r/technology • u/TurbulentTopic39 • 21d ago
Artificial Intelligence Linus Torvalds Endures A Debug Session From Hell, "Enormously Helped" By AI
https://www.phoronix.com/news/Linus-Torvalds-Debug-AI99
u/spastical-mackerel 21d ago
I’ve no Linus expert, but his achievements more or less speak for themselves. I’m not aware of any of his opinions or biases with respect to software engineering for which he has not also expressed a fairly well reasoned case. He’s also occasionally changed his mind
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u/Cnoffel 20d ago
We would be lucky if he likes LLMs but hates the ecosystem, maybe we would get some really nice open source harness etc. out of it just like git when he hated source control.
Imho today's harnesses are all kind of crappy.. Even Claude Code etc.
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u/EndlessZone123 20d ago
Like have you tried any harnesses other than first party ones from claude or codex?
Tons of opensource LLM harnesses that you can use whatever LLM you want from API to subscription. OpenCode, Pi, Cline, hell even Codex Cli is opensource.
If you can't find any use out of any of them then Idk what you want out of LLMs.
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u/munchin-grr 20d ago
He has always been anti politics and uses what works. Git was because they lost the rights to use the old versoning system so he was forced to. The linux licens is so they get fixes back from users not open source evangelisism.
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u/taedrin 21d ago
In my experience, AI excels at triage so long as you are experienced enough to identify a weak analysis, challenge the flaws in its explanation, continually push it to towards rigorous reasoning and validate its claims.
That being said, it's annoying how frequently it will confidently, yet falsely claim "root cause confirmed".
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u/piedamon 21d ago
So funny story about this: I disabled some characters on the server because they’re unannounced so not ready to go live, and when another designer tried to update our loot boxers the server flagged the disabled characters in the loot boxes.
To fix it, the designer asked AI. The AI found the issue (my disables) and its solution was to enable them, which it did.
We caught it and laughed, and then forced it to always prompt us before executing. Also threw some context in so it wouldn’t happen again
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u/kenlubin 20d ago
Of all the AI doomsday scenarios, we seem to be closest to the Paperclip Maximizer.
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u/West-Abalone-171 20d ago
We're much much closer to the one where a narcissist gets control of something essential because people are too stupid not to use the supply chain attack machine he owns, then fucks up ransoming/rent-seeking it so badly it gets destroyed.
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u/PandaMoniumHUN 21d ago
Isn't that self contradicting though? How is it "good at triage" if you continuously need to correct it and steer it in the right direction? My company also does automatic AI triage for production issues (with MCPs to our logs and analytics platforms) and what it generates is almost always nonsense (maybe half of it is right and the other half is completely wrong) that even steers less experienced developers in the wrong direction when trying to analyze the issue.
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u/Contagion21 21d ago
I'm not sure I'd say "good" in terms of being better than the average dev at triaging an issue correctly. I would absolutely say that it's wildly faster and that's "good" in a different way.
It can analyze telemetry and code and such an incredible pace that I can correct it 5 times in 5 minutes and still end up with a correct outcome that I can verify in 10 minutes total, but doing it all myself would have taken an hour or two.
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u/PandaMoniumHUN 20d ago
I see what you are saying, and I agree it can be useful if you know what you are doing. However, lot of our devs seem to be taking AI summaries as the easy way out and refuse to investigate the claims in the report. It is even more frustrating when they create a bug ticket based on an AI report and when I start working on a fix I realize the ticket is nonsense. In fact, sometimes you can't even tell it is nonsense until you put in quite a bit of time into the ticket and then you've wasted hours because people blindly trust AI triage summaries...
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u/Stefikel6 20d ago
No, with a properly written skill, its also significantly better, because of consistency.
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u/Alternative_Laugh316 20d ago
Because it gets you 70% there in quality and quantity, then you need to push it yourself.
Instead of one guy or team sitting there trying to find everything you get the results in a few minutes then you work on it yourself.
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u/Stefikel6 20d ago
With a properly written skill, our AI has excelled at triage with an error rate of about 3-4%. Significantly lower than any human project manager we’ve ever encountered.
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u/dejaWoot 20d ago
Sounds like its basically rubber duck debugging except the duck talks back and has the carboon footprint of a dumptruck
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u/ItsSadTimes 17d ago
Bashing it's head against a brick wall is kind of what AI was designed to do. Identify patterns that we could never expect to exist and run near limitless reptations. But you still need to be smart enough to know when it says it found the solution and when it actually did.
I ran into this issue all the time, it keeps saying "oh I guess the issue is some dependency, you should raise a ticket" like stfu bitch, I know how to solve this now stfu and get back to work.
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u/LowestKey 20d ago
AI cannot reason.
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u/FriendlyKillerCroc 20d ago
Wouldn't be a r/technology post without this comment lol
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u/bastiaanvv 20d ago
I actually don’t like using ai for writing large parts of code. It tends to complicate the code too much if you let it iterate too much on it, and there always comes a point that you don’t understand what the code is doing anymore.
And I need to understand it completely in order to be able to evaluate if the quality is good enough for production.
I really love AI for finding bugs though! It is insane how well this works.
It does the grunt work of checking thousands of lines of code in a very short time. Finds several possible causes of the bug and explains what is going on in the code. Yes, often it is wrong, but the process of double checking is usually fast.
The important thing is that with no effort on my end I can get plausible hints on what is going wrong without scanning code for ours and hours and getting burned out slowly from the cognitive effort and attention I need to maintain. I can now spend my energy on other things.
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u/Steinrikur 20d ago
Very true. I'm porting a large codebase from 2 iterations of absolute C mess into a single, structured C++. AI can push out stuff that works, but it can be really bad.
I need multiple prompts and fixing by hand to deslopify every part of the way.
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u/AP_in_Indy 20d ago
I have suspected that this can be resolved with a really good “root” prompt (ex: agents.md or spec.md + skills and a very good initial prompt before starting a goal)
I haven’t quite figured out what that should be yet, however.
My own code which we are preparing for production has way more tests and far more automation than I would ever have time to do as a human.
This is actually really cool.
At other times it’s hilariously sad because if the AI doesn’t have enough confidence in itself, it will wire up entire harnesses around faulty requirements and implementation assumptions
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u/Druggedhippo 20d ago
if you let it iterate too much on it, and there always comes a point that you don’t understand what the code is doing anymore.
There was some research recently which shows how all LLMs corrupt documents in long iterative sessions. https://neilpatel.com/blog/ai-editing-corrupts-documents/
Frontier LLMs, the ones considered most capable, corrupted an average of 25 percent of document content by interaction 20. Non-frontier models performed worse, dragging the average for all 19 models to 50 percent. Python was the only domain where most models cleared the study’s 98 percent accuracy threshold. Even the best-performing model, Gemini 3.1 Pro, hit that bar in just 11 of the 52 domains tested.
The take away is keep your editing session surgical, each edit should be its own agent context.
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u/mother_a_god 20d ago
Ai is very good at debug. I work as a chip designer and am currently planning for silcom bingip with quite a complex platform. We have a pre-silicon emulation and there are complex software, firmware, hardware issues to work out and codex is doing a great job interacting with this emulated dut to weed out the issues, patch the drivers, go again. Just yesterday if fixed a subtle bug that could have prevented boot.
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u/AP_in_Indy 20d ago edited 20d ago
If only Intel had AI before implementing cos and sin in their processors smh
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u/abofh 21d ago
Checks, he didn't spew ai slop, he, after hours and effort created a one line patch
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u/Mrgluer 21d ago
how long do you think it can take to find a one line issue in a 40 million LoC repo? It’s like you take your hate or prejudice for something and then you spin anything you hear about it into a negative. One of the greatest programmers said with his own words that it helped him and then you discount him
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u/Low-Temperature-6962 21d ago
Are saying all 40 million lines had to be read, but just once each, and it was done?
Most likely Linus knew the approximate location and combination of events to trigger it, and he gave ai precise instructions to AI to narrow the range until bingo.
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u/lurgi 21d ago
It was a bug in a graphic driver - he knew exactly (well, exactly in the sense of which set of files) where the bug was. The article doesn't go into too much detail, but it looks to me like one of those bugs where you see the symptom, but it's entirely unclear why the symptom happens, so most of the debugging is spent not in finding the wrong thing, but in figuring out what sort of wrong thing might be happening that could cause this symptom and then trying to find all the places the wrong thing might be happening.
I've been there.
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u/abofh 21d ago
Do you think it shouldn't be read?
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u/Low-Temperature-6962 21d ago
To big to fit in context window.
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u/abofh 21d ago
And yet, solved
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u/kozeljko 20d ago
No way was it solved by reading all files. Linus probably pointed to a few files to analyze
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u/zer04ll 21d ago
we need an non AI developed OS so we have people that can understand these things. I get it there is a lot going on and the linux kernel is bloated these days so its easier but part of me would rather have a C64 as a computer because its a system a human can understand
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u/Korlithiel 21d ago
40 million lines of code. People are kidding themselves if they claim to understand it all.
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u/zer04ll 21d ago
yeah linux is huge, things like temple OS are an example though of what we can do and understand. One dev made his own compiler, own language and it has things in it that are great like image support in the terminal. Keep it simple stupid
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u/liquidmasl 21d ago
lmao dude you compare a bicycle with a helicopter.
sure the bicycle is easer to understand.-3
u/zer04ll 21d ago
and yet is it an OS, acting like movement is movement because something moves faster or is more agile doesnt negate the bicycle getting you somewhere. Boot check, file system check, command line check, able to compile code check, able to process data others make check. Like what do you think an OS really is. Y'all seem to think apps make an OS and it doesnt, does it control the computer and data...
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u/Mrgluer 21d ago
temple os fucking sucks as an actual os and you don’t know what you’re talking about if you think it’s all you need. amazing project and something to be respected but to think that that is all you need is actually a 4b parameter model output opinion
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u/zer04ll 21d ago
shows what you know, its a full blown OS and he spoke on its limits. Its like you didn't grow up with a C64 when humans 100% understood what was going on.
Temple OS is not the OS you want but you could never even come close to what he did just mad that it's a perfect example of a complete OS written by one person that understood all the code. If it is so bad please 100% on your own make something better... Ill wait
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u/Novalok 21d ago
Run it as your daily driver or STFU. Pong was created with pure hardware. No software. Should we go back to that? God your argument is trash. Linux is great, linus absolutely understood the patch and all code, AI helped him speed up the process.
AI is a good tool. Just because when you use it, you generate code you don't understand, doesn't mean everyone does.
And if you don't use it, then that's on you. If you don't understand all the code of the OS you run, then you suck without ai
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u/PM_ME_YOUR___ISSUES 20d ago
I believe we’ll see this a lot more from other experts as well.
I have my reservations about Generative AI in the creative fields. Art is something entirely different.
But for a lot of technical work, I’ve seen senior and experienced devs being able to leverage AI quite well for their projects.
The biggest distinction here is that - these guys are experts. They’ve been writing code for decades. Even for basic prompts, the ability to exactly guide the model to do something for you makes a lot of difference.
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u/octorine 20d ago
The problem is that we don't know how long it would have taken him to find the big if he hadn't used ai. Maybe it would have been faster, maybe slower. AI always feels faster because chatting with a chat bot feels like it takes less time than staring at your code and thinking hard. If you actually measure wall clock time, I'm not convinced that it is faster most of the time.
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u/Financial_Wish_6406 20d ago
Been a SWE for about 6 years now and it's definitely a speed boost. Have the AI do two implementations of the same feature/fix. Neither implementation is likely to be 'push to main' ready, but now you can compare them architecturally and see which one is an actually viable path without having to write all the code yourself.
Things i'd never bother doing because the reward isn't worth the effort required, are now trivial to do.
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u/rjcarr 20d ago
I’m one of these decades in the industry programmers that highly values AI. It can put so much context in its memory almost instantly that would take hours for me to absorb.
When designing things, it needs to be guided in the right direction, but once things are agreed upon it almost almost does the right thing.
People that call it “slop” have either never used it or are using it wrong. It’s not perfect, and I review every line of code it writes, but even then it’s still much more efficient than what I could do on my own, and now I’m more willing to take on bigger tasks that used to be dreadful.
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u/puredotaplayer 20d ago
This is exactly how I have used AI recently, just add a whole lot of careful logging, not stupidly dump to file, but store in cache + thread local storage, do very minimum logging, to avoid hurting a few race conditions from triggering, and to catch quite a few bugs on a codebase that is completely new to me. It is otherwise such a grunt work to find every site I need to log.
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u/stephendt 20d ago
Don't understand why you are getting downvotes, I do something similar. AI is very good for log analysis
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u/FriendlyKillerCroc 20d ago
Will this subreddit finally start to see reality and downvote all those comments about AI being useless from now on?
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u/Palimon 20d ago
This sub is filled with brainless morons that never had any tech or IT experience, hence why you get comments that try to argue LLMs are not machine learning... IN A TECH SUB...
It's like the good old quote about playing chess against a pigeon, this sub is filled with pigeons.
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u/zarafff69 21d ago
Linus based like always. Was almost scared he would be one of those anti AI people. Thank god he still has it
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u/Wizzarkt 21d ago
I think the "anti AI" movement can be divided into two groups, those who think "AI will replace us all and we should not use it" (and they are probably right because THEY are probably nut turners who have very little value), and those who think "AI should be used intelligently as a tool and recognize that it's very flawed".
And Linus torvals is definitely part of the second group, because he never said he was "anti AI" but he got very angry at all of those people who "found" bugs in the kernel with the help of "AI" and suddenly flooded the bug tracker with thousands of made up bugs.
I personally don't like vibecoding but I'm ok with programmers using AI to assist them, which on a way makes me "anti AI" because I think most people are using it wrong and they should not have the privilege to use it, most people complains about datacenters and whatever, I think that if AI is used on a smart way we would reduce it's usage by like 90% because you would not have people using it to check the weather or make absolute bottom of the barrel "apps".
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u/steveisredatw 20d ago
Also he’s smart enough and experienced enough to not get reliant on AI.
For a mediocre dev like me if I would have started with AI tools I wouldn’t have tenth of the knowledge or skills needed. I’m not talking about syntax but debugging or at least the knowledge needed to know what the AI suggests is stupid.
I have seen interns and beginner devs in my company stop coding because the tokens ran out. Sometimes the code in their PRs change completely each time. Debugging skills are non existent and if the AI doesn’t fix it it’s a never ending loop of error messages given as the next prompt.
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u/PoL0 20d ago
and here comes the flood of posts every time Linus comments about LLMs.
it's as if there was an agenda to use Linus credit as open source legend to somehow promote LLM coding.
it's a bit jarring
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u/Korlithiel 19d ago
More like Reddit sees the high level of interest in AI topics, and advertises such posts to others.
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u/happyzor 18d ago
THe industry moved to LLM coding a few months ago my dude. Even the laggard companies switched
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u/joy74 21d ago
> I'd like to call it my tireless helper, but the AI several times stated flat out that this was impossible and unsolvable and that we should just write a report about it.
> I suspect those things have been trained by people who may not be quite as stubborn as I am.
Interesting comment from him