[ovs-git] [ovn-org/ovn] ab38ea: ovn-controller: Use partial map updates for ct zones.

[Ilya Maximets]

  Branch: refs/heads/branch-20.12
  Home:   https://github.com/ovn-org/ovn
  Commit: ab38ea893727e7e46bcc7c040bf16c318886b6d9
      https://github.com/ovn-org/ovn/commit/ab38ea893727e7e46bcc7c040bf16c318886b6d9
  Author: Ilya Maximets <i.maximets at ovn.org>
  Date:   2020-12-17 (Thu, 17 Dec 2020)

  Changed paths:
    M controller/ovn-controller.c

  Log Message:
  -----------
  ovn-controller: Use partial map updates for ct zones.

There could be hundreds or thousands of ct zones in external-ids map.
Iteration over all of them and reconstruction of the whole new map
is unnecessary and only hurts performance of both ovn-controller and
ovsdb-server on the node.  Replacing with partial map updates to avoid
unnecessary work.

Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
Signed-off-by: Numan Siddique <numans at ovn.org>

(cherry-picked from master commit 5fdee339f4bf086df5ebe237aad42274e8cdab11)