On Thu, Jul 2, 2015 at 11:47 PM, Santosh R <skrasta...@gmail.com> wrote: > Hi, > > I am testing VxLAN performance between VMs using 3.18 host kernel. > For this I am using below command to bring up the VM. > # qemu-system-x86_64 -m 4096 -smp 4 -boot c -device > virtio-net-pci,netdev=tap0,mac=00:11:22:33:44:55 -netdev > tap,id=tap0,script=no,vhost=on -drive file=/root/vdisk_rhel65.img & > > Using the below setup, I am not getting good performance between VMs. > > VM1--tap1--bridge1--vxlan1--10G Nic1 <---> 10G > Nic2--vxlan2--bridge2--tap2--VM2 > This has already been reported. If zero UDP checksums are in use and the device does not provide checksum unnecessary for the encapsulation checksum or checksum complete, then GRO is not done at the device. Also, GRO was not implemented at the vxlan device. Please see the patches I posted to address the latter.
Thanks, Tom > The reason being, when VM1 sends traffic to VM2, the received packets > are correctly aggregated at Nic2-vxlan2…bridge2 in host2. > But they get segmented at tap2 interface as it doesn’t support VxLAN > segmentation offload (tx-udp_tnl-segmentation: off [fixed]). > > When bridge interface tries to forward this packet to tap interface > (br_dev_queue_push_xmit -> __dev_queue_xmit -> validate_xmit_skb), > netif_needs_gso will succeed (skb_gso_ok returns 0) resulting in > packet segmentation (which was earlier aggregated). > > Is this an expected behaviour? Does tap interface support > tx-udp_tnl-segmentation? > > I had tried to discuss this issue with qemu-devel forum. Here is the > link http://lists.nongnu.org/archive/html/qemu-devel/2015-06/msg07159.html > > Driver is updating csum_level of sk_buff to 1 and calls napi_gro_frags > for VxLAN packets. > > # brctl show > bridge name bridge id STP enabled interfaces > br-vx 8000.323a9146b2d2 no tap0 > vxlan0 > # ethtool -k eth35 > Features for eth35: > rx-checksumming: on > tx-checksumming: on > tx-checksum-ipv4: on > tx-checksum-ip-generic: off [fixed] > tx-checksum-ipv6: on > tx-checksum-fcoe-crc: off [fixed] > tx-checksum-sctp: off [fixed] > scatter-gather: on > tx-scatter-gather: on > tx-scatter-gather-fraglist: off [fixed] > tcp-segmentation-offload: on > tx-tcp-segmentation: on > tx-tcp-ecn-segmentation: on > tx-tcp6-segmentation: on > udp-fragmentation-offload: off [fixed] > generic-segmentation-offload: on > generic-receive-offload: on > large-receive-offload: off [fixed] > rx-vlan-offload: on > tx-vlan-offload: on > ntuple-filters: off [fixed] > receive-hashing: off [fixed] > highdma: on > rx-vlan-filter: off [fixed] > vlan-challenged: off [fixed] > tx-lockless: off [fixed] > netns-local: off [fixed] > tx-gso-robust: off [fixed] > tx-fcoe-segmentation: off [fixed] > tx-gre-segmentation: off [fixed] > tx-ipip-segmentation: off [fixed] > tx-sit-segmentation: off [fixed] > tx-udp_tnl-segmentation: on > tx-mpls-segmentation: off [fixed] > fcoe-mtu: off [fixed] > tx-nocache-copy: off > loopback: off [fixed] > rx-fcs: off [fixed] > rx-all: off [fixed] > tx-vlan-stag-hw-insert: off [fixed] > rx-vlan-stag-hw-parse: off [fixed] > rx-vlan-stag-filter: off [fixed] > l2-fwd-offload: off [fixed] > busy-poll: on [fixed] > > # ethtool -k vxlan0 > Features for vxlan0: > rx-checksumming: on > tx-checksumming: on > tx-checksum-ipv4: off [fixed] > tx-checksum-ip-generic: on > tx-checksum-ipv6: off [fixed] > tx-checksum-fcoe-crc: off [fixed] > tx-checksum-sctp: off [fixed] > scatter-gather: on > tx-scatter-gather: on > tx-scatter-gather-fraglist: off [fixed] > tcp-segmentation-offload: on > tx-tcp-segmentation: on > tx-tcp-ecn-segmentation: on > tx-tcp6-segmentation: on > udp-fragmentation-offload: on > generic-segmentation-offload: on > generic-receive-offload: on > large-receive-offload: off [fixed] > rx-vlan-offload: off [fixed] > tx-vlan-offload: on > ntuple-filters: off [fixed] > receive-hashing: off [fixed] > highdma: off [fixed] > rx-vlan-filter: off [fixed] > vlan-challenged: off [fixed] > tx-lockless: on [fixed] > netns-local: off [fixed] > tx-gso-robust: off [fixed] > tx-fcoe-segmentation: off [fixed] > tx-gre-segmentation: off [fixed] > tx-ipip-segmentation: off [fixed] > tx-sit-segmentation: off [fixed] > tx-udp_tnl-segmentation: off [fixed] > tx-mpls-segmentation: off [fixed] > fcoe-mtu: off [fixed] > tx-nocache-copy: off > loopback: off [fixed] > rx-fcs: off [fixed] > rx-all: off [fixed] > tx-vlan-stag-hw-insert: on > rx-vlan-stag-hw-parse: off [fixed] > rx-vlan-stag-filter: off [fixed] > l2-fwd-offload: off [fixed] > busy-poll: off [fixed] > > # ethtool -k tap0 > Features for tap0: > rx-checksumming: off [fixed] > tx-checksumming: on > tx-checksum-ipv4: off [fixed] > tx-checksum-ip-generic: on > tx-checksum-ipv6: off [fixed] > tx-checksum-fcoe-crc: off [fixed] > tx-checksum-sctp: off [fixed] > scatter-gather: on > tx-scatter-gather: on > tx-scatter-gather-fraglist: on > tcp-segmentation-offload: on > tx-tcp-segmentation: on > tx-tcp-ecn-segmentation: on > tx-tcp6-segmentation: on > udp-fragmentation-offload: off [fixed] > generic-segmentation-offload: on > generic-receive-offload: on > large-receive-offload: off [fixed] > rx-vlan-offload: off [fixed] > tx-vlan-offload: on > ntuple-filters: off [fixed] > receive-hashing: off [fixed] > highdma: off [fixed] > rx-vlan-filter: off [fixed] > vlan-challenged: off [fixed] > tx-lockless: off [fixed] > netns-local: off [fixed] > tx-gso-robust: off [fixed] > tx-fcoe-segmentation: off [fixed] > tx-gre-segmentation: off [fixed] > tx-ipip-segmentation: off [fixed] > tx-sit-segmentation: off [fixed] > tx-udp_tnl-segmentation: off [fixed] > tx-mpls-segmentation: off [fixed] > fcoe-mtu: off [fixed] > tx-nocache-copy: off > loopback: off [fixed] > rx-fcs: off [fixed] > rx-all: off [fixed] > tx-vlan-stag-hw-insert: on > rx-vlan-stag-hw-parse: off [fixed] > rx-vlan-stag-filter: off [fixed] > l2-fwd-offload: off [fixed] > busy-poll: off [fixed] > > Thanks > -Santosh > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
