ot

5 ms·

31.
Generate evolving textures by blending images(github.com)
1 points by ot 7mo ago|0 comments
32.
Apache Iggy's migration to thread-per-core architecture powered by io_uring(iggy.apache.org)
2 points by ot 7mo ago|0 comments
33.
by ot 7mo ago
This is drawing broad conclusions from a specific RW mutex implementation. Other implementations adopt techniques to make the readers scale linearly in the read-mostly case by using per-core state (the drawback is that write locks need to s
34.
by ot 8mo ago
Glad that Moby Dick is in there.
35.
The Anthropic Hive Mind(steve-yegge.medium.com)
4 points by ot 8mo ago|1 comments
36.
Designing AI resistant technical evaluations(anthropic.com)
3 points by ot 9mo ago|0 comments
37.
by ot 9mo ago
> Presumably you mean you just double check the page value after the rdtsc to make sure it hasn't changed and retry if it has? Yes, that's exactly what a seqlock (reader) is.
38.
by ot 9mo ago
Yes you need some lazy setup in thread-local state to use this. And short-lived threads should be avoided anyway :)
39.
by ot 9mo ago
You can do even faster, about 8ns (almost an additional 10x improvement) by using software perf events: PERF_COUNT_SW_TASK_CLOCK is thread CPU time, it can be read through a shared page (so no syscall, see perf_event_mmap_page), and then yo
40.
by ot 9mo ago
If you look below the vDSO frame, there is still a syscall. I think that the vDSO implementation is missing a fast path for this particular clock id (it could be implemented though).
41.
by ot 9mo ago
That's probably true for small primitive types, but if your objects are expensive to move (like a large struct) it might be beneficial to minimize swaps.
42.
by ot 9mo ago
Yeah, was just about to edit the comment :)
43.
by ot 9mo ago
The query is incorrect, it will return any posting that contains the words "vision" and "pro", not necessarily consecutive. It looks like phrasal search is supported, searching "vision pro" in quotes only retur
44.
by ot 10mo ago
> can avoid or defer a lot of the expected memory allocations of async operations Is this true in realistic use cases or only in minimal demos? From what I've seen, as soon as your code is complex enough that you need two compilatio
45.
by ot 10mo ago
Is it so hard for people to understand that Europe is a continent, EU is a federation of European countries, and the two are not the same?
46.
by ot 11mo ago
> It kind of doesn’t matter if there are users [...] The point is that PCG is better No that's not the point that the article makes and that I'm questioning, it says "everyone shrugged" which implies consensus, and I&
47.
by ot 11mo ago
> Since nobody had figured out any downsides to PCG's yet, everyone shrugged and said "might as well just go with that then", and that is where, as of 2019, the art currently stands. The problem is solved, and life is good
48.
by ot 1y ago
But then you could add another level of slower (but still faster than RAM) and larger cache. So it is after all the CPU caches, but the first of all the memory caches. A more mathematically correct name would be L_omega.
49.
by ot 1y ago
Reminds me of the old quote > everyone only uses 20% of C++, the problem is that everyone uses a different 20%
50.
by ot 1y ago
> It was so easy once we saw it that there was no reason to keep the placemat for notes, and we left it behind. Or maybe we did bring it back to the lab; I'm not sure. But it's gone now. https://commandcenter.blogspo
51.
by ot 1y ago
It is a linear percentage of the amount of time the CPU is not idle. It is not linear in the amount of useful work, but that's not what "utilization" means. The lie is the assumption that CPU time is linear in useful work, bu
52.
by ot 1y ago
Utilization is not a lie, it is a measurement of a well-defined quantity, but people make assumptions to extrapolate capacity models from it, and that is where reality diverges from expectations. Hyperthreading (SMT) and Turbo (clock scalin
53.
by ot 1y ago
I'm not sure which comment you're responding to, because I'm not talking about shared_ptr, but about how atomic operations in general are implemented on x86. I don't believe that shared_ptr uses seq-cst because I can jus
54.
by ot 1y ago
The joke is almost 5 minutes into the talk: he didn't start with one. His point is that in the first few minutes the audience is still warming up and many wouldn't pay attention to the joke.
55.
by ot 1y ago
Not a L1/L2/... cache flush, but a store buffer flush, at least on x86. This is true for LOCK instructions. Loads/stores (again on x86) are always acquire/release, so they don't need additional fences if you don&#x2
56.
by ot 1y ago
From Wikipedia ( https://en.wikipedia.org/wiki/Hirudo_medicinalis ) > Because of the minuscule amounts of hirudin present in leeches, it is impractical to harvest the substance for widespread medical use. Hirudin (and
57.
by ot 1y ago
> Trump works transactionally Why can't we just call this corruption? Is there any other, more charitable, interpretation of "transactional"?
58.
by ot 1y ago
The SWAR escaping algorithm [1] is very similar to the one I implemented in Folly JSON a few years ago [2]. The latter works on 8 byte words instead of 4 bytes, and it also returns the position of the first byte that needs escaping, so that
59.
by ot 1y ago
Now it's O(0.5)
60.
by ot 1y ago
Yes, but crucially, only 1/period, not on every single "should log?" call, which is what I was referring to above. The per-thread mutexes are uncontended virtually all the time.

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