Collect 100 slow tests by default

If we do not want _all_ tests durations, it makes sense to reuse the existing slow test collection and aggregation

Bug: v8:10168
Change-Id: I500acdb799f41ee6f0fb2c57afb95e1e1830b2dd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2064221
Auto-Submit: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66342}

tools/testrunner/base_runner.py

@@ -344,8 +344,8 @@ class BaseTestRunner(object):
                            "color, mono)")
     parser.add_option("--json-test-results",
                       help="Path to a file for storing json results.")
-    parser.add_option('--json-test-times',
-                      help='Path to a file for storing json test times.')
+    parser.add_option('--slow-tests-cutoff', type="int", default=100,
+                      help='Collect N slowest tests')
     parser.add_option("--exit-after-n-failures", type="int", default=100,
                       help="Exit after the first N failures instead of "
                            "running all tests. Pass 0 to disable this feature.")

tools/testrunner/testproc/progress.py

@@ -385,7 +385,8 @@ class JsonTestProgressIndicator(ProgressIndicator):
 
     # Sort tests by duration.
     self.tests.sort(key=lambda __duration_cmd: __duration_cmd[1], reverse=True)
-    slowest_tests = self._test_records(self.tests[:20])
+    cutoff = self.options.slow_tests_cutoff
+    slowest_tests = self._test_records(self.tests[:cutoff])
 
     complete_results.append({
       "arch": self.arch,
@@ -399,8 +400,6 @@ class JsonTestProgressIndicator(ProgressIndicator):
     with open(self.options.json_test_results, "w") as f:
       f.write(json.dumps(complete_results))
 
-    self._save_test_times()
-
   def _test_records(self, tests):
     return [
       {
@@ -411,9 +410,3 @@ class JsonTestProgressIndicator(ProgressIndicator):
         "marked_slow": test.is_slow,
       } for (test, duration, cmd) in tests
     ]
-
-  def _save_test_times(self):
-    if self.options.json_test_times:
-      test_times = self._test_records(self.tests)
-      with open(self.options.json_test_times, "w") as f:
-        f.write(json.dumps(test_times))