> ... Instrumented code or sampling profilers? A sampling profiler would be helpful. Although most hash map related samples would likely fall on atomic ops it

> ... Instrumented code or sampling profilers? A sampling profiler would be helpful. Although most hash map related samples would likely fall on atomic ops it presumably uses for synchronization. On the other hand, you'd know whether you need to optimize this in the first place. Instrumented profiler would yield garbage data for a lot of reasons, I wouldn't use that, except maybe over a large group of hash map operations. > ... I'd first reach for the CPU performance counters I count CPU performance counters as profiling.