Re: [PATCH v2 4/5] workqueue: Show all busy workers in stall diagnostics

[Breno Leitao]

On Tue, Jun 16, 2026 at 02:57:06PM +0200, Petr Mladek wrote:
> On Tue 2026-06-16 05:44:12, Breno Leitao wrote:
> > Hello Petr,
> > 
> > On Tue, Jun 16, 2026 at 02:38:11PM +0200, Petr Mladek wrote:
> > > On Thu 2026-06-11 07:50:04, Breno Leitao wrote:
> > > >
> > > > Unfortunately I didn't get the other pr_info(), because of console settings,
> > > > but, I can say the following from this issue and previous code:
> > > > 
> > > > 1) in show_cpu_pool_hog, found_running variable is set to false.
> > > > 2) hash_for_each() never found any running task
> > > > 3) The following code was trigger and was very helpful:
> > > > 
> > > >          if (!found_running)
> > > >                 trigger_single_cpu_backtrace(cpu);
> > > 
> > > Great. So, the extra complexity was worth it. Should I clean it and
> > > send a proper patch? Or would you like to do so?
> > 
> > I am happy to do so. I had a chat with tejun yesterday, and I got the
> > impression he is OK with this patch as well.
> 
> Great!
> 
> > > Also I wonder whether it would make sense to revert the commit
> > > 8823eaef45da7f ("workqueue: Show all busy workers in stall
> > > diagnostics").
> > 
> > This patch undo that change already. Would you like to see a full revert
> > or, are you OK with this patch reverting that behaviour? Maybe with
> > a fixes: tag?
> 
> I do not mind how exactly it is done. Reworking the behavior is
> perfectly fine. And the fixes tag would make sense when it was
> not a full revert.

Thanks. I've sent an RFC patchset for us to discuss it there.

https://lore.kernel.org/all/20260616-wq_dump_petr-v1-0-b57473ca6d18@xxxxxxxxxx/

Thanks for your help so far,
--breno