Re: [syzbot] possible deadlock in worker_thread

Leon Romanovsky
2022-02-13T15:33:54Z

On Sun, Feb 13, 2022 at 02:14:09AM +0900, Tetsuo Handa wrote:
> On 2022/02/13 1:37, Bart Van Assche wrote:
> > On 2/11/22 21:31, Tetsuo Handa wrote:
> >> But this report might be suggesting us that we should consider
> >> deprecating (and eventually getting rid of) system-wide workqueues
> >> (declared in include/linux/workqueue.h), for since flush_workqueue()
> >> synchronously waits for completion, sharing system-wide workqueues
> >> among multiple modules can generate unexpected locking dependency
> >> chain (like this report).
> >
> > I do not agree with deprecating system-wide workqueues. I think that
> > all flush_workqueue(system_long_wq) calls should be reviewed since
> > these are deadlock-prone.
> >
> > Thanks,
> >
> > Bart.
>

I second to Bart's request to do not deprecate system-wide workqueues.

Thanks

>