Just wait [LWN.net]

Just wait

Posted Jun 22, 2024 10:54 UTC (Sat) by wsy (subscriber, #121706)
Parent article: Rust for filesystems

Sometimes it's just easier to wait until older guys retire than to convince them to adapt to new way of doing things.

Just wait

Posted Jun 22, 2024 12:08 UTC (Sat) by willy (subscriber, #9762) [Link] (20 responses)

https://en.wikipedia.org/wiki/Planck%27s_principle

"Science advances one funeral at a time"

I'm disappointed by how resistant some fellow hackers are to Rust. It's the first language in 50 years to be enough of an advantage over C to be worth switching to.

Just wait

Posted Jun 22, 2024 12:37 UTC (Sat) by liw (subscriber, #6379) [Link] (17 responses)

If it were only a matter of teaching kernel hackers the Rust language, that'd be a solvable problem. (I say, as someone who does Rust training for free and for money.) But I fear there's usually more resistance to change than just having to learn a new language or a new tool.

Just wait

Posted Jun 23, 2024 8:52 UTC (Sun) by Wol (subscriber, #4433) [Link] (3 responses)

> But I fear there's usually more resistance to change than just having to learn a new language or a new tool.

It usually involves changing your entire way of thinking.

Look at that post a few days back over P4 - where the comment was "someone comes along thinking they can rewrite it in C", and several man-years of effort later, they realise that actually, someone using a domain specific language can do double the work in half the time, if not even better.

Going back even further, someone commented people who've learnt Rust usually make far better C programmers because, even though C doesn't enforce memory safety etc, because Rust insists that you code in memory-safe ways, they code memory-safe in C anyways.

It's like me and databases - 4th normal form is the best for a whole bunch of reasons, but because my experience is with a database where 4th normal form was the OBVIOUS way to do it, when I'm forced to work with relational I do it without thinking. Unfortunately I'm usually working with stuff designed by others where I'm thinking "what the hell were they thinking?".

Cheers,
Wol

Just wait

Posted Jun 23, 2024 17:48 UTC (Sun) by Kaligule (guest, #167650) [Link] (2 responses)

Please, what is P4?

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Posted Jun 23, 2024 19:37 UTC (Sun) by softball (subscriber, #160655) [Link]

They are possibly referring to: https://lwn.net/Articles/977310/

P4

Posted Jun 24, 2024 22:04 UTC (Mon) by riking (subscriber, #95706) [Link]

https://p4.org/ is a programmable packet processing specification language. You use it to write firewall or routing rules, or queue dropping priorities, or whatever the hardware of the router you bought allows you to load a P4 program to do.

Just wait

Posted Jun 25, 2024 13:36 UTC (Tue) by zuki (subscriber, #41808) [Link] (12 responses)

I find the attitude of "I don't care about Rust, I'll not learn Rust" annoying and destructive.

There's also the distinction that there are different levels of "knowing" a language. It's quite easy to get to the level where one can do small modifications to existing code, or to copy existing functionality and extend it to cover additional cases. It's much harder to know which of the many possible ways of structuring code and which abstractions to use for a new problem. But fortunately, for ongoing maintenance, this first easier level is all that is needed. The second higher level is only necessary e.g. to implement or review new Rust abstractions in the kernel or new drivers, but a different set of people can handle that.

I think it's entirely reasonable to ask maintainers to also care about the Rust code.

Just wait

Posted Jun 25, 2024 14:36 UTC (Tue) by pizza (subscriber, #46) [Link]

> I think it's entirely reasonable to ask maintainers to also care about the Rust code.

I agree in principle -- but we're a long, long way from the "ongoing maintenance" phase.

The current status quo is that, in order to meaningfully contribute to kernel-Rust, you have to essentially be an expert in all-things-Rust, including living on the bleeding edge of Rust language/feature development.

> I find the attitude of "I don't care about Rust, I'll not learn Rust" annoying and destructive.

You may find it annoying but it is an entirely rational (and reasonable!) attitude to take given that hyper-unstable nature of kernel-Rust and the already-overwhelming "just maintaining existing stuff" workload.

After all, "Let those who care about X do the work" has been the kernel development philosophy since approximately forever.

Just wait

Posted Jun 25, 2024 14:51 UTC (Tue) by somlo (subscriber, #92421) [Link] (5 responses)

Having never used the Go language, I managed to "cut'n'paste" my way into writing a useful (and also stylistically and functionally correct) patch against Docker. So in principle you *should* be right about your first level of "knowing" a language concept.

However, unlike Go, I find Rust hard to skim over -- for the lack of a better word, it's too "syntax-y" for my brain :) So your "anyone should be able to deal with it" statement is actually a much bigger ask than you think, depending on the actual language's legibility to newcomers.

I then tried working my way through "The Rust Programming Language", and was mostly able to follow along and understand what's going on, and even managed to write ok-ish small programs in the process.

But without being a real, $DAYJOB Rust programmer, when I look at production code a few months later, it's back to a wall-of-syntax "foo::bar => <blah:::xyz>" incomprehensible gibberish... :D
This may be just an undiagnosed learning disability on my part, or it might be that Rust syntax is simply less legible to a large swath of the otherwise OK programmer population.

I'm also constantly high-key annoyed at how compiling a program involves downloading crap off the Internet, as part of the compilation process (this is the part where I might just be old and grumpy, and the whole download-crap-from-the-Internet thing is interfering with my lawn care routine).

Anyhow, if kernel maintainers' experience is anything like mine, I can't blame them for putting a "low pass filter" on this thing: maybe it goes away if they ignore it long enough, and they won't have to waste time on it.

Now, if based on the description of my pain points above there's a more targeted way of learning Rust in a way that sticks, I'm happy to take hints and advice...

Just wait

Posted Oct 15, 2024 13:46 UTC (Tue) by Rudd-O (guest, #61155) [Link] (1 responses)

> "foo::bar => <blah:::xyz>" incomprehensible gibberish... :D

I found this exceedingly difficult to wrap around, the `match` and `if let` constructs felt backwards in a very weird way.

I got used eventually, but it was a solid month until it "clicked".

Now it annoys me that other languages don't do this.

Just wait

Posted Oct 16, 2024 8:20 UTC (Wed) by taladar (subscriber, #68407) [Link]

It is the way the order of those statements work in all languages I am aware of, from simple assignments over destructuring bind in Common Lisp and pattern matching in languages like Haskell.

Just wait

Posted Jan 19, 2026 10:47 UTC (Mon) by taladar (subscriber, #68407) [Link]

Interestingly enough I have the opposite experience. Go is extreme gibberish because it is so hard to spot the actual high-level flow among the sea of virtually identical copies of low level concerns in the code.

Rust on the other hand is quite clear and readable 99% of the time because it has very little of this accidental complexity all over and where it does it often isn't essential to understanding what the code is trying to do.

Just wait

Posted Jan 19, 2026 16:01 UTC (Mon) by Wol (subscriber, #4433) [Link]

> This may be just an undiagnosed learning disability on my part,

Probably unlikely

> or it might be that Rust syntax is simply less legible to a large swath of the otherwise OK programmer population.

Far more likely. The brain acquires a whole lot of abilities as it matures, and there are things that are just incomprehensible to people too young to understand it. Seeing as this acquisition stops at various stages along the path for different people, for some people "too young" maybe under 14, for others "too young" means forever.

The number of people who can't get to grips with eg Lisp (me), Haskell (lots of people, I haven't tried), Rust (I get the impression that's not too bad if $DAYJOB), yup, there are some things people just can't get because they're not old enough to have acquired the ability :-)

(Fortran, C, that sort of stuff, that's basically how we're taught Maths in Primary School! :-)

Cheers,
Wol

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Posted Jan 19, 2026 16:22 UTC (Mon) by dskoll (subscriber, #1630) [Link]

I also find Rust incomprehensible, but I suspect that is because I retired from software development 3 years ago and I have no motivation to learn it. If I had to learn it for a job, I'm fairly sure I could pick it up.

Changing code when you barely understand the language

Posted Jun 25, 2024 15:40 UTC (Tue) by farnz (subscriber, #17727) [Link]

The other thing to bear in mind is that different languages have different challenge levels when you're not very good at them. At one extreme, you have languages where just about everything you could reasonably consider "language source code" is accepted by implementations as "valid" code, and if you barely understand the language, it's really hard to avoid making mistakes.

At the other extreme, you have languages where the compiler will definitely complain if you make a change that won't work, and thus it's a lot easier to avoid making mistakes because the compiler tells you that what you've implemented is not going to work.

And in the middle of those two extremes, we have real languages, where some things that won't work cause the compiler to complain (such as including a file that doesn't exist like #include <linus/asm.h>), while other things that won't work compile and fail later.

The interesting question is whether Rust is strict enough that someone with good C skills and minimal Rust skills can be confident that the Rust toolchain will complain if they make the "obvious" fix, but it's wrong, or whether they have to learn more Rust so that they can do the checks themselves (or ask someone else to check their work).

Just wait

Posted Jul 4, 2024 2:23 UTC (Thu) by mrugiero (guest, #153040) [Link]

> I think it's entirely reasonable to ask maintainers to also care about the Rust code.

I'm not sure if I'm inventing this, but I believe the deal was that maintainers got to decide whether Rust made it into in their subsystems? If that's the case, it's only reasonable to expect them to either reject the patches or commit to keep them working. Otherwise we're in a kind of Seinfeld's car reservation situation.

Just wait

Posted Jul 17, 2024 12:19 UTC (Wed) by that_kca (guest, #172467) [Link] (2 responses)

> I find the attitude of "I don't care about Rust, I'll not learn Rust" annoying and destructive.

I mean is it any more annoying or destructive than the "Everything must be written in rust" evangelism that many of the rust fans parrot?

I imagine if rust spent less of the design/engineering points in being hard to learn the language might find more people willing to pick it up.

But then the majority of the rust internet community would probably run to something else.

Just wait

Posted Jul 17, 2024 13:40 UTC (Wed) by Wol (subscriber, #4433) [Link] (1 responses)

> I mean is it any more annoying or destructive than the "Everything must be written in rust" evangelism that many of the rust fans parrot?

Rust FANS, or Rust PROGRAMMERS.

Generally you'll find the people who make the most noise, are the people who do the least work. That's not always a bad thing, you need your evangelists (after all, I make a heck of a lot of noise about Pick/MV), but there are too many people who think it's a silver bullet when they've never really used it.

It DOES sound great. And given that all the evidence says it's not vulnerable to a huge class of errors that regularly bite C/C++, there's good reason to - as a minimum - try it out. But it's noticeable that a lot of people are too busy using it to evangelise it. That to me is a good sign.

Cheers,
Wol

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Posted Jul 17, 2024 16:55 UTC (Wed) by andresfreund (subscriber, #69562) [Link]

Wol. You regularly post close to half of the comments here. I'd appreciate if you could try to appreciate the perspective of the readers of the comment section into consideration a bit more. Nobody writes *that* much interesting stuff.

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Posted Jun 22, 2024 14:05 UTC (Sat) by khim (subscriber, #9252) [Link] (1 responses)

> It's the first language in 50 years to be enough of an advantage over C to be worth switching to.

Sure, but the flip side is that it is the first language in 50 years that offers genuine advantage large enough to switch.

The only way to convince people to switch is to write more good Rust code, ultimately.

Just wait

Posted Jun 22, 2024 14:21 UTC (Sat) by adobriyan (guest, #30858) [Link]

> The only way to convince people to switch is to write more good Rust code, ultimately.

Just imagine what bug-for-bug compatible Linux.rs kernel could do...

Just wait

Posted Jan 16, 2026 23:00 UTC (Fri) by georgh-cat (guest, #158897) [Link]

I just rewatched in youtube, and it was really really painful to see all that harsh reaction for people that I admire for their kernel work.

You might be right.

So sad.