Re: [PATCH 7/8] perf script: Add python support for stat events

[Namhyung Kim <namhyung@kernel.org>]

On Tue, Dec 22, 2015 at 04:43:33PM +0100, Jiri Olsa wrote:
> Add support to get stat events data in perf python scripts.
> 
> The python script shall implement following
> new interface to process stat data:
> 
>   def stat__<event_name>_[<modifier>](cpu, thread, time, val, ena, run):
> 
>     - is called for every stat event for given counter,
>       if user monitors 'cycles,instructions:u" following
>       callbacks should be defined:
> 
>       def stat__cycles(cpu, thread, time, val, ena, run):
>       def stat__instructions_u(cpu, thread, time, val, ena, run):
> 
>   def stat__interval(time):
> 
>     - is called for every interval with its time,
>       in non interval mode it's called after last
>       stat event with total measured time in ns
> 
> The rest of the current interface stays untouched..
> 
> Please check example CPI metrics script in following patch
> with command line examples in changelogs.
> 
> Tested-by: Kan Liang <kan.liang@intel.com>
> Link: http://lkml.kernel.org/n/tip-jojiaelyckrw6040wqc06q1j@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  .../util/scripting-engines/trace-event-python.c    | 114 +++++++++++++++++++--
>  1 file changed, 108 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index a8e825fca42a..8436eb23eb16 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -41,6 +41,9 @@
>  #include "../thread-stack.h"
>  #include "../trace-event.h"
>  #include "../machine.h"
> +#include "thread_map.h"
> +#include "cpumap.h"
> +#include "stat.h"
>  
>  PyMODINIT_FUNC initperf_trace_context(void);
>  
> @@ -859,6 +862,103 @@ static void python_process_event(union perf_event *event,
>  	}
>  }
>  
> +static void get_handler_name(char *str, size_t size,
> +			     struct perf_evsel *evsel)
> +{
> +	char *p = str;
> +
> +	scnprintf(str, size, "stat__%s", perf_evsel__name(evsel));
> +
> +	while ((p = strchr(p, ':'))) {
> +		*p = '_';
> +		p++;
> +	}
> +}
> +
> +static void
> +process_stat(struct perf_evsel *counter, int cpu, int thread, u64 time,
> +	     struct perf_counts_values *count)
> +{
> +	PyObject *handler, *t;
> +	static char handler_name[256];
> +	int n = 0;
> +
> +	t = PyTuple_New(MAX_FIELDS);
> +	if (!t)
> +		Py_FatalError("couldn't create Python tuple");
> +
> +	get_handler_name(handler_name, sizeof(handler_name),
> +			 counter);
> +
> +	handler = get_handler(handler_name);
> +	if (!handler) {
> +		pr_debug("can't find python handler %s\n", handler_name);
> +		return;
> +	}
> +
> +	PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
> +	PyTuple_SetItem(t, n++, PyInt_FromLong(thread));
> +	PyTuple_SetItem(t, n++, PyLong_FromLong(time));
> +	PyTuple_SetItem(t, n++, PyLong_FromLong(count->val));
> +	PyTuple_SetItem(t, n++, PyLong_FromLong(count->ena));
> +	PyTuple_SetItem(t, n++, PyLong_FromLong(count->run));

What about 32-bit systems?  It seems the PyLong_FromLong() takes long
but the counts are u64.


> +
> +	if (_PyTuple_Resize(&t, n) == -1)
> +		Py_FatalError("error resizing Python tuple");
> +
> +	call_object(handler, t, handler_name);
> +
> +	Py_DECREF(t);
> +}
> +
> +static void python_process_stat(struct perf_stat_config *config,
> +				struct perf_evsel *counter, u64 time)
> +{
> +	struct thread_map *threads = counter->threads;
> +	struct cpu_map *cpus = counter->cpus;
> +	int cpu, thread;
> +
> +	if (config->aggr_mode == AGGR_GLOBAL) {
> +		process_stat(counter, -1, -1, time,
> +			     &counter->counts->aggr);
> +		return;
> +	}
> +
> +	for (thread = 0; thread < threads->nr; thread++) {
> +		for (cpu = 0; cpu < cpus->nr; cpu++) {
> +			process_stat(counter, cpus->map[cpu],
> +				     thread_map__pid(threads, thread), time,
> +				     perf_counts(counter->counts, cpu, thread));
> +		}
> +	}
> +}
> +
> +static void python_process_stat_interval(u64 time)
> +{
> +	PyObject *handler, *t;
> +	static const char handler_name[] = "stat__interval";
> +	int n = 0;
> +
> +	t = PyTuple_New(MAX_FIELDS);
> +	if (!t)
> +		Py_FatalError("couldn't create Python tuple");
> +
> +	handler = get_handler(handler_name);
> +	if (!handler) {
> +		pr_debug("can't find python handler %s\n", handler_name);
> +		return;
> +	}
> +
> +	PyTuple_SetItem(t, n++, PyLong_FromLong(time));

Ditto.

Thanks,
Namhyung


> +
> +	if (_PyTuple_Resize(&t, n) == -1)
> +		Py_FatalError("error resizing Python tuple");
> +
> +	call_object(handler, t, handler_name);
> +
> +	Py_DECREF(t);
> +}
> +
>  static int run_start_sub(void)
>  {
>  	main_module = PyImport_AddModule("__main__");
> @@ -1201,10 +1301,12 @@ static int python_generate_script(struct pevent *pevent, const char *outfile)
>  }
>  
>  struct scripting_ops python_scripting_ops = {
> -	.name = "Python",
> -	.start_script = python_start_script,
> -	.flush_script = python_flush_script,
> -	.stop_script = python_stop_script,
> -	.process_event = python_process_event,
> -	.generate_script = python_generate_script,
> +	.name			= "Python",
> +	.start_script		= python_start_script,
> +	.flush_script		= python_flush_script,
> +	.stop_script		= python_stop_script,
> +	.process_event		= python_process_event,
> +	.process_stat		= python_process_stat,
> +	.process_stat_interval	= python_process_stat_interval,
> +	.generate_script	= python_generate_script,
>  };
> -- 
> 2.4.3
>