The raw_syscalls:sys_enter tracer for instance passes has one argument
named 'arg' which is an array of 6 integers. Right the python scripts
gets only 0 passed as an argument. The reason is that
pevent_read_number() can not handle data types of 48 and returns always
0.
This patch changes this by passing num array as list of nums which fit
the description. As a result python will now see a list named arg which
contains 6 (integer) items.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/1401207274-8170-2-git-send-email-bigeasy@linutronix.de
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
With the Sebastian's change of handling num array argument (of raw
syscall enter), the script still failed to work like this:
$ perf record -e raw_syscalls:* sleep 1
$ perf script -g python
$ perf script -s perf-script.py
...
Traceback (most recent call last):
File "perf-script.py", line 42, in raw_syscalls__sys_enter
(id, args),
TypeError: %u format: a number is required, not list
Fatal Python error: problem in Python trace event handler
Aborted (core dumped)
This is because the generated script tries to print the array arg as
unsigned integer (%u). Since the python seems to convert arguments to
strings by default, just using %s solved the problem for me.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/1401338695-18837-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Coming in v3.16, trace events will be able to save bitmasks in raw
format in the ring buffer and output it with the __get_bitmask() macro.
In order for userspace tools to parse this, it must be able to handle
the __get_bitmask() call and be able to convert the data that's in
the ring buffer into a nice bitmask format. The output is similar to
what the kernel uses to print bitmasks, with a comma separator every
4 bytes (8 characters).
This allows for cpumasks to also be saved efficiently.
The first user is the thermal:thermal_power_limit event which has the
following output:
thermal_power_limit: cpus=0000000f freq=1900000 cdev_state=0 power=5252
Link: http://lkml.kernel.org/r/20140506132238.22e136d1@gandalf.local.home
Suggested-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Javi Merino <javi.merino@arm.com>
Link: http://lkml.kernel.org/r/20140603032224.229186537@goodmis.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
We are using the Python scripting interface in perf to extract kernel
events relevant for performance analysis of HPC codes. We noticed that
the "perf script" call allocates a significant amount of memory (in the
order of several 100 MiB) during it's run, e.g. 125 MiB for a 25 MiB
input file:
$> perf record -o perf.data -a -R -g fp \
-e power:cpu_frequency -e sched:sched_switch \
-e sched:sched_migrate_task -e sched:sched_process_exit \
-e sched:sched_process_fork -e sched:sched_process_exec \
-e cycles -m 4096 --freq 4000
$> /usr/bin/time perf script -i perf.data -s dummy_script.py
0.84user 0.13system 0:01.92elapsed 51%CPU (0avgtext+0avgdata
125532maxresident)k
73072inputs+0outputs (57major+33086minor)pagefaults 0swaps
Upon further investigation using the valgrind massif tool, we noticed
that Python objects that are created in trace-event-python.c via
PyString_FromString*() (and their Integer and Long counterparts) are
never free'd.
The reason for this seem to be missing Py_DECREF calls on the objects
that are returned by these functions and stored in the Python
dictionaries. The Python dictionaries do not steal references (as
opposed to Python tuples and lists) but instead add their own reference.
Hence, the reference that is returned by these object creation functions
is never released and the memory is leaked. (see [1,2])
The attached patch fixes this by wrapping all relevant calls to
PyDict_SetItemString() and decrementing the reference counter
immediately after the Python function call.
This reduces the allocated memory to a reasonable amount:
$> /usr/bin/time perf script -i perf.data -s dummy_script.py
0.73user 0.05system 0:00.79elapsed 99%CPU (0avgtext+0avgdata
49132maxresident)k
0inputs+0outputs (0major+14045minor)pagefaults 0swaps
For comparison, with a 120 MiB input file the memory consumption
reported by time drops from almost 600 MiB to 146 MiB.
The patch has been tested using Linux 3.8.2 with Python 2.7.4 and Linux
3.11.6 with Python 2.7.5.
Please let me know if you need any further information.
[1] http://docs.python.org/2/c-api/tuple.html#PyTuple_SetItem
[2] http://docs.python.org/2/c-api/dict.html#PyDict_SetItemString
Signed-off-by: Joseph Schuchart <joseph.schuchart@tu-dresden.de>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: http://lkml.kernel.org/r/1381468543-25334-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Running the check-perf-trace scripts causes segfaults in both the Perl
and Python cases:
# perf script record check-perf-trace
# perf script -s libexec/perf-core/scripts/python/check-perf-trace.py
trace_begin
Segmentation fault (core dumped)
The reason is that the 'pevent' field was added to
perf_scripting_context but it wasn't hooked up with an actual pevent in
either case, so when one of the 'common' fields is accessed (in
util/trace-event-parse.c:get_common_fields()), pevent->events tries to
dereference a NULL pointer.
This sets the pevent field when the scripting context is set up.
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: http://lkml.kernel.org/r/d2b1b8166a6ca0a36e1f5255b88a8289058ba236.1358527965.git.tom.zanussi@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
