Hi Matt, On 3/14/15, 8:47 AM, "Wiles, Keith" <keith.wiles at intel.com> wrote:
>Hi Matt > >On 3/13/15, 3:49 PM, "Matt Smith" <mgsmith at netgate.com> wrote: > >> >>Hi, >> >>I?ve been using DPDK pktgen 2.8.0 (built against DPDK 1.8.0 libraries) to >>send traffic on a server using an Intel 82599 (X520-2). Traffic gets sent >>out port 1 through another server which also an Intel 82599 installed and >>is forwarded back into port 0. When I send using a single source and >>destination IP address, this works fine and packets arrive on port 0 at >>close to the maximum line rate. >> >>If I change port 1 to range mode and send traffic from a range of source >>IP addresses to a single destination IP address, for a second or two the >>display indicates that some packets were received on port 0 but then the >>rate of received packets on the display goes to 0 and all incoming >>packets on port 0 are registered as rx errors. >> >>The server that traffic is being forwarded through is running the >>ip_pipeline example app. I ruled this out as the source of the problem by >>sending directly from port 1 to port 0 of the pktgen box. The issue still >>occurs when the traffic is not being forwarded through the other box. >>Since ip_pipeline is able to receive the packets and forward them without >>getting rx errors and it?s running with the same model of NIC as pktgen >>is using, I checked to see if there were any differences in >>initialization of the rx port between ip_pipeline and pktgen. I noticed >>that pktgen has a setting that ip_pipeline doesn't: >> >>const struct rte_eth_conf port_conf = { >> .rxmode = { >> .mq_mode = ETH_MQ_RX_RSS, >> >>If I comment out the .mq_mode setting and rebuild pktgen, the problem no >>longer occurs and I now receive packets on port 0 at near line rate when >>testing from a range of source addresses. >> >>I recall reading in the past that if a receive queue fills up on an 82599 >>, that receiving stalls for all of the other queues and no more packets >>can be received. Could that be happening with pktgen? Is there any >>debugging I can do to help track it down? > >I have seen this problem on some platforms a few times and it looks like >you may have found a possible solution to the problem. I will have to look >into the change and see if this is the problem, but it does seem to >suggest this may be the issue. When the port gets into this state the port >receives the number mbufs matching the number of descriptors and the rest >are ?missed? frames at the wire. The RX counter is the number of missed >frames. > >Thanks for the input >++Keith I added code to hopefully setup the correct RX/TX conf values. The HEAD of the Pktgen-DPDK v2.8.4 should build and work with DPDK 1.8.0 or 2.0.0-rc1. I did still see some RX errors and reduced bit rate, but the traffic does not stop on my machine. Please give version 2.8.4 a try and let me know if you still see problems. Regards, ++Keith >> >>The command line I have been launching pktgen with is: >> >>pktgen -c f -n 3 -m 512 -- -p 0x3 -P -m 1.0,2.1 >> >>Thanks, >> >>-Matt Smith >> >> >> >> >> > > >