> Switching from a single radix-tree to an array of radix-trees to reduce > contention seems a bit hacky. That we can do this and have everything > continue to work tells me that we're simply using an inappropriate data > structure to hold this info.
What would you use instead? A tree with fine grained locking? FWIW too fine grained locking (e.g. on every node) is usually a bad idea: it slows down the single thread performance and it causes much more overhead when there is actual contention because too much time is spent bouncing cache lines around. So I actually like the "a little bit more fine grained, but not too much" approach. Or a hash table? Not sure if this would work here. -Andi
