selftests: tc-testing: move back to per test ns setup

Surprisingly in kernel configs with most of the debug knobs turned on,
pre-allocating the test resources makes tdc run much slower overall than
when allocating resources on a per test basis.

As these knobs are used in kselftests in downstream CIs, let's go back
to the old way of doing things to avoid kselftests timeouts.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202311161129.3b45ed53-oliver.sang@intel.comSigned-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20231117171208.2066136-3-pctammela@mojatatu.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/tc-testing/plugin-lib/nsPlugin.py

@@ -17,35 +17,33 @@ except ImportError:
     netlink = False
     print("!!! Consider installing pyroute2 !!!")
 
-def prepare_suite(obj, test):
-    original = obj.args.NAMES
+class SubPlugin(TdcPlugin):
+    def __init__(self):
+        self.sub_class = 'ns/SubPlugin'
+        super().__init__()
+
+    def pre_suite(self, testcount, testlist):
+        from itertools import cycle
 
+        super().pre_suite(testcount, testlist)
+
+    def prepare_test(self, test):
         if 'skip' in test and test['skip'] == 'yes':
             return
 
         if 'nsPlugin' not in test['plugins']:
             return
 
-    shadow = {}
-    shadow['IP'] = original['IP']
-    shadow['TC'] = original['TC']
-    shadow['NS'] = '{}-{}'.format(original['NS'], test['random'])
-    shadow['DEV0'] = '{}id{}'.format(original['DEV0'], test['id'])
-    shadow['DEV1'] = '{}id{}'.format(original['DEV1'], test['id'])
-    shadow['DUMMY'] = '{}id{}'.format(original['DUMMY'], test['id'])
-    shadow['DEV2'] = original['DEV2']
-    obj.args.NAMES = shadow
-
         if netlink == True:
-        obj._nl_ns_create()
+            self._nl_ns_create()
         else:
-        obj._ns_create()
+            self._ns_create()
 
         # Make sure the netns is visible in the fs
         while True:
-        obj._proc_check()
+            self._proc_check()
             try:
-            ns = obj.args.NAMES['NS']
+                ns = self.args.NAMES['NS']
                 f = open('/run/netns/{}'.format(ns))
                 f.close()
                 break
@@ -53,31 +51,15 @@ def prepare_suite(obj, test):
                 time.sleep(0.1)
                 continue
 
-    obj.args.NAMES = original
-
-class SubPlugin(TdcPlugin):
-    def __init__(self):
-        self.sub_class = 'ns/SubPlugin'
-        super().__init__()
-
-    def pre_suite(self, testcount, testlist):
-        from itertools import cycle
-
-        super().pre_suite(testcount, testlist)
-
-        print("Setting up namespaces and devices...")
-
-        with Pool(self.args.mp) as p:
-            it = zip(cycle([self]), testlist)
-            p.starmap(prepare_suite, it)
-
-    def pre_case(self, caseinfo, test_skip):
+    def pre_case(self, test, test_skip):
         if self.args.verbose:
             print('{}.pre_case'.format(self.sub_class))
 
         if test_skip:
             return
 
+        self.prepare_test(test)
+
     def post_case(self):
         if self.args.verbose:
             print('{}.post_case'.format(self.sub_class))