use -j$(nproc) for ctest

[mitchdz]

note that llvm-lit is not explicitly added as well since it by default uses all available cpus[0].

[0] - https://llvm.org/docs/CommandGuide/lit.html#cmdoption-lit-j

[schweitzpgi]

Amazing idea! 😄

[mitchdz]

I had some inspiration 🙂

[schweitzpgi]

Hope this speeds things up without causing thrashing or OOM errors.

[mitchdz]

Hope this speeds things up without causing thrashing or OOM errors.

That's my concern. I wonder if this was never done for reasons of tests not setting down properly, but we should see soon.

[bmhowe23]

Hope this speeds things up without causing thrashing or OOM errors.

That's my concern. I wonder if this was never done for reasons of tests not setting down properly, but we should see soon.

I know that it causes issues on my machine (despite having 128GB memory), but that will be machine specific. It is also not very reliable to do this on a machine with a GPU because at least some of our tests expect to have access to the GPU's full memory, so the random run-to-run variation of timing will cause problems in that situation. (Still worth testing in the CI, though.)

[mitchdz]

These tests are CPU only tests, so we should be good with GPU interference. Memory is a valid concern though, especially on shared runners.

[mitchdz]

Looks like it doesn't really improve the time that much 🙁

[github-actions]

CUDA Quantum Docs Bot: A preview of the documentation can be found here.