8226575: OperatingSystemMXBean should be made container aware

[Severin Gehwolf]

On Wed, 2019-12-04 at 08:32 -0500, Bob Vandette wrote:
> You can try to use containerMetrics.getPerCpuUsage() instead of containerMetrics.getEffectiveCpuSetCpus().
> The length of the array returned is the number of host cpus.  Maybe Severin can confirm if this true in cgroupv2 as
> well.

If I'm not mistaken getPerCpuUsage() is not supported in cgroupv2.

Thanks,
Severin