This is a sampling profiler for FreeBSD, in the spirit of sample(1) or spindump(8) on Mac OS X.
It uses frame-pointer-based stack walking, so code compiled with -fomit-frame-pointer will confuse it. It supports multiple kernel threads.
It can use either of two symbolication engines: (1) a FreeBSD-specific one that queries the dynamic linker info and parses ELF symbol tables, or (2) a hackier but in some cases fuller-featured one (e.g., C++ demangling, "artificial" symbols) that puppets LLDB.
Example usage:
# drspin `pgrep sophie` 5
Sampling process sophie [42205] for 5 seconds with 1 millisecond of run time between samples...
Sampling completed. Processing symbols...
Process: sophie [42205]
Thread 0x187f0:
4992 _start + 256 (in sophie) (0x207780)
4884 main + 352 (in sophie) (0x208211)
4546 _ZN5Input14get_next_frameEPb + 190 (in sophie) (0x20ba2c)
4546 av_read_frame + 655 (in libavformat.so.59) (0x8003321df)
4545 read_frame_internal + 108 (in libavformat.so.59) (0x80033227c)
...