Re: [PATCH net-next v1 1/1] net: openvswitch: ovs_packet_cmd_execute put sw_flow mainbody in stack

From: Eddy Tao
Date: Sun Feb 19 2023 - 22:04:45 EST


Hi, Simon:

    To have better visibility of the effect of the patch, i did another test below

Disabling data-path flow installation to steer traffic to slow path only, thus I can observe the performance on slow path, where ovs_packet_cmd_execute is extensively used


Testing topology

            |-----|
      nic1--|     |--nic1
      nic2--|     |--nic2
VM1(16cpus) | ovs |   VM2(16 cpus)
      nic3--|     |--nic3
      nic4--|     |--nic4
            |-----|
2 netperf client threads on each vnic

netperf -H $peer -p $((port+$i)) -t TCP_STREAM  -l 60
netperf -H $peer -p $((port+$i)) -t TCP_RR  -l 60 -- -R 1 -r 120,240
netperf -H $peer -p $((port+$i)) -t TCP_CRR -l 60 -- -R 1 -r 120,240

  Mode Iterations   Variance    Average

TCP_STREAM     10      %3.83       1433 ==> before the change
TCP_STREAM     10      %3.39       1504 ==> after  the change

TCP_RR         10      %2.35      45145 ==> before the change
TCP_RR         10      %1.06      47250 ==> after  the change

TCP_CRR        10      %0.54      11310 ==> before the change
TCP_CRR        10      %2.64      12741 ==> after  the change


Considering the size and simplicity of the patch, i would say the performance benefit is decent.

Thanks

eddy