Giant-free polling [PATCH]

[Andre Oppermann]

Sam Leffler wrote:
> 
> Pawel Jakub Dawidek wrote:
> > On Fri, Mar 11, 2005 at 01:14:38PM -0800, Julian Elischer wrote:
> > +> >P> There is still an unresolved problem (in your and our patch as well) of
> > +> >P> using ifnet structure fields without synchronization, as we don't have
> > +> >P> access tointerface's internal mutex, which protects those fields.
> > +> >
> > +> >
> > +>
> > +> you need to add an interface method that has access to it..
> >
> > I was thinking more about moving interface mutex into ifnet structure,
> > but Robert has some objections IIRC.
> >
> 
> I don't know what Robert's objections are but I've considered doing it
> for a while to deal with some locking issues in net80211-based drivers.
>   The only issue I can see is if this mutex boxes drivers into a locking
> model that interlocks the rx+tx paths.

We don't want this.  This would paint us into a corner with modern
high speed hardware that can hanle the rx+tx paths simulaneously.
Depending on the hardware DMA model and driver architecture you
want to have a different locking model.  I agree with Robert in
objecting to this.

-- 
Andre