DietPi-Software | MicroK8s: High idle CPU load on RPi

[dmgolembiowski]

Follow up issue on behalf of @silverraindog and @MichaIng related to the MicroK8s installation. I'm invested in a boot image for this so I'm opening this issue.

The details from the pull request included:

Thanks!

Can you verify it on your system via modinfo vxlan?

Yup, I see similar output to what you've posted.
TL;DR - I believe this was what they were talking about:

Hmm, reading though the linked solution from your link (https://github.com/k3s-io/k3s/issues/4234) indicates that on Ubuntu it was the missing `vxlan` kernel module, which is indeed shipped with that package on Ubuntu: https://packages.ubuntu.com/linux-modules-extra-raspi

With the official Raspberry Pi kernel we use, it is however shipped OOTB:

# modinfo vxlan
filename:       /lib/modules/5.10.92-v7+/kernel/drivers/net/vxlan.ko
alias:          rtnl-link-vxlan
description:    Driver for VXLAN encapsulated traffic
author:         Stephen Hemminger <[email protected]>
version:        0.1
license:        GPL
srcversion:     A772666323B3A673FA6A7F1
depends:        udp_tunnel,ip6_udp_tunnel
intree:         Y
name:           vxlan
vermagic:       5.10.92-v7+ SMP mod_unload modversions ARMv7 p2v8
parm:           udp_port:Destination UDP port (ushort)
parm:           log_ecn_error:Log packets received with corrupted ECN (bool)
2022-02-17 04:39:51 root@micha:/var/log# modinfo vxlan
filename:       /lib/modules/5.10.92-v7+/kernel/drivers/net/vxlan.ko
alias:          rtnl-link-vxlan
description:    Driver for VXLAN encapsulated traffic
author:         Stephen Hemminger <[email protected]>
version:        0.1
license:        GPL
srcversion:     A772666323B3A673FA6A7F1
depends:        udp_tunnel,ip6_udp_tunnel
intree:         Y
name:           vxlan
vermagic:       5.10.92-v7+ SMP mod_unload modversions ARMv7 p2v8
parm:           udp_port:Destination UDP port (ushort)
parm:           log_ecn_error:Log packets received with corrupted ECN (bool)

Can you verify it on your system via modinfo vxlan?

Originally posted by @MichaIng in #5239 (comment)

Thanks!

Can you verify it on your system via modinfo vxlan?

Yup, I see similar output to what you've posted.
...
Merging this now, so we can test on dev branch. We can fine tune via dedicated PRs/commits.

---

Anything I can do to help debug?

[MichaIng]

Can you check journalctl and in case logs files in /var/log/pods for hints? The vxlan module is present OOTB with our kernel, so your issue is not related to the linked one from the K3s repo.

[MichaIng]

@dmgolembiowski
Is this still an issue without our current MicroK8s implementation?

[dmgolembiowski]

Sorry, I haven't tested this yet.

[MichaIng]

I'll mark this as closed for now. In the meantime next Linux LTS is available on most SBCs, so if the issue persists, let's open a new issue with fresh logs and comparison with other systems where CPU load is significantly lower.