1#@!#!123s

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Filename : ioblktime.stp
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#!/usr/bin/stap

global req_time%[25000], etimes

probe ioblock.request
{
  req_time[$bio] = gettimeofday_us()
}

probe ioblock.end
{
  t = gettimeofday_us()
  s =  req_time[$bio]
  delete req_time[$bio]
  if (s) {
    etimes[devname, bio_rw_str(rw)] <<< t - s
  }
}

/* for time being delete things that get merged with others */
probe kernel.{trace("block_bio_frontmerge"),
              trace("block_bio_backmerge")}
{
  delete req_time[$bio]
}

probe timer.s(10), end {
  ansi_clear_screen()
  printf("%10s %3s %10s %10s %10s\n",
         "device", "rw", "total (us)", "count", "avg (us)")
  foreach ([dev,rw] in etimes - limit 20) {
    printf("%10s %3s %10d %10d %10d\n", dev, rw,
           @sum(etimes[dev,rw]), @count(etimes[dev,rw]), @avg(etimes[dev,rw]))
  }
  delete etimes
}