[dpdk-users] Intel X550 packet receive length truncation (ixgbe PMD)

[terry.montague.1980 at btinternet.com]

HI Keith,

I'm not using pktgen - I am just experiencing what appears to be the same effect - I see receive data truncation to 1024bytes on incoming Rx datagrams. 

If I then increase the MBUF size to 2048 + 128, I can receive 1500 byte datagrams, but after receiving 31 of them (or what appears to  rx_free_thresh - 1) the Rx stops, although the ret_eth_stats_get() ipackets fields shows that the total number of datagrams I'm sending into the adaptor is being processed.  Looks to be a RX ring problem? 

I'm using DPDK 17.05


Terry



----Original message----
>From : keith.wiles at intel.com
Date : 26/09/17 - 02:50 (BST)
To : terry.montague.1980 at btinternet.com
Cc : users at dpdk.org
Subject : Re: [dpdk-users] Intel X550 packet receive length truncation (ixgbe PMD)


> On Sep 25, 2017, at 5:46 PM, terry.montague.1980 at btinternet.com wrote:
> 
> Hi all,
> I appear to have stumbled into the problem where received data coming into the X550 (ixgbe PMD) is truncated in length to 1024 bytes.
> I've followed this issue : https://github.com/pktgen/Pktgen-DPDK/issues/103 
> and adjusted the size of the mbufs created by rte_pktmbuf_pool_create() to be RTE_MBUF_DEFAULT_DATAROOM + RTE_PKTMBUF_HEADROOM  :  i.e. 2048 + 128 bytes.
> However, the receive side now stops receiving packets, 31 packets after startup. If I change the value of rxConfig.rx_free_thresh sent into rte_eth_rx_queue_setup() to 64, then it stops after 63 incoming packets.
> Any ideas anyone ? What am I doing wrong?


What is the version of DPDK and Pktgen you are using?

> Many thanks
> Terry.

Regards,
Keith