cgroup support for memory and cpu limiting

[marina-vrublevsky]

In this PR:

1. Add PID to memory and cpu cgroup
2. Limit memory of cgroup
3. Limit amount of cores usage of cgroup

To Do:

1. Add memory and cpu usage methods
2. Support for cgroup v2

[michelhe]

Generally I don't like the terminology of cgroups_client, I suggest simply cgroups, would be a good module name IMO

[michelhe]

For now, not done

[Jongy]

I'd like to review it as well, but first let's sync IRL on the purpose and what we try to achieve here, description wasn't clear enough to me

[marina-vrublevsky]

Generally I don't like the terminology of cgroups_client, I suggest simply cgroups, would be a good module name IMO

@michelhe As i stated in the description (todo.2) there is currently another cgroups.py
we need to decide if we want to merge them

[michelhe]

Generally I don't like the terminology of cgroups_client, I suggest simply cgroups, would be a good module name IMO

@michelhe As i stated in the description (todo.2) there is currently another cgroups.py we need to decide if we want to merge them

It only consists of a single of function, you can just put it in the __init__.py of this module

[Jongy]

I'll complete the pass later. Meanwhile - we still have naming weirdnesses here, so let's define clear names, following https://man7.org/linux/man-pages/man7/cgroups.7.html:

• A cgroup type i.e memory, cpu,cpuacct is called subsystem. Ensure all cgroup_type and controller are renamed to subsystem. (You may also choose controller, I don't mind, but be consistent)
• A cgroup path (i.e /, /docker/....) is called cgroup
• Any other?

[Jongy]

Few last. Please test it as we discussed in private

Reviewed