Re: [PATCH 0/5] Rust abstractions for network device drivers

[Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>]

On Fri, Jun 16, 2023 at 4:43 PM Andrew Lunn <andrew@lunn.ch> wrote:
>
> I said in another email, i don't want to suggest premature
> optimisation, before profiling is done. But in C, these functions are
> inline for a reason. We don't want the cost of a subroutine call. We
> want the compiler to be able to inline the code, and the optimiser to
> be able to see it and generate the best code it can.

See my reply in v2 to your message where I mentioned some of the
options we are considering [1] -- not sure if you saw it:

> Yeah, other use cases will also need that solved, e.g. Andreas for his
> NVMe work.
>
> We discussed reimplementing performance-critical bits in Rust as you
> suggest, as well as cross-language LTO. We also talked about possible
> alternative approaches like "manual local LTO" for the helpers only
> via feeding their LLVM IR to `rustc`, which may recover most of the
> performance without having to go for full LTO and its associated
> kernel link times.

[1] https://lore.kernel.org/rust-for-linux/CANiq72kyUhvmG6KB32X1vuhNzOOJbs7R1JbK+vnPELX4tG73RA@mail.gmail.com/

Cheers,
Miguel