Ask HN: Resources on the Design of DTrace?

Can anyone recommend any useful talks, slides, documents, clones, etc.. of DTrace that would help me get up to speed with how DTrace does what it does so efficiently?

I plan to learn from reading the open source code, but I’d like to at least have some idea of its internal design, before I do.

Apart from a talk by Arun Thomas, can anyone recommend anything? Thanks.