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

["Paul E. McKenney" <paulmck@us.ibm.com>]

On Tue, Apr 25, 2006 at 01:33:37PM +0200, Martin Schwidefsky wrote:
> On Tue, 2006-04-25 at 04:23 -0700, Paul E. McKenney wrote:
> > > 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.
> > 
> > Please note that the rcu_pending() interface was never intended for
> > external use -- it is purely internal to the RCU infrastructure.
> > If there is a new external use for rcu_pending(), then it would need to
> > be documented.  But I would rather this one stay internal -- different
> > RCU implementations might need different things.
> > 
> > So, what are we trying to do here?
> 
> We are trying to find out if an idle cpu needs to continue to tick every
> HZ or if we can put it into deep sleep. If there is any kind of rcu work
> pending that requires the idle cpu to call in later via a timer
> interrupt, we need to know.

OK, this confirms my guess that you are acting as part of the RCU
implementation rather than as a normal user of the RCU API.

						Thanx, Paul