tools/perf/python/tracepoint.py

   1 #! /usr/bin/env python
   2 # SPDX-License-Identifier: GPL-2.0
   3 # -*- python -*-
   4 # -*- coding: utf-8 -*-
   5
   6 import perf
   7
   8 class tracepoint(perf.evsel):
   9     def __init__(self, sys, name):
  10         config = perf.tracepoint(sys, name)
  11         perf.evsel.__init__(self,
  12                             type   = perf.TYPE_TRACEPOINT,
  13                             config = config,
  14                             freq = 0, sample_period = 1, wakeup_events = 1,
  15                             sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU | perf.SAMPLE_RAW | perf.SAMPLE_TIME)
  16
  17 def main():
  18     tp      = tracepoint("sched", "sched_switch")
  19     cpus    = perf.cpu_map()
  20     threads = perf.thread_map(-1)
  21
  22     evlist = perf.evlist(cpus, threads)
  23     evlist.add(tp)
  24     evlist.open()
  25     evlist.mmap()
  26
  27     while True:
  28         evlist.poll(timeout = -1)
  29         for cpu in cpus:
  30             event = evlist.read_on_cpu(cpu)
  31             if not event:
  32                 continue
  33
  34             if not isinstance(event, perf.sample_event):
  35                 continue
  36
  37             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" % (
  38                    event.sample_time,
  39                    event.prev_comm,
  40                    event.prev_pid,
  41                    event.prev_prio,
  42                    event.prev_state,
  43                    event.next_comm,
  44                    event.next_pid,
  45                    event.next_prio)
  46
  47 if __name__ == '__main__':
  48     main()