fiohist.stp

#!/usr/bin/stap
global pid = 0, trace = 0
global opens, reads, writes, totals

probe begin {
  printf("starting probe\n")
  %( $# > 1 %? log("ERROR: argument can't be more than 1") exit() %)
  %( $# == 1 %? pid = $1 %: trace = 1 %)
}

probe syscall.open {
  if (trace || pid() == pid) {
    e=execname();
    opens[e] <<< 1 # statistics array
  }
}

probe syscall.read.return {
  if (trace || pid() == pid) {
    count = $return
    if ( count >= 0 ) {
      e=execname();
      reads[e] <<< count # statistics array
      totals[e] += count
    }
  }
}

probe syscall.write.return {
  if (trace || pid() == pid) {
    count = $return
    if (count >= 0 ) {
      e=execname();
      writes[e] <<< count # statistics array
      totals[e] += count
    }
  }
}

probe end {
  header = 1 
  foreach (name in totals- limit 10) { # sort by total io
    if (header) {
      printf("\nIO Summary:\n\n")
      printf("\n%16s %8s %8s %8s %8s %8s %8s %8s\n",
        "", "", "", "read", "read", "", "write", "write")
      printf("%16s %8s %8s %8s %8s %8s %8s %8s\n",
        "name", "open", "read", "KB tot", "B avg", "write", "KB tot", "B avg")
      header = 0
    }
    printf("%16s %8d %8d %8d %8d %8d %8d %8d\n",
      name, @count(opens[name]),
      @count(reads[name]),
      (@count(reads[name]) ? @sum(reads[name])>>10 : 0 ),
      (@count(reads[name]) ? @avg(reads[name]) : 0 ),
      @count(writes[name]),
      (@count(writes[name]) ? @sum(writes[name])>>10 : 0 ),
      (@count(writes[name]) ? @avg(writes[name]) : 0 ))
  }

  header = 1
  foreach (name in reads- limit 10) { # sort by reads
    if (header) {
      printf("\nRead I/O size (bytes):\n\n")
      header = 0
    }
    printf("process name: %s\n", name)
    print(@hist_log(reads[name]))
  }

  header = 1
  foreach (name in writes- limit 10) { # sort by writes
    if (header) {
      printf("\nWrite I/O size (bytes):\n\n")
      header = 0
    }
    printf("process name: %s\n", name)
    print(@hist_log(writes[name]))
  }
}