Re: [PATCH v3 10/16] rust: add devres abstraction

[Alice Ryhl <aliceryhl@google.com>]

On Tue, Oct 22, 2024 at 11:33 PM Danilo Krummrich <dakr@kernel.org> wrote:
>
> Add a Rust abstraction for the kernel's devres (device resource
> management) implementation.
>
> The Devres type acts as a container to manage the lifetime and
> accessibility of device bound resources. Therefore it registers a
> devres callback and revokes access to the resource on invocation.
>
> Users of the Devres abstraction can simply free the corresponding
> resources in their Drop implementation, which is invoked when either the
> Devres instance goes out of scope or the devres callback leads to the
> resource being revoked, which implies a call to drop_in_place().
>
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>

How is this intended to be used? Every single field I add of this type
is going to result in an additional synchronize_rcu() call in my
destructor. Those calls are pretty expensive.

Alice