Re: [PATCH RFC v2 rcu 3/8] srcu: Check for consistent per-CPU per-srcu_struct NMI safety

[Frederic Weisbecker]

On Thu, Sep 29, 2022 at 11:07:26AM -0700, Paul E. McKenney wrote:
> This commit adds runtime checks to verify that a given srcu_struct uses
> consistent NMI-safe (or not) read-side primitives on a per-CPU basis.
> 
> Link: https://lore.kernel.org/all/20220910221947.171557773@xxxxxxxxxxxxx/
> 
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
> Cc: Petr Mladek <pmladek@xxxxxxxx>
> ---
>  include/linux/srcu.h     |  4 ++--
>  include/linux/srcutiny.h |  4 ++--
>  include/linux/srcutree.h |  9 +++++++--
>  kernel/rcu/srcutree.c    | 38 ++++++++++++++++++++++++++++++++------
>  4 files changed, 43 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/srcu.h b/include/linux/srcu.h
> index 2cc8321c0c86..565f60d57484 100644
> --- a/include/linux/srcu.h
> +++ b/include/linux/srcu.h
> @@ -180,7 +180,7 @@ static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp
>  	int retval;
>  
>  	if (IS_ENABLED(CONFIG_NEED_SRCU_NMI_SAFE))
> -		retval = __srcu_read_lock_nmisafe(ssp);
> +		retval = __srcu_read_lock_nmisafe(ssp, true);
>  	else
>  		retval = __srcu_read_lock(ssp);

Shouldn't it be checked also when CONFIG_NEED_SRCU_NMI_SAFE=n ?

Thanks.