Re: [WIP 0/3] Memory model and atomic API in Rust

Kent Overstreet
2024-03-23T01:42:49Z

On Fri, Mar 22, 2024 at 05:49:23PM -0700, Boqun Feng wrote:
> On Fri, Mar 22, 2024 at 05:15:08PM -0700, Boqun Feng wrote:
> [...]
> > >
> > > I wonder about that. The disadvantage of only supporting LKMM atomics is
> > > that we'll be incompatible with third party code, and we don't want to
> > > be rolling all of our own data structures forever.
> > >
> >
> > A possible solution to that is a set of C++ memory model atomics
> > implemented by LKMM atomics. That should be possible.
> >
>
> Another possible "solution" works in the opposite direction, since the
> folder rust/kernel/sync/atomic is quite stand-alone, we can export that
> as a Rust crate (library), and third party code can support using LKMM
> atomics instead of Rust own atomics ;-) Of course if the project is
> supposed to work with Linux kernel.

Not just from the Rust side, the C side would be useful as well. I've
got a quicky, dirty, hacky version of that in bcachefs-tools, and I
would switch immediately if someone took that over and made it a real
project, and I'm quite sure other projects would as well.