Re: [syzbot] possible deadlock in worker_thread

Tejun Heo
2022-02-22T18:27:08Z

On Tue, Feb 15, 2022 at 09:05:38AM -0800, Bart Van Assche wrote:
> On 2/15/22 04:48, Tetsuo Handa wrote:
> > I do not want to do like
> >
> > - system_wq = alloc_workqueue("events", 0, 0);
> > + system_wq = alloc_workqueue("events", __WQ_SYSTEM_WIDE, 0);
> >
> > because the intent of this change is to ask developers to create their own WQs.
>
> I want more developers to use the system-wide workqueues since that reduces
> memory usage. That matters for embedded devices running Linux.

Each wq is just a frontend interface to backend shard pool and doesn't
consume a lot of memory. The only consumption which would matter is when
WQ_MEM_RECLAIM is specified which creates its dedicated rescuer thread to
guarantee forward progress under memory contention, but we aren't talking
about those here.

Thanks.

--
tejun