Why is compaction disabled on the Rockchip kernel?

General Discussion
1

Hello,

I am using dietpi with the kernel 6.1.115-vendor-rk35xx #1 SMP Mon Apr 6 11:36:06 UTC 2026 aarch64 GNU/Linux on Radxa Rock 5B.

Recently I’ve been observing that some of my containers don’t see the full “available memory”, especially if I enable zram. ChatGPT suggested that it may be an issue with memory compaction.

And indeed the kernel config says:
# CONFIG_COMPACTION is not set
Is this a known issue on Rockchip 6.1?

Maybe it wouldn’t hurt to enable this?

2

Best to my knowledge this is a vendor kernel. But something @MichaIng can confirm.

3

Yes, this is a vendor kernel (dietpi default). But this doesn’t necessarily mean compaction can’t be enabled, does it?

4

I’m not 100% sure but usually vendor kernel means it’s maintained by vendor, not by us. But I could be wrong. @MichaIng knows for sure.