Time Before Session Starts Increases Exponentially With Number Of Workers

Hello,
I'm upgrading from Python 3.8 to Python 3.10. In my previous configuration, this was the pytest set up:

platform linux -- Python 3.8.6, pytest-3.10.1, py-1.9.0, pluggy-0.13.1
plugins: random-order-1.0.4, random-0.2, xdist-1.20.1, forked-1.3.0

It's a test suite with several thousands of tests. Using -n auto, everything was working fine on 32 workers.

Because of the upgrade, I had to upgrade also pytest and pytest-xdist. I tested a few versions, but I get the same problem with all of them. The current set-up:

platform linux -- Python 3.10.8, pytest-6.2.5, py-1.9.0, pluggy-0.13.1
plugins: xdist-2.0.0, forked-1.3.0, random-0.2, random-order-1.0.4

What happens is that between the pytest call and the start session message there is a gap of several minutes. Here's a list of minutes depending on the number of workers
1: 3:25
2: 5:48
3: 16:52
4: 17:27
8: 57:39

An example of the log:

build	28-Nov-2022 16:01:26	8
build	28-Nov-2022 16:59:05	============================= test session starts ==============================
build	28-Nov-2022 16:59:05	platform linux -- Python 3.10.8, pytest-6.2.5, py-1.9.0, pluggy-0.13.1 -- /usr/local/bin/python

(8 is the number of workers, it's written by the same script that runs pytest right before it, like

echo "8"
pytest -v testSuite -n 8

With the old version, there was absolutely no time gap, while now it takes almost an hour just to start

Any insight of what might be the problem?

Start by reproducing pytest -v testSuite -n 8 and the reported worker timings with the listed Python, pytest, and plugin versions. Compare startup behavior against the older configuration and isolate which upgrade or initialization phase causes the delay; done means identifying a reproducible cause and preventing the worker-count-dependent startup regression.