Linux-for-Rust or Rust-for-Linux [LWN.net]

Linux-for-Rust or Rust-for-Linux

Posted Aug 30, 2024 17:55 UTC (Fri) by Wol (subscriber, #4433)
In reply to: Linux-for-Rust or Rust-for-Linux by jgg
Parent article: Rust-for-Linux developer Wedson Almeida Filho drops out

> Your concern about inlines is news to me, that sounds kind of fatal honestly.

I was under the impression that - compiling huge monolithic blobs - Rust was quite capable of spotting and inlining functions like that all by itself. What's the point of an "inline" keyword if you can rely on the compiler to spot it?

(Dunno whether I like the downsides of huge blobs - it makes libraries more complicated - but it's horses for courses, or pick you poison, whichever suits ...)

Cheers,
Wol

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Linux-for-Rust or Rust-for-Linux

Posted Aug 30, 2024 20:12 UTC (Fri) by pbonzini (subscriber, #60935) [Link] (4 responses)

These are cross-language calls, so the call from Rust to C (say, to spin_lock()) will not be inlined.

Linux-for-Rust or Rust-for-Linux

Posted Aug 30, 2024 22:55 UTC (Fri) by roc (subscriber, #30627) [Link] (2 responses)

Mozilla has been inlining across the Rust-C++ boundary, using LTO, for five years: https://www.reddit.com/r/cpp/comments/ch7g6n/mozilla_just...

Linux-for-Rust or Rust-for-Linux

Posted Aug 31, 2024 5:38 UTC (Sat) by pbonzini (subscriber, #60935) [Link] (1 responses)

Linux however it's typically compiled with GCC. I remember people working on LTO for Linux a few years ago but I think that's not particularly common.

Linux-for-Rust or Rust-for-Linux

Posted Aug 31, 2024 6:16 UTC (Sat) by roc (subscriber, #30627) [Link]

OK, but the important thing is that there's an obvious fix for cross-language inlining if that becomes important.

Linux-for-Rust or Rust-for-Linux

Posted Aug 31, 2024 18:02 UTC (Sat) by Cyberax (✭ supporter ✭, #52523) [Link]

Even without LTO, a simple practical solution might be to duplicate some of the hottest code (e.g. spin_lock) in Rust. It's not great, but most of such code has been stable for quite a while.