Re: [PATCH -next 1/8] rcu: Fix rcu_read_unlock() deadloop due to softirq

[Mathieu Desnoyers]

On 2026-01-08 10:39, Frederic Weisbecker wrote:
> Le Wed, Jan 07, 2026 at 10:35:44PM -0500, Joel Fernandes a écrit :
> > > By the way, when I last tried to do it from rcu_qs, it was not fixing the original bug with the IRQ work recursion.
> > >
> > > I found that it was always resetting the flag. But probably it is not even the right place to do it in the first place.
> >
> > I think we need to reset the flag in rcu_report_exp_rdp() as well if exp_hint
> > is set and we reported exp qs.
>
> To avoid needlessly reaching the rcu_read_unlock() slowpath whenever the exp QS has
> already been reported, yes indeed.

This seems related to:

https://lore.kernel.org/lkml/6c96dbb5-bffc-423f-bb6a-3072abb5f711@xxxxxxxxxxxx/

Is it the same issue ?

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com