Qunata server memory stress cause "rcu_sched detected stalls on cpus/tasks"

[Zhanglei Mao]

We are facing a problem during the certification test. System always stop at below screen while memory stress. In the following re-producing, kernel seems un-normal and it can’t capture above info into the syslog or kernel log, but the console will show same warning as screen shot attachment file.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1796217

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.19 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'.

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/v4.19-rc7

[Joseph Salisbury (jsalisbury)]

Also, are there prior kernel versions that do no exhibit this bug?

[Zhanglei Mao (zhanglei-mao)]

A good feedback from partner is "I just update Ubuntu kernel to v4.19 and Memory Stress can got pass result this time."

[Jeff Lane  (bladernr)]

How about the 4.4 kernel? And are they using a normal HDD/SSD for the root filesystem, or are they using a NVMe of some sort?

I'm currently following another bug where the memory test fails reliably when using an NVMe as the root filesystem but passes when a SSD or HDD is used. In that case, 4.4 can pass, but 4.15 and 4.18 fail.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu Bionic) because there has been no activity for 60 days.]