[cesarb]

Aren't splay trees terrible because they turn all reads into writes? (Which means the cache lines bounce between readers, instead of being shared as they would be with pure reads.)

[Polyisoprene]

Yeah, having reads rebalancing the tree in a multithreaded subsystem is probably not optimal. Might be that the Splay-trees have outstayed their welcome :)

FreeBSD’s tree.h used to have, iirc, both RB- and Splay-trees.