I'm ambivalent about Rust these days.
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That Mantis is running a closed software stack on a SAMA5D3 SoC. It primarily acts as a Braille terminal for a PC or mainstream mobile device, and also has a handful of other applications, including a book reader that can download books over WiFi. But it could *be* a personal computer all by itself; it's already running Linux. Yes, it would be a personal computer with CPU performance somewhere in the neighborhood of a Pentium II. But we used to do real personal computing on those.
8/?
@matt my first Linux box was a 166MHz Cyrix 6x86 (so, much slower floating point than a Pentium or AMD at the same clock, but, pin compatible and similar instruction set, I think). It was a huge jump up from the Amiga 3000 I had before, and very usable for all sorts of things. I am pretty spoiled in terms of compute now, but I was writing software (well, learning to write software) on that machine. But, yeah, can't run a modern Linux or build Rust apps in 64MB. Maybe Zig, though?
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So, do I want to go back to writing, and encouraging others to write, software in C? Absolutely not. I'm convinced by the arguments that memory safety by default, that can be checked by machine rather than requiring constant programmer discipline, is a moral imperative, considering the consequences of memory safety vulnerabilities for security and privacy.
11/?
So do we have to accept that some level of computing power well above that of a Pentium II is simply the baseline for a modern general-purpose computer? Maybe. Perhaps the idea of something like the Mantis Braille display, with its battery efficiency, being a general-purpose personal computer is simply an impossible dream that I have to let go of. But, that was always an extreme example anyway.
12/?
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So, we could have a general-purpose personal computer that runs for 15 hours on a 2000 mAh battery. Maybe more with TTS output rather than a Braille display; I gather that Braille displays are fairly power-hungry because of all the pins moving up and down. But I believe that a general-purpose personal computer needs to be good for modifying its own software, at all levels of the stack. Rust fails hard on that criterion on this low-power CPU that has performance that used to be good.
10/?
@matt maybe gccrs (when it’s ready) will be less resource hungry. There is also Mutabah’s compiler you can try now.
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@matt my first Linux box was a 166MHz Cyrix 6x86 (so, much slower floating point than a Pentium or AMD at the same clock, but, pin compatible and similar instruction set, I think). It was a huge jump up from the Amiga 3000 I had before, and very usable for all sorts of things. I am pretty spoiled in terms of compute now, but I was writing software (well, learning to write software) on that machine. But, yeah, can't run a modern Linux or build Rust apps in 64MB. Maybe Zig, though?
@swelljoe My first Linux box was a 486SX at 33 MHz in 1996. I think I put Linux on it when it still had only 4 MB of RAM. Hard to believe you could actually compile real C code, including the kernel, on that little.
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So do we have to accept that some level of computing power well above that of a Pentium II is simply the baseline for a modern general-purpose computer? Maybe. Perhaps the idea of something like the Mantis Braille display, with its battery efficiency, being a general-purpose personal computer is simply an impossible dream that I have to let go of. But, that was always an extreme example anyway.
12/?
Were there other paths to a software stack with minimal unsafe code at the bottom that required far fewer machine resources to compile, that the industry chose not to take? Maybe the Rust Graydon wanted that had no future (https://graydon2.dreamwidth.org/307291.html)? I guess it's kind of moot, because the industry didn't take one of those paths, meaning there's no big library ecosystem on which to build, say, a new personal computing platform with a TTS/Braille-first UI framework.
13/?
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@inkreas.ing How long does a release build take?
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Were there other paths to a software stack with minimal unsafe code at the bottom that required far fewer machine resources to compile, that the industry chose not to take? Maybe the Rust Graydon wanted that had no future (https://graydon2.dreamwidth.org/307291.html)? I guess it's kind of moot, because the industry didn't take one of those paths, meaning there's no big library ecosystem on which to build, say, a new personal computing platform with a TTS/Braille-first UI framework.
13/?
OK, I guess Rust compile time isn't so bad on older computers that people actually use as personal computers. See this reply that came in from Bluesky. https://bsky.app/profile/did:plc:54jgbo4psy24qu2bk4njtpc4/post/3mlptu6oycc2g 5 seconds for a debug build on a 2009 MacBook. I feel better now.
14/?
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@inkreas.ing What CPU model does that MacBook have? And how much RAM? Thanks.
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So, we could have a general-purpose personal computer that runs for 15 hours on a 2000 mAh battery. Maybe more with TTS output rather than a Braille display; I gather that Braille displays are fairly power-hungry because of all the pins moving up and down. But I believe that a general-purpose personal computer needs to be good for modifying its own software, at all levels of the stack. Rust fails hard on that criterion on this low-power CPU that has performance that used to be good.
10/?
@matt that's cool. I run primarily 100 percent with Braille unless Braille just won't read something.
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@swelljoe My first Linux box was a 486SX at 33 MHz in 1996. I think I put Linux on it when it still had only 4 MB of RAM. Hard to believe you could actually compile real C code, including the kernel, on that little.
@matt I had the Amiga C compiler Matt Dillon (of FreeBSD and Dragon BSD) made and I tinkered with it. I think I used it as far back as the Amiga 2000, which I think only had 1MB. I probably upgraded it in some way, but don't remember details, probably 2MB. The 3000 used weird ass ZIP RAM, and I distinctly remember I upgraded it to 8MB. But, I'm confident I wouldn't enjoy working with those kind of limitations for serious programming.
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OK, I guess Rust compile time isn't so bad on older computers that people actually use as personal computers. See this reply that came in from Bluesky. https://bsky.app/profile/did:plc:54jgbo4psy24qu2bk4njtpc4/post/3mlptu6oycc2g 5 seconds for a debug build on a 2009 MacBook. I feel better now.
14/?
Still, I can't help but wonder. Consider a counterfactual where the original ARM processor, the one that famously ran on about 100 mW (meaning that it could, by accident, run only on leakage current), had shipped in a personal computer that had been wildly successful, and it then became an industry norm that all personal computers going forward simply must use that little power. Where would we be now? Still writing large amounts of unsafe C code? Or would we have found a different path?
15/?
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@inkreas.ing I gather that incremental build is a debug build? If so, do you find that, for a desktop application using an all-Rust GUI stack, the debug build is noticeably slower than the release build on that 2009 MacBook?
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@inkreas.ing Was Rust compilation in particular painful before you upgraded the RAM to 8 GB?
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@inkreas.ing Ah, OK. Do you have LTO enabled in the release profile?
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@inkreas.ing If you've got some time to kill, could you please run UnixBench (https://github.com/kdlucas/byte-unixbench) and post the results somewhere, maybe a gist? I know I might seem weirdly fixated on your anecdote, but yours is the oldest x86-based machine I've heard of so far that someone is using to develop an application in Rust, and I'd like to be able to compare it against other systems. Thanks!
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@inkreas.ing Oh, I forgot that we had talked about this topic before.
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But, the Rust compiler is well-known for requiring significant computing power and memory. As just one recent anecdote, the prolific Hacker News commenter Thomas Ptacek recently mentioned that waiting for a Rust compile to finish was a factor in him deciding to comment on a controversial thread. And he was presumably running the Rust compiler on a high-end computer, the kind that we well-off software developers tend to use.
3/?
@matt I _highly_ doubt those assessments, because huge C/C++ code bases will compile for longer in my experience.
I think it always depends on what you are comparing to here. Sure there are other languages that compile faster, because they don't rely on the LTO way of doing things, but especially C++ are not better in terms of compilation speed.
I even had people complain about rusticl compile times, but the C++ drivers just took way longer looking at the data.
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@matt I _highly_ doubt those assessments, because huge C/C++ code bases will compile for longer in my experience.
I think it always depends on what you are comparing to here. Sure there are other languages that compile faster, because they don't rely on the LTO way of doing things, but especially C++ are not better in terms of compilation speed.
I even had people complain about rusticl compile times, but the C++ drivers just took way longer looking at the data.
@matt Though yes, the memory usage is bigger, so if you are memory constrainted you will run into issues.
But not sure there is a nice way out of this situation sadly...
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Still, I can't help but wonder. Consider a counterfactual where the original ARM processor, the one that famously ran on about 100 mW (meaning that it could, by accident, run only on leakage current), had shipped in a personal computer that had been wildly successful, and it then became an industry norm that all personal computers going forward simply must use that little power. Where would we be now? Still writing large amounts of unsafe C code? Or would we have found a different path?
15/?
@matt THis is a really fascinating thread, I myself have been wondering lately what specifically makes rustc such a resource hog on those lower-power chips. Is it primarily the heavy lifting of proc-macros and crate expansion, or is the borrow checker's analysis just that computationally expensive? If the former, that seems like a problem that can be solved. If the latter, there are systems programming languages that compile way faster than Rust, see also Zig, but it doesn't provide the same safety features. It's not as unsafe as C, but you can still dereference null and get a crash.
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Still, I can't help but wonder. Consider a counterfactual where the original ARM processor, the one that famously ran on about 100 mW (meaning that it could, by accident, run only on leakage current), had shipped in a personal computer that had been wildly successful, and it then became an industry norm that all personal computers going forward simply must use that little power. Where would we be now? Still writing large amounts of unsafe C code? Or would we have found a different path?
15/?
@matt For making an user its own developer, the ideal is a language which need not compile and can be tested in real time, e.g. lisp and forth. Maybe something like they say about the 80s lisp machine, a machine programmed in a single language botton up and top down.
