There is no vDSO for calls to stat(2). The claim in the article was that by setting the TZ environment variable to ":/etc/localtime", one could save "thousands" of stat system calls. Even for old-fashioned system calls where you use trap 0x80, Linux is still amazingly fast.

This can actually be a problem, since there are applications like git which assume stat is fast, and so it aggressively stat's all of the working files in the repository to check the mod times to see if anything has changed. That's fine on Linux, but it's a disaster on Windows, where the stat system call is dog-slow. Still, I'd call that a Windows bug, not a git bug.