rustc-perf VS wg

> what do people use to run benchmarks on CI?

Typically, you purchase/rent a server that does nothing but sequentially run queued benchmarks (and the size/performance of this server doesn't really matter, as long as the performance is consistent), then sends the report somewhere for hosting and processing. Of course, this could be triggered by something running in CI, and the CI job could wait for the results, if benchmarking is an important part of your workflow.

But CI and benchmarks really shouldn't be run on the same host.

> What does the rust project use?

It's not clear exactly where the Rust benchmark "perf-runner" is hosted, but here are the specifications of the machine at least: https://github.com/rust-lang/rustc-perf/blob/414230abc695bd7...

> What do other projects use?

Essentially what I described above, a dedicated machine that runs benchmarks. The Rust project seems to do it via GitHub comments (as I understand https://github.com/rust-lang/rustc-perf/tree/master/collecto...), others have API servers that respond to HTTP requests done from CI/chat, others have remote GUIs that triggers the runs. I don't think there is a single solution that everyone/most are using.

A lot of effort is spent to reduce the size of structs in the Rust compiler

https://nnethercote.github.io/2023/03/24/how-to-speed-up-the...

3% and 6% of improvement doesn't seem like much, but at the level of rustc those big wins

Performance of Rustc must be continously tracked (here https://perf.rust-lang.org/) because if you don't proactively fight against bloat, the tendency is that the code will become slower over time (due to new features etc)

hmm really really hard to answer :'), it's tradeoffs I think, no matter what you think Rust (cmiiw, I'm not qualified to say this) has (and probably in the future will adds more with guards on compiler metrics https://perf.rust-lang.org/) several phases that given the diffs to other language, might not available to any language compiler out there, if it's available I think rustc already did their best in here (some already being parallized etc etc, might be wrong since I can't refs any reference MRs, but it does exists though labels regarding this)

About a year ago I was looking for a tool like Rust perf for my application code. I did some research and found a lot of prior art. However, nothing checked all the boxes I was looking for, so I built Bencher!

https://www.pingcap.com/blog/rust-compilation-model-calamity... is a good overview. In general it varies depending on the crate but we track the performance at https://perf.rust-lang.org/ - if you look at cargo, for example, over 60% of the time is spent in codegen through LLVM: https://perf.rust-lang.org/detailed-query.html?commit=222d1f...

Something like https://perf.rust-lang.org/?

The performance full-report link is dead: https://github.com/rust-lang/rustc-perf/blob/master/triage/2022-10-04.md

Inspired by James Munns's call, and as 2023 is coming to an end, I figure it's a good opportunity to reflect and look forward to 2024. It's been a bit over 1.5 years since I embarked on my embedded Rust journey and it's been nothing less than exciting since. So here it goes.

Because you are an embedded guy. There is the https://github.com/rust-embedded/wg working-group. Rust on embedded is really on a got track forward. There are many chips/vendors that are supported both in no std / std rust world, but still there is a lot of niche things where you can actively help to be the first to get it run in Rust.

To specifically answer your question, here:

* <http://www.areweembeddedyet.com/>

It currently redirects to:

* <https://rust-embedded.org>

Which doesn't really contain anything other than a link to <https://github.com/rust-embedded>.

(via <https://github.com/rust-embedded/wg/issues/15>)

Then the Rust Embedded workgroup provides: - Direction on how to using generics and zero-sized types to achieve functional safety - svd2rust, which provides safe abstractions to peripheral access from SVD files and achieves this functional safety - The embedded HAL spec, which makes porting to different vendors/hardware easy - Peripheral access controllers and HALs for various vendors & hardware

The Rust Embedded Devices Working Group curates a list of useful embedded Rust resources, including Peripheral Access Crates (autogenerated from SVD files), embedded-hal Implementation Crates (hand-written libraries implementing the traits (interfaces) specified by the embedded-hal), and Board Support Crates.

You should also look at https://github.com/rust-embedded/wg/issues/41 and https://github.com/rust-lang/rust/pull/55011#issuecomment-429336055.

Here's an interesting discussion, consolidated here. My view is you should use a restricted scope atomic (as best as can be supported) and interact with that through a handler struct. I.e. no global state.

Most of the issues are explained in EWG RFC 419. The TL;DR is that some resources need to implement Send to be usable from interrupts, but they must not be sent across cores.