** Tags added: verified-test-kernel-works -- 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/1618299
Title: IPv6 with LVS Performance issue in latest 3.13LTS kernels Status in linux package in Ubuntu: In Progress Status in linux source package in Trusty: In Progress Bug description: We experienced a major performance regression between 12.04's 3.2 kernels and 14.04's 3.13 kernels when using IPv6 with the LVS load-balancing facility. Through analysis of perf events and a workaround we've determined that an upstream fix is available which addresses the issue. Ubuntu has picked up the "IPv6: remove rt6i_genid" fix that appears to address our issue in their 3.16 and later kernels. This was checked into the upstream 3.16 kernel back in late 2014. This fix addressed an issue introduced by the (late 2012) "ipv6: use net->rt_genid to check dst validity", which is the source of our issue due to the mismatch between a dst/route instantiation's rt6i_genid and the IPv6 rt_genid field. Since we have drivers and other software tied to the 3.13 kernels in the field this report is requesting that the backport of that upstream fix be done to the 3.13 LTS kernels as well since we were planning on several more years for those deployed systems. It seems relatively straight-forward. In our 3.13 kernel we used the "systemtap" facility in a test system to temporarily address the "obsolete" determination mistakenly made by the ip6_dst_check() function to check dst validity on behalf of the LVS (ip_vs) code. By updating rt6i_genid to the current global value we were able to restore our test systems to the previous performance obtained with the 3.2 kernels. But clearly we want the official upstream fix incorporated, which pulls the troublesome rt6i_genid field out altogether since its mishandling affected more than IPv6/LVS support based on the upstream mail threads. Those were made in mid-2014 to the upstream kernel folks, such as a per-socket route caching issue. Note that the apport-bug collected info from a 3.13.0-87 system but we see the issue on all 3.13.0-xxx kernels. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-87-generic 3.13.0-87.133 ProcVersionSignature: Ubuntu 3.13.0-87.133-generic 3.13.11-ckt39 Uname: Linux 3.13.0-87-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.21 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: marc 2433 F.... pulseaudio Date: Mon Aug 29 20:05:57 2016 HibernationDevice: RESUME=UUID=c4187d86-ea40-4f53-af39-1b7e83964502 InstallationDate: Installed on 2014-04-30 (852 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) Lsusb: Bus 001 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub Bus 001 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: VMware, Inc. VMware Virtual Platform ProcEnviron: LANGUAGE=en_US TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 svgadrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-87-generic root=UUID=92211e82-1c0b-42e6-bb12-0003b7f6db54 ro quiet splash crashkernel=384M-:128M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-3.13.0-87-generic N/A linux-backports-modules-3.13.0-87-generic N/A linux-firmware 1.127.22 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/20/2014 dmi.bios.vendor: Phoenix Technologies LTD dmi.bios.version: 6.00 dmi.board.name: 440BX Desktop Reference Platform dmi.board.vendor: Intel Corporation dmi.board.version: None dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 1 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvr6.00:bd05/20/2014:svnVMware,Inc.:pnVMwareVirtualPlatform:pvrNone:rvnIntelCorporation:rn440BXDesktopReferencePlatform:rvrNone:cvnNoEnclosure:ct1:cvrN/A: dmi.product.name: VMware Virtual Platform dmi.product.version: None dmi.sys.vendor: VMware, Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1618299/+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
