[Bug 1635891] Re: Random hangs after upgrade to 4.4.0-45, possibly cgroup related

The task "linux (Ubuntu)" has expired because it has had no new comments or updates for more than three years. If this issue is still present in an Ubuntu LTS kernel still under active support, please reopen the bug and provide updated details. If this issue was reported against an Ubuntu kernel no longer under active support but the issue still exists in a currently supported Ubuntu kernel, please open a new bug against that kernel version and provide the updated details, with a reference link to the original bug. This action was performed by an automated process maintained by the Ubuntu Kernel Team. ** Tags added: kernel-autoclosed kernel-autoclosed-expired ** Changed in: linux (Ubuntu) Status: Confirmed => Expired -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/1635891 Title: Random hangs after upgrade to 4.4.0-45, possibly cgroup related Status in linux package in Ubuntu: Expired Bug description: Apologize in advance is anything is missing from this bug report. After upgrading to 4.4.0-45 we have started to experience random kernel lockups. I have attached a sample from the syslog which I managed to catch after one of these events. In other cases, nothing was written to the syslog. I notice that the cgroup system features here and there in the log, and the hanging server uses cgroups and namespaces heavily, so I suspect it is related. Sadly I don't know enough of the kernel to decipher the error I got further than that. Another unusual thing we do on this server, which may possibly be related, is that we regularly clear the caches ("echo 3 > /proc/sys/vm/drop_caches") /Pehr ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-45-generic 4.4.0-45.66 ProcVersionSignature: Ubuntu 4.4.0-45.66-generic 4.4.21 Uname: Linux 4.4.0-45-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Oct 22 22:52 seq crw-rw---- 1 root audio 116, 33 Oct 22 22:52 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: Date: Sat Oct 22 23:37:59 2016 HibernationDevice: RESUME=/dev/mapper/template--16--vg-swap_1 InstallationDate: Installed on 2016-04-22 (183 days ago) InstallationMedia: Ubuntu-Server 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.3) IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' Lsusb: Error: command ['lsusb'] failed with exit code 1: MachineType: VMware, Inc. VMware Virtual Platform PciMultimedia: ProcFB: 0 svgadrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-45-generic root=/dev/mapper/template--16--vg-root ro cgroup_enable=memory swapaccount=1 RelatedPackageVersions: linux-restricted-modules-4.4.0-45-generic N/A linux-backports-modules-4.4.0-45-generic N/A linux-firmware 1.157.4 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/17/2015 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:bd09/17/2015: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/1635891/+subscriptions