Re: [PATCH 0/4] Workqueue: rename system workqueue and add WQ_PERCPU

[Marco Crivellari]

Hi,

> I assume the huge patches were made with coccinelle?

Yes, the majority of P4 at least. Considering my lack of experience with
Coccinelle I made just the big parts with it, then I just "grepped" for the
rest (well, I used LazyVim and its "search and replace").

P 1-2: only with the "search and replace" of LazyVim.

Thanks!



On Mon, May 5, 2025 at 8:51 AM Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
>
> On 2025-05-03 10:28:30 [+0200], Marco Crivellari wrote:
> > Hi!
> Hi,
>
> > This series is the follow up of the discussion from:
> >       "workqueue: Always use wq_select_unbound_cpu() for WORK_CPU_UNBOUND."
> >       https://lore.kernel.org/all/20250221112003.1dSuoGyc@xxxxxxxxxxxxx/
> >
> > 1)  [P 1-2] system workqueue rename:
> >
> >       system_wq is a per-CPU workqueue, but his name is not clear.
> >       system_unbound_wq is to be used when locality is not required.
> >
> >       system_wq renamed in system_percpu_wq, while system_unbound_wq
> >       became system_dfl_wq.
> >
> > 2)  [P 3] Introduction of WQ_PERCPU.
> >
> >       This patch adds a new WQ_PERCPU flag to explicitly request the legacy
> >       per-CPU behavior. WQ_UNBOUND will be removed once the migration is
> >       complete.
> >
> >       Every alloc_workqueue() caller should use one among WQ_PERCPU or
> >       WQ_UNBOUND. This is actually enforced warning if both or none of them
> >       are present at the same time.
> >
> > 3)  [P 4] alloc_workqueue() callee should pass explicitly WQ_PERCPU.
> >
> >       This patch ensures that every caller that needs per-cpu workqueue
> >       will explicitly require it, using the WQ_PERCPU flag.
>
> Sounds like a plan.
> I assume the huge patches were made with coccinelle?
>
> Sebastian



--

Marco Crivellari

L3 Support Engineer, Technology & Product




marco.crivellari@xxxxxxxx