Fascinating, and a few reactions spring to mind.
First, I have to admit, the resolution simultaneously blew me away and was very nostalgic. Forgetting that some instructions are not atomic is just the thing that I saw people commit in architecture support in kernel (I don't remember if I ever used an opportunity to do it, it's quite possible, even on sun4c).
Also, my (former) colleague DaveJ (who's now consumed by Facebook -- I remember complaints about useful people "gone to Google and never heard from again", but Facebook is the same hole nowadays) once said, approximately: "Everyone loves to crap on Gentoo hackers for silly optimizations and being otherwise unprofessional, but when it's something interesting it's always (or often) them." Gentoo crew is underrated, including their userbase.
Go also happens to have a (rather insane, in my opinion) policy of reinventing its own standard library, so it does not use any of the standard Linux glibc code to call vDSO, but rather rolls its own calls (and syscalls too).
Usually you hear about this when their DNS resolver blows up, but it can be elsewhere, as in this case.
(h/t to a chatter in #animeblogger)
UPDATE: CKS adds that some UNIXen officially require applications to use libc.