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Some parts of the industry with a lot of money and influence decided this is the way forward. IMHO Rust has the same issue as C++: it is too complex and a memo

by uecker 1y ago

Some parts of the industry with a lot of money and influence decided this is the way forward. IMHO Rust has the same issue as C++: it is too complex and a memory safe C would be far more useful. It is sad that not more resources are invested into this.

gpm 1y ago
I'm entirely unconvinced that a low-level† memory safe C that is meaningfully simpler than rust is even possible, let alone desirable. IMHO Basically all of rust's complexity comes from implementing the structure necessary to make it memory safe without making it too difficult to use††. Even if it is though, we don't have it. It seems like linux should go with the solution we have in hand and can see works, not a solution that hasn't been developed or proved possible and practical. Nor is memory safety the only thing rust brings to the table, it's also brings a more expressive type system that prevents other mistakes (just not as categorically) and lets you program faster. Supposing we got this memory safe C that somehow avoided this complexity... I don't think I'd even want to use it over the more expressive memory safe language that also brings other benefits. † A memory-safe managed C is possible of course (see https://fil-c.org/ https://fil-c.org/), but it seems unsuitable for a kernel. †† There are some other alternatives to the choices rust made, but not meaningfully less complex. Separately you could ditch the complexity of async I guess, but you can also just use rust as if async didn't exist, it's a purely value added feature. There's likely one or two other similar examples though they don't immediately come to mind.
- uecker 1y ago
  I don't think so. First, Rust did not come from nowhere, there were memory safe C variants before it that stayed closer to C. Second, I do not even believe that memory safety is that important that this trumps other considerations, e.g. the complexity of having two languages in the kernel (even if you ignore the complexity of Rust). Now, it is not my decision but Google's and other company's influence. But I still think it is a mistake and highlights more the influence of certain tech companies on open source than anything else.
  - gpm 1y ago
    > First, Rust did not come from nowhere, there were memory safe C variants before it that stayed closer to C. Can you give an example? One that remained a low level language, and remained ergonomic enough for practical use? > Second, I do not even believe that memory safety is that important that this trumps other considerations In your previous comment you stated "a memory safe C would be far more useful. It is sad that not more resources are invested into this". It seems to me that after suggesting that people should stop working on what they are working on and work on memory safe C instead you ought to be prepared to defend the concept of a memory safe C. Not to simply back away from memory safety being a useful concept in the first place. I'm not particularly interested in debating the merits of memory safety with you, I entered this discussion upon the assumption that you had conceded them.
    - Jweb_Guru 1y ago
      > Can you give an example? One that remained a low level language, and remained ergonomic enough for practical use? They can't, of course, because there was no such language. Some people for whatever reason struggle to acknowledge that (1) Rust was not just the synthesis of existing ideas (the borrow checker was novel, and aspects of its thread safety story like Send and Sync were also AFAIK not found in the literature), and (2) to the extent that it was the synthesis of existing ideas, a number of these were locked away in languages that were not even close to being ready for industry adoption. There was no other Rust alternative (that genuinely aimed to replace C++ for all use cases, not just supplement it) just on the horizon or something around the time of Rust 1.0's release. Pretty much all the oxygen in the room for developing such a language has gone to Rust for well over a decade now, and that's why it's in the Linux kernel and [insert your pet language here] is not. BTW, this is also why people being are incentivized to figure out ways to solve complex cases like Rcu-projection through extensible mechanisms (like the generic field projection proposal) rather than ditching Rust as a language because it can't currently handle these ergonomically. The lack of alternatives to Rust is a big driving factor for people to find these abstractions. Conversely, having the weight of the Linux kernel behind these feature requests (instead of e.g. some random hobbyist) makes it far more likely for them to actually get into the language.

by uecker 1y ago

gpm 1y ago

I'm entirely unconvinced that a low-level† memory safe C that is meaningfully simpler than rust is even possible, let alone desirable. IMHO Basically all of rust's complexity comes from implementing the structure necessary to make it memory safe without making it too difficult to use††. Even if it is though, we don't have it. It seems like linux should go with the solution we have in hand and can see works, not a solution that hasn't been developed or proved possible and practical. Nor is memory safety the only thing rust brings to the table, it's also brings a more expressive type system that prevents other mistakes (just not as categorically) and lets you program faster. Supposing we got this memory safe C that somehow avoided this complexity... I don't think I'd even want to use it over the more expressive memory safe language that also brings other benefits. † A memory-safe managed C is possible of course (see https://fil-c.org/ https://fil-c.org/), but it seems unsuitable for a kernel. †† There are some other alternatives to the choices rust made, but not meaningfully less complex. Separately you could ditch the complexity of async I guess, but you can also just use rust as if async didn't exist, it's a purely value added feature. There's likely one or two other similar examples though they don't immediately come to mind.

uecker 1y ago
I don't think so. First, Rust did not come from nowhere, there were memory safe C variants before it that stayed closer to C. Second, I do not even believe that memory safety is that important that this trumps other considerations, e.g. the complexity of having two languages in the kernel (even if you ignore the complexity of Rust). Now, it is not my decision but Google's and other company's influence. But I still think it is a mistake and highlights more the influence of certain tech companies on open source than anything else.
- gpm 1y ago
  > First, Rust did not come from nowhere, there were memory safe C variants before it that stayed closer to C. Can you give an example? One that remained a low level language, and remained ergonomic enough for practical use? > Second, I do not even believe that memory safety is that important that this trumps other considerations In your previous comment you stated "a memory safe C would be far more useful. It is sad that not more resources are invested into this". It seems to me that after suggesting that people should stop working on what they are working on and work on memory safe C instead you ought to be prepared to defend the concept of a memory safe C. Not to simply back away from memory safety being a useful concept in the first place. I'm not particularly interested in debating the merits of memory safety with you, I entered this discussion upon the assumption that you had conceded them.
  - Jweb_Guru 1y ago
    > Can you give an example? One that remained a low level language, and remained ergonomic enough for practical use? They can't, of course, because there was no such language. Some people for whatever reason struggle to acknowledge that (1) Rust was not just the synthesis of existing ideas (the borrow checker was novel, and aspects of its thread safety story like Send and Sync were also AFAIK not found in the literature), and (2) to the extent that it was the synthesis of existing ideas, a number of these were locked away in languages that were not even close to being ready for industry adoption. There was no other Rust alternative (that genuinely aimed to replace C++ for all use cases, not just supplement it) just on the horizon or something around the time of Rust 1.0's release. Pretty much all the oxygen in the room for developing such a language has gone to Rust for well over a decade now, and that's why it's in the Linux kernel and [insert your pet language here] is not. BTW, this is also why people being are incentivized to figure out ways to solve complex cases like Rcu-projection through extensible mechanisms (like the generic field projection proposal) rather than ditching Rust as a language because it can't currently handle these ergonomically. The lack of alternatives to Rust is a big driving factor for people to find these abstractions. Conversely, having the weight of the Linux kernel behind these feature requests (instead of e.g. some random hobbyist) makes it far more likely for them to actually get into the language.