Kernel panic during system boot with sched_autogroup_enabled = 0

Bug #1422016 reported by Kent Wolfe
28
This bug affects 6 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Confirmed
High
Unassigned

Bug Description

# lsb_release -rd
Description: Ubuntu 14.04.1 LTS
Release: 14.04

# uname -a
Linux napa 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

A kernel panic occurs while disabling the automatic task group creation within /etc/sysctl.conf using "kernel.sched_autogroup_enabled = 0".

After adding the "noautogroup" kernel parameter to GRUB, the system will boot without issue.

I have attached a screen shot of the stack trace as I was unable to capture the stack trace using netconsole, linux-crashdump, and /var/log/kern.log. Oddly enough, while trying one last approach (serial console) to capture the full trace within virtual box using a host pipe and setting console=ttyS0, the system booted without issue and disabled automatic task group creation.

According to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1055222, a fix for the issue has hit the Precise kernel and should be released in 3.2.0-36.

Tags: bot-comment
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Kent Wolfe (kgwolfe) wrote :
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Kent Wolfe (kgwolfe) wrote :
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Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in ubuntu:
status: New → Confirmed
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Ubuntu Foundations Team Bug Bot (crichton) wrote :

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1422016/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

tags: added: bot-comment
Kent Wolfe (kgwolfe)
affects: ubuntu → linux (Ubuntu)
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Joseph Salisbury (jsalisbury) wrote :

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.19 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.19-vivid/

Changed in linux (Ubuntu):
importance: Undecided → High
status: Confirmed → Incomplete
Revision history for this message
troy engel (troyengel) wrote :

I confirm it's fixed in 3.19.0-031900, it's still broken in 14.04.02 LTS with kernel 3.16.0-30-generic. With further testing, whatever is broken was fixed between 3.18rc2 and 3.18rc3 kernels:

 Broken: 3.18.0-031800rc2 [1]
 Fixed: 3.18.0-031800rc3 [2]

The number of commits between these two is rather high making it difficult to easily spot what may have fixed the bug; the diff from rc2 to rc3 is 621,132 bytes. The test setup is easy - using VirtualBox, create a new VM accepting all defaults. Install 14.04.02 LTS using all defaults, all very generic. In all broken cases specifying "noautogroup" on the kernel params bypasses the bug.

I was able to record a MKV @100fps and extract two PNG files showing the best I can capture; it goes by so fast that even at 100fps I can't capture a few missing lines.

[1] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18-rc2-vivid/
[2] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18-rc3-vivid/

Revision history for this message
troy engel (troyengel) wrote :
Changed in linux (Ubuntu):
status: Incomplete → Confirmed
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