ksoftirqd/0 uses 100% CPU

[Lawrence Chan]

This generally happens after my computer has been on for quite some time, but it's a bit sporadic so I'm not sure how to reproduce it reliably. My guess is suspend cycles or wifi kill switch bugs could be causing it, but there is no immediate effect from either of those so I'm not sure.

There were some similar bug reports from much older kernels and most of them have seen no activity or have fixes released.

Top output:

top - 20:45:52 up 1:32, 1 user, load average: 2.14, 1.87, 1.54
Tasks: 169 total, 3 running, 166 sleeping, 0 stopped, 0 zombie
Cpu(s): 3.7%us, 3.0%sy, 0.0%ni, 76.0%id, 1.7%wa, 0.1%hi, 15.5%si, 0.0%st
Mem: 4055756k total, 1330708k used, 2725048k free, 85064k buffers
Swap: 2096440k total, 0k used, 2096440k free, 462676k cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
    4 root 15 -5 0 0 0 R 101 0.0 30:55.97 ksoftirqd/0

ProblemType: Bug
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: llchan 2378 F.... pulseaudio
 /dev/snd/pcmC0D0p: llchan 2378 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf3500000 irq 22'
   Mixer name : 'Realtek ALC662 rev1'
   Components : 'HDA:10ec0662,15580481,00100101 HDA:10573055,00305557,00100900'
   Controls : 26
   Simple ctrls : 16
Date: Thu Nov 19 20:59:03 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=300263f3-af10-4c63-9c30-f9e67309aba4
MachineType: CLEVO CO. M570TU
NonfreeKernelModules: openafs nvidia
Package: linux-image-2.6.31-14-generic 2.6.31-14.48
ProcCmdLine: root=UUID=dc744942-1692-4a1e-8b91-09a137553f6a ro quiet splash acpi_osi=Linux
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-14-generic N/A
 linux-firmware 1.24
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Uname: Linux 2.6.31-14-generic x86_64
WpaSupplicantLog:

dmi.bios.date: 04/10/2009
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: 1.00.16
dmi.board.asset.tag: Tag 12345
dmi.board.name: M570TU
dmi.board.vendor: CLEVO CO.
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvr1.00.16:bd04/10/2009:svnCLEVOCO.:pnM570TU:pvrNotApplicable:rvnCLEVOCO.:rnM570TU:rvrNotApplicable:cvnNoEnclosure:ct9:cvrN/A:
dmi.product.name: M570TU
dmi.product.version: Not Applicable
dmi.sys.vendor: CLEVO CO.

[Lawrence Chan (element103)]

this has started happening much more frequently and when it does occur, there is nothing i can do except restart the computer.

i would like to debug this but don't know where to start, so if anyone has suggestions...

[Evgeny Shavkunov (eshavkunov)]

This happens to me as well.
I believe it started to appear after some update for 9.04; after upgrade to 9.10 it happens much more often (lake every 2 days).
I do not see anything suspicious in logs (actually in most cases there is nothing in logs at all for sometime before it happens) or in /proc/interrupts.

Ireally don't know where to look. The only thing that helps is restart.

One more thing about restarts: when ksoftirqd/0 was starting to eat my CPU in 9.04 I couldn't reboot - it was just black screen after I press reboot. Now laptop reboots normally. So it seems that there is at least some progress with this bug :)

[Jeremy Foshee (jeremyfoshee)]

Hi Lawrence,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 485619

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

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[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

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