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

From: Paul E. McKenney
Date: Sun Oct 02 2022 - 12:10:56 EST


On Sun, Oct 02, 2022 at 05:57:25PM +0200, Frederic Weisbecker wrote:
> On Sun, Oct 02, 2022 at 05:55:16PM +0200, Frederic Weisbecker wrote:
> > On Thu, Sep 29, 2022 at 11:07:25AM -0700, Paul E. McKenney wrote:
> > > @@ -1090,7 +1121,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp,
> > > int ss_state;
> > >
> > > check_init_srcu_struct(ssp);
> > > - idx = srcu_read_lock(ssp);
> > > + idx = __srcu_read_lock_nmisafe(ssp);
> >
> > Why do we need to force the atomic based version here (even if
> > CONFIG_NEED_SRCU_NMI_SAFE=y)?
>
> ...even if CONFIG_NEED_SRCU_NMI_SAFE=n that is...

Heh! I also got it consistently backwards in my reply. I will trust
your ability to translate. ;-)

Thanx, Paul