drivers/staging/ktap/samples/basic/function_time.kp

   1 #!/usr/bin/env ktap
   2
   3 #Demo for thread-local variable
   4 #
   5 #Note this kind of function time tracing already handled concurrent issue,
   6 #but not aware on the recursion problem, user need to aware this limitation,
   7 #so don't use this script to trace function which could be called recursive.
   8
   9 self = {}
  10 count_max = 0
  11 count_min = 0
  12 count_num = 0
  13 total_time = 0
  14
  15 printf("measure time(us) of function vfs_read\n");
  16
  17 trace probe:vfs_read {
  18         if (execname() == "ktap") {
  19                 return
  20         }
  21
  22         self[tid()] = gettimeofday_us()
  23 }
  24
  25 trace probe:vfs_read%return {
  26         if (execname() == "ktap") {
  27                 return
  28         }
  29
  30         if (self[tid()] == nil) {
  31                 return
  32         }
  33
  34         local durtion = gettimeofday_us() - self[tid()]
  35         if (durtion > count_max) {
  36                 count_max = durtion
  37         }
  38         local min = count_min
  39         if (min == 0 || durtion < min) {
  40                 count_min = durtion
  41         }
  42
  43         count_num = count_num + 1
  44         total_time = total_time + durtion
  45
  46         self[tid()] = nil
  47 }
  48
  49 trace_end {
  50         printf("avg\tmax\tmin\n");
  51         printf("-------------------\n")
  52
  53         printf("%d\t%d\t%d\n", total_time/count_num,
  54                 count_max, count_min)
  55 }
  56
  57