Abstracting struct ifnet

[Luigi Rizzo]

On Fri, Feb 17, 2012 at 08:52:31AM -0800, Marcel Moolenaar wrote:
> 
> On Feb 17, 2012, at 12:23 AM, Luigi Rizzo wrote:
> >> 
> >> Thoughts, feedback and suggestion are welcome,
> > 
> > I do like the idea, but the amount of changes will be massive
> > (see below). The thing that worries me the most is that it
> > will introduce huge changes between different releases, unless
> > we backport the accessors (while keeping the underlying struct ifnet
> > frozen so we preserve the kernel ABI).
> 
> Hi Luigi,
> 
> That's a good point. When we have something to work with on -current
> and ideally with only a few drivers changed, we not only have a
> hybrid approach in -current, which allows us to stage the work, we
> also have the inherent support for backward compatibility. This then
> can be put in 9-stable to allow for "the new network" drivers to be
> used in a 9-stable code base as well.
> 
> As for the amount of change: yes, it's large. But I think it's a
> good investment and an enabler for structural ifnet rework.

I definitely agree that it is a good investment, especially considering that
I am doing this all the times when i port FreeBSD stuff to linux...

The linux version of netmap, which i just completed, was mostly
done playing tricks to remap struct ifnet to struct net_device...

cheers
luigi