Ivan Petkov <ivanppetkov@gmail.com> skribis:

On Apr 4, 2019, at 1:59 AM, Ludovic Courtès <ludo@gnu.org> wrote:

The build nodes may be slower than the front-end, but still, it seems

unlikely that it would take more than 6h there.  (That could happen if

the test suite, which lasts 2.1h, were “embarrassingly parallel”, but

we’re running tests with ‘-j1’.)

To summarize, there are two problems:

1. Rust takes too long to build.  What can we do about it?  Enable

   parallel builds?

Rust tests are designed to run in parallel, as long as you have enough

RAM, file descriptors, etc. available on the machine for the amount of

concurrency being used. The compiler test suite is largely just compiling

files, so the most important resource is probably available RAM/swap.

Perhaps we could start with:

 "-j" (number->string (min (parallel-job-count) 2))

?

Maybe if the bootstrapped versions don’t ever change skipping the check

phase will be safe, but I think we should try running parallel tests first

and see how far that gets us.

Sounds like a good start.

So the only reason we’re running tests sequentially is because of memory
usage concerns?

Thanks,
Ludo’.