Re: work item still be scheduled to execute after destroy_workqueue?

[Lai Jiangshan]

On Tue, Dec 6, 2022 at 12:35 PM richard clark
<richard.xnu.clark@xxxxxxxxx> wrote:

> >
> A WARN is definitely reasonable and has its benefits. Can I try to
> submit the patch and you're nice to review as maintainer?
>
> Thanks,
> Richard
> >

Sure, go ahead.

What's in my mind is that the following code is wrapped in a new function:

        mutex_lock(&wq->mutex);
        if (!wq->nr_drainers++)
                wq->flags |= __WQ_DRAINING;
        mutex_unlock(&wq->mutex);


and the new function replaces the open code drain_workqueue() and
is also called in destroy_workqueue() (before calling drain_workqueue()).


__WQ_DRAINING will cause the needed WARN on illegally queuing items on
destroyed workqueue.

Thanks
Lai