Comment 0 for bug 2067516

SRU Justification:

[Impact]

We discovered a network packets per second (PPS) performance issue in one of our upcoming EC2 instance platform on Graviton.The issue is addressed by setting a value for the numa_cma parameter. While this parameter is supported in 24.04, the parameter is not available in 22.04 or 20.04 today, which could impact customers running 22.04 or 20.04 on the new EC2 platform.

[Fix]

We are requesting the the following changes be backported to 22.04 and 20.04 for ARM:
https://git.launchpad.net/~canonical-kernel/ubuntu/+source/linux-aws/+git/noble/commit/kernel/dma/contiguous.c?id=22e4a348f87c59df2c02f1efb7ba9a56b622c7b8
https://git.launchpad.net/~canonical-kernel/ubuntu/+source/linux-aws/+git/noble/commit/kernel/dma/contiguous.c?id=bf29bfaa54901a4bdee2a18cd10eb951a884a5f9

EC2 Nitro team is only asking for the change in ARM, however we will leave to Canonical's discretion to make the same changes in x86.

We also request Canonical set kernel params to "numa_cma=1:32M" for all OSes that support this parameter - 24.04, 22.04 and 20.04.

[Test Plan]
aws tested

[Where problems could occur]

[Other info]
sf# 00385923