tests/cgroup: on cgroup1 systems, the swap limit is set to limits.memory * 2

[simondeziel]

No description provided.

[simondeziel]

As mentioned in chat, I think that trying to make all tests work on 20.04 with modern LXD is going to be a time sync. Expanding the exclusion matrix to limit what is tested on 20.04 is probably the way to go (rather than merging this PR).

Even with the swaptotal issue fixed, the tests/cgroup script fails a bit later on the limits.network.priority test, see https://github.com/simondeziel/lxd-ci/actions/runs/10478158697/job/29020868221#step:8:498

[tomponline]

Lets wait until @mihalicyn has a look, if this is expected behaviour then we can indeed test for it.

[tomponline]

@mihalicyn @simondeziel do we still need this?

[tomponline]

Any news chaps @mihalicyn @simondeziel ?

[simondeziel]

This has stopped being a pain point in CI because we no longer test 5.0 on cgroup1 systems (20.04). I'm not sure if the PR does the right thing (accept different limits based on the LXD version) or if LXD should always use the same limit between every versions.

I guess it's a bit late to change LXD's behaviour now so this PR should be considered if we want to start testing 5.0 on 20.04 again.