mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-27 06:04:23 +08:00
58b32c1b53
To not sample, what we want are just the PERF_RECORD_ lifetime events for threads, using the default, PERF_TYPE_HARDWARE + PERF_COUNT_HW_CYCLES and freq=1 (the default), makes perf reenable irq_vectors:local_timer_entry, disabling nohz, not good for some use cases where all we want is to get notifications when threads comes and goes... Fix it by using PERF_TYPE_SOFTWARE (no counter rotation) and PERF_COUNT_SW_DUMMY (created by Adrian so that we could have access to those PERF_RECORD_ goodies). Reported-by: Luiz Fernando Capitulino <lcapitulino@redhat.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jaroslav Skarvada <jskarvad@redhat.com> Cc: Jeremy Eder <jeder@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-kfsijirfrs6xfhkcdxeoen06@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
52 lines
1.7 KiB
Python
Executable File
52 lines
1.7 KiB
Python
Executable File
#! /usr/bin/python
|
|
# -*- python -*-
|
|
# -*- coding: utf-8 -*-
|
|
# twatch - Experimental use of the perf python interface
|
|
# Copyright (C) 2011 Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
#
|
|
# This application is free software; you can redistribute it and/or
|
|
# modify it under the terms of the GNU General Public License
|
|
# as published by the Free Software Foundation; version 2.
|
|
#
|
|
# This application is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
# General Public License for more details.
|
|
|
|
import perf
|
|
|
|
def main():
|
|
cpus = perf.cpu_map()
|
|
threads = perf.thread_map()
|
|
evsel = perf.evsel(type = perf.TYPE_SOFTWARE,
|
|
config = perf.COUNT_SW_DUMMY,
|
|
task = 1, comm = 1, mmap = 0, freq = 0,
|
|
wakeup_events = 1, watermark = 1,
|
|
sample_id_all = 1,
|
|
sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU)
|
|
|
|
"""What we want are just the PERF_RECORD_ lifetime events for threads,
|
|
using the default, PERF_TYPE_HARDWARE + PERF_COUNT_HW_CYCLES & freq=1
|
|
(the default), makes perf reenable irq_vectors:local_timer_entry, when
|
|
disabling nohz, not good for some use cases where all we want is to get
|
|
threads comes and goes... So use (perf.TYPE_SOFTWARE, perf_COUNT_SW_DUMMY,
|
|
freq=0) instead."""
|
|
|
|
evsel.open(cpus = cpus, threads = threads);
|
|
evlist = perf.evlist(cpus, threads)
|
|
evlist.add(evsel)
|
|
evlist.mmap()
|
|
while True:
|
|
evlist.poll(timeout = -1)
|
|
for cpu in cpus:
|
|
event = evlist.read_on_cpu(cpu)
|
|
if not event:
|
|
continue
|
|
print "cpu: %2d, pid: %4d, tid: %4d" % (event.sample_cpu,
|
|
event.sample_pid,
|
|
event.sample_tid),
|
|
print event
|
|
|
|
if __name__ == '__main__':
|
|
main()
|