how to utilize multi tx queue to sent packets?

hi

I am doing some test according to the
website:http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmap

use packet_mmap tx_ring to send packet.

I modified the sample code "packetmmap.c" to make it send packets have
different outer ip.
so that with the help of RSS, I can achieve higher throughput.

but one thing I saw at the tx side, is that all the packets are sent
via the same tx_queue,which is conflict with what I saw at the rx
side.
any idea to make it sent packets via different tx_queues? (spread
across the tx_queues)


thanks
jon