Re: [PATCH v3 2/2] workqueue: Add warnings and ensure one among WQ_PERCPU or WQ_UNBOUND is present

[Marco Crivellari]

Hi,

On Thu, May 28, 2026 at 6:25 PM Tejun Heo <tj@xxxxxxxxxx> wrote:
>
> On Thu, May 28, 2026 at 06:01:59PM +0200, Marco Crivellari wrote:
> ...
> > @@ -5850,6 +5850,23 @@ static struct workqueue_struct *__alloc_workqueue(const char *fmt,
> >               pr_warn_once("workqueue: name exceeds WQ_NAME_LEN. Truncating to: %s\n",
> >                            wq->name);
> >
> > +     /*
> > +      * One among WQ_PERCPU and WQ_UNBOUND must be set, but not both.
> > +      * - If neither is set, default to WQ_PERCPU
> > +      * - If both are set, default to WQ_UNBOUND
> > +      *
> > +      * This code can be removed after workqueue are unbound by default
> > +      */
> > +     if (!(flags & (WQ_UNBOUND | WQ_PERCPU))) {
> > +             pr_warn_ratelimited("workqueue: %s is using neither WQ_PERCPU or WQ_UNBOUND. "
> > +                     "Setting WQ_PERCPU.\n", wq->name);
> > +             flags |= WQ_PERCPU;
> > +     } else if((flags & WQ_PERCPU) && (flags & WQ_UNBOUND)) {
> > +             pr_warn_ratelimited("workqueue: %s uses both WQ_PERCPU and WQ_UNBOUND. "
> > +                     "Dropped WQ_PERCPU, keeping WQ_UNBOUND.\n", wq->name);
> > +             flags &= (~WQ_PERCPU);
> > +     }
>
> Let's just WARN_ONCE() on these. These are outright bugs, right?

Yes, they are. I will change this to use WARN_ONCE() for the next version.

Thanks!
-- 

Marco Crivellari

SUSE Labs