Azure: Jammy fio test causes panic

[Tim Gardner]

SRU Justification

[Impact]

During Storage performance tests, 16 disks are attached and fio is ran. The fio command does not consistently result in a kernel panic, but the test runs fio enough times to result in consistent kernel panic. The panic is most often observed on instances with many cores and disks.

[Test Case]

Using an instance with 96 cores and 16 disks:

sudo fio --ioengine=libaio --bs=1024K --filename=/dev/sda:/dev/sdb:/dev/sdc:/dev/sdd:/dev/sde:/dev/sdf:/dev/sdg:/dev/sdh:/dev/sdi:/dev/sdj:/dev/sdk:/dev/sdl:/dev/sdm:/dev/sdn:/dev/sdo:/dev/sdp --readwrite=read --runtime=120 --iodepth=32 --numjob=96 --name=iteration23 --direct=1 --size=8192M --group_reporting --overwrite=1

Test results from Microsoft and myself are positive. No panics were observed.

[Regression Potential]

The fix is an upstream patch from 5.17, commit 0bd2fbee9d0b7f801a9c0264d90b1e0d8053f395 ('scsi: storvsc: Fix unsigned comparison to zero'). Regression potential is low.

[Other Info]

SF: #00346757

[Tim Gardner (timg-tpi)]

Patch submitted: https://lists.ubuntu.com/archives/kernel-team/2022-November/134828.html

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

This bug is awaiting verification that the linux-azure/5.15.0-1030.37 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-jammy' to 'verification-done-jammy'. If the problem still exists, change the tag 'verification-needed-jammy' to 'verification-failed-jammy'.

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!

[Tim Gardner (timg-tpi)]

Microsoft tested and accepted. Marking verification-done-jammy

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

This bug is awaiting verification that the linux-azure-5.15/5.15.0-1033.40~20.04.1 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-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

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!