I wasn't sure where it appeared first, either! I had to dig out that old related work section. There may be work that predates the '98 reference, but it may not

I wasn't sure where it appeared first, either! I had to dig out that old related work section. There may be work that predates the '98 reference, but it may not have gotten much attention. (I had assumed Hoard would be the first in the literature, but that's from 2000.) I think when it shows up is more related to the available hardware at the time, and what people were doing with it. It's not a huge stretch to imagine thread-local pools, but I don't think enough people were paying attention to the problem before then.