 80% of developers that use it want to use it again next year.
https://survey.stackoverflow.co/2023/#overview
Rust is on its seventh year as the most loved language with 87% of developers saying they want to continue using it.
https://survey.stackoverflow.co/2022/#overview
8 years in a row. I can understand the perspective of someone who spent years honing their craft in C/C++ and not wanting to learn a new language. But, the Harassment of the “Rust in Linux Lead” is ridiculous. I’m not saying you are harassing. But, saying it’s a tech bro thing is just negative and doesn’t do justice to how many devs just like rust.
It’s also possible the number of people who like it do not outnumber the people who don’t like it
If anything I think that the current rust discourse is a fad. I’m not sure what it is about rust that makes people have so strong opinions about it but I can’t wait for it to become a “normal” language so that people can chill about it a bit.
I only have something against the syntax, but nothing against anything else about it, nor is my comment meant as a negative against the language. What I referred to was simply about how that stupid sentence is not a good comment and completely personal opinion. I am sure a lot of programming languages would have gotten the same label at one point in time. And many times they have been superseded by the next big thing.
The existing maintainers won’t live forever, having Rust in the Kernel is a bet on the future.
You’re drastically reducing your talent base by requiring membership in two groups of experts. Well done.
The comma splice gives it away, but you’re new at organizing groups and practicing set theory, aren’t you?
No. That does not mean they have to program in both languages. If the programmer only understand one language (which would be a shame), then they only need to program in their field. This increases the talent base, not reduces it. C programmers do not need to be a Rust expert, so what in the world are you saying there? They just need to cooperate!
I took notes for the benefit of anyone who doesn’t like their info in video form. My attempt to summarize what Linus says:
He enjoys the arguments, it’s nice that Rust has livened up the discussion. It shows that people care.
It’s more contentious than it should be sometimes with religious overtones reminiscent of vi versus emacs. Some like it, some don’t, and that’s okay.
Too early to see if Rust in the kernel ultimately fails or succeeds, that will take time, but he’s optimistic about it.
The kernel is not normal C. They use tools that enforce rules that are not part of the language, including memory safety infrastructure. This has been incrementally added over a long time, which is what allowed people to do it without the kind of outcry that the Rust efforts produce by trying to change things more quickly.
There aren’t many languages that can deal with system issues, so unless you want to use assembler it’s going to be C, C-like, or Rust. So probably there will be some systems other than Linux that do use Rust.
If you make your own he’s looking forward to seeing it.
So probably there will be some systems other than Linux that do use Rust.
Isn’t there Redox OS?
Edit: yes, it’s still alive and kicking.
How is it that no matter what the damn topic is, Linus always seems to be the most level-headed in the room? I really admire him for that…
Edit: Lol, Linus, not Linux. Linus. xD
Linus did have emotion control issues and was not always completely rational, but he’s gone a long way towards being incredibly responsible to his child that powers the world.
Also, he long understands that Linux ain’t a hobby project, which some programmers still get to think.
He uses a version of Emacs called MicroEmacs.
I recall seeing his MicroEmacs configuration a while back when I was exploring options to start using Emacs.
TIL that version appears to be on the AUR: MicroEMACS/PK 4.0.15 customized by Linus Torvalds.
Last updated in 2014, it probably has serious cobwebs now. Even the upstream hasn’t been touched in 6 years.
MicroEmacs
In testing, to settle a bet by a rabid cult-of-vi peer, I opened a given set of files in each editor, each a day apart because I couldn’t be arsed to clear caches. This guy, otherwise a prince, was railing about emacs, but otherwise suffered days of waiting.
10/10 the memory usage by his precious vi was same-or-more than emacs.
There’s so many shared libs pulled in by the shell that all the fuddy doomsaying about bloat is now just noise.
I avoid vi because even in 1992 it was crusty and wrong-headed. 30 years on the hard-headed cult and the app haven’t changed.
I don’t see how microEmacs can improve on what we have by default, and I worry that the more niche the product is the harder it will be to find answers online. But I’m willing to be swayed if anyone can pitch its virtues.
If you make your own he’s looking forward to seeing it.
Not a programmer whatsoever but I’ve heard about Zig and people comparing it to Rust, what’s the deal with it?
Zig is indeed designed specifically for such tasks as system programming and interoperability with C code. However it is not yet ready for production usage as necessary infrastructure is not yet done and each new version introduces breaking changes. Developers recomend waiting version 1.0 before using it in any serious project.
Zig is “c”, but modern and safe.
The big selling points compared to Rust are:
- A better syntax
- No hidden control flow
- No hidden memory allocation
- Really great interop with C (it’s almost as if you just include the C code as you would in a C code base…)
- Fast compile time
- it’s more readable
- it’s simpler to learn
The syntax is really close to the C language; any C programmer can pick up Zig really fast.
IMO Zig is a far better choice to go in the kernel than Rust.
Linux has tried to include CPP in it, and it failed.
So imagine if trying to fit in a C-like cousin failed, how far they are to fit an alien language like Rust…
For more information: https://ziglang.org/learn/why_zig_rust_d_cpp/
Zig is a very new and immature language. It won’t be kernel-ready for at l’East another 10 years.
a better syntax
That’s pretty suggestive. Rust syntax is pretty good. Postfix try is just better for example.
Zig also uses special syntax for things like error and nullability instead of having them just be enums, making the language more complex and less flexible for no benefit.
Syntax is also not everything. Rust has extremely good error messages. Going through Zig’s learning documentation, half the error messages are unreadable because I have to scroll to see the actual error and data because it’s on the same line as the absolute path as the file were the error comes from
No hidden memory allocation
That’s a library design question, not a language question. Rust for Linux uses its own data collections that don’t perform hidden memory allocations instead of the ones from the standard library.
it’s more readable
I don’t know, Rust is one of the most readablelangueage for me.
Fast compile time
Is it still the case once you have a very large project and make use of comptime?
it’s simpler to learn
Not true. Because it doesn’t have the guardrails that rust has, you must build a mental model of where the guardrails should be so you don’t make mistakes. Arguably this is something that C maintainers already know how to do, but it’s also not something they do flawlessly from just looking at the bugs that regularly need to be fixed.
Being able to write code faster does not equate being able to write correct code faster.
Really great interop with C
Yes, because it’s basically C with some syntax sugar. Rust is a Generational change.
Zig is “c”, but modern and safe.
Zig is safer than C, but not on a level that is comparable to Rust, so it lacks its biggest selling point. Unfortunately just being a more modern language is not enough to sell it.
So imagine if trying to fit in a C-like cousin failed
C++ was not added to Linux because Linus Torvalds thought it was an horrible language, not because it was not possible to integrate in the kernel.
Linux has tried to include CPP in it, and it failed.
So imagine if trying to fit in a C-like cousin failed, how far they are to fit an alien language like Rust…
But that wasn’t about the syntax, but about the fastnesses, size and control, want it? Things that shouldn’t be much of an issue to Rust.
So probably there will be some systems other than Linux that do use Rust
There’s one called Redox that is entirely written in Rust. Still in fairly early stages, though. https://www.redox-os.org/
Have you actually ever used Ada? It’s like programming with handcuffs on.
I have played with Ada but not done anything “real” with it. I think I’d be ok with using it. It seems better than C in most regards. I haven’t really looked into Rust but from what I can gather, its main innovation is the borrow checker, and Ada might get something like that too (influenced by Rust).
I don’t understand why Linux is so huge and complicaed anyway. At least on servers, most Linux kernels are running under hypervisors that abstract away the hardware. So what else is going on in there? Linux is at least 10x as much code as BSD kernels from back in the day (idk about now). It might be feasible to write a usable Posix kernel as a hypervisor guest in a garbage collected language. But, I haven’t looked into this very much.
Here’s an ok overview of Ada: http://cowlark.com/2014-04-27-ada/index.html
Start the linuxa or alinux project and off you trot. Find a better name than I did here and you’ll be fine.
