The point of the btree example is to test how good programming languages are at allocating tree-like structures that can't be preplanned. It's a valid argument that this is a rare real-world requirement, but it's not contrived to be slower.
> The point of the btree example is to test how good programming languages are at allocating tree-like structures that can't be preplanned.
Forcing allocations for every node isn't justified by a desire to demonstrate dynamically sized binary trees. A naive dynamically-sized tree would just keep a list of node buffers and allocate a new node buffer every time the previous one fills up (perhaps with subsequent buffers doubling in size). The benchmark is, by all appearances, contrived to be slower.
1. That’s plainly not the case here since other languages are allowed to use custom allocators
2. Why use a binary tree benchmark in the first place if you’re going to limit the implementation to certain naive implementations (and again, only for one language)? Why not just measure allocations outright or at least call the benchmark “allocator performance”?
3. Showing allocation performance doesn’t help anyone understand the actual performance of the language, which is transparently what everyone uses these benchmarks for. If they wanted a general idea for language performance they would allow trivial, idiomatic optimizations. A benchmark that shows allocation performance is worthless, and a suite of benchmarks that includes a benchmark for allocation performance but not GC latency is worse than worthless: it’s misleading because latency is the more important concern and it’s what these bump allocators trade in order to get their fast allocation performance.
Looking at the fastest Java, Haskell, Racket, OCaml, JavasScript, C#... they're all doing per-node allocation using the standard allocator, and all beating Go. The limit is not just for Go. I don't know why you think that Go is the only one being disadvantaged here.
I believe this is all addressed in my original post: https://news.ycombinator.com/item?id=28293381. If you have specific questions/concerns, I'm happy to address them, but I don't see the point in repeating myself.
1. btree; see the Rust version which uses a bump allocator for example
2. Doesn't matter whether it's exactly one language.
> You are allowed an opinion about what is or is not compelling.
It's not a matter of opinion. The definitional purpose of benchmarks is to indicate something about reality; if you contrive rules that cause the benchmarks to deviate from reality, they lose their utility as benchmarks. I've demonstrated that the rules are contrived (i.e., they prohibit real-world, idiomatic optimizations), so I think we can say as a matter of fact that these benchmarks aren't useful.
Of course, no one can force anyone else to see reason (but I don't have any interest in talking with unreasonable people).
1. See all of the other arguments in this thread about "contrived rules"
> You have repeatedly claimed "only for one language".
How many languages are in practice prevented from using pre-allocation? How big is the cohort? Does it matter if it's exactly one or if it's two or three? Why are you fixating on this relatively irrelevant point rather than the more substantial point that has been reiterated a dozen times?
> Apparently that is your opinion.
In the same sense that "the sky is blue" is merely my opinion.
Not special treatment, just a rules that allow for idiomatic programs. Of course I’ve said as much a dozen times now and you won’t engage with it, so I don’t expect you to now. ¯\_(ツ)_/¯
