Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

  - Force period term to overload global settings, i.e. previously this
    command line:

     $ perf record -e 'cpu/instructions,period=20000/',cycles -c 1000 sleep 1

    would result in both events having a period equal to 1000, with the fix we
    get something saner:

     $ perf evlist -v | grep period
     cpu/instructions,period=20000/: ... { sample_period, sample_freq }: 20000, ...
     cycles: ... { sample_period, sample_freq }: 1000 ...
     $

   (Jiri Olsa)

Infrastructure changes:

  - Use the dummy software event with freq=0 in the twatch.py python
    binding example, to avoid disabling nohz. (Arnaldo Carvalho de Melo)

  - Add some missing constants to the python binding. (Arnaldo Carvalho de Melo)

  - Fix mismatched declarations for elf_getphdrnum, that happens
    only in the corner case where this function is not found on
    the system.  (Arnaldo Carvalho de Melo)

  - Add build test for having ending double slash. (Jiri Olsa)

  - Introduce callgraph_set for callgraph option. (Kan Liang)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/tools/perf/python/twatch.py b/tools/perf/python/twatch.py
index 2225162ee1fc1..b9d508336ae6f 100755
--- a/tools/perf/python/twatch.py
+++ b/tools/perf/python/twatch.py
@@ -18,10 +18,20 @@ import perf
 def main():
 	cpus = perf.cpu_map()
 	threads = perf.thread_map()
-	evsel = perf.evsel(task = 1, comm = 1, mmap = 0,
+	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)