K 10
svn:author
V 9
vmaffione
K 8
svn:date
V 27
2020-09-01T20:58:23.642281Z
K 7
svn:log
V 617
r364770

iflib: netmap: publish all the receive buffer

At initialization time, the netmap RX refill function used to
prepare the NIC RX ring with N-1 buffers rather than N (with
N equal to the number of descriptors in the NIC RX ring).
This is not how netmap is supposed to work, as it would keep
kring->nr_hwcur not in sync with the NIC "next index to refill"
(i.e., fl->ifl_pidx). Instead we prepare N buffers, although we
still publish (with isc_rxd_flush()) only the first N-1 buffers,
to avoid the NIC producer pointer to overrun the NIC consumer
pointer (for NICs where this is a real issue, e.g. Intel ones).

END