Merge pull request #21968 from ceph/backport-21605

luminous: mon: High MON cpu usage when cluster is changing

Reviewed-by: Sage Weil <sage@redhat.com>

diff --cc src/mon/OSDMonitor.cc
Simple merge

diff --cc src/osd/OSD.cc
Simple merge

diff --cc src/osd/OSDMap.cc
Simple merge

diff --cc src/osd/osd_types.cc
Simple merge