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Date:   Mon, 3 Oct 2022 00:06:19 +0200
From:   Frederic Weisbecker <frederic@kernel.org>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@fb.com, rostedt@goodmis.org,
        Thomas Gleixner <tglx@linutronix.de>,
        John Ogness <john.ogness@linutronix.de>,
        Petr Mladek <pmladek@suse.com>
Subject: Re: [PATCH RFC v2 rcu 3/8] srcu: Check for consistent per-CPU
 per-srcu_struct NMI safety
Message-ID: <20221002220619.GA298433@lothringen>
References: <20220929180714.GA2874192@paulmck-ThinkPad-P17-Gen-1>
 <20220929180731.2875722-3-paulmck@kernel.org>
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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@linutronix.de/
> 
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: John Ogness <john.ogness@linutronix.de>
> Cc: Petr Mladek <pmladek@suse.com>
> ---
>  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.