Re: [PATCH -rcu/dev 1/4] hazptrtorture: Release all deferred hazard pointers before stopping

[Andrea Parri <parri.andrea@gmail.com>]

On Wed, Oct 28, 2026 at 04:51:12PM -0700, Paul E. McKenney wrote:
> On Wed, Oct 28, 2026 at 10:26:18AM -0700, Paul E. McKenney wrote:

[...]

> > So doesn't the above torture_must_stop() instead need to be
> > kthread_should_stop()?
> >
> > As it is, hazptr_torture_do_pending() will still stop before the
> > hazptr_torture_reader() instances do, correct?

Its loop does exit first, but v1's for_each_possible_cpu() pass comes
after torture_kthread_stopping(), which returns only once
hazptr_torture_cleanup() stops do_pending, after the readers.

> Well, one thing that I am missing is that changing from
> torture_must_stop() to kthread_should_stop() might cause trouble
> if rcutorture execution is terminated by system shutdown.

Agreed: on a shutdown that hazptrtorture did not start itself, the
reboot notifier sets FULLSTOP_SHUTDOWN, and nothing calls
kthread_stop().

> So my next suggestion is that this be added just after
> hazptr_torture_reader() exits its do-while loop:
>
> 	for_each_possible_cpu(cpu)
> 		hazptr_torture_do_one_pending(cpu, &rand);
>
> Thoughts?

Works for me, thanks!  I have been testing it, instead of the
for_each_possible_cpu() pass that v1 adds after
torture_kthread_stopping(), and keeping the torture_must_stop() loop
condition.  I will send v2 with it if it holds up.

Thanks,
  Andrea