linux-stable.git/tools/perf/util/python.c, branch v4.19.78

perf python: Do not force closing original perf descriptor in evlist.get_pollfd()

2019-02-12T18:47:18+00:00

[ Upstream commit a389aece97938966616ce0336466b98b0351ef10 ]

Ondřej reported that when compiled with python3, the python extension
regresses in evlist.get_pollfd function behaviour.

The evlist.get_pollfd function creates file objects from evlist's fds
and returns them in a list. The python3 version also sets them to 'close
the original descriptor' when the object dies (is closed), by passing
True via the 'closefd' arg in the PyFile_FromFd call.

The python's closefd doc says:

  If closefd is False, the underlying file descriptor will be kept open
  when the file is closed.

That's why the following line in python3 closes all evlist fds:

  evlist.get_pollfd()

the returned list is immediately destroyed and that takes down the
original events fds.

Passing closefd as False to PyFile_FromFd to fix this.

Reported-by: Ondřej Lysoněk 
Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Jaroslav Škarvada 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Fixes: 66dfdff03d19 ("perf tools: Add Python 3 support")
Link: http://lkml.kernel.org/r/20181226112121.5285-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf python: Fix pyrf_evlist__read_on_cpu() interface

2018-08-20T11:54:59+00:00

Jaroslav reported errors from valgrind over perf python script:

  # echo 0 > /sys/devices/system/cpu/cpu4/online
  # valgrind ./test.py
  ==7524== Memcheck, a memory error detector
  ...
  ==7524== Command: ./test.py
  ==7524==
  pid 7526 exited
  ==7524== Invalid read of size 8
  ==7524==    at 0xCC2C2B3: perf_mmap__read_forward (evlist.c:780)
  ==7524==    by 0xCC2A681: pyrf_evlist__read_on_cpu (python.c:959)
  ...
  ==7524==  Address 0x65c4868 is 16 bytes after a block of size 459,36..
  ==7524==    at 0x4C2B955: calloc (vg_replace_malloc.c:711)
  ==7524==    by 0xCC2F484: zalloc (util.h:35)
  ==7524==    by 0xCC2F484: perf_evlist__alloc_mmap (evlist.c:978)
  ...

The reason for this is in the python interface, that allows a script to
pass arbitrary cpu number, which is then used to access struct
perf_evlist::mmap array. That's obviously wrong and works only when if
all cpus are available and fails if some cpu is missing, like in the
example above.

This patch makes pyrf_evlist__read_on_cpu() search the evlist's maps
array for the proper map to access.

It's linear search at the moment. Based on the way how is the
read_on_cpu used, I don't think we need to be fast in here.  But we
could add some hash in the middle to make it fast/er.

We don't allow python interface to set write_backward event attribute,
so it's safe to check only evlist's mmaps.

Reported-by: Jaroslav Škarvada 
Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Joe Mario 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180817114556.28000-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools lib traceevent, perf tools: Rename pevent_read_number_* APIs

2018-08-13T18:22:05+00:00

In order to make libtraceevent into a proper library, variables, data
structures and functions require a unique prefix to prevent name space
conflicts. That prefix will be "tep_" and not "pevent_". This changes
APIs: pevent_read_number, pevent_read_number_field

Signed-off-by: Tzvetomir Stoyanov (VMware) 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Cc: Yordan Karadzhov (VMware) 
Cc: linux-trace-devel@vger.kernel.org
Link: http://lkml.kernel.org/r/20180808180700.804271434@goodmis.org
Signed-off-by: Steven Rostedt 
Signed-off-by: Arnaldo Carvalho de Melo

tools lib traceevent, perf tools: Rename pevent find APIs

2018-08-13T18:21:51+00:00

In order to make libtraceevent into a proper library, variables, data
structures and functions require a unique prefix to prevent name space
conflicts. That prefix will be "tep_" and not "pevent_". This changes
APIs: pevent_find_any_field, pevent_find_common_field,
pevent_find_event, pevent_find_field

Signed-off-by: Tzvetomir Stoyanov (VMware) 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Cc: Yordan Karadzhov (VMware) 
Cc: linux-trace-devel@vger.kernel.org
Link: http://lkml.kernel.org/r/20180808180700.316995920@goodmis.org
Signed-off-by: Steven Rostedt 
Signed-off-by: Arnaldo Carvalho de Melo

tools lib traceevent, perf tools: Rename struct pevent to struct tep_handle

2018-08-10T18:29:35+00:00

In order to make libtraceevent into a proper library, variables, data
structures and functions require a unique prefix to prevent name space
conflicts. That prefix will be "tep_" and not "pevent_". This changes
the struct pevent to struct tep_handle.

Signed-off-by: Tzvetomir Stoyanov (VMware) 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Cc: Yordan Karadzhov (VMware) 
Cc: linux-trace-devel@vger.kernel.org
Link: http://lkml.kernel.org/r/20180808180659.706175783@goodmis.org
Signed-off-by: Steven Rostedt 
Signed-off-by: Arnaldo Carvalho de Melo

perf python: Reference Py_None before returning it

2018-03-23T19:45:20+00:00

Python None objects are handled just like all the other objects with
respect to their reference counting. Before returning Py_None, its
reference count thus needs to be bumped.

Signed-off-by: Petr Machata 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Petr Machata 
Link: http://lkml.kernel.org/r/b1e565ecccf68064d8d54f37db5d028dda8fa522.1521675563.git.petrm@mellanox.com
Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Simplify perf_mmap__read_init()

2018-03-08T13:05:53+00:00

It isn't necessary to pass the 'start', 'end' and 'overwrite' arguments
to perf_mmap__read_init().  The data is stored in the struct perf_mmap.

Discard the parameters.

Signed-off-by: Kan Liang 
Suggested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1520350567-80082-8-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Simplify perf_mmap__read_event()

2018-03-08T13:05:53+00:00

It isn't necessary to pass the 'overwrite', 'start' and 'end' argument
to perf_mmap__read_event().  Discard them.

Signed-off-by: Kan Liang 
Suggested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1520350567-80082-7-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Simplify perf_mmap__consume()

2018-03-08T13:05:52+00:00

It isn't necessary to pass the 'overwrite' argument to
perf_mmap__consume().  Discard it.

Signed-off-by: Kan Liang 
Suggested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1520350567-80082-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf python: Switch to new perf_mmap__read_event() interface

2018-03-05T13:47:07+00:00

The perf python binding still use the legacy interface.

No functional change.

Committer notes:

Tested before and after with:

  [root@jouet perf]# export PYTHONPATH=/tmp/build/perf/python
  [root@jouet perf]# tools/perf/python/twatch.py
  cpu: 0, pid: 1183, tid: 6293 { type: exit, pid: 1183, ppid: 1183, tid: 6293, ptid: 6293, time: 17886646588257}
  cpu: 2, pid: 13820, tid: 13820 { type: fork, pid: 13820, ppid: 13820, tid: 6306, ptid: 13820, time: 17886869099529}
  cpu: 1, pid: 13820, tid: 6306 { type: comm, pid: 13820, tid: 6306, comm: TaskSchedulerFo }
  ^CTraceback (most recent call last):
    File "tools/perf/python/twatch.py", line 68, in 
      main()
    File "tools/perf/python/twatch.py", line 40, in main
      evlist.poll(timeout = -1)
  KeyboardInterrupt
  [root@jouet perf]#

No problems found.

Signed-off-by: Kan Liang 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1519945751-37786-3-git-send-email-kan.liang@linux.intel.com
[ Changed bool parameters from 0 to 'false', as per Jiri comment ]
Signed-off-by: Arnaldo Carvalho de Melo