Почему сетевой адаптер Mellanox CX-5 распределяет трафик одного TCP-потока на несколько очередей, RSS, похоже, не работа ⇐ Linux

[Anonymous]

I started a TCP flow by iperf3 and found 2-3 IRQ queues of the NIC (100Gbps) got lots of interrupts (by checking the /proc/interrupts file).
RSS should distributed the traffic of this flow to one queue. I also checked the hash rule: [root@testmachine ~]# ethtool -n enp4s0f0 rx-flow-hash tcp4 TCP over IPV4 flows use these fields for computing Hash flow key: IP SA IP DA L4 bytes 0 & 1 [TCP/UDP src port] L4 bytes 2 & 3 [TCP/UDP dst port]

I checked two systems both have the same problem: Ubuntu 20.04 and Centos7. The NIC is 100Gbps and has 48 queues.

What's going on?

Before start this TCP flow, every IRQ of this NIC got very little increase per 10 seconds, after I started one TCP flow (without -P option of iperf3 commamd), 2-3 IRQs increased a lot (increased several thousands per IRQ in several seconds).


Источник: https://stackoverflow.com/questions/780 ... -one-queue