Interrupts + Polling mode (similar to Linux's NAPI)

[Andrew Brampton]

Hi,
Linux has a feature called NAPI, which amongst other things has this
Interrupt initiated polling mode. Whilst the network traffic is quiet
the network interfaces use interrupts, however as soon as the load
becomes higher polling kicks in and stays like that until the load
drops again.

I know that FreeBSD can do interrupts or polling, but not together. I
think that that NAPI pretty neat as it provides the benefits of both
interrupts and polling, namely low CPU load (when the network is not
busy), and high performance. I was wondering if anyone has considered
this approach in FreeBSD? If not why not? Is there some reason why the
binary FreeBSD approach is better? Or is it just that no one has
dedicated the time and effort to implement this feature?

Thanks
Andrew