All, We're seeing an odd 8ms latency under low load through a virtualized DPDK application. Even a very simple, basic, l2fwd style application exhibits this behavior. Our environment is:
Host: CentOS 7.4 - fully updated 2 x Intel Gold 6148 CPU 384 GB of RAM in 12 x 32GB configuration Intel XL710 NIC configured for SR-IOV using host PF (driver is CentOS default version) Guest: KVM (libvirt) based - cpu mode = host-model, features = acpi, apic, pae CentOS 7.4 - full updated 8 logic cores 32 GB of RAM 2 DPDK NICs are SR-IOV XL710 VFs passed through Running a single ICMP echo request/response (ping) through an l2fwd equivalent on the VM results in mostly 8ms RTTs with a few sub-1ms RTTs. Switching to a Linux bridge we see sub-1ms latencies. Using the physical function on the physical host with the same application we do not see such latency. Any ideas? Thanks, Stefan
