Hacker News: themulticaster

New comment by themulticaster in "eMudhra intermediate CA compromise"

themulticaster — Tue, 20 Oct 2026 17:52:40 +0000

Apparently they've only been included in early October https://www.mail-archive.com/dev-security-policy@mozilla.org...

New comment by themulticaster in "40 percent of fMRI signals do not correspond to actual brain activity"

themulticaster — Wed, 17 Dec 2025 01:53:17 +0000

> [...] but the real reason is their uni can't afford a PET scanner for them to use.

This is incorrect, TUM has a PET scanner (site in German): https://nuklearmedizin.mri.tum.de/de/Patienten-Zuweiser/Pet-... Can't comment regarding the other observations.

New comment by themulticaster in "Bus Bunching"

themulticaster — Thu, 24 Jul 2025 11:52:54 +0000

There's both: GTFS is a standard for the regular schedule, and GTFS-RT is a standard for realtime information.

Link: https://gtfs.org/documentation/realtime/reference/

New comment by themulticaster in "No-Panic Rust: A Nice Technique for Systems Programming"

themulticaster — Tue, 04 Feb 2025 11:56:30 +0000

no-panic uses link-time shenanigans to prevent panics in the compiled binary, but this isn't 100% reliable (as explained in the README, just pointing this out)

New comment by themulticaster in "The long road to lazy preemption in the Linux CPU scheduler"

themulticaster — Sat, 19 Oct 2024 13:58:13 +0000

The user you replied to likely means something different: The priority of the event often depends on the exact contents on the event and not the hardware event source. For example, say you receive a "read request completed" interrupt from a storage device. The kernel now needs to pass on the data to the process which originally requested it. In order to know how urgent the original request and thus the handling of the interrupt is, the kernel needs to check which sector was read and associate it with a process. Merely knowing that it came from a specific storage device is not sufficient.

By the way, NMI still exist on x86 to this day, but AFAIK they're only used for serious machine-level issues and watchdog timeouts.

New comment by themulticaster in "iPhone 16 Pro and iPhone 16 Pro Max"

themulticaster — Tue, 10 Sep 2024 21:08:29 +0000

When it comes to exchangeable lens cameras (DSLRs/DSLMs), as you increase the number of pixels you very quickly reach a point where you're limited by the optical performance of the lens instead of the sensor. Lots of systems offer a choice between a 24MP and a high pixel count camera (e.g. Nikon Z6/Z7), and you'll find that the high pixel count sibling requires very good lenses to actually achieve a meaningful improvement over 24MP. For these cameras, common wisdom says to stay with 24MP apart from certain niche use cases.

In other words, I wouldn't expect a improvement in capturing actual 48MP pictures in phone cameras, apart perhaps from pixel binning to a smaller size and similar techniques.

Disclaimer: I haven't followed camera tech very closely recently, and I'm not an expert. Take my opinion with a grain of salt.

New comment by themulticaster in "Some notes on Rust, mutable aliasing and formal verification"

themulticaster — Thu, 16 May 2024 11:08:02 +0000

Isabelle/HOL has Quickcheck, which is precisely what you think it is. Although it only works if the free variables in the thesis you'd like to prove are sufficiently simple AFAIK (think integers or lists). The more powerful alternative to Quickcheck is Nitpick, which is a purpose-built counterexample finder.

The workflow you'd like already exists one to one in Isabelle: You can simply type "nitpick" halfway through a proof and it will try to generate a counterexample in that exact context.

New comment by themulticaster in "Not knowing the /proc file system"

themulticaster — Wed, 25 Oct 2023 12:33:36 +0000

Of all the BSDs, I'm only a little familiar with OpenBSD through its OpenSSH fame, so I'm a little surprised to hear that a (probably) somewhat related project would use XML in a system call. In other words, if an OpenSSH release introduced XML as a wire format I'd assume it to be an April fools's joke. [1] But I guess OpenBSD and NetBSD are less related than I thought.

New comment by themulticaster in "Google has sent internet into 'spiral of decline', claims DeepMind co-founder"

themulticaster — Sun, 15 Oct 2023 17:14:08 +0000

When choosing a bowl for your potato salad, you need to keep some important properties of potato salad bowls in mind. Different bowls have different designs that make some better suited to storing potato salad than others. For example, a higher quality bowl might have been manufactured to a higher standard than a subpar bowl. You might also want to choose different bowls depending on the amount of potato salad you want to prepare. There are bigger bowls and smaller bowls, differing in size and thus in the amount of potato salad they can accommodate. A smaller bowl is great when you're aiming to cook for just a few people, while a larger bowl is ideal for bigger groups. Brand name bowls like the classic SALADBOWL(tm) are preferred by some potato salad fans, while others appreciate the great price offered by newer, less established brands. Keep in mind that while a cheaper bowl is more affordable, it can also break more easily, so it's not a bad idea to compare the warranty period offered by different manufacturers.

Disclaimer: Not a native speaker, I hope I got the annoying structure of those "what to look for when buying X" blog articles right...

New comment by themulticaster in "Introduction to sysclean(8)"

themulticaster — Wed, 27 Sep 2023 10:45:48 +0000

Based on its name I think it's used in Arch Linux packages (at least makepkg says it is generating an mtree file at some point during the build process IIRC). However it appears mtree (the tool) isn't packages, so perhaps it's only using the mtree specification format?

New comment by themulticaster in "Will Cyber Security Be Replaced by AI?"

themulticaster — Sun, 17 Sep 2023 21:14:45 +0000

Yeah, I think coming up with definitions of "understanding" or "reasoning" that GPT-4 and friends supposedly don't fulfill is moving goalposts.

To continue your line of thinking, when we add salt and pepper to a dish we've cooked, are we really doing it because we have a developed a thorough understanding of the human olfactory and gustatory systems [1] system, or because it tasted good previously when applied to similar recipes?

And when it comes to understanding basic math, perhaps the patterns are still a tad to complicated for LLMs. Maybe there are too many surprising rules that appear out of nowhere and break the learnt patterns. But children struggle with those rules as well when they first come across them. Think about division through zero - when coming across the rule for the first time, you might wonder why it exists, instead of e.g. defining the result to be infinity. The answer to that question (not just "because that's the way things work!") is not obvious at all, to be honest I wouldn't be confident enough to attempt giving an explanation here.

[1] I have to admit I had to look gustatory system up: it's the biological term for the system behind the sense of taste.

New comment by themulticaster in "Patterns with Rust Types"

themulticaster — Sat, 02 Sep 2023 16:14:10 +0000

The anti-pattern described as Deref Polymorphism is not the same as using Deref with the newtype pattern, in order to allow using the wrapped type transparently. In the latter case, the Target type of the Deref trait is always going to be perfectly clear. In case of the antipattern described on the linked page, it is not perfectly clear what the Target type is going to be.

In short, a Deref impl for some type T signals that T represents some level of indirection, and following/dereferencing that indirection can always be done in an unsurprising and trivial manner.

New comment by themulticaster in "Mold 2.0"

themulticaster — Wed, 26 Jul 2023 23:40:10 +0000

Yes, it should just work for all projects if you put in in ~/.cargo/config.toml, or as a per-project setting.

Git life pro tip (that you didn't know you needed until now): You can use .git/info/exclude (present in every Git repository) as a local, private version of .gitignore. It has the same syntax as .gitignore, but isn't tracked by Git. So you could add .cargo/config.toml to .git/info/exclude, changing the linker locally without Git considering it as an untracked file. I generally use this feature to ignore files that are specific to my development setup which I don't want to list in .gitignore.

New comment by themulticaster in "Microwaved plastic containers release microplastics into food"

themulticaster — Fri, 30 Jun 2023 12:45:01 +0000

As far as I know, non stick surfaces are mostly (always?) made out of PTFE (brand name Teflon), which is a little unusual in that it starts releasing toxic gases when it's heated way before it shows any signs of structural damage or deformation. This gets dangerous to humans from about 240C, but even at 220C PTFE will release trace amounts that can be toxic to birds.

With this in mind, I'm baffled about how many products with non-stick surfaces are marketed as safe up to 240C, considering that household ovens are often bad at controlling temperatures and can swing 20-30C above and below the set temperature.

New comment by themulticaster in "OpenGL 3.1 on Asahi Linux"

themulticaster — Tue, 06 Jun 2023 21:41:32 +0000

Is the Neural Engine/CoreML used in "normal" desktop apps on macOS, or is it limited to specialized ML centered apps? In other words, where should I expect performance improvements if there was a hypothetical Mesa for compute accelerators? Spontaneously, I can only think of image editors like Photoshop offering AI-based tools.

New comment by themulticaster in "OpenLLaMA: An Open Reproduction of LLaMA"

themulticaster — Wed, 03 May 2023 11:29:30 +0000

I'd see that as a benefit of llama.cpp - it's specifically designed to be usable on consumer hardware such as laptops, without professional GPUs.

New comment by themulticaster in "An introduction to lockless algorithms (2021)"

themulticaster — Mon, 24 Apr 2023 15:07:57 +0000

I'd like to add some context as to why lockless algorithms are popular in the Linux kernel. Roughly speaking, there are two possible scenarios in which kernel code is executed: Either in context of a process (e.g. while handling a syscall) or while handling an interrupt [1]. Now, a mutex usually sets the current thread to sleep if it tries to lock a currently locked mutex. Even in kernel land, this is perfectly fine as long as the kernel is in process context. However, while handling an interrupt there is no current thread that can be put to sleep. Therefore you can't use a mutex for kernel data structures that will be accessed during interrupts, and that applies to a lot of data structures.

This is why some common locking advice does not really apply to kernel code. Another example would be "avoid using spinlocks, prefer a mutex" - spinlocks are widely used in the kernel since they're the most straightforward alternative to mutexes.

Not disagreeing with the parent post, just wanted to add some context why LWN likes to talk about lockless algorithms.

[1] Actually, the kernel differentiates between hardirqs and softirqs, but that's not important here.

New comment by themulticaster in "Reddit has been down for more than an hour"

themulticaster — Tue, 14 Mar 2023 22:54:17 +0000

This is the way. In theory, you're only supposed to downvote comments that don't contribute to the discussion. For me, that mostly amounts to very rude/unhelpful comments or extremely flawed arguments (flat earth level, not just arguments I strongly disagree with).

On the other hand, I find it's easy to be downvoted into oblivion for no apparent reason. I find it hard to just ignore and forget about those threads, even though I know I should. Example (sorry, I have to get this off my chest): a redditor with a history of substance abuse started with winemaking (as a hobby) and asked how many glasses of wine they could safely consume. A physician (verified in that subreddit) responded that two glasses every day would be fine. I commented (as a medical layperson) that suggesting OP that it's safe to drink two glasses of wine every day (not just every now and then) might not be a good idea considering their history, at least to my knowledge. Suffice to say, that day I learned that some people seem to be easily offended when commenting about reasonable alcohol consumption considering past addictions. Or perhaps I'm vastly overestimating the risks of substance abuse disorders...

New comment by themulticaster in "Effortless Performance Improvements in C++: std:unordered_map"

themulticaster — Thu, 02 Mar 2023 22:30:02 +0000

Well, using the identity function as a hash does not provide any avalanche effect at all. And as parent comments point out, certain hash map implementations require a strong hash function. I'm guessing that the identity function probably isn't a "good" hash function as required by abseil's swiss tables and similar hash maps, but to be honest I haven't looked into this any further. Put another way, I'd have expected std::hash to be at least a very basic hash function (like FNV-1 for example).

New comment by themulticaster in "Effortless Performance Improvements in C++: std:unordered_map"

themulticaster — Thu, 02 Mar 2023 13:59:58 +0000

I was genuinely surprised when I stumbled upon this Stack Overflow question [1] where someone asked why std::hash is the identity function for int, and some commenters argue that it is a perfectly sensible choice for a hash function.

[1] https://stackoverflow.com/questions/38304877/why-stdhashint-...