perf with source annotation is pretty nice if you're profiling for individual hotspots. But I have not found any solution that lets me spot amdahl bottlenecks w

perf with source annotation is pretty nice if you're profiling for individual hotspots. But I have not found any solution that lets me spot amdahl bottlenecks which get drowned out in raw cycles spent by the parallel parts. In java this is trivial with thread utilization timlines that incorporate sampling. Maybe this could be solved by weighting samples by the inverse of number of running threads at the time