Re: [PATCH RFC v2 rcu 2/8] srcu: Create an srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe()

Paul E. McKenney
2022-10-18T15:18:58Z

On Tue, Oct 18, 2022 at 04:37:01PM +0206, John Ogness wrote:
> Hi Paul,
>
> Sorry for the late response here. I am now trying to actually use this
> series.
>
> On 2022-09-29, "Paul E. McKenney" <paulmck@kernel.org> wrote:
> > diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
> > index d471d22a5e21..f53ad63b2bc6 100644
> > --- a/kernel/rcu/Kconfig
> > +++ b/kernel/rcu/Kconfig
> > @@ -72,6 +72,9 @@ config TREE_SRCU
> > help
> > This option selects the full-fledged version of SRCU.
> >
>
> You are missing a:
>
> +config ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
> + bool
> +
>
> Otherwise there is no CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS, so for
> example CONFIG_NEED_SRCU_NMI_SAFE always ends up with y on X86.

Good catch, thank you! Pulling this in with attribution.

Thanx, Paul

> > +config NEED_SRCU_NMI_SAFE
> > + def_bool HAVE_NMI && !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !TINY_SRCU
> > +
>
> John