apport information ** Tags added: apport-collected bionic
** Description changed: Using IPVS with One-Packet Scheduling on UDP causes CPU soft lockup on traffic. Steps to reproduce: 1. Install ipvsadm and netcat-openbsd 2. Execute `ipvsadm -a -u 127.0.0.1:1234 -s rr --ops && ipvsadm -A -u 127.0.0.1:1234 -r 127.0.0.1:1235 -m -w 1` 3. Execute `nc -l -k -u 1235` to actually have a listening service 4. In another terminal, generate traffic `while sleep 0.01; do date | nc -u -w 0 127.0.0.1 1234; done` In only takes several packets (around 100 in my tests) to cause the soft lockup to appear. Even with lower packet rates (sleep 1 for example), the bug occurs. This problem is already fixed in the current 4.20 vanilla kernel but is present in the 4.15 vanilla kernel (tested packages from the kernel- ppa). So basically, this would be a backport. Ubuntu release: Ubuntu 18.04.1 LTS Kernel version: Ubuntu 4.15.0-43.46-generic 4.15.18 + --- + ProblemType: Bug + AlsaDevices: + total 0 + crw-rw---- 1 root audio 116, 1 Jan 10 11:37 seq + crw-rw---- 1 root audio 116, 33 Jan 10 11:37 timer + AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay' + ApportVersion: 2.20.9-0ubuntu7.5 + Architecture: amd64 + ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord' + AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: + DistroRelease: Ubuntu 18.04 + IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig' + Lsusb: + Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd + Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub + MachineType: QEMU Standard PC (i440FX + PIIX, 1996) + Package: linux (not installed) + PciMultimedia: + + ProcFB: 0 EFI VGA + ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-43-generic root=UUID=27723a0b-84b7-4d41-ac73-d96bb9bc770a ro + ProcVersionSignature: Ubuntu 4.15.0-43.46-generic 4.15.18 + RelatedPackageVersions: + linux-restricted-modules-4.15.0-43-generic N/A + linux-backports-modules-4.15.0-43-generic N/A + linux-firmware 1.173.2 + RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill' + Tags: bionic + Uname: Linux 4.15.0-43-generic x86_64 + UnreportableReason: This report is about a package that is not installed. + UpgradeStatus: No upgrade log present (probably fresh install) + UserGroups: + + _MarkForUpload: False + dmi.bios.date: 04/01/2014 + dmi.bios.vendor: SeaBIOS + dmi.bios.version: rel-1.11.1-0-g0551a4be2c-prebuilt.qemu-project.org + dmi.chassis.type: 1 + dmi.chassis.vendor: QEMU + dmi.chassis.version: pc-i440fx-2.12 + dmi.modalias: dmi:bvnSeaBIOS:bvrrel-1.11.1-0-g0551a4be2c-prebuilt.qemu-project.org:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.12:cvnQEMU:ct1:cvrpc-i440fx-2.12: + dmi.product.name: Standard PC (i440FX + PIIX, 1996) + dmi.product.version: pc-i440fx-2.12 + dmi.sys.vendor: QEMU ** Attachment added: "CRDA.txt" https://bugs.launchpad.net/bugs/1811226/+attachment/5228259/+files/CRDA.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1811226 Title: ipvsadm --ops causes CPU soft lockup on traffic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1811226/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
