On 10/03/16 07:51, Wu, Jingjing wrote: > 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.
You mean getting default_txconf from rte_eth_dev_info_get() and explicitly turn ETH_TXQ_FLAGS_NOMULTSEGS to 0? (filling tx_flags with zeros doesn't work very well) That's a way to solve it for me, but I'm rather talking about using defaults which doesn't cause memory leak quite easily. > >> Regards, >> >> Zoltan
