Re: Real-Time Preemption and RCU

[Bill Huey (hui) <bhuey@lnxw.com>]

On Tue, Mar 22, 2005 at 02:17:27AM -0800, Bill Huey wrote:
> > A notion of priority across a quiescience operation is crazy anyways[-,-] so
> > it would be safe just to use to the old rwlock-semaphore "in place" without
> > any changes or priorty handling add[i]tions. The RCU algorithm is only concerned
> > with what is basically a coarse data guard and it isn't time or priority
> > critical.
> 
> A little jitter in a quiescence operation isn't going to hurt things right ?. 

The only thing that I can think of that can go wrong here is what kind
of effect it would have on the thread write blocking against a bunch of
RCU readers. It could introduce a chain of delays into, say, a timer event
and might cause problems/side-effects for other things being processed.
RCU processing might have to decoupled processed by a different thread
to avoid some of that latency weirdness.

What do you folks think ?

bill