60350 2011-05-06 00:38:16 -0700 run_webkit_tests_unittest.MainTest is very slow 2012-03-12 18:24:19 -0700 1 1 1 Unclassified WebKit Tools / Tests 528+ (Nightly build) All All RESOLVED FIXED P2 Normal --- 1 abarth webkit-unassigned dpranke eric oldest_to_newest 399390 0 abarth 2011-05-06 00:38:16 -0700 run_webkit_tests_unittest.MainTest accounts for 57% of the total running time of test-webkitpy even though it only accounts for 5.4% of the tests: $ ./Tools/Scripts/test-webkitpy webkitpy.layout_tests.run_webkit_tests_unittest.MainTest Ran 56 tests in 14.183s $ ./Tools/Scripts/test-webkitpy webkitpy.layout_tests.run_webkit_tests_unittest.MainTest Ran 1036 tests in 24.807s I don't know why these tests are so slow, but there's something wrong with them. 399567 1 abarth 2011-05-06 09:42:52 -0700 Sorry: $ ./Tools/Scripts/test-webkitpy Ran 1036 tests in 24.807s 399716 2 dpranke 2011-05-06 12:19:57 -0700 This bug does not depend on 60354 or vice versa. I am clearing the field. 399746 3 dpranke 2011-05-06 12:59:10 -0700 There is a time.sleep() in layout_tests/manager.py that is there to avoid what appears to be some sort of race condition when we spawn off a bunch of DumpRenderTrees when running the real tests. This accounts for ~7 seconds, and we could push this down to a port-specific hook to be mocked out when running the unittests. That's the only really obvious thing in the profiling stats. I think the combination of moving to the new manager/worker model and the fact that we've been gradually accumulating more tests that get executed for each combination of flags to NRWT accounts for the rest of the slowness. There's simply a lot of different test paths to execute, and these tests do a lot of work to cover them all. 399751 4 abarth 2011-05-06 13:06:49 -0700 Another perspective is that this test suite is taking a poor approach to testing this code and that this code is not well-designed for testability. Unfortunately, I don't think this is the right moment to refactor NRWT for testability because actually turning it on for the rest of the project is a higher priority. 576857 5 dpranke 2012-03-12 18:24:19 -0700 it's much faster now :). Closing.