Mixed mount of HugePages leads to process hang

[tiagolobocastro]

Describe the bug
On k8s, io-engine container hangs whilst trying to flock /dev/hugepages

To Reproduce
Setup your system with default 1GiB hugepage size and allocate 2MiB hugepages.

Expected behavior
Should work :)

Additional context
The problem is that we end up with both 1Gi and 2Mi hugepages mounted on /dev/hugepages.

/ # mount | grep huge
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=1024M)
nodev on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)

EAL init is not able to cope with this and hangs as soon as it tries to flock /dev/hugepages.

I think the fix is to ensure we mount 1Gi and 2Mi on separate mounts, example:

        - name: hugepage
          mountPath: /dev/hugepages-2MiB

In fact today helm-chart is not very flexible as it simply calls out 2MiB hugepages. We should add some vars to allow choosing which hugepages to use...