I am new to perf and I am trying to profile a kernel module that I've loaded. I am able to list all of the functions that can be probed with:
sudo perf probe -m "path_to_module" --funcs
but I am primarly interested in obtaining the entry time and exit time of a single function and all of it's children functions (ones called from the function I want).
I am able to set a probe at the beginning and the end of the function which is listed in the --funcs output but can't seem to understand how to observe the entry and exit points of all of it's children functions. Using sudo perf report --stdio I am able to see the call stack and some of the functions called from that probe but half of those functions are not available at --funcs output and some can't seem to get probed.
Is there a way to, given the kernel module path and choosing a function from the list of --funcs get the output of entry and exit times of that function and all of the children functions called from that function (the ones that belong to the kernel module anyway)?