As part of the BuildFaster project (see https://wiki.mozilla.org/ReleaseEngineering/BuildFaster), we are investigating whether certain slow mochitests can be sped up. Several of the bidi tests in layout are about 10x slower on debug than opt. Some times from a recent run (in ms): /tests/layout/base/tests/test_bug570378-persian-4b.html macosx-debug, 23292 macosx64-debug, 21369 linux64-debug, 24078 linux-debug, 29585 /tests/layout/base/tests/test_bug441782-1d.html macosx-debug, 21280 macosx64-debug, 19591 linux64-debug, 21964 linux-debug, 24234 /tests/layout/base/tests/test_bug570378-persian-5d.html macosx-debug, 23395 macosx64-debug, 21533 linux64-debug, 24201 linux-debug, 29730 /tests/layout/base/tests/test_bug570378-persian-2f.html macosx-debug, 23148 macosx64-debug, 21613 linux64-debug, 20819 linux-debug, 26537 /tests/layout/base/tests/test_bug570378-arabic-1e.html macosx-debug, 24773 macosx64-debug, 22820 linux64-debug, 21635 linux-debug, 28182 /tests/layout/base/tests/test_bug467672-3g.html macosx-debug, 24447 macosx64-debug, 22637 linux64-debug, 21551 linux-debug, 30351 /tests/layout/base/tests/test_bug467672-5c.html macosx-debug, 22911 macosx64-debug, 21142 linux64-debug, 20210 linux-debug, 25960 /tests/layout/base/tests/test_bug570378-arabic-1c.html macosx-debug, 23146 macosx64-debug, 21460 linux64-debug, 20531 linux-debug, 23972 /tests/layout/base/tests/test_bug570378-persian-3c.html macosx-debug, 22514 macosx64-debug, 21568 linux64-debug, 22499 linux-debug, 26769 The opt times for all these tests were around 2000ms.

Ehsan, as the original author of these tests, would you be willing to investigate if these tests may be sped up on debug builds? Interesting on my own mac, the debug test execution time was about the same as the opt execution time; I'm not sure why they are so much slower on the tinderbox machines.

(In reply to comment #1) > Ehsan, as the original author of these tests, would you be willing to > investigate if these tests may be sped up on debug builds? Do we know if bug 479352 has not helped with these tests?

(In reply to comment #2) > > Do we know if bug 479352 has not helped with these tests? Hmm yes, in fact without that fix, on my macosx64 machine, /tests/layout/base/tests/test_bug570378-persian-4b.html takes ~18s, with that fix, it takes ~4s.