Non-interrupt packet sending and receiving

[Ryan Stone]

You might want to take a look at the projects/sv branch, which
implement kernel core dumps over the network.  We had to solve a
similar problem there (in lem, em, igb and ixgbe) and ended up
piggybacking on most of the DEVICE_POLLING code to do it.  The work
ended up stalling over objections over calling into the mbuf allocator
(which I guess may be a stumbling block for your work).  Unfortunately
we weren't able to come up with a clean way to share the existing
rx/tx paths in the drivers while separating the mbuf allocations out.