Scala performance analysis with perf and Flame Graphs

I’ve been toying with Scala profiling lately. I find CPU Flame Graphs to be cool and useful, so decided to see what I can do with that. After some hacking and automating I got this:

One thing I find strange here is that scala.collection methods are shown as yellow, which according to The Source means they are C++ code. Overall, it seems like in this very simple case, it’s possible to see where the problems are. If there were any kernel-level operations involved, like network communication, the chart would be even more useful.