Hi, Zoltan > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Zoltan Kiss > Sent: Wednesday, March 2, 2016 3:19 AM > To: dev at dpdk.org > Subject: [dpdk-dev] ixgbe TX function selection > > Hi, > > I've noticed that ixgbe_set_tx_function() selects the non-SG function > even if (dev->data->scattered_rx == 1). That seems a bit dangerous, as > you can turn that on inadvertently when you don't set max_rx_pkt_len and > buffer size in certain ways. I've learnt it in the hard way, as my > segmented packets were leaking memory on the TX path, which doesn't > cries if you send out segmented packets. > How should this case be treated? Assert on the non-SG TX side for the > 'next' pointer? Or turning on SG if RX has it? It doesn't seem to be a > solid way as other interfaces still can have SG turned on. >
If you look into the ixgbe_set_tx_function, you will find tx function selection is decided by the tx_flags on queue configure, which is passed by rte_eth_txconf. So even you set dev->data->scattered_rx to 1, if the tx_flags is ETH_TXQ_FLAGS_NOMULTSEGS, ixgbe_xmit_pkts_simple is still selected as tx function. So, you'd better to set tx_flags=0, and have a try. > Regards, > > Zoltan