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Date: Wed, 27 Mar 2024 13:53:33 +0000
To: Wedson Almeida Filho <wedsonaf@gmail.com>
From: Benno Lossin <benno.lossin@proton.me>
Cc: rust-for-linux@vger.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@samsung.com>, Alice Ryhl <aliceryhl@google.com>, linux-kernel@vger.kernel.org, Wedson Almeida Filho <walmeida@microsoft.com>
Subject: Re: [PATCH 2/2] samples: rust: add in-place initialisation sample
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On 27.03.24 04:23, Wedson Almeida Filho wrote:
> diff --git a/samples/rust/rust_inplace.rs b/samples/rust/rust_inplace.rs
> new file mode 100644
> index 000000000000..ba8d051cac56
> --- /dev/null
> +++ b/samples/rust/rust_inplace.rs
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +//! Rust minimal in-place sample.
> +
> +use kernel::prelude::*;
> +
> +module! {
> +    type: RustInPlace,
> +    name: "rust_inplace",
> +    author: "Rust for Linux Contributors",
> +    description: "Rust minimal in-place sample",
> +    license: "GPL",
> +}
> +
> +#[pin_data(PinnedDrop)]
> +struct RustInPlace {
> +    numbers: Vec<i32>,
> +}
> +
> +impl kernel::InPlaceModule for RustInPlace {
> +    fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
> +        pr_info!("Rust minimal sample (init)\n");

This text needs updating.

> +        pr_info!("Am I built-in? {}\n", !cfg!(MODULE));
> +        try_pin_init!(Self {
> +            numbers: {
> +                let mut numbers =3D Vec::new();
> +                numbers.push(72, GFP_KERNEL)?;
> +                numbers.push(108, GFP_KERNEL)?;
> +                numbers.push(200, GFP_KERNEL)?;
> +                numbers
> +            },
> +        })

I think it might be useful to also have a field that needs pin-init, eg
a `Mutex` or similar. What about placing the `Vec` inside of a mutex?

--=20
Cheers,
Benno

> +    }
> +}
> +
> +#[pinned_drop]
> +impl PinnedDrop for RustInPlace {
> +    fn drop(self: Pin<&mut Self>) {
> +        pr_info!("My numbers are {:?}\n", self.numbers);
> +        pr_info!("Rust minimal inplace sample (exit)\n");
> +    }
> +}
> --
> 2.34.1
>=20