neutron-lib: use cpu_count

Make use of cpu_count from neutron-lib utilities

Change-Id: I297417eb48e868b3d7e7e06060c8d7bce44d4589

neutron/agent/metadata/config.py

@@ -12,10 +12,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.utils import host
 from oslo_config import cfg
 
 from neutron._i18n import _
-from neutron.common import utils
 
 
 SHARED_OPTS = [
@@ -106,7 +106,7 @@ UNIX_DOMAIN_METADATA_PROXY_OPTS = [
                       "'all': set metadata proxy socket mode to 0o666, to use "
                       "otherwise.")),
     cfg.IntOpt('metadata_workers',
-               default=utils.cpu_count() // 2,
+               default=host.cpu_count() // 2,
                help=_('Number of separate worker processes for metadata '
                       'server (defaults to half of the number of CPUs)')),
     cfg.IntOpt('metadata_backlog',

neutron/common/utils.py

@@ -22,7 +22,6 @@ import decimal
 import errno
 import functools
 import importlib
-import multiprocessing
 import os
 import os.path
 import random
@@ -39,6 +38,7 @@ from eventlet.green import subprocess
 import netaddr
 from neutron_lib import constants as n_const
 from neutron_lib.utils import helpers
+from neutron_lib.utils import host
 from oslo_concurrency import lockutils
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -177,11 +177,12 @@ def get_dhcp_agent_device_id(network_id, host):
     return 'dhcp%s-%s' % (host_uuid, network_id)
 
 
+@removals.remove(
+    message="Use cpu_count from neutron_lib.utils.host",
+    version="Ocata",
+    removal_version="Pike")
 def cpu_count():
-    try:
-        return multiprocessing.cpu_count()
-    except NotImplementedError:
-        return 1
+    return host.cpu_count()
 
 
 class exception_logger(object):

neutron/conf/agent/l3/ha.py

@@ -13,11 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib.utils import host
 from oslo_config import cfg
 
 from neutron._i18n import _
 from neutron.agent.linux import keepalived
-from neutron.common import utils as common_utils
 
 
 OPTS = [
@@ -36,7 +36,7 @@ OPTS = [
                default=2,
                help=_('The advertisement interval in seconds')),
     cfg.IntOpt('ha_keepalived_state_change_server_threads',
-               default=(1 + common_utils.cpu_count()) // 2,
+               default=(1 + host.cpu_count()) // 2,
                sample_default='(1 + <num_of_cpus>) / 2',
                min=1,
                help=_('Number of concurrent threads for '