[RFC 1/2] rust: Introduce atomic API helpers

[Peter Zijlstra]

On Thu, Jun 13, 2024 at 07:38:51AM +0200, Greg Kroah-Hartman wrote:
> On Wed, Jun 12, 2024 at 03:30:24PM -0700, Boqun Feng wrote:
> > +// Generated by scripts/atomic/gen-rust-atomic-helpers.sh
> > +// DO NOT MODIFY THIS FILE DIRECTLY
> 
> Why not just build this at build time and not check the file into the
> tree if it is always automatically generated?  That way it never gets
> out of sync.  We do this for other types of auto-generated files in the
> kernel today already.

Part of the problem is, is that a *TON* of files depend on the atomic.h
headers. If we'd generate it on every build, you'd basically get to
rebuild the whole kernel every single time.

Also, these files don't change too often. And if you look, there's a
hash in those files which is used to check if things somehow got stale.