Tests: Skip multiprocess test when using 1 cpu

When only one cpu is present, the "backup_workers"
option cannot be set to 2 because the maximum value
of it is set to processutils.get_worker_count().

This is rare, so skip this test when only 1 cpu
is present.

Closes-Bug: #2083541
Change-Id: I83df179a032c1a60eee31eaac1bd4a0c9a4e307d

cinder/tests/unit/test_cmd.py

@@ -22,6 +22,7 @@ from unittest import mock
 import ddt
 import fixtures
 import iso8601
+from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_db import exception as oslo_exception
 from oslo_utils import timeutils
@@ -128,6 +129,10 @@ class TestCinderBackupCmd(test.TestCase):
     @mock.patch('oslo_log.log.setup')
     def test_main_multiprocess(self, log_setup, monkey_patch, service_create,
                                get_launcher, mock_semaphore):
+        if processutils.get_worker_count() < 2:
+            raise test.testtools.TestCase.skipException(
+                'requires more than 1 cpu (to set backup_workers >1)')
+
         CONF.set_override('backup_workers', 2)
         mock_semaphore.side_effect = [mock.sentinel.semaphore1,
                                       mock.sentinel.semaphore2]