Re: [PATCH 0/4] RCU: various merge candidates

[Arjan van de Ven <arjan@infradead.org>]

On Mon, 2006-08-28 at 21:59 +0530, Dipankar Sarma wrote:
> On Mon, Aug 28, 2006 at 06:15:48PM +0200, Arjan van de Ven wrote:
> > On Mon, 2006-08-28 at 21:38 +0530, Dipankar Sarma wrote:
> > > This patchset consists of various merge candidates that would
> > > do well to have some testing in -mm. This patchset breaks
> > > out RCU implementation from its APIs to allow multiple
> > > implementations, 
> > 
> > 
> > can you explain why we would want multiple RCU implementations?
> > Isn't one going to be plenty already?
> 
> Hi Arjan,
> 
> See this for a background - http://lwn.net/Articles/129511/
> 
> Primarily, rcupreempt allows read-side critical sections to
> be preempted unline classic RCU currently in mainline. It is
> also a bit more aggressive in terms of grace periods by counting
> the number of readers as opposed to periodic checks in classic
> RCU.
> 

hi,

thanks for the explenation, this for sure explains one half of the
equation; the other half is ... "why do we not always want this"?

Greetings,
   Arjan van de Ven