10mo ago

Linus Torvalds: Speaks on the Rust vs C Linux Divide

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

96 comments

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.
- I took notes for the benefit of anyone who doesn’t like their info in video form.
  I love you.
- This is a great summary. Thanks!
- C, C-like, or Rust
  As always, Ada gets no respect.
  
  Start the linuxa or alinux project and off you trot. Find a better name than I did here and you'll be fine.
  
  Nor does Forth (which used to be a common choice for "first thing to bootstrap on this new chip architecture we have no real OS for yet"). Alas, they're just not popular languages these days.
  
  I blame Ian Dury.
  Possibly NSFW.
  https://www.youtube.com/watch?v=1kFnHPHBcb4
  
  Have you actually ever used Ada? It's like programming with handcuffs on.
  
  This is how they want to frame it. C has footguns, therefore use Rust—instead of Rust is one of the options you could use.
- Good human.
- 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/
- Doing the lord's work, thank you.
- On a tangential note, what does Linus used, Vi or Emacs?
  
  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.
  
  If we can believe random strangers in the internet, then Linus uses a self maintained lighter version of Emacs, or has. Looks like Linus is an Emacs guy.
  
  my money is on vi or vi derivates.
- 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 feasible for systems programming and some, (most notably, the Primeagen in one video) claim it should have gone into the kernel instead of Rust, but I don't know Zig so I don't feel qualified to comment beyond that.
- Thank you for the summary!
- 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.
  
  I think Linus mentioned Redox directly during the interview
- vi versus emacs
  You write "vi versus the world" funny.
  
  I use Micro except for when I forget to install it and can't, at which point I use Nano
  
  it's a polite way of saying, "intelligence vs emacs"
- I think it can be summed up to C is more mature than Rust so we wait for Rust to shine Rust can overcome some complex things in C and vice versa
- Thank you for the write-up!!
- 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.
- Good bot!
- Linus Torvalds has made some interesting comments on the Rust vs C debate in the Linux kernel. He enjoys the discussions because it shows that people care about the project, even though things can get a little heated like the classic vi vs emacs arguments. The Rust conversation is still in its early days, and while Linus is optimistic about its future in the kernel, it’s too soon to say whether it will ultimately succeed or fail.
  He points out that the Linux kernel isn't just "normal" C it's C with additional tools and rules that ensure memory safety and other protections. This incremental approach has allowed for changes without causing the kind of backlash that Rust has faced with its more dramatic changes.
  At the end of the day, the kernel has to deal with system-level issues, and unless you're working in assembly, it’s going to be C, C-like, or Rust. Linus is looking forward to seeing how other systems outside of Linux might adopt Rust for their own needs.
  If you're interested in exploring more of these tech discussions or maybe looking for some related tools, you can download APK for access to various Linux utilities on mobile.
I don't want to watch a video about it.
I'd like to know it, but a couple of sentences wouldn't have hurt
- FWIW, it's a 9 min video and doesn't contain anything earth shattering or easily summarized. Basically there is some friction between C and Rust devs, and Linus doesn't think that it's such a bad thing (there has be interesting discussion) and it's way too early to call Rust in the kernel a failure.
  
  1, 90 or 9 minutes, in any case it needs a speaker to be watched, and often mobile data cap when not at home.
  and a fair amount of rewinds for a lot of non-native english ~~speakers~~ knowers
  
  Thx!
- Rust is harder to write but infinitely safer, and equivalent in speed.
  
  It's harder to write because it forces you to be careful.
- I also dont like videos for this stuff. Summarized using kagi's universal summarizer, sharing here:
  The integration of Rust into the Linux kernel has been a contentious topic, with some long-term maintainers resisting the changes required for memory-safe Rust code.
  The debate over Rust vs. C in the Linux kernel has taken on "almost religious overtones" in certain areas, reflecting the differing design philosophies and expectations.
  Linus Torvalds sees the Rust discussion as a positive thing, as it has "livened up some of the discussions" and shows how much people care about the kernel.
  Not everyone in the kernel community understands everything about the kernel, and specialization is common - some focus on drivers, others on architectures, filesystems, etc. The same is true for Rust and C.
  Linus does not think the Rust integration is a failure, as it's still early, and even if it were, that's how the community learns and improves.
  The challenge is that Rust's memory-safe architecture requires changes to the existing infrastructure, which some long-time maintainers, like the DRM subsystem people, are resistant to.
  The Linux kernel has developed a lot of its own memory safety infrastructure over time for C, which has allowed incremental changes, whereas the Rust changes are more "in your face."
  Despite the struggles with Rust integration, Linus believes Linux is so widely used and entrenched that alternative "bottom-up grown-up from the start Rust kernels" are unlikely to displace it.
  Linus sees the embedded/IoT space as an area where alternative kernels built around different languages like Rust may emerge, but does not see Linux losing its dominance as a general-purpose OS.
  Overall, Linus views the Rust debate as a positive sign of the community's passion and an opportunity to learn, even if the integration process is challenging.
- YouTube has a transcribe feature you could use. Or you could keep scrolling if this content isn't relevant to you.
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.
- 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.
- 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!
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.
- I don't think its completely unnecessary, it helps save some time
Spoken like a wise elder!
What exactly makes rust memory safe? That's the big selling point of it right? Is the compiler just more strict?
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.

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