Red Hat's Long, Rust'ed Road Ahead For Nova As Nouveau Driver Successor

[Alexmitter]

Riscv is supported without host tools. That's probably your problem, but is plenty enough for the kernel. Don't mix apples and oranges.

Its not Tier 1, its Tier 2 which means nah good luck getting anything to compile.

[Alexmitter]

rustc_codegen_gcc

That one still depends on rustc. I prefer the other effort to get full support directly into GCC to succeed.

[dralley]

Its not Tier 1, its Tier 2 which means nah good luck getting anything to compile.

The definition of tier 2 support is literally "guaranteed to build" and the tests are run periodically but not for every release. Bugs are theoretically more likely but compiling shouldn't be an issue.

[oleid]

Its not Tier 1, its Tier 2 which means nah good luck getting anything to compile.

The compiler is guaranteed to build in tier2 and several people perform regular tests.
It is not worse that for GCC. Did you ever wonder how people guarantee that GCC works?

https://gcc.gnu.org/testing/

Several people perform regular builds and regression test runs and send their test results to the gcc-testresults mailing list.

It is not even tested in a CI! Test result are send to a mailing list and - I don't know- maybe someone takes a look.
Aparrently, somebody runs the test suite once a week on riscv and there are many unexpected failures.

I don't see how the rust support is any worse -- especially since they don't do the platform code generation themselves, they use llvm or gcc backends.
Thus, using a fixed version of a codegen backend, it is plenty enough to do a compile test for a nightly. The additional tests for riscv are i.e. provided by interested groups as Espressif.


As for firefox on debian: According to Reddit the only thing missing is javascript JIT. And that was two years ago.

Also, people are using rust on RISCV, but apparently the kernel still has issues.

[moltonel]

Its not Tier 1, its Tier 2 which means nah good luck getting anything to compile.

Tier 1 on Rustc is a higher bar than most compilers aim for, even tier 2 is a stronger guarantee than what our beloved gcc offers (because a failed build actually blocks the git merge). But I don't hear you suggesting we should avoid gcc ? Your "good luck getting anything to compile" is a laughable exaggeration, we use a few tier 2 platforms at work and never had a problem with rustc.

That one still depends on rustc. I prefer the other effort to get full support directly into GCC to succeed.

So you're attaching more importance to some soft criteria than pragmatic/technical ones. Or more likely you just want any excuse to tell people to avoid Rust, and you'll find a new one when gccrs eventually becomes usable in a few years.

[moltonel]

As for firefox on debian: According to Reddit the only thing missing is javascript JIT. And that was two years ago.

Seem like FF riscv jit was merged about 1 year ago. In any case, spidermonkey and its jit are in C++, not Rust.

[oleid]

Seem like FF riscv jit was merged about 1 year ago. In any case, spidermonkey and its jit are in C++, not Rust.

Oh sure, what is missing here is just a riscv backend for the jit.

[jacob]

Didnt see this one comming, but glad it is, more rust is always nice.

Actually this had been talked about for a while but my understanding was that the Nouveau people planned to RIIR, not that it was going to be a brand new project.

[jacob]

the reality is that nvidia is pushing the market ahead and competition is merely catching up. it's been this way for years.

in the consumer (gaming) gpu, amd has honestly done nothing revolutionary. the typical gaming gpu has become an afterthought for nvidia as of now. they are making obscene amounts of money on AI hardware - judging by their latest keynote it's not going to change anytime soon.

for the majority of people - the smart thing is to get nvidia right now. you don't like it, i don't like it. it is what it is. gaming is a fraction of gpu usage as of this point, even though there are dedicated non-gaming cards for non-gaming tasks.

if you are not a power user, might as well get amd/intel gpu.

Well their whole "AI" business depends on Linux. It's the perfect opportunity to tell them to be good denizens like AMD or Intel, or to GTFO. They will never voluntarily GTFO.

[jacob]

Nope, absolutely not. The best thing I was able to compile with that POS toolchain on riscv was a small example. Nothing else worked so far. Firefox still not in the debian repo either, why? Because the rust code in it can't be compiled without dirty hacks. Basically all rust containing packages are not available on the riscv port of debian.

And beside that, Linux is supported on Alpha, ARC, ARM, C-Sky, Hexagon, LoongArch, m68k, Microblaze, MIPS, Nios II, OpenRISC, PA-RISC, PowerPC, RISC-V, s390, SuperH, SPARC, x86, Xtensa and that compiler officially only properly supports i686, x86_64 and aarch64 as by their own documentation.

I would not have allowed any Rust code into the kernel before rust can be compiled for all the supported platforms and via GCC.

Yeah well. How many people running Linux on m68k or s390 need a Nvidia GPU driver? Not every bit needs to work on every architecture. Besides, it's really only a matter of time before support for these archs gets relegated to unofficial and then dropped. It's nice when things work on them, but development should not be held back because of them.

As for your problems with rust on riscv, I never used riscv but are you sure it's really a toolchan problem and not a hardware problem (as in, too little RAM, too weak CPU...)?