kernel-packages team mailing list archive

[Stefan Bader <stefan.bader@xxxxxxxxxxxxx>]

I had a dream... well honestly this idea came to me around then. So I was fishing in the same availability zone to get another case of this (was not sure I could just go back to yours). Then installed a 12.04 (3.2.x) kernel and bingo, same problem.
So at least I can stop trying to think of a way the changes between 3.2 and 3.13 may have caused this. And the reason I added the comment about the observation that it may not happen initially but then on a reboot and after that on every reboot was this: I have the feeling that the uptime of the host also is one part of the equation. So this seems:

- Intel CPU, the nonstop_tsc of the E5-2650 might be something to look at
- A certain uptime of the host
- Maybe the tsc/systime related code in the hypervisor

Well, it could also be independent of the CPU and only rely on the
uptime and it is just pure bad luck that the only hosts we currently
find are of a certain type. Only way to prove or bust this would be to
find a unaffected guest showing an uptime of those 58 days. Figuring out
the involvement of the hypervisor code is nearly impossible as Amazon
uses a special version of 3.4.3.

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https://bugs.launchpad.net/bugs/1349883

Title:
  dmesg time wildly incorrect on paravirtual EC2 instances.

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  On Ubuntu 14.04 EC2 instances, during startup the dmesg time goes from
  0 seconds to thousands of seconds. This causes kernel logs to be
  recorded for months in the future.

  This appears to be related to the kernel trusting the TSC clock on Xen servers, as described here:
  https://forums.aws.amazon.com/thread.jspa?threadID=59753

  But I am not sure that is the cause.

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: linux-image-3.13.0-32-generic 3.13.0-32.57
  ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
  Uname: Linux 3.13.0-32-generic x86_64
  AlsaDevices:
   total 0
   crw-rw---- 1 root audio 116,  1 Jul 29 14:41 seq
   crw-rw---- 1 root audio 116, 33 Jul 29 14:41 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.14.1-0ubuntu3.2
  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:
  CRDA: Error: [Errno 2] No such file or directory: 'iw'
  CurrentDmesg: [7562292.301737] init: plymouth-upstart-bridge main process ended, respawning
  Date: Tue Jul 29 14:47:54 2014
  Ec2AMI: ami-00dc1368
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1c
  Ec2InstanceType: m1.small
  Ec2Kernel: aki-919dcaf8
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lspci:
   
  Lsusb: Error: [Errno 2] No such file or directory: 'lsusb'
  PciMultimedia:
   
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB:
   
  ProcKernelCmdLine: root=LABEL=cloudimg-rootfs ro console=hvc0
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-32-generic N/A
   linux-backports-modules-3.13.0-32-generic  N/A
   linux-firmware                             N/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  WifiSyslog:
  --- 
  AlsaDevices:
   total 0
   crw-rw---- 1 root audio 116,  1 Jul 29 14:41 seq
   crw-rw---- 1 root audio 116, 33 Jul 29 14:41 timer
  AplayDevices: Error: [Errno 2] No such file or directory
  ApportVersion: 2.14.1-0ubuntu3.2
  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
  CurrentDmesg: [7562292.301737] init: plymouth-upstart-bridge main process ended, respawning
  DistroRelease: Ubuntu 14.04
  Ec2AMI: ami-00dc1368
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1c
  Ec2InstanceType: m1.small
  Ec2Kernel: aki-919dcaf8
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory
  Lspci:
   
  Lsusb: Error: [Errno 2] No such file or directory
  Package: linux (not installed)
  PciMultimedia:
   
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB:
   
  ProcKernelCmdLine: root=LABEL=cloudimg-rootfs ro console=hvc0
  ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-32-generic N/A
   linux-backports-modules-3.13.0-32-generic  N/A
   linux-firmware                             N/A
  RfKill: Error: [Errno 2] No such file or directory
  Tags:  trusty ec2-images
  Uname: Linux 3.13.0-32-generic x86_64
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm admin ssh sudo
  WifiSyslog:
   
  _MarkForUpload: True

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