cma alloc failure in large 5.15 arm instances
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-aws (Ubuntu) |
Fix Released
|
Medium
|
Tim Gardner | ||
Jammy |
Fix Released
|
Medium
|
Tim Gardner | ||
Kinetic |
Fix Released
|
Medium
|
Tim Gardner |
Bug Description
When launching large arm64 instances on the focal or jammy ami, cma allocation errors appear in the dmesg out:
[ 0.063255] cma: cma_alloc: reserved: alloc failed, req-size: 4096 pages, ret: -12
As far as I can tell, this does not impact instance launch in a meaningful way, but I am unsure of the other implications of this. I was able to confirm that these messages are only present in 5.15, as they do not show up in the bionic image, and rolling back focal to linux-aws 5.4 avoids them as well.
This was present in at least 2 instance types and only appears to pop up in large sizes (2x4 does not produce them, 64x124 (c6gn.16xlarge) does)
This could be as simple as just disabling CMA in the linux-aws pkg, as it appears this is already the case in linux-azure(LP: #1949770).
Attaching dmesg out to the report.
# Replication
+ Launch a large arm64 instance (c6gn.16xlarge)
+ Observe the messages in kern.log / dmesg
Changed in linux-aws (Ubuntu Jammy): | |
assignee: | nobody → Tim Gardner (timg-tpi) |
importance: | Undecided → Medium |
status: | New → Fix Committed |
Changed in linux-aws (Ubuntu Kinetic): | |
assignee: | nobody → Tim Gardner (timg-tpi) |
importance: | Undecided → Medium |
status: | New → In Progress |
Changed in linux-aws (Ubuntu Kinetic): | |
status: | In Progress → Invalid |
Changed in linux-aws (Ubuntu Kinetic): | |
status: | Invalid → In Progress |
Changed in linux-aws (Ubuntu Jammy): | |
status: | In Progress → Fix Committed |
Changed in linux-aws (Ubuntu Kinetic): | |
status: | In Progress → Fix Committed |
This bug is awaiting verification that the linux-azure/ 5.15.0- 1021.26 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!