Re: [PATCH v0 20/42] rcu: Check notifier registration return value

[Paul E. McKenney]

On Mon, Nov 08, 2021 at 11:11:35AM +0100, Borislav Petkov wrote:
> From: Borislav Petkov <bp@xxxxxxx>
> 
> Avoid homegrown notifier registration checks.
> 
> No functional changes.
> 
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>

Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

Or I would be happy to take this as soon as the first patch appears
somewhere that I can base off of.  (I could duplicate it in -rcu, I
suppose.)

							Thanx, Paul

> Cc: rcu@xxxxxxxxxxxxxxx
> ---
>  kernel/rcu/tree_stall.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
> index 5e2fa6fd97f1..0c1d631214f4 100644
> --- a/kernel/rcu/tree_stall.h
> +++ b/kernel/rcu/tree_stall.h
> @@ -101,7 +101,9 @@ static struct notifier_block rcu_panic_block = {
>  
>  static int __init check_cpu_stall_init(void)
>  {
> -	atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block);
> +	if (atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block))
> +		pr_warn("RCU warning suppress notifier already registered\n");
> +
>  	return 0;
>  }
>  early_initcall(check_cpu_stall_init);
> -- 
> 2.29.2
>