Resource control for containers

[marcoy]

We need to limit the disk usage, bandwidth, etc...

[xavileon]

I understand this as per container limit. Some comments:

• Disk limit is no longer possible. Quotas per directory wouldn't work because host and containers share the same username namespace. Blocked by COW strategy for NodeManager #11 and Performance Evaluation #12.
• Memory limit: hard and soft limits implemented through memlock_hard and memlock_soft tags (need testing) via cgroups
• CPU limits: cgroups do not support hard limits on %CPU. Only support defining shares (tag cpu_share). Tested.
• BW limits: classify net flows with cgroups (net_cls controller) and limit bw through tc.

Anything else?