Callgraph visualization

[brancz]

Icicle graphs are the most popular way to explore performance data, but callgraphs can also be a very useful visualization when different stack traces call the same function for example.

[metalmatze]

As a workaround (until we decide to put up with graphviz or find an alternative) we should make pprof profiles downloadable so that people can use go tool pprof profile.pb.gz and get that functionality.

[brancz]

We should do that regardless!

[metalmatze]

Example screenshot

[syepes]

@brancz Will this feature be added back to parca? We are still running some conprof instances just to have this kind of builtin visualization, as it simplifies the debugging

[metalmatze]

@monicawoj is actually actively investigating this! :tada: https://github.com/parca-dev/parca/pull/1132