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Subject: Re: [TECH TOPIC] Rust for Linux
From: Johannes Berg <johannes@sipsolutions.net>
To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>, Linus Walleij
	 <linus.walleij@linaro.org>
Cc: Leon Romanovsky <leon@kernel.org>, ksummit@lists.linux.dev
Date: Tue, 06 Jul 2021 21:13:14 +0200
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On Tue, 2021-07-06 at 16:30 +0200, Miguel Ojeda wrote:
> 
> But that does not mean we are not rewriting a second kernel either --
> for instance, we have red-black trees "abstracted" in the Rust side by
> reusing C's API.
> 
> In other words, what we are doing is "abstract" the C APIs into Rust
> APIs that can ensure as many invariants as possible statically, using
> Rust facilities for that. Thus Rust is one more consumer of the C
> APIs.

I couldn't really find a good place too hang this question, so it's here
now ;-)

Mostly from what I've seen you've been talking about rust being the
'leaves' in the graph, in the sense that it consumes C APIs exposed by
the kernel elsewhere, etc. In drivers using things, for example.

How about the other way around? What if we'd want to slowly replace
(parts of) a subsystem with rust code, but leave drivers? Or let's say
write some data structures in rust because of the stated benefits, but
let C consumers exist?

johannes