fix(pool): vm pools to respect cgroupsv2 memory limit - #10721

Description

When determining memory based on a percentage of the total available, use the constrained memory value if present to avoid OOM in scenarios where the process has been restricted to less memory than the host physically has.

For example, if running tests in a Kubernetes pod, the container resource requets/limits are used to configure the cgroupsv2 namespace. Exceeding this will result in being OOM killed.

Vitest might see that it's scheduled on a node with 128GiB of RAM even though the container itself has been limited to 4GiB.

It will then allow each worker to have 1/N * 128Gi instead of 1/N * 4Gi of memory.
This can quickly result in an OOM situation, requiring manually setting the vmMemoryLimit and maxWorkers in the conf.

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  • ⬆️ Adding tests is unfortunately not straightforward here, requires mocking process stuff. I'm happy to give it a shot if given guidance on preferred approach from a maintainer.
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Tests

• Run the tests with pnpm test:ci.

Documentation

• If you introduce new functionality, document it. You can run documentation with pnpm run docs command.
  • ⬆️ I don't think this warrants a change in the current docs, but I'm happy to clarify that it does respect cgroupsv2 now if desired.

Changesets

• Changes in changelog are generated from PR name. Please, make sure that it explains your changes in an understandable manner. Please, prefix changeset messages with feat:, fix:, perf:, docs:, or chore:.
  • ⬆️ I marked this as feat but feel free to retitle as fix if desired!