[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

** Changed in: linux (Ubuntu)
 Assignee: Dan Streetman (ddstreet) => (unassigned)

** Changed in: linux (Ubuntu Xenial)
 Assignee: Dan Streetman (ddstreet) => (unassigned)

** Changed in: linux (Ubuntu Yakkety)
 Assignee: Dan Streetman (ddstreet) => (unassigned)

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Tobias]

Still not solved. 
Bug happens on Fresh install of Kubuntu 21.04 with reccomended HDD distribution 
on modern Lapotp (Ryzen5, 5500U).
And on older Laptop (~2014) with Ubuntu 20.04 & 21.04, Kubuntu 21.04 and 
Lubuntu 20.04 & 20.10 & 21.04. (experienced often, sometimes every few hours) 
Kswapd0 process rapidly increases in CPU then uses all resources (no result 
after hours) necessating reboot.

Killing a high Ram process (in the few seconds till all CPU is taken)
(p.e. Firefox) stops the Kswapd0 process.

Am willing to provide additional data / reformat old laptop for tests
etc.

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[JPT]

Still not solved. 
Linux 5.0.0-29-generic #31-Ubuntu SMP Thu Sep 12 13:05:32 UTC 2019 x86_64 
x86_64 x86_64 GNU/Linux
This system has i5-9600K and 16 GB RAM, no swap.

This happens everytime I run a VirtualbBox VM.
The VM has got 4 GB RAM.
I updated my VMs to current default settings for Windows and reduced CPU count 
to 1. 
This solved the issue until I ran video compression on the host system 
concurrently. 
So the problem still happens when CPU usage is high and a VM is running. 
This time I succeeded in rescuing the system avoiding a reboot. 
I switched to console mode and waited a lot of time (like an hour) until I was 
able to kill VirtualBox. 
What I saw was: kswapd0 was running crazy.

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You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Brad Figg]

** Tags added: cscc

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Petr Doležal]

Recently got a new laptop with a fresh install of Ubuntu 18.04 and now
updated to kernel 4.19.21-041921-generic.

It still happens even with 16 GB of memory and 4GB more in swap on SSD.
What is more dangerous is now that laptop has hyperthreading it goes
absolutely crazy and heats up insanely. At that point, the system is so
frozen no commands can fix it as one never gets to write them.
Restarting the machine with a button is the only option.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Bug Watch Updater]

** Bug watch added: Linux Kernel Bug Tracker #110501
   https://bugzilla.kernel.org/show_bug.cgi?id=110501

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Bug Watch Updater]

Launchpad has imported 55 comments from the remote bug at
https://bugzilla.kernel.org/show_bug.cgi?id=65201.

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On 2013-11-19T19:40:40+00:00 nleo wrote:

kswapd0 randomly load one core of CPU by 100%

Linux localhost 3.12.0-1-ARCH #1 SMP PREEMPT Wed Nov 6 09:06:27 CET 2013
x86_64 GNU/Linux

No swap enabled

Befor on same laptop was installed Ubuntu 12.04 and kernel 3.2 32-bit
pae, and there is no such problem.

[root@localhost ~]# free -mh
 total   used   free sharedbuffers cached
Mem:  3.8G   2.4G   1.3G 0B   150M   508M
-/+ buffers/cache:   1.8G   2.0G
Swap:   0B 0B 0B


[root@localhost ~]# cat /proc/meminfo
MemTotal:3935792 kB
MemFree: 1381360 kB
Buffers:  154216 kB
Cached:   533096 kB
SwapCached:0 kB
Active:  1958896 kB
Inactive: 438004 kB
Active(anon):1740916 kB
Inactive(anon):   136292 kB
Active(file): 217980 kB
Inactive(file):   301712 kB
Unevictable:   0 kB
Mlocked:   0 kB
SwapTotal: 0 kB
SwapFree:  0 kB
Dirty:  2064 kB
Writeback: 0 kB
AnonPages:   1709628 kB
Mapped:   196696 kB
Shmem:167620 kB
Slab:  81516 kB
SReclaimable:  61312 kB
SUnreclaim:20204 kB
KernelStack:1696 kB
PageTables:13088 kB
NFS_Unstable:  0 kB
Bounce:0 kB
WritebackTmp:  0 kB
CommitLimit: 1967896 kB
Committed_AS:3498576 kB
VmallocTotal:   34359738367 kB
VmallocUsed:  361304 kB
VmallocChunk:   34359300731 kB
HardwareCorrupted: 0 kB
AnonHugePages:157696 kB
HugePages_Total:   0
HugePages_Free:0
HugePages_Rsvd:0
HugePages_Surp:0
Hugepagesize:   2048 kB
DirectMap4k:   18476 kB
DirectMap2M: 4059136 kB

And I can't kill it. I heared that it's not good idea, but just for
lulz)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/comments/0


On 2013-11-20T23:32:02+00:00 atomlin wrote:

(In reply to nleo from comment #0)
> kswapd0 randomly load one core of CPU by 100%

You cannot issue a SIGKILL to 'kswapd' since it is
a kernel thread.

> CommitLimit: 1967896 kB
> Committed_AS:3498576 kB
   ^^^

Seem to be over committing memory.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/comments/1


On 2013-11-22T00:57:01+00:00 akpm wrote:

(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Tue, 19 Nov 2013 19:40:40 + bugzilla-dae...@bugzilla.kernel.org
wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=65201
> 
> Bug ID: 65201
>Summary: kswapd0 randomly high cpu load
>Product: Memory Management
>Version: 2.5
> Kernel Version: 3.12
>   Hardware: x86-64
> OS: Linux
>   Tree: Mainline
> Status: NEW
>   Severity: normal
>   Priority: P1
>  Component: Other
>   Assignee: a...@linux-foundation.org
>   Reporter: n...@nm.ru
> Regression: No
> 
> kswapd0 randomly load one core of CPU by 100%
> 
> Linux localhost 3.12.0-1-ARCH #1 SMP PREEMPT Wed Nov 6 09:06:27 CET 2013
> x86_64
> GNU/Linux
> 
> No swap enabled
> 
> Befor on same laptop was installed Ubuntu 12.04 and kernel 3.2 32-bit pae,
> and
> there is no such problem.
> 
> [root@localhost ~]# free -mh
>  total   used   free sharedbuffers cached
> Mem:  3.8G   2.4G   1.3G 0B   150M   508M
> -/+ buffers/cache:   1.8G   2.0G
> Swap:   0B 0B 0B

hm, I wonder what kswapd is up to.

Could you please make it happen again and then

dmesg -n 7
dmesg -c
echo m > /proc/sysrq-trigger
echo t > /proc/sysrq-trigger
dmesg -s 100 > foo

then send us foo?

> 
> [root@localhost ~]# cat /proc/meminfo
> MemTotal:3935792 kB
> MemFree: 1381360 kB
> Buffers:  154216 kB
> Cached:   533096 kB
> SwapCached:0 kB
> Active:  1958896 kB
> Inactive: 438004 kB
> Active(anon):1740916 kB
> Inactive(anon):   136292 kB
> Active(file): 217980 kB
> Inactive(file):   301712 kB
> Unevictable:   0 kB
> Mlocked:   0 kB
> SwapTotal: 0 kB
> SwapFree:  0 kB
> Dirty:  2064 kB
> Writeback: 0 kB
> AnonPages:   1709628 kB
> Mapped:

Re: [Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Mathieu Perona]

Sorry !

Le jeu. 26 oct. 2017 à 14:55, Dan Streetman  a
écrit :

> Mathieu,
>
> I'm not mailing you, this is a public bug report, you subscribed
> yourself to this bug:
>
> 2017-01-26 10:14:29 Mathieu Perona  bug added
> subscriber Mathieu Perona
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
>
> Title:
>   kswapd0 100% CPU usage
>
> Status in Linux:
>   Unknown
> Status in linux package in Ubuntu:
>   Fix Released
> Status in linux source package in Xenial:
>   Fix Released
> Status in linux source package in Yakkety:
>   Fix Released
>
> Bug description:
>   As per bug 721896 and various others:
>
>   I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
>   Occasionally (about once a day), kswapd0 falls into a busy loop and
>   spins on 100% CPU usage indefinitely. This can be provoked by
>   copying/writing large files (e.g. dding a 256MB file), but it happens
>   occasionally otherwise. System memory usage (not including
>   buffers/caches) currently sits at 36%, which is typical[1]. Initially
>   I had no swap space configured; I've since tried enabling a 256MB swap
>   file, but the problem continues to occur and no swap space is used.
>   The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
>
>   Happy to provide further information/take further debugging actions.
>
>
>   [1] Full output from `free`:
>total   used   free sharedbuffers cached
>   Mem:   1014936 483448 531488  28556   9756 112700
>   -/+ buffers/cache: 360992 653944
>   Swap:   262140  0 262140
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 15.10
>   Package: linux-image-4.2.0-18-generic 4.2.0-18.22
>   ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>   Uname: Linux 4.2.0-18-generic x86_64
>   AlsaDevices:
>total 0
>crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
>crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
>   AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
>   ApportVersion: 2.19.1-0ubuntu5
>   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: N/A
>   Date: Fri Nov 20 20:44:30 2015
>   Ec2AMI: ami-1c552a76
>   Ec2AMIManifest: (unknown)
>   Ec2AvailabilityZone: us-east-1d
>   Ec2InstanceType: t2.micro
>   Ec2Kernel: unavailable
>   Ec2Ramdisk: unavailable
>   IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
>   Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to
> initialize libusb: -99
>   MachineType: Xen HVM domU
>   PciMultimedia:
>
>   ProcEnviron:
>TERM=screen
>PATH=(custom, no user)
>LANG=en_US.UTF-8
>SHELL=/bin/bash
>   ProcFB: 0 xen
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1
> console=ttyS0 net.ifnames=0
>   RelatedPackageVersions:
>linux-restricted-modules-4.2.0-18-generic N/A
>linux-backports-modules-4.2.0-18-generic  N/A
>linux-firmwareN/A
>   RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
>   SourcePackage: linux
>   UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   dmi.bios.date: 05/06/2015
>   dmi.bios.vendor: Xen
>   dmi.bios.version: 4.2.amazon
>   dmi.chassis.type: 1
>   dmi.chassis.vendor: Xen
>   dmi.modalias:
> dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
>   dmi.product.name: HVM domU
>   dmi.product.version: 4.2.amazon
>   dmi.sys.vendor: Xen
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions
>

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

Mathieu,

I'm not mailing you, this is a public bug report, you subscribed
yourself to this bug:

2017-01-26 10:14:29 Mathieu Perona  bug added
subscriber Mathieu Perona

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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More help   : https://help.launchpad.net/ListHelp

Re: [Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Mathieu Perona]

Dear Dan,

I am not sure you are mailing the right person. Anyway, the issue still
arises when copying large files from a FAT drive to an EXT one. kswapd uses
all available CPU power (but leaves much of the RAM unused) and copy
throughput declines.

Anyway, I solved the problem by transferring my external drive to an EXT4
filesystem, at the expense of interoperability.

Best


Le jeu. 26 oct. 2017 à 13:26, Dan Streetman  a
écrit :

> this bug is fix released.  please open a new bug.
>
> note that you may just have been out of memory.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
>
> Title:
>   kswapd0 100% CPU usage
>
> Status in Linux:
>   Unknown
> Status in linux package in Ubuntu:
>   Fix Released
> Status in linux source package in Xenial:
>   Fix Released
> Status in linux source package in Yakkety:
>   Fix Released
>
> Bug description:
>   As per bug 721896 and various others:
>
>   I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
>   Occasionally (about once a day), kswapd0 falls into a busy loop and
>   spins on 100% CPU usage indefinitely. This can be provoked by
>   copying/writing large files (e.g. dding a 256MB file), but it happens
>   occasionally otherwise. System memory usage (not including
>   buffers/caches) currently sits at 36%, which is typical[1]. Initially
>   I had no swap space configured; I've since tried enabling a 256MB swap
>   file, but the problem continues to occur and no swap space is used.
>   The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
>
>   Happy to provide further information/take further debugging actions.
>
>
>   [1] Full output from `free`:
>total   used   free sharedbuffers cached
>   Mem:   1014936 483448 531488  28556   9756 112700
>   -/+ buffers/cache: 360992 653944
>   Swap:   262140  0 262140
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 15.10
>   Package: linux-image-4.2.0-18-generic 4.2.0-18.22
>   ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>   Uname: Linux 4.2.0-18-generic x86_64
>   AlsaDevices:
>total 0
>crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
>crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
>   AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
>   ApportVersion: 2.19.1-0ubuntu5
>   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: N/A
>   Date: Fri Nov 20 20:44:30 2015
>   Ec2AMI: ami-1c552a76
>   Ec2AMIManifest: (unknown)
>   Ec2AvailabilityZone: us-east-1d
>   Ec2InstanceType: t2.micro
>   Ec2Kernel: unavailable
>   Ec2Ramdisk: unavailable
>   IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
>   Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to
> initialize libusb: -99
>   MachineType: Xen HVM domU
>   PciMultimedia:
>
>   ProcEnviron:
>TERM=screen
>PATH=(custom, no user)
>LANG=en_US.UTF-8
>SHELL=/bin/bash
>   ProcFB: 0 xen
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1
> console=ttyS0 net.ifnames=0
>   RelatedPackageVersions:
>linux-restricted-modules-4.2.0-18-generic N/A
>linux-backports-modules-4.2.0-18-generic  N/A
>linux-firmwareN/A
>   RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
>   SourcePackage: linux
>   UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   dmi.bios.date: 05/06/2015
>   dmi.bios.vendor: Xen
>   dmi.bios.version: 4.2.amazon
>   dmi.chassis.type: 1
>   dmi.chassis.vendor: Xen
>   dmi.modalias:
> dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
>   dmi.product.name: HVM domU
>   dmi.product.version: 4.2.amazon
>   dmi.sys.vendor: Xen
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions
>

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

this bug is fix released.  please open a new bug.

note that you may just have been out of memory.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Simon West]

8 months on and one of my systems is exhibiting what would appear to be
the same bug... it was running Ubuntu 17.04 happily and just got
upgraded to 17.10 with today's updates. (Yeah... upgrade, not
reinstall... not enough time to re-download all the Insync files!)

These were the first lines of `top` as the computer started going into
slowdown:

 PID USER  PR  NIVIRTRESSHR S  %CPU %MEM TIME+ COMMAND 
   54 root  20   0   0  0  0 R  47.2  0.0   2:46.26 kswapd0 
 1678 tracey20   0 3917924 139976  4 D   1.2  3.6   1:01.26 insync  

kswapd0 went higher then it locked up.

I have a small swapfile, although the system is running on an SSD.
root@tracey-:~# swapon --show
NAME  TYPE SIZE   USED PRIO
/swapfile file   2G 498.5M   -1

I have vm.swappiness=1 in /etc/sysctl.conf

This is memory when the system is running normally:

root@tracey-:~# free -h
  totalusedfree  shared  buff/cache   available
Mem:   3.7G2.2G339M998M1.2G392M
Swap:  2.0G498M1.5G

Suggestions please?

Frustrated of Lyme Regis

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

As a comment to those expecting that disabling swap will prevent kswapd
from doing anything, that's incorrect.  kswapd also is responsible for
clearing out the page cache, so even with swap disabled you'll still see
it doing work, especially during heavy IO that uses the page cache.  For
example, copying large files from fast drives.  That's completely
normal.  What this bug is about, is kswapd trying over and over to do
its normal work, but making no progress, so it continues to use 100% cpu
while the rest of the system is doing nothing.  That bug should be fixed
now.

If anyone continues to see *this* bug - kswapd using 100% cpu while your
system is doing nothing and kswapd never recovers - you can report it
here, but you should also open a new bug and reference it in your
comment (this bug is fixed and closed).  However, if all you see is
kswapd using cpu while you're doing things - especially file IO - that
isn't this bug, and it probably isn't actually a bug at all.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Mathieu Perona]

As a complement to my previous comment: both computers have a
significant amount of RAM (4 and 8 Go respectively) and the swap
partition is shown as not used by the system monitor.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Mathieu Perona]

As of 2017-01-26, I experience this bug on two 16.10 boxes. This kswap0d
behavior is 100% reproductible when I copy large files (more than c. 500
Mo) from or to a NTFS hard drive.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

This bug is fixed released already, any new problems should be opened in
a new bug.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Wilhelm Buchmueller]

Running 4.8.13-100.fc23.i686+PAE, no desktop, swapon and swapoff, swappiness 0, 
60, and 100.
kswapd0 usage high while reading from /dev/sda (not mounted, internal SSD with 
500+MB/s read).
After stop reading, kswapd0 usage is gone.
No Problem when reading from USB-HDD.

Problem with high-speed reading?

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Tuomo Sipola]

Running Ubuntu 16.10 Yakkety. Old 4.4.0-45-generic kernel works nicely.
All the new 4.8.0 kernels eventually go berzerk with kswapd0, just today
the newest 4.8.0-32-generic. Normal usage, just a couple of terminals,
Chromium, Nautilus windows and Evince PDF documents open.

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You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

> I can see it every now and then with Yakkety and linux 4.8.0-27.
> Can you advice any action?

what do you mean by "every now and then"?  you mean kswapd runs at 100%
for a short time, occasionally?  that's normal.

> kswapd0 no longer takes 100% CPU, but it still emerges to the top of the list 
> in top as it still
> manages to take more then the other processes

this sounds like kswapd is just doing its job now.  if you stop all your
applications, does kswapd still take up cpu time indefinitely?

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Skylinux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Launchpad Bug Tracker]

This bug was fixed in the package linux - 4.8.0-30.32

---
linux (4.8.0-30.32) yakkety; urgency=low

  * CVE-2016-8655 (LP: #1646318)
- packet: fix race condition in packet_set_ring

 -- Brad Figg   Thu, 01 Dec 2016 08:02:53 -0800

** Changed in: linux (Ubuntu)
   Status: Invalid => Fix Released

** CVE added: http://www.cve.mitre.org/cgi-
bin/cvename.cgi?name=2016-8655

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Skylinux:
  Unknown
Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[velis]

Following this thread I had the same issue, running stock 16.04 (xenial) with 
kernel 4.4.0-38.
I have upgraded the kernel to 4.8.10-040810 and the end result is the same but 
symptoms are a bit different:

note: 1GB of RAM, no swap at all

(old kernel)
with 50% of RAM in buffers / cache, kswapd0 took all the CPU it could (~75%). 
iostat was pretty much at 0% utilisation. server ground to a halt immediately 
when free ram expired without ever "eating into" the buffers / cache.

(new kernel)
again, with 50% of RAM in buffers / cache, kswapd0 no longer takes 100% CPU, 
but it still emerges to the top of the list in top as it still manages to take 
more then the other processes. For a difference, now ~75% cpu processes are 
*WA*iting. A second difference is that now, after free ram is consumed, for a 
while buffers / cache are also being reduced in favour of the RAM hungry app. 
However, even this goes only down to about 40 - 43% or RAM being used by 
buffers / cache.

Hopefully this is making at least some sense.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Luc Pi]

> Dan Streetman (ddstreet) wrote on 2016-10-01: #127
> 
> The patch series that fixes this is included in yakkety 
> (if anyone reproduces this on a yakkety kernel, please let me know), 

I can see it every now and then with Yakkety and linux 4.8.0-27.
Can you advice any action?

$ uname -a
Linux luc-MacBook 4.8.0-27-generic #29-Ubuntu SMP Thu Oct 20 21:01:44 UTC 2016 
i686 i686 i686 GNU/Linux

$ lsb_release -a
Description:Ubuntu 16.10
Codename:   yakkety

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Launchpad Bug Tracker]

This bug was fixed in the package linux - 4.8.0-27.29

---
linux (4.8.0-27.29) yakkety; urgency=low

  [ Seth Forshee ]

  * Release Tracking Bug
- LP: #1635377

  * proc_keys_show crash when reading /proc/keys (LP: #1634496)
- SAUCE: KEYS: ensure xbuf is large enough to fix buffer overflow in
  proc_keys_show (LP: #1634496)

  * Revert "If zone is so small that watermarks are the same, stop zone balance"
in yakkety (LP: #1632894)
- Revert "UBUNTU: SAUCE: (no-up) If zone is so small that watermarks are the
  same, stop zone balance."

  * lts-yakkety 4.8 cannot mount lvm raid1 (LP: #1631298)
- SAUCE: (no-up) dm raid: fix compat_features validation

  * kswapd0 100% CPU usage (LP: #1518457)
- SAUCE: (no-up) If zone is so small that watermarks are the same, stop zone
  balance.

  * [Trusty->Yakkety] powerpc/64: Fix incorrect return value from
__copy_tofrom_user (LP: #1632462)
- SAUCE: (no-up) powerpc/64: Fix incorrect return value from
  __copy_tofrom_user

  * Ubuntu 16.10: Oops panic in move_page_tables/page_remove_rmap after running
memory_stress_ng. (LP: #1628976)
- SAUCE: (no-up) powerpc/pseries: Fix stack corruption in htpe code

  * Paths not failed properly when unmapping virtual FC ports in VIOS (using
ibmvfc) (LP: #1632116)
- scsi: ibmvfc: Fix I/O hang when port is not mapped

  * [Ubuntu16.10]KV4.8: kernel livepatch config options are not set
(LP: #1626983)
- [Config] Enable live patching on powerpc/ppc64el

  * CONFIG_AUFS_XATTR is not set (LP: #1557776)
- [Config] CONFIG_AUFS_XATTR=y

  * Yakkety update to 4.8.1 stable release (LP: #1632445)
- arm64: debug: avoid resetting stepping state machine when TIF_SINGLESTEP
- Using BUG_ON() as an assert() is _never_ acceptable
- usb: misc: legousbtower: Fix NULL pointer deference
- Staging: fbtft: Fix bug in fbtft-core
- usb: usbip: vudc: fix left shift overflow
- USB: serial: cp210x: Add ID for a Juniper console
- Revert "usbtmc: convert to devm_kzalloc"
- ALSA: hda - Adding one more ALC255 pin definition for headset problem
- ALSA: hda - Fix headset mic detection problem for several Dell laptops
- ALSA: hda - Add the top speaker pin config for HP Spectre x360
- Linux 4.8.1

  * PSL data cache should be flushed before resetting CAPI adapter
(LP: #1632049)
- cxl: Flush PSL cache before resetting the adapter

  * thunder nic: avoid link delays due to RX_PACKET_DIS (LP: #1630038)
- net: thunderx: Don't set RX_PACKET_DIS while initializing

  * crypto/vmx/p8_ghash memory corruption (LP: #1630970)
- crypto: ghash-generic - move common definitions to a new header file
- crypto: vmx - Fix memory corruption caused by p8_ghash
- crypto: vmx - Ensure ghash-generic is enabled

  * arm64: SPCR console not autodetected (LP: #1630311)
- of/serial: move earlycon early_param handling to serial
- [Config] CONFIG_ACPI_SPCR_TABLE=y
- ACPI: parse SPCR and enable matching console
- ARM64: ACPI: enable ACPI_SPCR_TABLE
- serial: pl011: add console matching function

  * include/linux/security.h header syntax error with !CONFIG_SECURITYFS
(LP: #1630990)
- SAUCE: (no-up) include/linux/security.h -- fix syntax error with
  CONFIG_SECURITYFS=n

  * sha1-powerpc returning wrong results (LP: #1629977)
- crypto: sha1-powerpc - little-endian support

 -- Seth Forshee   Thu, 20 Oct 2016 14:09:37
-0500

** Changed in: linux (Ubuntu Yakkety)
   Status: Invalid => Fix Released

** Changed in: linux (Ubuntu Yakkety)
   Status: Invalid => Fix Released

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Launchpad Bug Tracker]

This bug was fixed in the package linux - 4.8.0-27.29

---
linux (4.8.0-27.29) yakkety; urgency=low

  [ Seth Forshee ]

  * Release Tracking Bug
- LP: #1635377

  * proc_keys_show crash when reading /proc/keys (LP: #1634496)
- SAUCE: KEYS: ensure xbuf is large enough to fix buffer overflow in
  proc_keys_show (LP: #1634496)

  * Revert "If zone is so small that watermarks are the same, stop zone balance"
in yakkety (LP: #1632894)
- Revert "UBUNTU: SAUCE: (no-up) If zone is so small that watermarks are the
  same, stop zone balance."

  * lts-yakkety 4.8 cannot mount lvm raid1 (LP: #1631298)
- SAUCE: (no-up) dm raid: fix compat_features validation

  * kswapd0 100% CPU usage (LP: #1518457)
- SAUCE: (no-up) If zone is so small that watermarks are the same, stop zone
  balance.

  * [Trusty->Yakkety] powerpc/64: Fix incorrect return value from
__copy_tofrom_user (LP: #1632462)
- SAUCE: (no-up) powerpc/64: Fix incorrect return value from
  __copy_tofrom_user

  * Ubuntu 16.10: Oops panic in move_page_tables/page_remove_rmap after running
memory_stress_ng. (LP: #1628976)
- SAUCE: (no-up) powerpc/pseries: Fix stack corruption in htpe code

  * Paths not failed properly when unmapping virtual FC ports in VIOS (using
ibmvfc) (LP: #1632116)
- scsi: ibmvfc: Fix I/O hang when port is not mapped

  * [Ubuntu16.10]KV4.8: kernel livepatch config options are not set
(LP: #1626983)
- [Config] Enable live patching on powerpc/ppc64el

  * CONFIG_AUFS_XATTR is not set (LP: #1557776)
- [Config] CONFIG_AUFS_XATTR=y

  * Yakkety update to 4.8.1 stable release (LP: #1632445)
- arm64: debug: avoid resetting stepping state machine when TIF_SINGLESTEP
- Using BUG_ON() as an assert() is _never_ acceptable
- usb: misc: legousbtower: Fix NULL pointer deference
- Staging: fbtft: Fix bug in fbtft-core
- usb: usbip: vudc: fix left shift overflow
- USB: serial: cp210x: Add ID for a Juniper console
- Revert "usbtmc: convert to devm_kzalloc"
- ALSA: hda - Adding one more ALC255 pin definition for headset problem
- ALSA: hda - Fix headset mic detection problem for several Dell laptops
- ALSA: hda - Add the top speaker pin config for HP Spectre x360
- Linux 4.8.1

  * PSL data cache should be flushed before resetting CAPI adapter
(LP: #1632049)
- cxl: Flush PSL cache before resetting the adapter

  * thunder nic: avoid link delays due to RX_PACKET_DIS (LP: #1630038)
- net: thunderx: Don't set RX_PACKET_DIS while initializing

  * crypto/vmx/p8_ghash memory corruption (LP: #1630970)
- crypto: ghash-generic - move common definitions to a new header file
- crypto: vmx - Fix memory corruption caused by p8_ghash
- crypto: vmx - Ensure ghash-generic is enabled

  * arm64: SPCR console not autodetected (LP: #1630311)
- of/serial: move earlycon early_param handling to serial
- [Config] CONFIG_ACPI_SPCR_TABLE=y
- ACPI: parse SPCR and enable matching console
- ARM64: ACPI: enable ACPI_SPCR_TABLE
- serial: pl011: add console matching function

  * include/linux/security.h header syntax error with !CONFIG_SECURITYFS
(LP: #1630990)
- SAUCE: (no-up) include/linux/security.h -- fix syntax error with
  CONFIG_SECURITYFS=n

  * sha1-powerpc returning wrong results (LP: #1629977)
- crypto: sha1-powerpc - little-endian support

 -- Seth Forshee   Thu, 20 Oct 2016 14:09:37
-0500

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Fix Released

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Raniz]

After upgrading to 4.4.0-45 from 4.4.0-21 the issue seems to have gone
away.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Øystein Gisnås]

I have verified that the bug is fixed on 4.8.0-26.28 (yakkety),
4.4.0-43.63 (xenial) and 4.4.0-45.66 (xenial). Doing the same on
4.4.0-42.62 (xenial) reproduced the bug. All tests done on EC2 t2.small.

** Tags removed: verification-needed-yakkety
** Tags added: verification-done-yakkety

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[PierreF]

If the verification apply also on 16.04, it does fix the issue.

We had a server that triggered the bug at least once a day (I suspect
unattended-upgrade run every morning to trigger it). Since the upgrade -
2 days and half ago - the server had no issue.

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Felix Bünemann]

The fix is already released in 16.04, make sure you have updated to
linux-image 4.4.0-43.63 or later.

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[CaptSaltyJack]

Will we see this fix make it to 16.04 LTS?

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Seth Forshee]

This bug is awaiting verification that the kernel in -proposed solves
the problem. Please test the kernel and update this bug with the
results. If the problem is solved, change the tag 'verification-needed-
yakkety' to 'verification-done-yakkety'.

If verification is not done by 5 working days from today, this fix will
be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how
to enable and use -proposed. Thank you!


** Tags added: verification-needed-yakkety

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Launchpad Bug Tracker]

This bug was fixed in the package linux - 4.4.0-43.63

---
linux (4.4.0-43.63) xenial; urgency=low

  [ Seth Forshee ]

  * Release Tracking Bug
- LP: #1632375

  * kswapd0 100% CPU usage (LP: #1518457)
- SAUCE: (no-up) If zone is so small that watermarks are the same, stop zone
  balance.

 -- Seth Forshee   Tue, 11 Oct 2016 07:54:56
-0500

** Changed in: linux (Ubuntu Xenial)
   Status: Fix Committed => Fix Released

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Andy Whitcroft]

** Changed in: linux (Ubuntu Yakkety)
   Status: Fix Committed => Invalid

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Invalid
Status in linux source package in Xenial:
  Fix Committed
Status in linux source package in Yakkety:
  Invalid

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Seth Forshee]

** Changed in: linux (Ubuntu Yakkety)
   Status: Confirmed => Fix Committed

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Fix Committed
Status in linux source package in Xenial:
  Fix Committed
Status in linux source package in Yakkety:
  Fix Committed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Seth Forshee]

** Also affects: linux (Ubuntu Xenial)
   Importance: Undecided
   Status: New

** Changed in: linux (Ubuntu Xenial)
   Status: New => Fix Committed

** Changed in: linux (Ubuntu Xenial)
   Importance: Undecided => High

** Changed in: linux (Ubuntu Xenial)
 Assignee: (unassigned) => Dan Streetman (ddstreet)

** Also affects: linux (Ubuntu Yakkety)
   Importance: High
 Assignee: Dan Streetman (ddstreet)
   Status: Confirmed

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed
Status in linux source package in Xenial:
  Fix Committed
Status in linux source package in Yakkety:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

On review of the patch series, it's simply too large and complex to
backport for this situation; it makes, and depends on, a rather large
amount of change to the mm subsystem, and there are easier and smaller
ways to work around this bug in the xenial kernel.

Specifically, a comparison of the Xen balloon driver vs. the virtio
balloon driver shows an important difference; while the Xen balloon
driver hot-adds memory as soon as it initializes, the virtio driver does
not hot-add memory; it only adjusts its size to adjust the amount of
free memory.  Most importantly, the Xen balloon driver initially hot-
adds memory but does not make any (except a very small amount) available
for system use.

I'm looking at the Xen balloon driver to see how it can be changed to
fix this bug.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

The patch series that fixes this is included in yakkety (if anyone
reproduces this on a yakkety kernel, please let me know), so this only
needs fixing in xenial.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dan Streetman]

The problem is a bit complex.  The Xen hypervisor uses memory
ballooning, to control how many memory pages the guest can use.  The
kernel enumerates its e820 memory at boot, and since it's only 1G in
this case, it all gets placed into the DMA32 zone.  Then later during
boot when the Xen balloon driver is initialized, it dynamically adds the
balloon memory.  The kernel always places hot-added memory into the
Normal zone however, so the system winds up with the balloon memory, and
only the balloon memory, in the Normal zone.  Since the balloon driver
starts at, or very close to, its memory target, only a very small number
of pages are made available, which results in a Normal memory zone
that's tiny - only 9 managed pages on the instance I tested.  You can
read the /proc/zoneinfo file to find the number of managed pages in the
Normal zone.

Then when the system encounters memory pressure (i.e. very little free
memory left), it wakes up the kswapd daemon to start freeing memory.
The kswapd daemon then tries to "balance" memory by "balancing" each
zone - DMA, DMA32, and Normal zones.  However, it's essentially
impossible for it to free pages from the Normal zone, because there are
so few pages that whenever one is freed, the next page allocation takes
it (because pages are usually allocated from the Normal zone first), and
kswapd winds up in a continuous cycle of trying to free pages from the
Normal zone forever.

This is also why disabling the udev memory hotadd (see comment 69) works
around the problem - it prevents the Xen balloon driver from
adding/enabling any of the pages in the Normal zone, so kswapd never has
to bother trying to balance it, and thus there's no problem.

This appears to be fixed by Mel Gorman's 34-commit patch series that changes 
kswapd memory balancing to "per node" instead of "per zone":
https://marc.info/?l=linux-mm=146797052519026

That's a rather large patchset to backport to the xenial kernel, but
I'll give it a try.

** Changed in: linux (Ubuntu)
 Assignee: (unassigned) => Dan Streetman (ddstreet)

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Poldi]

I have the same issue on 16.04

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Richard Trout]

Thanks #123 (as easy as?) works for me as a workaround.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Paul Buonopane]

>From man 7 udev:

The udev rules are read from the files located in the system rules
directory /lib/udev/rules.d, the volatile runtime directory
/run/udev/rules.d and the local administration directory
/etc/udev/rules.d. All rules files are collectively sorted and processed
in lexical order, regardless of the directories in which they live.
However, files with identical filenames replace each other. Files in
/etc have the highest priority, files in /run take precedence over files
with the same name in /lib. This can be used to override a system-
supplied rules file with a local file if needed; a symlink in /etc with
the same name as a rules file in /lib, pointing to /dev/null, disables
the rules file entirely. Rule files must have the extension .rules;
other extensions are ignored.

As such, the best way to work around this is:

sudo ln -s /dev/null /etc/udev/rules.d/40-vm-hotadd.rules

Unlike deleting or modifying the original file, this will persist across
upgrades without requiring manual conflict resolution.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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Re: [Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Gregg King]

Did you try this from Rasmussen up above?

sudo touch /etc/udev/rules.d/40-vm-hotadd.rules
reboot

That fixed it for me on EC2

On Saturday, 3 September 2016, Andy Robertson 
wrote:

> All of my t2.micro & nano instances are affected by this in AWS EC2
> after upgrading to Ubuntu16.
>
> doing "echo 1 > /proc/sys/vm/drop_caches" (also tried echo 3) works for
> a short period of time, but it comes back within a few minutes.
>
> I moved a couple instances over to f1.micro on GCP / GCE (1 vCPU, 0.6 GB
> memory) and the problem seems to have gone away.  I can't do this with
> all of my instances yet though so a fix in AWS would be nice.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
>
> Title:
>   kswapd0 100% CPU usage
>
> Status in Linux:
>   Unknown
> Status in linux package in Ubuntu:
>   Confirmed
>
> Bug description:
>   As per bug 721896 and various others:
>
>   I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
>   Occasionally (about once a day), kswapd0 falls into a busy loop and
>   spins on 100% CPU usage indefinitely. This can be provoked by
>   copying/writing large files (e.g. dding a 256MB file), but it happens
>   occasionally otherwise. System memory usage (not including
>   buffers/caches) currently sits at 36%, which is typical[1]. Initially
>   I had no swap space configured; I've since tried enabling a 256MB swap
>   file, but the problem continues to occur and no swap space is used.
>   The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
>
>   Happy to provide further information/take further debugging actions.
>
>
>   [1] Full output from `free`:
>total   used   free sharedbuffers cached
>   Mem:   1014936 483448 531488  28556   9756 112700
>   -/+ buffers/cache: 360992 653944
>   Swap:   262140  0 262140
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 15.10
>   Package: linux-image-4.2.0-18-generic 4.2.0-18.22
>   ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>   Uname: Linux 4.2.0-18-generic x86_64
>   AlsaDevices:
>total 0
>crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
>crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
>   AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
>   ApportVersion: 2.19.1-0ubuntu5
>   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: N/A
>   Date: Fri Nov 20 20:44:30 2015
>   Ec2AMI: ami-1c552a76
>   Ec2AMIManifest: (unknown)
>   Ec2AvailabilityZone: us-east-1d
>   Ec2InstanceType: t2.micro
>   Ec2Kernel: unavailable
>   Ec2Ramdisk: unavailable
>   IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
>   Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to
> initialize libusb: -99
>   MachineType: Xen HVM domU
>   PciMultimedia:
>
>   ProcEnviron:
>TERM=screen
>PATH=(custom, no user)
>LANG=en_US.UTF-8
>SHELL=/bin/bash
>   ProcFB: 0 xen
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1
> console=ttyS0 net.ifnames=0
>   RelatedPackageVersions:
>linux-restricted-modules-4.2.0-18-generic N/A
>linux-backports-modules-4.2.0-18-generic  N/A
>linux-firmwareN/A
>   RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
>   SourcePackage: linux
>   UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   dmi.bios.date: 05/06/2015
>   dmi.bios.vendor: Xen
>   dmi.bios.version: 4.2.amazon
>   dmi.chassis.type: 1
>   dmi.chassis.vendor: Xen
>   dmi.modalias: dmi:bvnXen:bvr4.2.amazon:bd05/
> 06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
>   dmi.product.name: HVM domU
>   dmi.product.version: 4.2.amazon
>   dmi.sys.vendor: Xen
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions
>

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Paul Csiki]

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/comments/69

Seems to have resolved all this issues on AWS t2.micro instances.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Andy Robertson]

All of my t2.micro & nano instances are affected by this in AWS EC2
after upgrading to Ubuntu16.

doing "echo 1 > /proc/sys/vm/drop_caches" (also tried echo 3) works for
a short period of time, but it comes back within a few minutes.

I moved a couple instances over to f1.micro on GCP / GCE (1 vCPU, 0.6 GB
memory) and the problem seems to have gone away.  I can't do this with
all of my instances yet though so a fix in AWS would be nice.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[José Martínez]

I wrote a tiny batch script to reliably reproduce the bug. It mounts a
tmpfs filesystem and writes a file that fills 98% of the currently
available memory.

You can also pass it a custom percentage, like: ./fillmem.sh 95

<95% is hit and miss on a newly launched instance. 98% (the default) has
inmediately spun kswapd to 100% on all of my tests.

--

@andrewtappert: steal time means the T2 instance has run out of CPU
credits. They launch with just enough credits to burst the CPU to 100%
for 30 minutes.

I'm always getting SYS time on kswapd, until I hit the T2 credits limit.

** Attachment added: "fillmem.sh"
   
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+attachment/4715197/+files/fillmem.sh

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Andrew Tappert]

The original description says "kswapd0 falls into a busy loop and spins
on 100% CPU usage indefinitely".  But I think, while the effect may be
similar, the actual behavior is a bit different.  I think what is
happening is that kswapd is accessing pages of memory that are causing
the hypervisor (rather than the kernel) to do extra work.  If you look
at the overall CPU utilization of the instance, you'll see high "st"
(steal) time.  This can also be provoked manually, for example by trying
to read via /proc/kcore from the extra memory region that has been
identified in discussion above (for example, try to do a full memory
dump with the Volatility getkcore tool).

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Robin Miller]

To add - these servers are all built on the official Ubuntu Amazon EC2
AMIs of the 'ebs-ssd' variety.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Robin Miller]

We have been seeing this issue intermittently on a set of servers that
were running Ubuntu 15.10 and then 16.04. After overriding that udev vm
hotadd rule as suggested above a couple weeks ago, the issue has yet to
return (not a conclusive result, but so far so good).

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Felix Bünemann]

I have run into this issue when using the goofys s3 fuse filesystem
(https://github.com/kahing/goofys) on a t2.small instances when copying
large files (which causes many memory buffers to be allocated). I think
anything that stresses the memory subsystem will be able to trigger it.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Øystein Gisnås]

I've tried this on t1.micro (PV) and t2.micro (HVM) instances in eu-west-1. To 
reproduce, I used the following two commands:
sudo apt install docker.io
sudo docker run -p 80:8080 cptactionhank/atlassian-jira

The startup should work, but navigate to http://instanceaddress/ and
choose "I'll set it up myself" and "Built In" database. 10-20 seconds
after you click "Next", you should see the memory being exhausted and
kswapd0 use half of the CPU time.

Test results:
ubuntu/images/ebs-ssd/ubuntu-xenial-16.04-amd64-server-20160721 (PV): kswapd0 OK
ubuntu/images/hvm-ssd/ubuntu-xenial-16.04-amd64-server-20160721 (HVM): kswapd0 
high CPU usage

It's worth noting that the memory blocks varies between distro and PV/HVM:
Amazon Linux HVM: /sys/devices/system/memory/memory[0-7]
RHEL 7.2 HVM: /sys/devices/system/memory/memory[0-7]
Ubuntu 16.04 HVM: /sys/devices/system/memory/memory[0-8]
Ubuntu 16.04 PV: /sys/devices/system/memory/memory[0-4]

Why Ubuntu on HVM has an extra memory block is a mystery. It seems to be
offline by default, but enabled by the udev hotadd rule. And EC2 doesn't
support hotadd.

As Joern Heissler suggested, why not remove the hotadd rule from the
official images as a workaround? Although the underlying problem
probably is related to why the additional memory block is there at all.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Christopher Snowhill]

Is this known to affect paravirtualized instances, or is it restricted
to hvm? Can anyone tell me what conditions I need to create this in a
fresh instance? I'll spin up a PV t2.nano and see if I can reproduce it
there.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Joern Heissler]

Can this workaround please be added to the official EC2 images? EC2 cannot hot 
swap CPU or memory from what I know.
Having this workaround built in would mean not having to reboot every newly 
launched instance.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Argat]

The suggested workaround works for me also on AWS instances with 15.10:

sudo touch /etc/udev/rules.d/40-vm-hotadd.rules
reboot

Been stable now for over a week.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[quinn]

Is there a fix for this that doesn't require a reboot / something I
could add to an ec2 instance's user_data?

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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Re: [Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Gregg King]

Thank you so much Rasmus!

Your solution worked for me:
sudo touch /etc/udev/rules.d/40-vm-hotadd.rules
reboot

I could always trigger the CPU usage bug with this:
stress --cpu 8 --io 4 --vm 7 --vm-bytes 128M --vm-hang 3 --timeout 60s

If running it once didn't work, a second run would do it. Now I've run it
over and over and kswap hits 1-2% during the stress test and drops back
down as soon as it ends.

Like Rasmus says, it's an AWS instance which runs on Xen.


On 17 June 2016 at 07:37, Rasmus Larsen  wrote:

> I had this issue too on AWS.
>
> In my case, it was the udev rule for vm-hotadd and the fix as mentioned
> previously basically came down to "touch /etc/udev/rules.d/40-vm-
> hotadd.rules" which effectively disables the /lib/udev/rules.d/40-vm-
> hotadd.rules file (after a reboot).
>
> The udev rule basically seems to only be active for Xen or Hyper-V and
> while it seems the Hyper-V stuff was also present in previous versions,
> the Xen stuff seems to be introduced in 15.10 or newer.
>
> So if you're seeing this issue on anything running on Xen, including
> AWS, try:
>
> touch /etc/udev/rules.d/40-vm-hotadd.rules
> reboot
>
> This is probably a bug in Xen or a bug in the kernel.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
>
> Title:
>   kswapd0 100% CPU usage
>
> Status in Linux:
>   Unknown
> Status in linux package in Ubuntu:
>   Confirmed
>
> Bug description:
>   As per bug 721896 and various others:
>
>   I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
>   Occasionally (about once a day), kswapd0 falls into a busy loop and
>   spins on 100% CPU usage indefinitely. This can be provoked by
>   copying/writing large files (e.g. dding a 256MB file), but it happens
>   occasionally otherwise. System memory usage (not including
>   buffers/caches) currently sits at 36%, which is typical[1]. Initially
>   I had no swap space configured; I've since tried enabling a 256MB swap
>   file, but the problem continues to occur and no swap space is used.
>   The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
>
>   Happy to provide further information/take further debugging actions.
>
>
>   [1] Full output from `free`:
>total   used   free sharedbuffers cached
>   Mem:   1014936 483448 531488  28556   9756 112700
>   -/+ buffers/cache: 360992 653944
>   Swap:   262140  0 262140
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 15.10
>   Package: linux-image-4.2.0-18-generic 4.2.0-18.22
>   ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>   Uname: Linux 4.2.0-18-generic x86_64
>   AlsaDevices:
>total 0
>crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
>crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
>   AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
>   ApportVersion: 2.19.1-0ubuntu5
>   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: N/A
>   Date: Fri Nov 20 20:44:30 2015
>   Ec2AMI: ami-1c552a76
>   Ec2AMIManifest: (unknown)
>   Ec2AvailabilityZone: us-east-1d
>   Ec2InstanceType: t2.micro
>   Ec2Kernel: unavailable
>   Ec2Ramdisk: unavailable
>   IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
>   Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to
> initialize libusb: -99
>   MachineType: Xen HVM domU
>   PciMultimedia:
>
>   ProcEnviron:
>TERM=screen
>PATH=(custom, no user)
>LANG=en_US.UTF-8
>SHELL=/bin/bash
>   ProcFB: 0 xen
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1
> console=ttyS0 net.ifnames=0
>   RelatedPackageVersions:
>linux-restricted-modules-4.2.0-18-generic N/A
>linux-backports-modules-4.2.0-18-generic  N/A
>linux-firmwareN/A
>   RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
>   SourcePackage: linux
>   UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   dmi.bios.date: 05/06/2015
>   dmi.bios.vendor: Xen
>   dmi.bios.version: 4.2.amazon
>   dmi.chassis.type: 1
>   dmi.chassis.vendor: Xen
>   dmi.modalias:
> dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
>   dmi.product.name: HVM domU
>   dmi.product.version: 4.2.amazon
>   dmi.sys.vendor: Xen
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions
>

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Title:
  kswapd0 100% CPU usage

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Rasmus Larsen]

I had this issue too on AWS.

In my case, it was the udev rule for vm-hotadd and the fix as mentioned
previously basically came down to "touch /etc/udev/rules.d/40-vm-
hotadd.rules" which effectively disables the /lib/udev/rules.d/40-vm-
hotadd.rules file (after a reboot).

The udev rule basically seems to only be active for Xen or Hyper-V and
while it seems the Hyper-V stuff was also present in previous versions,
the Xen stuff seems to be introduced in 15.10 or newer.

So if you're seeing this issue on anything running on Xen, including
AWS, try:

touch /etc/udev/rules.d/40-vm-hotadd.rules
reboot

This is probably a bug in Xen or a bug in the kernel.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Andrew Noruk]

I'm also facing the kswap0 99% CPU issue. Typically, I notice it start
minutes after boot time, but restarting the MongoDB process on the
server will temporarily fix it, however the process will usually pop up
again randomly.

I used to run test instances of MongoDB on AWS t2.micros with no issues
but recently am being plagued by the kswap0 issue after I tried to
upgrade the base AMI to Ubuntu 16.04.

uname -a
Linux hostname 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC 2016 
x86_64 x86_64 x86_64 GNU/Linux

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[tomtom]

I can confirm that this issue also exist on AWS c4.large (vCPU 2, mem
3,75 GiB).

$ uname -a
Linux server 4.4.0-22-generic #39-Ubuntu SMP Thu May 5 16:53:32 UTC 2016 x86_64 
x86_64 x86_64 GNU/Linux
$ free -m
  totalusedfree  shared  buff/cache   available
Mem:   376213071204  6912512321
Swap:  2047  392008

-- 
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Thorsten von Eicken]

Is the ability to repro a hold-up on this issue? I can spend time to
provide STRs on an EC2 instance using the latest official 16.04 image,
but I don't want to go through the effort if repro isn't really a hold-
up.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

Whoops, it does seem to happen on 4.6.1-2, although the condition are
different. It seems, does anyone have a sure fire repro case?

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

I've fixed this in Arch Linux by moving to the 4.6.1-2-ARCH kernel, when
previously on the 4.5.? kernel. This problem also doesn't occur in
either the 4.0.7-2 or the 3.16-2 kernels for me at least.

I hear this is happening mostly on the 4.4.0-* kernel, which doesn't
seem to be an option in the Arch Linux
archive(https://archive.archlinux.org/packages/l/linux/), in fact none
of the *.*.0-* kernels are, if you can report a kernel that's in that
list I can test it. I have a feeling simply reinstalling any kernel
would have fixed it, and I had some sort of configuration problem
before.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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Re: [Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Gregg King]

I've had the issue mostly when running with no swap. I added 1GB swap
file and it fixed it on the machine with less memory usage, but the
machine with the database (using more memory most of the time) still has
the bug occur about once a day.

Ubuntu 16.04 for both, not happening on 14.04.

Sent from my iPhone

> On Jun 4, 2016, at 5:11 PM, Jonathan Vargas <1518...@bugs.launchpad.net> 
> wrote:
> 
> I face the same issue, running a t2.micro (1 GB) for a Nginx/Ruby
> application with really low demand. The kswapd0 process takes the CPU to
> 100% and the overall system performance is downgraded.
> 
> Linux server 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC
> 2016 x86_64 x86_64 x86_64 GNU/Linux
> 
> To reproduce it, I just create a 1GB file in the filesystem using "dd":
> 
> if=/dev/zero of=temp bs=1k count=1024k
> 
> I created a swap file to solve the issue but it continues. After
> dropping the page cache with:
> 
> echo 3 > /proc/sys/vm/drop_caches
> 
> the issue is solved temporarily.
> 
> 
> ** Attachment added: "Selection_320.png"
>   
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+attachment/4677030/+files/Selection_320.png
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
> 
> Title:
>  kswapd0 100% CPU usage
> 
> Status in Linux:
>  Unknown
> Status in linux package in Ubuntu:
>  Confirmed
> 
> Bug description:
>  As per bug 721896 and various others:
> 
>  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
>  Occasionally (about once a day), kswapd0 falls into a busy loop and
>  spins on 100% CPU usage indefinitely. This can be provoked by
>  copying/writing large files (e.g. dding a 256MB file), but it happens
>  occasionally otherwise. System memory usage (not including
>  buffers/caches) currently sits at 36%, which is typical[1]. Initially
>  I had no swap space configured; I've since tried enabling a 256MB swap
>  file, but the problem continues to occur and no swap space is used.
>  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
> 
>  Happy to provide further information/take further debugging actions.
> 
> 
>  [1] Full output from `free`:
>   total   used   free sharedbuffers cached
>  Mem:   1014936 483448 531488  28556   9756 112700
>  -/+ buffers/cache: 360992 653944
>  Swap:   262140  0 262140
> 
>  ProblemType: Bug
>  DistroRelease: Ubuntu 15.10
>  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
>  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>  Uname: Linux 4.2.0-18-generic x86_64
>  AlsaDevices:
>   total 0
>   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
>   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
>  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
>  ApportVersion: 2.19.1-0ubuntu5
>  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: N/A
>  Date: Fri Nov 20 20:44:30 2015
>  Ec2AMI: ami-1c552a76
>  Ec2AMIManifest: (unknown)
>  Ec2AvailabilityZone: us-east-1d
>  Ec2InstanceType: t2.micro
>  Ec2Kernel: unavailable
>  Ec2Ramdisk: unavailable
>  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
>  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to 
> initialize libusb: -99
>  MachineType: Xen HVM domU
>  PciMultimedia:
> 
>  ProcEnviron:
>   TERM=screen
>   PATH=(custom, no user)
>   LANG=en_US.UTF-8
>   SHELL=/bin/bash
>  ProcFB: 0 xen
>  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
> net.ifnames=0
>  RelatedPackageVersions:
>   linux-restricted-modules-4.2.0-18-generic N/A
>   linux-backports-modules-4.2.0-18-generic  N/A
>   linux-firmwareN/A
>  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
>  SourcePackage: linux
>  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
>  UpgradeStatus: No upgrade log present (probably fresh install)
>  dmi.bios.date: 05/06/2015
>  dmi.bios.vendor: Xen
>  dmi.bios.version: 4.2.amazon
>  dmi.chassis.type: 1
>  dmi.chassis.vendor: Xen
>  dmi.modalias: 
> dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
>  dmi.product.name: HVM domU
>  dmi.product.version: 4.2.amazon
>  dmi.sys.vendor: Xen
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Jonathan Vargas]

I face the same issue, running a t2.micro (1 GB) for a Nginx/Ruby
application with really low demand. The kswapd0 process takes the CPU to
100% and the overall system performance is downgraded.

Linux server 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC
2016 x86_64 x86_64 x86_64 GNU/Linux

To reproduce it, I just create a 1GB file in the filesystem using "dd":

if=/dev/zero of=temp bs=1k count=1024k

I created a swap file to solve the issue but it continues. After
dropping the page cache with:

echo 3 > /proc/sys/vm/drop_caches

the issue is solved temporarily.


** Attachment added: "Selection_320.png"
   
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+attachment/4677030/+files/Selection_320.png

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

Actually, this is even a problem with no active swap partition. What is
the actual problem here? Is kswapd0 just running for no reason?

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

Nope, setting it to performance doesn't seems to help.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

They seem to be set to "powersave", which is kinda ironic. I've set them
to performance and will report back later.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Haw Loeung]

OOI, does this fix this?

| for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
sudo sh -c "echo performance > $i"; done

If so, was the scaling governor set to "ondemand" by any chance?

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[MintPaw]

I can confirm that setting vm.min_free_kbytes=67584 on my 2gb chromebook
does not work for me (https://i.imgur.com/I7vEE5C.png)

After restarting and running heavy processes, kswapd0 still uses 100%
cpu until I reboot or run this follow very unfortunate script.

#!/bin/bash
if [ "$EUID" -ne 0 ]; then
echo "Rerunning as root"
sudo $0
exit
fi

swapoff -a
sleep 1
echo 3 > /proc/sys/vm/drop_caches
sleep 1
swapon /dev/sda2

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Edward Donovan]

** Bug watch added: Linux Kernel Bug Tracker #65201
   http://bugzilla.kernel.org/show_bug.cgi?id=65201

** Also affects: linux via
   http://bugzilla.kernel.org/show_bug.cgi?id=65201
   Importance: Unknown
   Status: Unknown

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in Linux:
  Unknown
Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1518457/+subscriptions

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Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mm]

I can confirm after after 6 days uptime: my hotfix (echo
"vm.min_free_kbytes=67584" > /etc/sysctl.d/60-workaround-kswapd-
allcpu.conf) still 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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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More help   : https://help.launchpad.net/ListHelp

[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mm]

I can the following hotfix works for me for several days on a 2GB Ram
system:

echo "vm.min_free_kbytes=67584" > /etc/sysctl.d/60-workaround-kswapd-
allcpu.conf

after that: reboot.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Reupen Shah]

I last commented when I was on 15.10, but was just hit by this on 16.04.
Again, EC2 t2.micro instance.

$ uname -a
Linux ip-172-31-45-223 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC 
2016 x86_64 x86_64 x86_64 GNU/Linux

$ top 
top - 21:32:32 up 6 days, 20 min,  1 user,  load average: 1.01, 1.02, 0.96
Tasks: 135 total,   2 running, 133 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us,100.0 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  1014560 total,   426728 free,   215352 used,   372480 buff/cache
KiB Swap:0 total,0 free,0 used.   733288 avail Mem

  PID USER  PR  NIVIRTRESSHR S %CPU %MEM TIME+ COMMAND
   30 root  20   0   0  0  0 R 99.7  0.0  44:42.28 kswapd0
 5434 ubuntu20   0   40512   3620   3032 R  0.3  0.4   0:00.03 top
1 root  20   0   37796   5880   4008 S  0.0  0.6   0:25.73 systemd

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You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mb]

Fresh install of 16.04 on EC2 Nano instance, and kswapd0 takes most of
the CPU when running a job with high CPU and high IO.

I've resorted to running the following command every minute as a cron
task:

# m  hdom  mon  dow  command
*****echo 3 > /proc/sys/vm/drop_caches

That works for 10 or 15 seconds, but after that kswapd0 comes back and
hogs the CPU again.

I'm using less than 20% of available memory, shouldn't need to swap.

See attached screenshot of top at the 25-second mark after dropping
caches.


** Attachment added: "Screenshot from 2016-05-19 15:25:29.png"
   
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+attachment/4666557/+files/Screenshot%20from%202016-05-19%2015%3A25%3A29.png

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[François Leurent]

Same issue here, uname -a
4.4.0-22-generic #39-Ubuntu SMP Thu May 5 16:53:32 UTC 2016 x86_64 x86_64 
x86_64 GNU/Linux
free -m
  totalusedfree  shared  buff/cache   available
Mem:   1836  681608  12 1591722
Swap:  1949   01949
(i'll edit this in a few minute, with top result (uptime is 0s)

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Gregg King]

I'm also seeing this on 16.04 on an AWS nano (~0.5GB RAM). More than
happy to help troubleshoot this if people let me know what info is
needed.

Here's some basic info from my machine:

$ uname -a
4.4.0-22-generic #39-Ubuntu SMP Thu May 5 16:53:32 UTC 2016 x86_64 x86_64 
x86_64 GNU/Linux

$ free -m
  totalusedfree  shared  buff/cache   available
Mem:486  73 140  20 272 362
Swap: 0   0   0


$ top
top - 01:44:48 up 3 days,  2:34,  1 user,  load average: 1.00, 1.01, 1.05
Tasks: 131 total,   2 running, 129 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us, 90.9 sy,  0.0 ni,  9.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :   498480 total,   143612 free,75852 used,   279016 buff/cache
KiB Swap:0 total,0 free,0 used.   370732 avail Mem

  PID USER  PR  NIVIRTRESSHR S %CPU %MEM TIME+ COMMAND
   29 root  20   0   0  0  0 R 99.9  0.0   4066:36 kswapd0
1 root  20   0   37908   6028   4048 S  0.0  1.2   0:08.79 systemd
2 root  20   0   0  0  0 S  0.0  0.0   0:00.00 kthreadd
- CUT THE REST -

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Impulse]

Confirm.
Linux impulse-X55VD 4.6.0-040600rc6-generic #201605012031 SMP Mon May 2 
00:33:26 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[erik]

I can see this bug on a system recently upgraded from Ubuntu 15.04 to 16.04.
I did not see this behaviour before upgrading.
The system is an Intel NUC Desktop with 8 GB RAM and kswapd0 completely locks 
up the system after a while.

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You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Andreas E.]

In the earliest linked report of this bug the deadlock occured also with
8GB RAM (and still the case in 15.10). Will test 16.04 later when it
stabilizes.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mm]

I can confirm this bug is only triggered when the machine got 2-3GB RAM
or less. I got two identical machines running Ubuntu 16.04. One got 8Gb
of RAM and on this machine kswapd0 doesn't deadlock at 100% CPU Usage.
On my 2GB RAM machine the issue is worse than under Ubuntu 15.10 

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mm]

I can also confirm the bug ist still present in Xubuntu 16.04 LTS
desktop

 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64
x86_64 x86_64 GNU/Linux

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mallardquacken]

confirmed on released version of 16.04 LTS desktop
# uname -a
Linux laptop 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 
x86_64 x86_64 x86_64 GNU/Linux

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Antony-gelberg]

After reading 82 comments, I'm not sure if this is a kernel or udev (or
other) bug. Any clues if anyone's working on this in relevant upstreams?

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Islam]

This is also affecting Ubuntu 15.10 Kernel 4.2.0-35-generic
I have  700MB free RAM 400 MB Cached and kswapd0 is taking more than 99% of the 
CPU.

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Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Reupen Shah]

This has also been affecting me on a t2.micro EC2 instance with Ubuntu
15.10, most recently occurred with:

4.2.0-30-generic #36-Ubuntu SMP Fri Feb 26 00:58:07 UTC 2016 x86_64
x86_64 x86_64 GNU/Linux

For me it often triggers when installing updates (probably kernel ones
in particular). Otherwise the server is not doing much so probably not
much of a surprise it doesn't trigger on other occasions.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Greg Fefelov]

Alexander,

please note that if a kernel process name contains "swap" as a
substring, it does not immediately mean that this process exclusively
does process memory swap-in/swap-out. kswapd is a kernel process name
for an important piece of memory management subsystem: it frees pages by
flushing them to disk or discarding when the system is low on memory,
saving you the trouble of OOMs. This includes both buffer cache and
process memory; however, disk buffers are freed first.

Generally that means that on a system with disabled swap you _will_ see
high cpu% in kswapd when you have almost no memory and buffers have not
been synced to disk yet. This is not a bug (but you should consider
installng more memory or having a stricter sync policy).

However, this discussion is very off topic, since this bug is not an
intended behavior.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Alexander Mashin]

I don't know, if the following comment be relevant to this particular bug, but 
here it is:
* If there is no swap, the kernel should not try to swap. As simple as this. If 
there is no swap file or partition, and there is kswapd0 in top, if even it 
doesn't consume 100% of CPU, it is a bug. Sysadmins are entitled to forbid 
swapping altogether (because it's evil, as on a web server swapping is 
effectively deny of service), and the most natural way to do so is not to mount 
a swap partition.
* If there is cached memory, there should be no swapping. Memory must be freed 
by flushing file buffers first. It is ridiculous that the kerner is generous to 
filesystems, caching their files, but not to the applications that really need 
memory, allowing either to swap or fork to fail. At the moment there is a 
misleading article somewhere in the Ubuntu knowledge base that claims that 
cached memory is not "eaten" and is as available as free. As long as the kernel 
is allowed to swap when there are file buffers, the latter are NOT free and 
available.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[JockeTF]

The workaround fixes the issue in Xenial Xerus (development branch) as
well.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Alexander Mashin]

I confirm that the bug is present on Amazon t2.nano instance with Ubuntu
15.10, kernel 4.2.0-30-generic, and can only be worked around by
commenting out line 2 in /lib/udev/rules.d/40-vm-hotadd.rules.

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[JockeTF]

I'm seeing this issue in Ubuntu Xenial Xerus (development branch).

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[mm]

As part of my workaround/fix I downgraded udev and upgraded RAM from 3GB
to 8GB on my homeserver.

Now I am experiencing the following which can't be normal either:

top - 13:50:48 up 1 day, 19:29,  1 user,  load average: 0,11, 0,15, 0,14
tasks: 200 total,   1 running, 198 sleeping,   0 stopped,   1 zombie
%Cpu(s):  6,1 be,  2,5 sy,  0,2 ni, 81,6 un,  9,1 wa,  0,0 hi,  0,4 si,  0,0 st
KiB Mem:   8067248 total,  4768336 used,  3298912 free,   477524 buffers
KiB Swap:  4194300 total,  4170948 used,23352 free.  2803672 cached Mem


FilenameTypeSizeUsedPriority
/var/cache/swap/swap0   file4194300 4170948 -1

 Linux # 4.2.0-25-generic #30-Ubuntu SMP Mon Jan 18 12:31:50 UTC
2016 x86_64 x86_64 x86_64 GNU/Linux

Any idea? I hope the system won't crash 

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Nelson Elhage]

One more note to anyone else trying to debug this: I can reproduce quite
reliably by copying a 3GiB file from S3 onto a gp2 EBS volume using `aws
s3 cp`.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Joseph Salisbury]

** Changed in: linux (Ubuntu)
   Status: In Progress => Confirmed

** Changed in: linux (Ubuntu)
 Assignee: Joseph Salisbury (jsalisbury) => (unassigned)

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Nelson Elhage]

I did some experimentation, and I can reproduce @oystein-gisnas's result
that nuking that file from `/lib/udev/rules.d/` and rebooting fixes the
issue.

However, removing that file and restarting udev does *not* seem to fix
the issue. So I suspect the problem is not with udev, but rather with
some kernel feature that udev is enabling or toggling as part of
processing that file.

Also, as an aside, editing that file isn't a good workaround, since
upgrading udev may clobber it again. If you instead create an
`/etc/udev/rules.d/40-vm-hotadd.rules`  containing the edited version,
that file will take precedence over the one in `/lib`, and also be
robust against udev upgrades.

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Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dennis Stevense]

Confirmed Nelson Elhage's workaround: copy /lib/udev/rules.d/40-vm-
hotadd.rules to /etc/udev/rules.d/ and comment out line 2 and reboot.

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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Nelson Elhage]

Some further debugging: On my t2.micro test case, the machine comes up
with 9 memory devices, the last of which is offline at boot. Bringing
that device online by hand (with the udev rules disabled) triggers the
bug.

# echo online > /sys/devices/system/memory/memory8/state

So something about bringing that node online causes the problem. The
udev bugfix causes udev to automatically bring it up, which is why that
introduced the issue, but it doesn't seem like udev is really the root
problem here.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Øystein Gisnås]

I've bisected systemd and found the commit that triggers the bug.
http://bazaar.launchpad.net/~thopiekar/systemd/systemd-packaging-ubuntu-
wily/revision/1706 seems to be the one. The commit is a bugfix that
effectively enables hotadd for Xen. That can explain why more or less
only Ubuntu 15.10 is affected, but the underlying mechanism is in the
kernel.

A working workaround on the latest 15.10 is to comment out line 2
(ATTR{[dmi/id]sys_vendor}=="Xen", GOTO="vm_hotadd_apply") in
/lib/udev/rules.d/40-vm-hotadd.rules

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Øystein Gisnås]

Could someone with good udev/kernel knowledge try to debug what's going
wrong with this hotadd? I've tried to run systemd-udevd in debug mode,
but it didn't show anything of interest.
https://wiki.ubuntu.com/DebuggingUdev is outdated, and I don't know how
to go on with debugging.

-- 
You received this bug notification because you are a member of Kernel
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https://bugs.launchpad.net/bugs/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Dennis Stevense]

A workaround that seems to work for me (and one that doesn't involve
dropping caches periodically) is to downgrade udev to 219-7ubuntu6 (as
suggested by Øystein above). On 15.10 wily, add vivid-updates to your
apt sources to be downgrade to this version of udev.

I noticed this bug is more likely to occur on servers with less memory /
more memory pressure. I was only able to reproduce it on our t2.micro
and t2.small instances on EC2, and using larger EC2 instances was our
first workaround. (In fact, after downgrading udev I was also downgrade
to smaller EC2 instances again.)

This bug also seems more likely to occur on servers with faster disk
I/O, given I was only able to reproduce it on instances with gp2 (SSD)
storage and not on standard (magnetic) storage on EC2.

Our use case is a bunch of EC2 instances all using the Ubuntu 15.10 wily
AMI, and currently running the latest 4.2.0-23-generic kernel.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Marten van Wezel]

As an addendum, is there a quick-fix for this? Meaning: can I revert to
kernel 3.xsomething easily in Ubuntu? Or are there all types of
unwelcome side effects to dropping from new-hotness to old-coldness,
kernel-wise?

signed, pro linux sysadmin for many years, back in the 2000's, now only
recently gotten back into it for only my home purposes, so I'm
completely behind on how kernel stuff fits together with things. (where
are my /dev/ devices, sob).

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Sean Groarke]

Marten

Not a fix, but a workaround.  (Well, of course every server is different
- but works good for me for now!)

Create in /etc/cron.hourly/ something like kswapd.
chmod +x kswapd

Then into it drop:
echo 1 > /proc/sys/vm/drop_caches

You'll get a lot of 
   [649613.095072] kswapd (29670): drop_caches: 1
in your dmesg/syslog.

But for me, this works great. Of course it depends on the bug not
occurring within the first hour of the "fix" being applied (i.e.
cron.hourly). And clearly this will vary from box to box. But on my AWS
server (low traffic web-server with a few other odds and sods on it)
this has effectively "solved" this issue enough, until we get a full
fix.

Sean

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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[Kernel-packages] [Bug 1518457] Re: kswapd0 100% CPU usage

[Marten van Wezel]

Egads, the thick plottens... turns out I have some type of error in my
system. In particular:

marten@MacMini-New:/usr/local/bin$ cat /proc/meminfo |grep MemTotal
MemTotal: 859916 kB

Yes you read that right, 860Mb. That's clearly incorrect. I'll go and
see if I can put in something better. For this thread though this might
be a good hint on how to debug things.

Sean- To your point - Yeah I have a 'fixkswapd' script that says:

marten@MacMini-New:/usr/local/bin$ cat fixkswapd 
schedtool -D -n 19 `pidof kswapd0`
echo 1 > /proc/sys/vm/drop_caches

Maybe my system has an *actual* memory problem rather than a bug. I'll
report back if/when I fix this.

-- 
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/1518457

Title:
  kswapd0 100% CPU usage

Status in linux package in Ubuntu:
  In Progress

Bug description:
  As per bug 721896 and various others:

  I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
  Occasionally (about once a day), kswapd0 falls into a busy loop and
  spins on 100% CPU usage indefinitely. This can be provoked by
  copying/writing large files (e.g. dding a 256MB file), but it happens
  occasionally otherwise. System memory usage (not including
  buffers/caches) currently sits at 36%, which is typical[1]. Initially
  I had no swap space configured; I've since tried enabling a 256MB swap
  file, but the problem continues to occur and no swap space is used.
  The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.

  Happy to provide further information/take further debugging actions.

  
  [1] Full output from `free`:
   total   used   free sharedbuffers cached
  Mem:   1014936 483448 531488  28556   9756 112700
  -/+ buffers/cache: 360992 653944
  Swap:   262140  0 262140

  ProblemType: Bug
  DistroRelease: Ubuntu 15.10
  Package: linux-image-4.2.0-18-generic 4.2.0-18.22
  ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
  Uname: Linux 4.2.0-18-generic x86_64
  AlsaDevices:
   total 0
   crw-rw 1 root audio 116,  1 Nov 19 19:40 seq
   crw-rw 1 root audio 116, 33 Nov 19 19:40 timer
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.19.1-0ubuntu5
  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: N/A
  Date: Fri Nov 20 20:44:30 2015
  Ec2AMI: ami-1c552a76
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1d
  Ec2InstanceType: t2.micro
  Ec2Kernel: unavailable
  Ec2Ramdisk: unavailable
  IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize 
libusb: -99
  MachineType: Xen HVM domU
  PciMultimedia:
   
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 xen
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic 
root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1 console=ttyS0 
net.ifnames=0
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-18-generic N/A
   linux-backports-modules-4.2.0-18-generic  N/A
   linux-firmwareN/A
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 05/06/2015
  dmi.bios.vendor: Xen
  dmi.bios.version: 4.2.amazon
  dmi.chassis.type: 1
  dmi.chassis.vendor: Xen
  dmi.modalias: 
dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
  dmi.product.name: HVM domU
  dmi.product.version: 4.2.amazon
  dmi.sys.vendor: Xen

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457/+subscriptions

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