This patch is being sent for use in the various Rust GPU drivers that
are under development. It provides the additional feature of work items
that are executed after a delay.
The design of the existing workqueue is rather extensible, as most of
the logic is reused for delayed work items even though a different work
item type is required. The new logic consists of:
* A new DelayedWork struct that wraps struct delayed_work.
* A new impl_has_delayed_work! macro that provides adjusted versions of
the container_of logic, that is suitable with delayed work items.
* A `enqueue_delayed` method that can enqueue a delayed work item.
This patch does *not* rely on the fact that `struct delayed_work`
contains `struct work_struct` at offset zero. It will continue to work
even if the layout is changed to hold the `work` field at a different
offset.
Please see the example introduced at the top of the file for example
usage of delayed work items.
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250711-workqueue-delay-v3-1-3fe17b18b9d1@google.com
[ Replaced `as _` with `as ffi::c_int` to clean warning. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
7c098cd5ea