Defer ringing the Tx doorbell if skb->xmit_more is set unless the Tx queue
is full or stopped.  To keep latency low, use a deferral limit of 8
packets.  We chose 8 because Octeon can fetch at most 8 packets in a single
PCI read, and our tests show that 8 results in low latency.
Signed-off-by: NIntiyaz Basha <intiyaz.basha@cavium.com>
Signed-off-by: NSatanand Burla <satananda.burla@cavium.com>
Signed-off-by: NFelix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>