Fidelity about fleetbench

[google]

Fidelity about fleetbench

[rjogrady]

Hi Jerry,
Great questions. Sorry for the late reply.

In short, the higher kIteration is, the more dcache misses we see, and fewer icache misses. The number 10 is a little arbitrary but was picked to induce what we found to be a realistic number of misses for both. Sorry I can't be more specific just now.

As you say, typically an application will do some processing on each protobuf message in turn, but it's not solely concerned with proto API operations. The working set size of 10 is trying to simulate that in such a way that the cache metrics look more like a normal application, while still spending most of the benchmark's CPU cycles in proto operations. It's a bit of a balancing act.

We are actively working on improving our fidelity in the proto benchmark, though, as well as the documentation. We'll try to indicate the rationale here more clearly.