Hi Eimear, I just experienced the same problem with firmware versions 4.23 and 4.33 (dpdk 2.0). Did not get to try the latest which is 4.5. Looking at the code, I don't see that this counter is being read any differently than its peer counters and I suspect the nic itself. Can you tell which firmware version you were using?
thanks /Arnon On Mon, Oct 19, 2015 at 2:43 PM, Eimear Morrissey < eimear.morrissey at ie.ibm.com> wrote: > > > Hi, > > I'm having issues measuring packets dropped at the NIC in both the 2.0.0 > and 2.1.0 versions of DPDK on an X710 Intel NIC. > > In dpdk-2.0.0 > Using rte_eth_xstats the rx_packets and rx_bytes counters increase as > expected, however rx_missed_errors is always 0 even if a sleep statement is > added between calls to rte_eth_rx_burst. However changing the coremask so > the application is running on a different socket than the card will cause > rx_missed_errors to increment for a limited amount of time and then stop. > Using rte_eth_stats, ipackets is incremented on packet receipt but the > q_ipackets and q_errors arrays remain zero. Even crossing sockets seems to > have no effect on q_errors. > > In dpdk-2.1.0 the behaviour is the same as above, except that the number of > fields returned by rte_eth_xstats_get is reduced (no rx_missed errors at > all) so running on a different socket no longer has any noticeable effect > on the stats. > > My understanding from the API manual is that the rte_eth_stats q_errors > array should count the packets missed because software isn't polling fast > enough, but that doesn't seem to be the case? Is there a standard DPDK way > to check this? The application is a forwarding one so there's no other way > to estimate drop except through NIC rx. > > Thanks, > Eimear > -- *Arnon Warshavsky* *Qwilt | work: +972-72-2221634 | mobile: +972-50-8583058 | arnon at qwilt.com <arnon at qwilt.com>*