kswapd takes 100% CPU although there is no swap
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Confirmed
|
Medium
|
Unassigned |
Bug Description
On a notebook with neither swap partition nor swap file (because of SSD and surplus of RAM), kswapd0 suddenly runs amok and takes 100% of CPU activity. When this happens, usually at most 5.5 of 8 GB RAM were in use, so there is no reason to swap.
This happens so suddenly, that no user input is possible anymore, eg. I can barely switch to tty to kill processes that take most RAM. The processor becomes extremely hot and I can only turn the computer off and reboot. I consider this as critical and harmful to my hardware.
I noticed that Ubuntu installs by default with swappiness 60. Now I changed that to 10 because I would never encounter the case that 8GB are in use, but it didn't have an effect.
Expected behavior:
- on systems without RAM, kswapd should never attempt to swap
- if there is not enough RAM, kernel should kill processes to free up RAM
- no process should be able to claim so much CPU activity, that the computer becomes unresponsive (it should always be possible to control/stop/kill processes over tty)
Actual behavior:
- kswapd tries to swap although there is no swap space
ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.19.0-22-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
/dev/snd/
CurrentDesktop: Unity
Date: Mon Jul 20 12:49:24 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-06-06 (43 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: LENOVO 20266
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.143.1
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/31/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 76CN31WW
dmi.board.
dmi.board.name: Yoga2
dmi.board.vendor: LENOVO
dmi.board.version: 31900058STD
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.name: 20266
dmi.product.
dmi.sys.vendor: LENOVO
tags: | added: bios-outdated-76cn43ww |
Changed in linux (Ubuntu): | |
status: | Confirmed → Incomplete |
tags: |
added: latest-bios-76cn43ww removed: bios-outdated-76cn43ww |
This change was made by a bot.