The semantics doesn't really matter either way. The comment I originally replied to basically implied the whole Linux kernel is one "unit" (or at least each ker

The semantics doesn't really matter either way. The comment I originally replied to basically implied the whole Linux kernel is one "unit" (or at least each kernel syscall is one unit... which isn't much difference due to large interdependencies between them). Using that definition, that's just basically saying "the kernel can benefit from ... tests". Of course the Linux kernel doesn't have "TDD-religion unit tests", but there's already more than enough "tests" for the Linux kernel, and there's more than enough benchmark tests for the Linux kernel (for the optimization argument). They're just not "unit" tests in any meaningful way. From the pedantic side of things, the original comment said "(TDD-religion) unit tests are overrated", then the reply was either "no they're not", or "no, unit tests (as originally defined) are not overrated". The latter is somewhat inconsistent with the "hard disagree", so either they were confused as to which definition they wanted, or cherry picked properties from both unit testing regimes.