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Date: Tue, 12 Aug 2025 10:11:43 +0200
Message-Id: <DC0AQ1UOF0TG.134431D3TCJ9W@kernel.org>
Cc: <rust-for-linux@vger.kernel.org>, "Fiona Behrens" <me@kloenk.dev>,
 <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 1/5] rust: implement `kernel::sync::Refcount`
From: "Benno Lossin" <lossin@kernel.org>
To: "Gary Guo" <gary@kernel.org>, "Miguel Ojeda" <ojeda@kernel.org>, "Alex
 Gaynor" <alex.gaynor@gmail.com>, "Boqun Feng" <boqun.feng@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>, "Tamir Duberstein" <tamird@gmail.com>, "Ingo
 Molnar" <mingo@kernel.org>, "Mitchell Levy" <levymitchell0@gmail.com>,
 "Lyude Paul" <lyude@redhat.com>, "Wedson Almeida Filho"
 <wedsonaf@gmail.com>, "Viresh Kumar" <viresh.kumar@linaro.org>
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References: <20250723233312.3304339-1-gary@kernel.org>
 <20250723233312.3304339-2-gary@kernel.org>
In-Reply-To: <20250723233312.3304339-2-gary@kernel.org>

On Thu Jul 24, 2025 at 1:32 AM CEST, Gary Guo wrote:
> +    /// Set a refcount's value.
> +    #[inline]
> +    pub fn set(&self, value: i32) {
> +        // SAFETY: `self.as_ptr()` is valid.
> +        unsafe { bindings::refcount_set(self.as_ptr(), value) }
> +    }

One more thing, I think this function could use some better docs. When
do you want to use it? (How) does it synchronize with other reads/writes?

---
Cheers,
Benno