Re: [PATCH] workqueue: rust: add delayed work items

[Alice Ryhl]

On Mon, Apr 14, 2025 at 07:47:19AM -1000, Tejun Heo wrote:
> On Fri, Apr 11, 2025 at 11:12:29AM +0000, Alice Ryhl wrote:
> > 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.
> > 
> > Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
> 
> FWIW, looks fine to me on the first glance. Please let me know how you want
> to route it. If you want it to be through the wq tree, please let me know
> what to do about the dependencies (I just applied the "remove
> HasWork::OFFSET" patch to wq/for-6.16 but don't have the other one).

Normally I think it is most natural for workqueue patches to go through
your tree, but it may be easier to take it through Miguel's tree with
your ack as an exception this merge window since the container_of change
will probably also affect other work.

It sounds like this is also the conclusion you and Miguel came to in the
thread on the HasWork::OFFSET patch.

(If you're planning to change the default workqueue configuration from
PERCPU to UNBOUNDED this merge window, then please let me know because
it might change the calculus here.)

Alice