Re: [PATCH v6 9/9] rust: sync: atomic: Add Atomic<{usize,isize}>

Benno Lossin
2025-07-11T19:05:47Z

On Fri Jul 11, 2025 at 3:45 PM CEST, Miguel Ojeda wrote:
> On Fri, Jul 11, 2025 at 11:00 AM Benno Lossin <lossin@kernel.org> wrote:
>>
>> Do we have a static assert with these cfgs that `isize` has the same
>> size as these?
>>
>> If not, then it would probably make sense to add them now.
>
> Yeah, according to e.g. Matthew et al., we may end up with 128-bit
> pointers in the kernel fairly soon (e.g. a decade):
>
> https://lwn.net/Articles/908026/
>
> I rescued part of what I wrote in the old `mod assumptions` which I
> never got to send back then -- most of the `static_asserts` are
> redundant now that we define directly the types in the `ffi` crate (I
> mean, we could still assert that `size_of::<c_char>() == 1` and so on,
> but they are essentially a tautology now), so I adapted the comments.
> Please see below (draft).

Ahhh yes the `mod assumptions` was the thing I remembered! I think it's
still useful as a file where we can put other global assumptions as
well.

---
Cheers,
Benno