Linux C++: how to profile time wasted due to cache misses?

Question

I know that I can use gprof to benchmark my code.

However, I have this problem -- I have a smart pointer that has an extra level of indirection (think of it as a prox

Answer 1

You could find a tool that accesses the CPU performance counters. There is probably a register in each core that counts L1, L2, etc misses. Alternately Cachegrind performs a cycle-by-cycle simulation.

However, I don't think that would be insightful. Your proxy objects are presumably modified by their own methods. A conventional profiler will tell you how much time those methods are taking. No profile tool would tell you how performance would improve without that source of cache pollution. That's a matter of reducing the size and structure of the program's working set, which isn't easy to extrapolate.

A quick Google search turned up boost::intrusive_ptr which might interest you. It doesn't appear to support something like weak_ptr, but converting your program might be trivial, and then you would know for sure the cost of the non-intrusive ref counts.