Noise and jitter in the VM should cancel out with repeated measurements.

Here's something interesting. If I run my test in a RHEL5 (Linux c. 2010) VirtualBox VM then it actually goes faster than a modern Linux kernel running on bare metal, taking only 14µs. If I run it in a RHEL7 VM then it needs 131µs.

So >1ms hello world execution should be a red flag. If that's actually the latency of GitHub's kernels and can't be explained by something like a shell script doing the time interval measurements, then it'd be interesting to learn what it's doing.