Re: [patch] RCU: introduce rcu_soon_pending() interface

[Andrew Morton <akpm@osdl.org>]

Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
>
> @@ -485,6 +485,14 @@ int rcu_pending(int cpu)
>  		__rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
>  }
>  
> +int rcu_soon_pending(int cpu)
> +{
> +	struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
> +	struct rcu_data *rdp_bh = &per_cpu(rcu_bh_data, cpu);
> +
> +	return (!!rdp->curlist || !!rdp_bh->curlist);
> +}

This patch sets my nerves a-jangling.

What are the units of soonness?  It's awfully waffly.  Can we specify this
more tightly?

Neither rcu_pending() nor rcu_soon_pending() are commented or documented. 
Pity the poor user trying to work out what they do, and how they differ. 
They're global symbols and they form part of the RCU API - they should be
kernel docified, please.

There's probably a reason why neither of these symbols are exported to
modules.  Once they're actually documented I mught be able to work out what
that reason is ;)