Description of problem:

We are using Red Hat best fir placement, /RedHat/Infrastructure/VM/Provisioning/Placement/redhat_best_placement_with_scope 

The current_memory_headroom and :current_memory_usage values seem to be static - i.e. does not reflect the host's current values. AFAICS,  current_memory_headroom defaults to host's physical memory, and current_memory_usage is always zero. I expect to get actual current values to determine which host is more suitable for placement. 

Please review the following code and log excepts - we have two RHEV hosts (bard and bifur) with 15GB RAM each, one is running 4 and the other one is 9 VMs at the moment. Also please see the attached screenshots for the actual RAM usage of the hosts.

** redhat_best_placement_with_scope
~~~~~~
HOST_SORT_ORDER = [:number_of_vms, :active_provisioning_memory, :current_memory_headroom, :current_memory_usage, :random]



** automation.log:
~~~~~
INFO -- : Q-task_id([miq_provision_44000000000094]) <AEMethod redhat_best_placement_with_scope> Sorted host Order:<[:number_of_vms, :active_provisioning_memory, :current_memory_headroom, :current_memory_usage, :random]> Results:<[[[4, 0, -15679, 0, 522], "bifur"], [[9, 0, -15679, 0, 417], "bard"]]>
~~~~~

Version-Release number of selected component (if applicable):

CFME 5.5.0.13.20151201120956_653c0d4 
RHEV 3.5.6


How reproducible:
Always 

Steps to Reproduce:
1. Verify that your are seeing rhev hosts utilization, If not configure the C&U 
2. Provision a virtual machine o rhev provider with auto placement

Actual results:
host.current_memory_headroom and host.current_memory_usage values are not taken 
into the consideration in placement because the values are not populated with 
actual usage metrics. 

Expected results:
host.current_memory_headroom and host.current_memory_usage values should match with the actual current utilization of the host

Additional info: