flamegraph VS pprof-rs

You can install cargo-flamegraph with cargo install flamegraph. There are some underlying requirements to be able to use cargo-flamegraph; you will want to take a look at the repo here to make sure you have the right dependencies.

I tried to diagnose the issue with flamegraph, but unfortunately the flamegraph didn't show anything beyond the next call for some reason

having some tools to identify slowness origins (flamegraph is one... but not sure it's the way to go)

I'm currently implementing a solution for the first part of the day 16. It work but it is really slow... I'd like to : - understand why - having some tools to identify slowness origins (flamegraph is one... but not sure it's the way to go) - eventually have some clue/solution/idea - have general feedback on what in my "coding style" is not appropriate for rust (I come from java/kotlin/ts even if I've already coded a bit in c/c++) : for example I love iterator & sequence but i feel they are not really suited to overuse in rust (mostly because of async & result).

Use a profiler. Flamegraph is a good way to visualise profiler output. This lets you identify which functions are taking up a large amount of time - and hence helps you identify where to focus your optimisation efforts.

You tried trying to see what takes the most time under load via flames? https://github.com/flamegraph-rs/flamegraph

Well, in cases like that the answer is straight forward, use a profiler like https://github.com/flamegraph-rs/flamegraph

I don't see any obvious problems with your algorithm. I've had luck using cargo-flamegraph to identify the slow parts of my code. That's going to show you which parts to focus on improving the performance of!

From the readme of cargo flamegraph:

On top of others' specific recommendations, don't forget to profile! Tools like perf on Linux and pprof within Rust will tell you which functions are taking the most time.

https://github.com/tikv/pprof-rs: Seems to work nicely per se, but I cant seem to find any useful information in the flamegraph for my setting. I see mostly functions in std::thread but cant find the time it costs to render stuff or to do the actual computations which should be the most time consuming things. Not sure whether this is necessarily something wrong with pprof-rs, maybe I'm just bad at finding stuff in the flamegraph svg or bevys ECS is making this hard.

Have you looked into using pprof?

The library doesn't actually do any profiling (The profiler for Rust is pprof-rs: https://github.com/tikv/pprof-rs) but it's goal is to manage data returned by profilers (abstracted behind a Backend) and send this data to a Pyroscope Server (or exported to flamegraph, though this is being implemented in the commandline application).

The libunwind part is actually not related to overhead, this is just a nuance of the way that pprof-rs unwinds stack traces.