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Date: Sat, 16 Aug 2025 21:35:26 +0200
Message-Id: <DC43RPUDBY6M.1TGSQKJV9BKSF@kernel.org>
From: "Benno Lossin" <lossin@kernel.org>
To: "Boqun Feng" <boqun.feng@gmail.com>
Cc: <linux-kernel@vger.kernel.org>, <rust-for-linux@vger.kernel.org>,
 <lkmm@lists.linux.dev>, <linux-arch@vger.kernel.org>, "Miguel Ojeda"
 <ojeda@kernel.org>, "Alex Gaynor" <alex.gaynor@gmail.com>, "Gary Guo"
 <gary@garyguo.net>, =?utf-8?q?Bj=C3=B6rn_Roy_Baron?=
 <bjorn3_gh@protonmail.com>, "Andreas Hindborg" <a.hindborg@kernel.org>,
 "Alice Ryhl" <aliceryhl@google.com>, "Trevor Gross" <tmgross@umich.edu>,
 "Danilo Krummrich" <dakr@kernel.org>, "Will Deacon" <will@kernel.org>,
 "Peter Zijlstra" <peterz@infradead.org>, "Mark Rutland"
 <mark.rutland@arm.com>, "Wedson Almeida Filho" <wedsonaf@gmail.com>,
 "Viresh Kumar" <viresh.kumar@linaro.org>, "Lyude Paul" <lyude@redhat.com>,
 "Ingo Molnar" <mingo@kernel.org>, "Mitchell Levy"
 <levymitchell0@gmail.com>, "Paul E. McKenney" <paulmck@kernel.org>, "Greg
 Kroah-Hartman" <gregkh@linuxfoundation.org>, "Linus Torvalds"
 <torvalds@linux-foundation.org>, "Thomas Gleixner" <tglx@linutronix.de>,
 "Alan Stern" <stern@rowland.harvard.edu>
Subject: Re: [PATCH v8 6/9] rust: sync: atomic: Add the framework of
 arithmetic operations
X-Mailer: aerc 0.20.1
References: <20250719030827.61357-1-boqun.feng@gmail.com>
 <20250719030827.61357-7-boqun.feng@gmail.com>
 <DC0AKAL1LW84.MR2RFTMX1H61@kernel.org> <aKCtbSDuJNrtdLNp@tardis-2.local>
In-Reply-To: <aKCtbSDuJNrtdLNp@tardis-2.local>

On Sat Aug 16, 2025 at 6:10 PM CEST, Boqun Feng wrote:
> On Tue, Aug 12, 2025 at 10:04:12AM +0200, Benno Lossin wrote:
>> On Sat Jul 19, 2025 at 5:08 AM CEST, Boqun Feng wrote:
>> > +/// Types that support atomic add operations.
>> > +///
>> > +/// # Safety
>> > +///
>> > +/// `wrapping_add` any value of type `Self::Repr::Delta` obtained by =
[`Self::rhs_into_delta()`] to
>>=20
>> Can you add a normal comment TODO here:
>>=20
>>     // TODO: properly define `wrapping_add` in this context.
>
> Yeah, this sounds good to me. How do you propose we arrange the normal
> comment with the doc comment, somthing like:
>
>     // TODO: properly define `wrapping_add` in this context.
>    =20
>     /// Types that support atomic add operations.
>     ///
>     /// # Safety
>     ///
>     /// `wrapping_add` any value of type `Self::Repr::Delta` obtained by =
[`Self::rhs_into_delta()`] to
>     ...
>     pub unsafe trait AtomicAdd<...> {
>         ...
>     }


Inline maybe?

    /// Types that support atomic add operations.
    ///
    /// # Safety
    ///
    // TODO: properly define `wrapping_add` in this context:
    /// `wrapping_add` any value of type `Self::Repr::Delta` obtained by [`=
Self::rhs_into_delta()`] to
    /// any value of type `Self::Repr` obtained through transmuting a value=
 of type `Self` to must
    /// yield a value with a bit pattern also valid for `Self`.

---
Cheers,
Benno