To be clear: the dispute over the history of BPF/eBPF is not interesting, and I don't want to litigate it anymore than they do.
I'm just here to say that eBPF and BPF are in fact pretty closely related. The eBPF design is uncannily similar to Begel, McCanne, and Graham's BPF+ design[1]; in particular, the BPF+ paper spends a fair amount of time describing an SSA-based compiler for a RISC-y register ISA, and eBPF... just uses (at this point) LLVM for a RISC-y register ISA.
Most notably, the fundamental execution integrity model has, until pretty recently, remained the same --- forward jumps only, limited program size. And that's to me the defining feature of the architecture.
The lineage isn't important to me, so much as the sort of continuous unbroken line from BPF to eBPF, regardless of what LKML says.
[1]: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.597...
