tools/perf/python/tracepoint.py

   1 #! /usr/bin/python
   2 # -*- python -*-
   3 # -*- coding: utf-8 -*-
   4
   5 import perf
   6
   7 class tracepoint(perf.evsel):
   8     def __init__(self, sys, name):
   9         config = perf.tracepoint(sys, name)
  10         perf.evsel.__init__(self,
  11                             type   = perf.TYPE_TRACEPOINT,
  12                             config = config,
  13                             freq = 0, sample_period = 1, wakeup_events = 1,
  14                             sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU | perf.SAMPLE_RAW | perf.SAMPLE_TIME)
  15
  16 def main():
  17     tp      = tracepoint("sched", "sched_switch")
  18     cpus    = perf.cpu_map()
  19     threads = perf.thread_map(-1)
  20
  21     evlist = perf.evlist(cpus, threads)
  22     evlist.add(tp)
  23     evlist.open()
  24     evlist.mmap()
  25
  26     while True:
  27         evlist.poll(timeout = -1)
  28         for cpu in cpus:
  29             event = evlist.read_on_cpu(cpu)
  30             if not event:
  31                 continue
  32
  33             if not isinstance(event, perf.sample_event):
  34                 continue
  35
  36             print "time %u prev_comm=%s prev_pid=%d prev_prio=%d prev_state=0x%x ==> next_comm=%s next_pid=%d next_prio=%d" % (
  37                    event.sample_time,
  38                    event.prev_comm,
  39                    event.prev_pid,
  40                    event.prev_prio,
  41                    event.prev_state,
  42                    event.next_comm,
  43                    event.next_pid,
  44                    event.next_prio)
  45
  46 if __name__ == '__main__':
  47     main()