Linus Torvalds says RISC-V will make the same mistakes as Arm and x86 : technology

[-] just_another_person@lemmy.world 217 points 1 month ago

He's being misquoted by the headline. He FEARS that it will make the same mistakes. Let's be clear about RISC is here in the first place: an open-source hardware architecture. Anyone with enough money and willpower to fork it for their needs will do so. It's anyone's game still. He's just simply saying that the same type of people who took over ARM and x86 are doomed to make the same mistakes. Not that RISC-V is bad.

[-] bitfucker@programming.dev 2 points 1 month ago

I'm being pedantic here but RISC-V is not a hardware architecture as in something that you can send to a manufacturer and get it made. It is an ISA. How you implement those ISA is up to you. Yes there are open implementations but I think it is important to distinguish it.

load more comments (2 replies)

[-] shaked_coffee@feddit.it 77 points 1 month ago

Anyone willing to summarize those mistakes here, for those who can't watch the video rn?

[-] transientpunk@sh.itjust.works 133 points 1 month ago* (last edited 1 month ago)

He doesn't list what the mistakes will be. He said that he fears that because hardware people aren't software people, that they will make the same mistakes that x86 made, which were then made by Arm later.

He did mention that fixing those mistakes was faster for Arm than x86, so that brings hope that fixing the mistakes on Risc V will take less time

[-] MonkderDritte@feddit.de 27 points 1 month ago* (last edited 1 month ago)

I think it was something with instruction sets? Pretty sure i read something about this months ago.

[-] Hotzilla@sopuli.xyz 6 points 1 month ago

No, it was about the prediction engines that contain security vulnerabilities. Problem is that software has no control over that, because hardware does future predictions for performance optimization.

[-] MonkderDritte@feddit.de 1 points 1 month ago

Aah, right, that.

load more comments (1 replies)

[-] Cocodapuf@lemmy.world 4 points 1 month ago

I mean, that's all chip architectures are, so yes.

[-] SpikesOtherDog@ani.social 23 points 1 month ago* (last edited 1 month ago)

Basically, his concern is that if they are not cooperating with software engineers that the product won't be able to run AAA games.

It's more of a warning than a prediction.

load more comments (10 replies)

[-] JayDee@lemmy.ml 11 points 1 month ago

Instruction creep maybe? Pretty sure I've also seen stuff that seems to show that Torvalds is anti-speculative-execution due to its vulnurabilities, so he could also be referring to that.

[-] Traister101@lemmy.today 4 points 1 month ago

Counterintuitive but more instructions are usually better. It enables you (but let's be honest the compiler) to be much more specific which usually have positive performance implications for minimal if any binary size. Take for example SIMD which is hyper specific math operations on large chunks of data. These instructions are extremely specific but when properly utilized have huge performance improvements.

load more comments (1 replies)

[-] KillingTimeItself@lemmy.dbzer0.com 66 points 1 month ago

smells like linus thinks there is going to be an ever increasing tech debt, and honestly, i think i agree with him on that one.

RISCV is likely going to eventually overstep it's role in someplaces, and bits and pieces of it will become archaic over time.

The gap between hardware and software level abstraction is huge, and that's really hard to fill properly. You just need a strict design criteria to get around that one.

I'm personally excited to see where RISCV goes, but maybe what we truly need is a universal software level architecture that can be used on various different CPU architectures providing maximum flexibility.

[-] Cocodapuf@lemmy.world 40 points 1 month ago

but maybe what we truly need is a universal software level architecture that can be used on various different CPU architectures providing maximum flexibility.

I think that's called Java.

[-] greywolf0x1@lemmy.ml 13 points 1 month ago

Or Emacs

[-] ICastFist@programming.dev 2 points 1 month ago

Then again, if you don't have the JVM/JRE, Java won't work, so first you need to write it in another language and in such a way that it works across a bunch of different ARM and x86 processors.

[-] Cocodapuf@lemmy.world 2 points 1 month ago

I don't know, if your platform doesn't have a jre... Is it really a platform?

[-] ICastFist@programming.dev 2 points 1 month ago

Dunno, would you consider the Xbox or Playstation platforms?

load more comments (3 replies)

[-] arality@programming.dev 15 points 1 month ago

software level architecture that can be used on various different CPU architectures providing maximum flexibility.

I've only done a little bare metal programming, but I really don't see how this is possible. Everything I've used is so vastly different, I think it would be impossible to create something like that, and have it work well.

[-] KillingTimeItself@lemmy.dbzer0.com 2 points 1 month ago* (last edited 1 month ago)

theoretically you could do it by defining an architecture operations standard, and then adhering to that somewhat when designing a CPU. While providing hardware flexibility as you could simply, not implement certain features, or implement certain other features. Might be an interesting idea.

That or something that would require minimal "instruction translation" between different architectures.

It's like x86. except if most of the features were optional.

[-] sugar_in_your_tea@sh.itjust.works 2 points 1 month ago

It sounds like you're just reinventing either the JVM (runtime instruction translation), compilers (LLVM IR), or something in between (JIT interpreters).

The problem is that it's a hard problem to solve generally without expensive tradeoffs:

interpreter like JVM - will always have performance overhead and can't easily target arch-specific optimizations like SIMD
compiler - need a separate binary per arch, or have large binaries that can do multiple
JIT - runtime cost to compiling optimizations

Each is fine and has a use case, but I really don't think we need a hardware agnostic layer, we just need languages that help alleviate issues with different architectures. For example, Rust's ownership model may help prevent bugs that out of order execution may expose. It could also allow programmers to specify more strict limits on types (e.g. non-zero numbers, for example), which could aid arch-specific optimizations).

[-] KillingTimeItself@lemmy.dbzer0.com 1 points 1 month ago

yeah pretty much. The JVM but marginally less skill issued lol.

[-] nixcamic@lemmy.world 7 points 1 month ago

universal software level architecture that can be used on various different CPU

Oh we already have dozens of those haha

load more comments (2 replies)

[-] lps@lemmy.ml 30 points 1 month ago

Well regardless, the world needs alternatives that are outside of restrictive US patent law and large monopolistic control. Thank god for pioneers:)

[-] erwan@lemmy.ml 20 points 1 month ago

ARM Inc is an English company owned by a Japanese company

[-] zaphod@sopuli.xyz 2 points 1 month ago

Pretty sure it's a plc, not and Inc.

[+] chemicalwonka@discuss.tchncs.de 17 points 1 month ago* (last edited 1 month ago)

[deleted]

[-] ricdeh@lemmy.world 36 points 1 month ago

Sorry, but that is completely wrong. RISC-V is an ISA, nothing less, nothing more, and it is completely, 100% open-source. The licensing of the hardware implementations is a different matter, but that's outside of the scope of RISC-V. As I said, it is just an ISA.

[-] barsoap@lemm.ee 9 points 1 month ago

There's plenty of designs out there that you can load onto an FPGA or, funds permitting, send off to a fab to burn into silicon.

[-] BobGnarley@lemm.ee 13 points 1 month ago

RISC-V is the only shot we have at usable open source hardware. I really, really hope it takes off.

[-] wewbull@feddit.uk 4 points 1 month ago

Whilst some open source implementations exist, RISC-V is not open source. It's an open standard. i.e. there's no license fee to implement it.

[-] BobGnarley@lemm.ee 2 points 1 month ago

I didn't know that I thought all RISC-V was open source :( I'm not as familiar with it as I'd like to be. I might just have to dive into it more and change that soon

[-] woelkchen@lemmy.world 1 points 3 weeks ago

I didn’t know that I thought all RISC-V was open source :(

If RISC-V was under some copyleft license where chip designs would have to be made open source, nobody from the chip industry would support RISC-V. They want "kinda like ARM but without licensing fees".

[-] Evil_Shrubbery@lemm.ee 9 points 1 month ago

Even if that happens, still open sauce

[-] NoMoreCocaine@lemmynsfw.com 2 points 1 month ago

Not really? I mean, only partially.

[-] SeattleRain@lemmy.world 6 points 1 month ago* (last edited 1 month ago)

It's open source nature protects against that. People mistake Linus as being in the same boat as Stallman but Linus was only open source by circumstance, he kind infamously doesn't seem to appreciate the role open source played in his own success.

It already directly addresses the mistakes of x86 and ARM. I don't know what he is so worried about.

[-] exu@feditown.com 16 points 1 month ago

Only the core part of the ISA is open source. Vendors are free to add whatever proprietary extensions they want and sell the resulting CPU.

You might get such a CPU to boot, but getting all functionality might be the same fight it is with arm CPUs currently.

load more comments (1 replies)

[-] cmhe@lemmy.world 12 points 1 month ago* (last edited 1 month ago)

Protects against what?

What I read here is just a vague critic from him of the relation between hard- and software developer. Which will not change just because the ISA is open source. It will take some iterations until this is figured out, this is inevevable.

Soft- and hardware developers are experts in their individual fields, there are not many with enough know-how of both fields to be effective.

Linus also points out, that because of ARM before, RISC-V might have a easier time, on the software side, but mistakes will still happen.

IMO, this article doesn't go into enough depths of the RISC-V specific issues, that it warrants RISC-V in the title, it would apply to any up and coming new ISA.

load more comments (1 replies)

[-] magnolia_mayhem@lemmy.world 2 points 1 month ago

Maybe, but the point is that it's open. There's a much higher chance that one of the companies that builds parts will make good decisions.

Technology

Our Rules

Approved Bots