Ubuntu
linux package

  1. Hirsute (21.04)
  2. Bug #1920944
  3. Comment #0

Comment 0 for bug 1920944

Revision history for this message
Andrea Righi (arighi) wrote : aws: proper fix for c5.18xlarge hibernation issues

[Impact]

In LP: #1918694 we applied a fix and a workaround to solve the hibernation issues on c5.18xlarge. The workaround was in the form of a SAUCE patch:

  "UBUNTU: SAUCE: aws: kvm: double the size of hv_clock_boot"

It looks like we can replace this workaround with a proper fix, by applying this patch:
https://<email address hidden>/T/#m7533e1d1e551bff425da029fd401bd87935edc33

[Test plan]

Create a c5.18xlarge instance, run the memory stress test script (the same test script that we are using to stress test hibernation), trigger the hibernate event, trigger the resume event. Repeat a couple of times and the problem is very likely to happen.

[Fix]

https://<email address hidden>/T/#m7533e1d1e551bff425da029fd401bd87935edc33

The fix has been tested extensively in the AWS infrastructure with positive results.

[Regression potential]

This new code introduced by the fix can be executed also when a CPU is put offline, so we may see potential regressions in the KVM CPU hotplugging.