Comment 9 for bug 1543149

Reviewed: https://review.openstack.org/292499
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d52ceaf269ae64575c48aa45002aa4fc5cfb2a86
Submitter: Jenkins
Branch: master

commit d52ceaf269ae64575c48aa45002aa4fc5cfb2a86
Author: Sahid Orentino Ferdjaoui <email address hidden>
Date: Mon Feb 8 09:37:37 2016 -0500

    virt: reserved number of mempages on compute host

    Users need to mark as reserved some amount of pages for third party
    components.

    The most common use case for using huge/large pages is NFV. In the
    current state of that feature we can't guarantee the necessary amount
    of pages to allow OVS-DPDK to run properly on the compute node, which
    result in the instance failing to boot on a well selected
    compute-node. OVS-DPDK needs 1 GB hugepages reserved. Since Nova does
    not take into account that page reserved for OVS-DPDK it results in
    the process not being able to acquire the necessary memory which
    results in a failed boot.

    This commit adds a new option 'reserved_huge_pages' which takes a list
    of string format to select on which host NUMA nodes and from which
    pagesize we want to reserve a certain amount of pages. It also updates
    NUMAPageTopology to contain a reserved memory pages attribute, which
    helps compute the available pages size on host for scheduling/claiming
    resources.

    Change-Id: Ie04d6362a4e99dcb2504698fc831a366ba746b44
    Closes-Bug: #1543149