If I understand this correctly, it basically has the second thread wait until the first one experiences a hardware interrupt, which implicitly synchronizes memory. This avoids the first thread from needing any synchronization primitives that would slow it down.

same trick QSBR uses for lock-free reclamation, just framed at the OS scheduler level instead of userspace

Oh boy this is a cool blog post. Encourage everyone to read it.

"GC"?