** Changed in: linux-aws (Ubuntu Groovy)
Status: New => Fix Committed
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-aws in Ubuntu.
https://bugs.launchpad.net/bugs/1902926
Title:
aws: improve hibernation reliability in groovy
Status in linux-aws package in Ubuntu:
New
Status in linux-aws source package in Groovy:
Fix Committed
Bug description:
[Impact]
The 5.8 kernel (groovy) is not still 100% reliable with hibernation,
especially on the Xen instance type. However, re-aligning the config
options as much as possible with the 5.4 kernel (focal) allows to
hibernate and resume with a success rate close to 100% (according to
our tests on the AWS cloud).
[Test case]
- spin up an AWS instance (for example a c4.8xlarge instance type)
- run a memory stress test
- hibernate
- resume
- verify that the system has been resumed correctly and the memory stress
test is still running
[Fix]
The following fixes must be applied to improve hibernation/resume
reliability:
- disable CONFIG_SUSPEND (suspend to memory is not supported in AWS and
it can introduce a deadlock condition with the Xen hibernation layer)
- make sure CONFIG_DMA_CMA is disabled (this introduces another
deadlock condition with Xen)
- disable CONFIG_FB_HYPERV: this would enable CONFIG_DMA_CMA and we
dont' want that (to prevent the Xen deadlock); moreover this driver
is not needed at all in the AWS environment
- disable CONFIG_XEN_FBDEV_FRONTEND: this is also not required in the
AWS environement and it has the potential of breaking hibernation
- disable CONFIG_INPUT_XEN_KBDDEV_FRONTEND
- compile xen-netfront as module
- disable CONFIG_XEN_BALLOON
- remove all sound-related modules (not really needed in the AWS cloud,
they were also disabled on 5.4)
[Regression potential]
These are all .config changes. With these changes we are basically
re-aligning with the previous 5.4 settings and we have experimentally
verified (tests) that these changes are increasing the success rate of
hibernation. So the regression potential is minimal.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1902926/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
