Merge pull request #12620 from varadakari/wip-rocksdb-histogram

os/bluestore: kvdb histogram

Reviewed-by: Sage Weil <sage@redhat.com>
Reviewed-by: Igor Fedotov <ifedotov@mirantis.com>

diff --cc src/kv/KeyValueDB.h
Simple merge

diff --cc src/kv/RocksDBStore.cc
Simple merge

diff --cc src/kv/RocksDBStore.h
Simple merge

diff --cc src/os/bluestore/BlueFS.cc
Simple merge

diff --cc src/os/bluestore/BlueFS.h
Simple merge

diff --cc src/os/bluestore/BlueStore.cc
Simple merge

diff --cc src/os/bluestore/BlueStore.h
Simple merge

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

diff --cc src/test/objectstore/store_test.cc
Simple merge