Hi, I've got some hosts that were happily running the 2.6.25.x host kernel, kvm-84, kernel.org kvm modules. The guests were running 2.6.25 to 2.6.29.x quite happily. Network was using virtio. Since I upgraded one of the hosts (Intel dual core) to 2.6.29.x yesterday, the virtio network performance of the guests on it dropped dramatically. (for some reason another AMD host did not seem to be affected...) Here are the tests I performed using wget and scp: * guest to guest: fast * guest to host: fast * host to internet: fast * guest to internet: slow!!! I was normally getting ~5MB/s to the host (speed to the internet was limited by the capacity of the DSL line), but since the upgrade the performance had dropped to around 20KB/s! Strangely enough, I could open many new connections to the guest and get more chunks all at 20KB/s! I switched the guests to using ne2k_pci and the performance has been restored... And this is where it gets even weirder... UDP packets get corrupted using ne2k_pci and rtl8139cp but not with virtio... So I can get performance or UDP, but not both... Let me know if there is anything more I can provide to help fix this regression. I can reproduce the problem quite easily without causing problems on the host. Cheers Antoine -- 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
