With Linux 3.7 perf is finally able to use DWARF information to generate the callgraph:
perf record --call-graph dwarf -- yourapp
perf report -g graph --no-children
Neat, but the curses GUI is horrible compared to VTune, KCacheGrind or similar… I recommend to try out FlameGraphs instead, which is a pretty neat visualization: http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html
Note: In the report step, -g graph
makes the results output simple to understand “relative to total” percentages, rather than “relative to parent” numbers. --no-children
will show only self cost, rather than inclusive cost – a feature that I also find invaluable.
If you have a new perf and Intel CPU, also try out the LBR unwinder, which has much better performance and produces far smaller result files:
perf record --call-graph lbr -- yourapp
The downside here is that the call stack depth is more limited compared to the default DWARF unwinder configuration.