Re: [PATCH tip/core/rcu 13/22] rcu: Fix grace-period hangs due to race with CPU offline

[Peter Zijlstra]

On Tue, Jun 26, 2018 at 10:10:39AM -0700, Paul E. McKenney wrote:
> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> index 3def94fc9c74..6683da6e4ecc 100644
> --- a/kernel/rcu/tree.h
> +++ b/kernel/rcu/tree.h
> @@ -363,6 +363,10 @@ struct rcu_state {
>  	const char *name;			/* Name of structure. */
>  	char abbr;				/* Abbreviated name. */
>  	struct list_head flavors;		/* List of RCU flavors. */
> +
> +	spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;

Are you really sure you didn't mean to use ____cacheline_aligned_in_smp
? This internode crap gives you full page alignment under certain rare
configs.