This is fact, you can't get high PPS with tap interface because they run in kernel space and it drive packets on kernel which isn't scalable.
Finally i have migrate all my compute nodes to SR-IOV and much happy now. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1423631 Title: tap interface drops many packets on highload systems Status in linux package in Ubuntu: Confirmed Status in qemu package in Ubuntu: Incomplete Status in qemu-kvm package in Ubuntu: Incomplete Bug description: I use qemu-kvm in openstack. On highload hypervisor tap interface of net-highload guest drops many TX packets. Network options of qemu-system-x86_64 "... -netdev tap,fd=30,id=hostnet0,vhost=on,vhostfd=31 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=fa:16:3e:86:67:7b,bus=pci.0,addr=0x3..." Network domin config: <interface type='bridge'> <mac address='fa:16:3e:86:67:7b'/> <source bridge='qbre4009073-0b'/> <target dev='tape4009073-0b'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> tape4009073-0b Link encap:Ethernet HWaddr fe:16:3e:86:67:7b inet6 addr: fe80::fc16:3eff:fe86:677b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1587622634 errors:0 dropped:0 overruns:0 frame:0 TX packets:1484106438 errors:0 dropped:460259 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:877878711500 (877.8 GB) TX bytes:3071846828531 (3.0 TB) --- AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Feb 18 12:06 seq crw-rw---- 1 root audio 116, 33 Feb 18 12:06 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.1-0ubuntu3.7 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory DistroRelease: Ubuntu 14.04 InstallationDate: Installed on 2014-07-01 (234 days ago) InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2) MachineType: Dell Inc. PowerEdge M620 Package: qemu-kvm PciMultimedia: ProcEnviron: TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-30-generic root=UUID=5965239d-820a-49a1-9d8e-23a4c1f87ce6 ro ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3 RelatedPackageVersions: linux-restricted-modules-3.16.0-30-generic N/A linux-backports-modules-3.16.0-30-generic N/A linux-firmware 1.127.11 RfKill: Error: [Errno 2] No such file or directory Tags: trusty Uname: Linux 3.16.0-30-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: _MarkForUpload: True dmi.bios.date: 01/21/2014 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.2.7 dmi.board.name: 0T36VK dmi.board.vendor: Dell Inc. dmi.board.version: A01 dmi.chassis.type: 25 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: PowerEdge M1000e dmi.modalias: dmi:bvnDellInc.:bvr2.2.7:bd01/21/2014:svnDellInc.:pnPowerEdgeM620:pvr:rvnDellInc.:rn0T36VK:rvrA01:cvnDellInc.:ct25:cvrPowerEdgeM1000e: dmi.product.name: PowerEdge M620 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1423631/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
