I wanted to post about this because I don't think it's common knowledge (I only just came to the realization today) and it has potential impact on the effectiveness of our unit tests.
Currently we run our Linux unit tests exclusively on Amazon EC2 m1.medium[1] instances which have only one CPU core. Previously we used to run Linux tests on in-house multicore hardware. This means that we're testing different threading behavior now. In more concrete terms, a threading bug[2] was found recently by AddressSanitizer but it only manifested on the build machines (conveniently we still run some limited xpcshell testing as part of `make check` as well as during packaging) and not in our extensive unit tests running on the test machines. This seems unfortunate. I'm not sure what the real impact of this is. Threading bugs can certainly manifest on single-core machines, but the scheduling behavior is different so they're likely to be different bugs. Is this an issue we should address? -Ted 1. http://aws.amazon.com/ec2/instance-types/#Instance_Types 2. https://bugzilla.mozilla.org/show_bug.cgi?id=990230 _______________________________________________ dev-platform mailing list [email protected] https://lists.mozilla.org/listinfo/dev-platform
