SystemTap (userland) with flamegraph by agentzh

a.stp

/*
code: https://groups.google.com/d/msg/openresty/u-puKWWONMk/bxsyQdWMkJIJ by agentzh
Require SystemTap 2.0 and linux kernel 3.5+
Example usage:
stap --ldd -d /path/to/nginx/sbin/nginx \
            -d /path/to/luajit/lib/libluajit-5.1.so.2.0.0 \
            --all-modules -D MAXMAPENTRIES=20240 \
            -D MAXACTION=20000 \
            -D MAXTRACE=100 \
            -D MAXSTRINGLEN=4096 \
            -D MAXBACKTRACE=100 -x 5857 a.stp > a.out
perl stackcollapse-stap.pl a.out > a.out2
perl flamegraph.pl a.out2 > a.svg
*/
global s;
global quit = 0;

probe timer.profile {
  if (pid() == target()) {
    if (quit) {
      foreach (i in s-) {
        print_ustack(i);
        printf("\t%d\n", @count(s[i]));
      }
      exit()
    } else {
      s[ubacktrace()] <<< 1;
    }
  }
}

probe timer.s(20) {
  quit = 1
}