On Thu, Nov 22, 2012 at 09:17:34PM +0200, George-Cristian Bîrzan wrote: > I'm trying to understand a performance problem (50% degradation in the > VM) that I'm experiencing some systems with qemu-kvm. Running Fedora > with 3.5.3-1.fc17.x86_64 or 3.6.6-1.fc17.x86_64, qemu 1.0.1 or 1.2.1 > on AMD Opteron 6176 and 6174, and all of them behave identically. > > A Windows guest is receiving a UDP MPEG stream that is being processed > by TSReader. The stream comes in at about 73Mbps, but the VM cannot > process more than 43Mbps. It's not a networking issue, the packets > reach the guest and with iperf we can easily do 80Mbps. Also, with > iperf, it can receive the packets from the streamer (even though it > doesn't detect things properly, but it was just a way to see ). > > However, on an identical host (a 6174 CPU, even), a Windows install > has absolutely no problem processing the same stream. > What Windows is this? Can you try changing "-cpu host" to "-cpu host,+hv_relaxed"? -- Gleb. -- 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
