Comment 4 for bug 1981113

Reviewed: https://review.opendev.org/c/openstack/neutron/+/861124
Committed: https://opendev.org/openstack/neutron/commit/edf48e46a1f0227f84b05ab39da005393e5fa73f
Submitter: "Zuul (22348)"
Branch: master

commit edf48e46a1f0227f84b05ab39da005393e5fa73f
Author: Miro Tomaska <email address hidden>
Date: Wed Oct 12 08:42:18 2022 -0500

    Improve agent provision performance for large networks

    Before this patch, the metadata agent would provision network namespace
    for all subnets under a network(datapath) as soon as the first
    VM(vif port) was mounted on the chassis. This operation can take very
    long time for networks with lots of subnets. See the linked bug for
    more details.
    This patch changes this mechanism to "lazy load" where metadata agent
    provisions metadata namespace with only the subnets belonging to the
    active ports on the chassis. This results in virtually constant
    throughput not effected by the number of subnets.

    Closes-Bug: #1981113
    Change-Id: Ia2a66cfd3fd1380c5204109742d44f09160548d2