Added cgroups v2 CPU implementation.

[Zyqsempai]

Partially fixes #104
Added cgroups v2 CPU implementation.

Signed-off-by: bpopovschi zyqsempai@mail.ru

[Zyqsempai]

@AkihiroSuda Can you add some acceptance criteria or checkpoints what should be done, for easier testing and validation for this and next PR's.

[codecov-io]

Codecov Report

Merging #107 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #107   +/-   ##
=======================================
  Coverage   45.42%   45.42%           
=======================================
  Files          23       23           
  Lines        1638     1638           
=======================================
  Hits          744      744           
  Misses        768      768           
  Partials      126      126

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6fb48e1...8f1875b. Read the comment docs.

[AkihiroSuda]

Please add to

cgroups/v2/utils.go

Line 32 in 6fb48e1

func defaults(unifiedMountpoint string) ([]Subsystem, map[Name]error) {

[AkihiroSuda]

wrt tests I think we can add metrics code to cmd/cgroups-playground and call it a day.

In future we should have proper Go tests

[AkihiroSuda]

The code seems for v1

See https://github.com/opencontainers/runc/blob/master/libcontainer/cgroups/fs/cpu_v2.go

[Zyqsempai]

@AkihiroSuda The problem is that https://github.com/opencontainers/runtime-spec/blob/master/specs-go/config.go#L297 this config still not updated to v2.
Should I open an issue and corresponding PR to runtime-spec?
For example how it's done in runc https://github.com/opencontainers/runc/blob/master/libcontainer/configs/cgroup_linux.go#L123

[AkihiroSuda]

No, you can just convert
https://github.com/containers/crun/blob/master/crun.1.md#cgroup-v2

[Zyqsempai]

@AkihiroSuda PTAL

[AkihiroSuda]

thanks, just a couple of nits

[Zyqsempai]

@AkihiroSuda Thanks for your reviews. Done.

[AkihiroSuda]

LGTM, thanks

[crosbymichael]

One thing before we go farther on this. Should v2 be simpler where we don't have separate files/controllers, cpu.go/memory.go but a single manager.go with all the settings?

[AkihiroSuda]

Good idea, could you open PR? (maybe after merging this one)

[crosbymichael]

Ya, I think we should merge then one and then i can work on a unified manager :)

[crosbymichael]

LGTM

@AkihiroSuda after this last edit, does it still LGTM for you?