How can I profile a linked-in port driver? OTP tools (fprof, etc.) apparently only profile Erlang code, and I don't have a C executable file to feed to gprof.
as far as linked-in port driver is .so library that is dynamically loaded into erl process (on linux) you can run valgrind --tool=callgrind --callgrind-out-file=file.out erl (see other options in docs for callgrind), then execute some tests from erl shell, exit from shell and load file.out in some tool like KCachegrind