On Thursday, March 24, 2011 at 6:22 PM, Avi Kivity wrote: Try vhost-net, that should have much better latencies. > Indeed, the latency is much better after switching to vhost-net, it drops from 3+ms to ~1.5ms on average when there is no network load on the KVM guest, but the latencies become bad again when there is heavy network load on the guest(~70Mbps RX and ~25Mbps TX). --------------------------- ping KVM guest (app211) from the host --------------------------- 64 bytes from app211 (192.168.1.211): icmp_seq=3582 ttl=64 time=3.08 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3583 ttl=64 time=1.10 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3584 ttl=64 time=1.03 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3585 ttl=64 time=3.55 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3586 ttl=64 time=1.29 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3587 ttl=64 time=0.710 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3588 ttl=64 time=64.4 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3589 ttl=64 time=0.271 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3590 ttl=64 time=0.563 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3591 ttl=64 time=1.66 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3592 ttl=64 time=0.939 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3593 ttl=64 time=0.819 ms 64 bytes from app211 (192.168.1.211): icmp_seq=3594 ttl=64 time=16.5 ms --------------------------- ping KVM guest (app211) from the host --------------------------- any idea? Thanks, Xupeng -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html