Hi, I have three multiCPU servers connected in a row. ServerA --- serverB --- serverC. All of them are interconnected with 40Gbps Mellanox X5 PCIe v4 cards with optical MPO cable. All servers are multicore beasts with two CPUs, all of them have HyperThreading off. - serverA (16 Xeon cores) is sending iperf3 traffic (small packets created by lower MTU 90B set on 40Gbps port) to serverC (32 Xeon cores) - serverB (128 Epyc cores) is setup as a linux bridge Server A is able to send around 20 Milions of iperf3 packets (Mpps) to server C through server B (no iptables/ebtables rules) Problem is when I add HFSC config, even simplified as much as possible, to a 40Gbps port on tested server B. Speed in packets drops down to some 2,6 Mpps, while CPUs are nearly idling. This is the HFSC config. It is just a minimalistic config - I`m looking for HFSC/linux bridge/... limits and I narrowed the problem down to this: # root qdisc a class: qdisc add dev eth0 root handle 1: hfsc default ffff class add dev eth0 parent 1: classid 1:1 hfsc ls m2 34gbit ul m2 34gbit # default qdisc a class class add dev eth0 parent 1:1 classid 1:ffff hfsc ls m2 34gbit ul m2 34gbit qdisc add dev eth0 parent 1:ffff handle ffff:0 sfq perturb 5 --> all iperf3 traffic is passing th default class ffff, which is expected in this testing setup (so no filters/iptables classifies/ipsets are not necessary) --> this is enough to have just 2,6 Mpps instead of 20Mpps... What I`m I missing? Thank you. Pep.
