bindings/python/examples/python2/softirqtimes.py

   1 #!/usr/bin/env python2
   2 # softirqtimes.py
   3 #
   4 # Babeltrace time of softirqs example script
   5 #
   6 # Copyright 2012 EfficiOS Inc.
   7 #
   8 # Author: Danny Serres <danny.serres@efficios.com>
   9 #
  10 # Permission is hereby granted, free of charge, to any person obtaining a copy
  11 # of this software and associated documentation files (the "Software"), to deal
  12 # in the Software without restriction, including without limitation the rights
  13 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14 # copies of the Software, and to permit persons to whom the Software is
  15 # furnished to do so, subject to the following conditions:
  16 #
  17 # The above copyright notice and this permission notice shall be included in
  18 # all copies or substantial portions of the Software.
  19
  20 # The script checks the number of events in the trace
  21 # and outputs a table and a .svg histogram for the specified
  22 # range (microseconds) or the total trace if no range specified.
  23 # The graph is generated using the cairoplot module.
  24
  25 # The script checks the trace for the amount of time
  26 # spent from each softirq_raise to softirq_exit.
  27 # It prints out the min, max (with timestamp),
  28 # average times, the standard deviation and the total count.
  29 # Using the cairoplot module, a .svg graph is also outputted
  30 # showing the taken time in function of the time since the
  31 # beginning of the trace.
  32
  33 import sys, math
  34 from output_format_modules import cairoplot
  35 from babeltrace import *
  36
  37 if len(sys.argv) < 2:
  38         raise TypeError("Usage: python softirqtimes.py path/to/trace")
  39
  40 ctx = Context()
  41 ret = ctx.add_trace(sys.argv[1], "ctf")
  42 if ret is None:
  43         raise IOError("Error adding trace")
  44
  45 time_taken = []
  46 graph_data = []
  47 max_time = (0.0, 0.0) # (val, ts)
  48
  49 # tmp template: {(cpu_id,  vec):TS raise}
  50 tmp = {}
  51 largest_val = 0
  52
  53 # Setting iterator
  54 bp = IterPos(SEEK_BEGIN)
  55 ctf_it = ctf.Iterator(ctx, bp)
  56
  57 # Reading events
  58 event = ctf_it.read_event()
  59 start_time = event.get_timestamp()
  60 while(event is not None):
  61
  62         event_name = event.get_name()
  63         error = True
  64         appendNext = False
  65
  66         if event_name == 'softirq_raise' or  event_name == 'softirq_exit':
  67                 # Recover cpu_id and vec values to make a key to tmp
  68                 error = False
  69                 scope = event.get_top_level_scope(ctf.scope.STREAM_PACKET_CONTEXT)
  70                 field = event.get_field(scope, "cpu_id")
  71                 cpu_id = field.get_uint64()
  72                 if ctf.field_error():
  73                         print("ERROR: Missing cpu_id info for {}".format(
  74                                 event.get_name()))
  75                         error = True
  76
  77                 scope = event.get_top_level_scope(ctf.scope.EVENT_FIELDS)
  78                 field = event.get_field(scope, "_vec")
  79                 vec = field.get_uint64()
  80                 if ctf.field_error():
  81                         print("ERROR: Missing vec info for {}".format(
  82                                 event.get_name()))
  83                         error = True
  84                 key = (cpu_id, vec)
  85
  86         if event_name == 'softirq_raise' and not error:
  87                 # Add timestamp to tmp
  88                 if key in tmp:
  89                         # If key already exists
  90                         i = 0
  91                         while True:
  92                                 # Add index
  93                                 key = (cpu_id, vec, i)
  94                                 if key in tmp:
  95                                         i += 1
  96                                         continue
  97                                 if i > largest_val:
  98                                         largest_val = i
  99                                 break
 100
 101                 tmp[key] = event.get_timestamp()
 102
 103         if event_name == 'softirq_exit' and not error:
 104                 # Saving data for output
 105                 # Key check
 106                 if not (key in tmp):
 107                         i = 0
 108                         while i <= largest_val:
 109                                 key = (key[0], key[1], i)
 110                                 if key in tmp:
 111                                         break
 112                                 i += 1
 113
 114                 raise_timestamp = tmp[key]
 115                 time_data = event.get_timestamp() - tmp.pop(key)
 116                 if time_data > max_time[0]:
 117                         # max_time = (val, ts)
 118                         max_time = (time_data, raise_timestamp)
 119                 time_taken.append(time_data)
 120                 graph_data.append((raise_timestamp - start_time, time_data))
 121
 122         # Next Event
 123         ret = ctf_it.next()
 124         if ret < 0:
 125                 break
 126         event = ctf_it.read_event()
 127
 128
 129 del ctf_it
 130
 131 # Standard dev. calc.
 132 try:
 133         mean = sum(time_taken)/float(len(time_taken))
 134 except ZeroDivisionError:
 135         raise TypeError("empty data")
 136 deviations_squared = []
 137 for x in time_taken:
 138         deviations_squared.append(math.pow((x - mean), 2))
 139 try:
 140         stddev = math.sqrt(sum(deviations_squared) / (len(deviations_squared) - 1))
 141 except ZeroDivisionError:
 142         stddev = '-'
 143
 144 # Terminal output
 145 print("AVG TIME: {} ns".format(mean))
 146 print("MIN TIME: {} ns".format(min(time_taken)))
 147 print("MAX TIME: {} ns, TS: {}".format(max_time[0], max_time[1]))
 148 print("STD DEV: {}".format(stddev))
 149 print("TOTAL COUNT: {}".format(len(time_taken)))
 150
 151 # Graph output
 152 cairoplot.scatter_plot ( 'softirqtimes.svg', data = graph_data,
 153         width = 5000, height = 4000, border = 20, axis = True,
 154         grid = True, series_colors = ["red"] )