On 30 January 2018 at 02:39, Victor Stinner
* "-j1" would explicitly turn off multiprocessing
Running tests "sequentially" but run them in one subprocess per test file is interesting for tests isolation. Runing tests one by one reduces the risk of triggering a race condition (test only failing when the system load is high).
-jN was always documented as "use multiprocessing".
Maybe we need a new option to explicitly disable multiprocessing instead?
vstinner@apu$ ./python -m test Run tests sequentially
vstinner@apu$ ./python -m test -j1 Run tests in parallel using 1 child processes
Hmm, that's a good point. Maybe a less intrusive alternative would be akin to what we did with the configure script for non-optimised builds: when we display the total duration at the end, append a note in the serial execution case. Something like: Total duration: 16 minutes 33 seconds (serial execution, pass '-j0' for parallel execution) Such a change would be a safe way to nudge new contributors towards "./python -m test -j0" for faster local testing, without risking backwards compatibility issues with existing test suite invocations in other contexts. Cheers, Nick. -- Nick Coghlan | email@example.com | Brisbane, Australia