[dpdk-users] Ixgbe empty queue stats

[dpdk-users] Ixgbe empty queue stats

[Trevor Highland]

Hi all,

We have a DPDK application that’s running using 82599 NICs with the ixgbe driver. Our application makes use of RSS and runs with 8 or 16 queues depending on the environment. I was reviewing xstats from a DPDK application that we run, and found that ‘rx_qN_packets’ was 0 for all queues except queue 0.

I was able to reproduce this using dpdk-testpmd from the 20.11 release. Additionally I used the ethregs tool and confirmed that the registers are indeed 0. Is this expected behavior, and is there a proper way to get per queue packet counts from hardware registers?

./dpdk-testpmd -l 0-8 -n 4 -m5120,5120 -- -i  --forward-mode=rxonly --rxq=2 --txq=2 --portmask=0xc --rxd=65536 --nb-cores=8 --rss-ip

I then run ‘start’

Truncated uput from ‘show port xstats all’
###### NIC extended statistics for port 2
rx_good_packets: 480147
tx_good_packets: 0
rx_good_bytes: 558567639
tx_good_bytes: 0
rx_missed_errors: 602293
rx_errors: 0
tx_errors: 0
rx_mbuf_allocation_errors: 0
rx_q0_packets: 480147
rx_q0_bytes: 558567639
rx_q0_errors: 0
rx_q1_packets: 0
###### NIC extended statistics for port 3
rx_good_packets: 419519
tx_good_packets: 0
rx_good_bytes: 438407091
tx_good_bytes: 0
rx_missed_errors: 441020
rx_errors: 0
tx_errors: 0
rx_mbuf_allocation_errors: 0
rx_q0_packets: 419519
rx_q0_bytes: 438407091
rx_q0_errors: 0
rx_q1_packets: 0
rx_q1_bytes: 0
rx_q1_errors: 0

Output at shutdown which shows both queues servicing packets
  ------- Forward Stats for RX Port= 2/Queue= 0 -> TX Port= 3/Queue= 0 -------
  RX-packets: 116794         TX-packets: 0              TX-dropped: 0

  ------- Forward Stats for RX Port= 3/Queue= 0 -> TX Port= 2/Queue= 0 -------
  RX-packets: 156055         TX-packets: 0              TX-dropped: 0

  ------- Forward Stats for RX Port= 2/Queue= 1 -> TX Port= 3/Queue= 1 -------
  RX-packets: 607297         TX-packets: 0              TX-dropped: 0

  ------- Forward Stats for RX Port= 3/Queue= 1 -> TX Port= 2/Queue= 1 -------
  RX-packets: 451971         TX-packets: 0              TX-dropped: 0

  ---------------------- Forward statistics for port 2  ----------------------
  RX-packets: 724010         RX-dropped: 0             RX-total: 724010
  TX-packets: 0              TX-dropped: 0             TX-total: 0
  ----------------------------------------------------------------------------

  ---------------------- Forward statistics for port 3  ----------------------
  RX-packets: 607924         RX-dropped: 0             RX-total: 607924
  TX-packets: 0              TX-dropped: 0             TX-total: 0
  ----------------------------------------------------------------------------

  +++++++++++++++ Accumulated forward statistics for all ports+++++++++++++++
  RX-packets: 1331934        RX-dropped: 0             RX-total: 1331934
  TX-packets: 0              TX-dropped: 0             TX-total: 0
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Thanks,
Trevor

Re: [dpdk-users] Ixgbe empty queue stats

[Stephen Hemminger]

On Wed, 24 Feb 2021 13:24:37 +0000
Trevor Highland <tsh@vectra.ai> wrote:

> Hi all,
> 
> We have a DPDK application that’s running using 82599 NICs with the ixgbe driver. Our application makes use of RSS and runs with 8 or 16 queues depending on the environment. I was reviewing xstats from a DPDK application that we run, and found that ‘rx_qN_packets’ was 0 for all queues except queue 0.
> 
> I was able to reproduce this using dpdk-testpmd from the 20.11 release. Additionally I used the ethregs tool and confirmed that the registers are indeed 0. Is this expected behavior, and is there a proper way to get per queue packet counts from hardware registers?
> 
> ./dpdk-testpmd -l 0-8 -n 4 -m5120,5120 -- -i  --forward-mode=rxonly --rxq=2 --txq=2 --portmask=0xc --rxd=65536 --nb-cores=8 --rss-ip
> 

Are you sending packets with different IP addresses?