[Lxc-users] capping CPU usage

[Trent W. Buck]

I had a bash process in a container go haywire and consume 100% of a
core yesterday.  It made me think:

    Is there a way to cap the AMOUNT of CPU a container can use?

I realize I can assign a container to a specific subset of cores
(cpuset), and change how free CPU is divvied up between containers
(cpu.shares), but I can't see any way to say something like

    This container can use AT MOST 80% of any given core.
    This container can use AT MOST 4 cores (concurrently).

I'm using a scaling governor, so my CPUs will use less power and
generate less heat when they're idling.  I don't want a haywire
container to be able to consume 100% of free compute time, because
that'll push all cores back to their highest clock (and thus increase my
power and cooling bill).