With Linux 4.9, loadBpfObjects() failed, error=argument list too long

[Ponny]

Describe the bug

I encountered an error while running the `cgroup_skb` example in Linux 4.9, error=`loading objects: field CountEgressPackets: program count_egress_packets: load program: argument list too long`. 

Although cgroup_skb dont support with Linux 4.9, but README.md mentions that working with Linux >= 4.9, so loadBpfObjects() should be ok but failed.

So i want to know whether Linux 4.9 is supported? 

Tks.

How to reproduce

Linux: 4.9.113

Code: examples/cgroup_skb

Version information

latest

[Lorenz Bauer]

Thanks for pointing this out! The story for 4.9 is slightly complicated: we still have it in CI, but we don't go out of our way to support it. We'll gladly take the fix if you figure out what is wrong, but we don't spend time on maintaining it.

I'll update the README to make this clearer.