diff options
Diffstat (limited to 'kernel/tools/perf/python')
| -rwxr-xr-x | kernel/tools/perf/python/twatch.py | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/kernel/tools/perf/python/twatch.py b/kernel/tools/perf/python/twatch.py index 2225162ee..c235c22b1 100755 --- a/kernel/tools/perf/python/twatch.py +++ b/kernel/tools/perf/python/twatch.py @@ -15,13 +15,23 @@ import perf -def main(): +def main(context_switch = 0, thread = -1): cpus = perf.cpu_map() - threads = perf.thread_map() - evsel = perf.evsel(task = 1, comm = 1, mmap = 0, + threads = perf.thread_map(thread) + 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_id_all = 1, context_switch = context_switch, 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) @@ -38,4 +48,21 @@ def main(): print event if __name__ == '__main__': + """ + To test the PERF_RECORD_SWITCH record, pick a pid and replace + in the following line. + + Example output: + +cpu: 3, pid: 31463, tid: 31593 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31593, switch_out: 1 } +cpu: 1, pid: 31463, tid: 31489 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31489, switch_out: 1 } +cpu: 2, pid: 31463, tid: 31496 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31496, switch_out: 1 } +cpu: 3, pid: 31463, tid: 31491 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31491, switch_out: 0 } + + It is possible as well to use event.misc & perf.PERF_RECORD_MISC_SWITCH_OUT + to figure out if this is a context switch in or out of the monitored threads. + + If bored, please add command line option parsing support for these options :-) + """ + # main(context_switch = 1, thread = 31463) main() |