Adding a "Inverted Tree" Mode

[michaeleisel]

It can sometimes be helpful to invert a flamegraph to find functions that per-call are not that expensive, but that are called all over the place, and those calls in total add up to something substantial (e.g. malloc). This is different from "icicle" flamegraphs, which just flip the y-axis, and are instead a new tree. If we think about a flamegraph in the .folded form:

foo;bar 5
foo;bar;baz 10
...

An inverted tree is just what we get when we reverse the order of function calls within each line (bar;foo 5 etc.).

[jlfwong]

Hi @michaeleisel! A variant of this is available in the sandwich view. If you click on one of the rows, you get a flamegraph & an inverted flamegraph rooted at the node selected

Does that satisfy your use case?

[michaeleisel]

I think I see what you're saying, that the "callers" section would contain all the callers for a particular stack frame. That is potentially helpful, but in general I would prefer to see the whole tree inverted.