make python test suites run in parallel
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 08a5ff0..c55d1fb 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -353,15 +353,27 @@
     _check_compiler(self.args.compiler, ['default'])
 
   def test_specs(self):
+    # load list of known test suites
+    with open('src/python/grpcio/tests/tests.json') as tests_json_file:
+      tests_json = json.load(tests_json_file)
     environment = dict(_FORCE_ENVIRON_FOR_WRAPPERS)
     environment['PYVER'] = '2.7'
-    return [self.config.job_spec(
-        ['tools/run_tests/run_python.sh'],
-        None,
-        environ=environment,
-        shortname='py.test',
-        timeout_seconds=15*60
-    )]
+    if self.config.build_config != 'gcov':
+      return [self.config.job_spec(
+          ['tools/run_tests/run_python.sh'],
+          None,
+          environ=dict(environment.items() +
+                       [('GPRC_PYTHON_TESTRUNNER_FILTER', suite_name)]),
+          shortname='py.test.%s' % suite_name,
+          timeout_seconds=5*60)
+          for suite_name in tests_json]
+    else:
+      return [self.config.job_spec(['tools/run_tests/run_python.sh'],
+                                   None,
+                                   environ=environment,
+                                   shortname='py.test.coverage',
+                                   timeout_seconds=15*60)]
+
 
   def pre_build_steps(self):
     return []