On Wed, 23 Oct 2024 at 10:11, Srivats P <pstavirs@xxxxxxxxx> wrote: > > Hi, > > Trying AF_XDP xdpsock txonly on an i40e (XL710), I'm seeing some > behaviour across packet size that I need help to understand. > > All tests with zero-copy mode (similar results with busy poll mode > also). The i40e driver version is the native kernel version 6.8.0-47 > included in Ubuntu 24.04. Flow control tx/rx is off. > > PktSize Max-pps Actual-pps > 64 > 59.5M ~18.9M > 512 > 9.4M ~7.5M > 1024 > 4.8M ~4.6M > 1518 > 3.3M ~3.0M > > Output logs below > > Since 64 byte packets can do around ~18.9M, I was expecting larger > packets (see 512 and 1518 above) to do line rate i.e. do close to > max-pps but they do less than that. > > Is this expected? I think it is hard to hit exactly line rate. Note that each queue on i40e can deliver max ~21 Mpps. How about trying with multiple queues and see what you get? > What factors could be playing a role in a lower rate for larger packet size? > > To determine how many cores/queues I need if I need to transmit X Gbps > - what factors do I need to use? > > Srivats > > $ sudo ./xdpsock -t -i enp1s0f0np0 -z -d5 -s64 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 1,88,28,546 1,88,39,104 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 1,88,25,658 3,76,73,792 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 1,92,29,105 5,69,07,520 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 1,96,44,299 7,65,55,904 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 1,96,46,711 9,62,06,336 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 0.00 > rx 0 0 > tx 0 9,62,06,720 > > > $ sudo ./xdpsock -t -i enp1s0f0np0 -z -d5 -s512 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 75,09,247 75,11,104 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 74,89,511 1,50,01,856 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 74,98,753 2,25,01,568 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 74,86,126 2,99,88,672 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 74,86,807 3,74,76,416 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 0.00 > rx 0 0 > tx 0 3,74,76,416 > > > $ sudo ./xdpsock -t -i enp1s0f0np0 -z -d5 -s1024 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 46,01,574 46,02,496 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 45,95,655 91,98,912 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 45,95,058 1,37,94,432 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 45,97,400 1,83,92,256 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 45,84,541 2,29,77,152 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 0.00 > rx 0 0 > tx 0 2,29,77,216 > > $ sudo ./xdpsock -t -i enp1s0f0np0 -z -d5 -s1518 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 30,00,232 30,00,960 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 29,94,793 59,96,224 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 29,95,064 89,91,616 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 29,96,147 1,19,88,160 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 1.00 > rx 0 0 > tx 29,94,991 1,49,83,552 > > sock0@enp1s0f0np0:0 txonly xdp-drv > pps pkts 0.00 > rx 0 0 > tx 0 1,49,83,552 >
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