Hello, I am using QEMU 1.6.0 on Linux 3.10.21. My VMs are using vhost-net in a typical OpenStack setup: VM1->tap->linux bridge->OVS->host1->physical network->host2->OVS->linux bridge->tap->VM2.
It seems that under heavy network load, the vhost-[pid] processes on the receiving side is using 100% CPU. The sender side has over 85% utilized. I am seeing unsatisfactory VM to VM network performance (using iperf 16 concurrent TCP connections, I can only get 1.5Gbps, while I've heard people got to over 6Gbps at least), and I wonder if it has something to do with vhost-net maxing out on CPU. If so, is there anything I can tune the system? On the host side, I have already tuned sysctl settings, spread the NIC interrupts, and I believe RSS is on too. Thanks. -Simon -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
