Hacker News: tavianator

New comment by tavianator in "ARC-AGI-3"

tavianator — Thu, 26 Mar 2026 02:21:31 +0000

> Airplanes don't have wings

???

New comment by tavianator in "Comma openpilot – Open source driver-assistance"

tavianator — Sat, 24 Jan 2026 04:16:49 +0000

No: https://en.wikipedia.org/wiki/Sony_Computer_Entertainment_Am...

New comment by tavianator in "A bug that taught me more about PyTorch than years of using it"

tavianator — Sun, 26 Oct 2025 13:56:48 +0000

Presumably that's just a mistake. The author calls it "stochastic gradient descent" correctly elsewhere in the article

There is no memory safety without thread safety

tavianator — Thu, 24 Jul 2025 15:35:39 +0000

Article URL: https://www.ralfj.de/blog/2025/07/24/memory-safety.html

Comments URL: https://news.ycombinator.com/item?id=44672003

Points: 456

# Comments: 503

New comment by tavianator in "lsr: ls with io_uring"

tavianator — Fri, 18 Jul 2025 16:57:49 +0000

I did try it a while ago and it wasn't profitable, but that was before I added stat() support. Batching those is probably good

New comment by tavianator in "lsr: ls with io_uring"

tavianator — Fri, 18 Jul 2025 16:27:00 +0000

My bfs project also uses io_uring: https://github.com/tavianator/bfs/blob/main/src/ioq.c

I'm curious how lsr compares to bfs -ls for example. bfs only uses io_uring when multiple threads are enabled, but maybe it's worth using it even for bfs -j1

New comment by tavianator in "Pathfinding"

tavianator — Thu, 15 May 2025 18:52:35 +0000

You may want to look into improvements to A* for grids, like Rectangular Symmetry Reduction.

New comment by tavianator in "Show HN: Helixdb – Open-source vector-graph database for AI applications (Rust)"

tavianator — Tue, 13 May 2025 20:45:22 +0000

> There was no other helix db

https://en.wikipedia.org/wiki/Helix_(database)

New comment by tavianator in "Understanding Memory Management, Part 5: Fighting with Rust"

tavianator — Tue, 06 May 2025 14:35:58 +0000

They were referencing the title of a specific paper, which invented type classes: https://dl.acm.org/doi/10.1145/75277.75283

New comment by tavianator in "Driving Compilers (2023)"

tavianator — Mon, 05 May 2025 12:07:25 +0000

The C standard (since C99) says that `main()` has an implicit `return 0`, you don't need to write it explicitly.

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 18:56:27 +0000

I was looking for a relevant paper and found this one, which isn't what I was looking for but is related: https://sigops.org/s/conferences/hotos/2023/papers/liargkova...

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 17:07:21 +0000

My actual "production" implementation of this concept does support that: https://github.com/tavianator/bfs/blob/main/configure

But I wanted the blog post sized version to be simpler for exposition.

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 16:00:55 +0000

Just tried reconfiguring LLVM:

    27.24s user 8.71s system 99% cpu 36.218 total

Admittedly the LLVM build time dwarfs the configuration time, but still. If you're only building a smaller component then the config time dominates:

    ninja libc  268.82s user 26.16s system 3246% cpu 9.086 total

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 15:51:47 +0000

Fixed! https://github.com/tavianator/tavianator.com/commit/aa9d99d5...

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 04:56:35 +0000

Nice! I used to do something similar, don't remember exactly why I had to switch but the two step process did become necessary at some point.

Just from a quick peek at that repo, nowadays you can write

#if __has_attribute(cold)

and avoid the configure test entirely. Probably wasn't a thing 10 years ago though :)

New comment by tavianator in "Parallel ./configure"

tavianator — Sat, 26 Apr 2025 04:35:58 +0000

Whoops! Forgot to do that when I switched from a ``` block to raw html

New comment by tavianator in "fd: A simple, fast and user-friendly alternative to 'find'"

tavianator — Wed, 19 Mar 2025 18:56:03 +0000

You might be interested in rawhide[1] or fselect[2]. (Note: I don't really use them myself, but they seem to offer something like what you're suggesting.)

Also, this is still a find-style syntax, but my bfs utility supports -exclude [3]. So you can write

    bfs -type f -exclude -path ./excluded_dir

which is a bit more ergonomic.

[1]: https://github.com/raforg/rawhide

[2]: https://github.com/jhspetersson/fselect

[3]: https://github.com/tavianator/bfs/blob/main/docs/USAGE.md#-e...

New comment by tavianator in "fd: A simple, fast and user-friendly alternative to 'find'"

tavianator — Wed, 19 Mar 2025 15:38:17 +0000

At least with GNU coreutils, you can use `-r`/`--relative`

New comment by tavianator in "fd: A simple, fast and user-friendly alternative to 'find'"

tavianator — Wed, 19 Mar 2025 15:36:09 +0000

Someday I will get that functionality into fd :)

New comment by tavianator in "Writing a simple pool allocator in C"

tavianator — Thu, 09 Jan 2025 14:28:57 +0000

I've replaced Valgrind with sanitizers for most of my workflow. Using the sanitizer APIs in your custom allocator is also easy: https://github.com/tavianator/bfs/blob/main/src/sanity.h https://github.com/tavianator/bfs/blob/31dffd6441ba80ea998ce...