perf script python: Allocate memory only if handler exists
Avoid allocating memory if hook handler is not available. This saves
unused memory allocation and simplifies error path.
Let handler in python_process_tracepoint point to either tracepoint
specific or trace_unhandled hook. Use dict to check if handler points to
trace_unhandled.
Remove the exit label in python_process_general_event and return when no
handler is available.
Signed-off-by: Arun Kalyanasundaram <arunkaly@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Seongjae Park <sj38.park@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20170721220422.63962-2-arunkaly@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 57b7a00..8a8f482 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -407,10 +407,7 @@
void *data = sample->raw_data;
unsigned long long nsecs = sample->time;
const char *comm = thread__comm_str(al->thread);
-
- t = PyTuple_New(MAX_FIELDS);
- if (!t)
- Py_FatalError("couldn't create Python tuple");
+ const char *default_handler_name = "trace_unhandled";
if (!event) {
snprintf(handler_name, sizeof(handler_name),
@@ -427,10 +424,19 @@
handler = get_handler(handler_name);
if (!handler) {
+ handler = get_handler(default_handler_name);
+ if (!handler)
+ return;
dict = PyDict_New();
if (!dict)
Py_FatalError("couldn't create Python dict");
}
+
+ t = PyTuple_New(MAX_FIELDS);
+ if (!t)
+ Py_FatalError("couldn't create Python tuple");
+
+
s = nsecs / NSEC_PER_SEC;
ns = nsecs - s * NSEC_PER_SEC;
@@ -445,7 +451,7 @@
/* ip unwinding */
callchain = python_process_callchain(sample, evsel, al);
- if (handler) {
+ if (!dict) {
PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
PyTuple_SetItem(t, n++, PyInt_FromLong(s));
PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
@@ -484,23 +490,23 @@
} else { /* FIELD_IS_NUMERIC */
obj = get_field_numeric_entry(event, field, data);
}
- if (handler)
+ if (!dict)
PyTuple_SetItem(t, n++, obj);
else
pydict_set_item_string_decref(dict, field->name, obj);
}
- if (!handler)
+ if (dict)
PyTuple_SetItem(t, n++, dict);
if (_PyTuple_Resize(&t, n) == -1)
Py_FatalError("error resizing Python tuple");
- if (handler) {
+ if (!dict) {
call_object(handler, t, handler_name);
} else {
- try_call_object("trace_unhandled", t);
+ call_object(handler, t, default_handler_name);
Py_DECREF(dict);
}
@@ -799,6 +805,12 @@
static char handler_name[64];
unsigned n = 0;
+ snprintf(handler_name, sizeof(handler_name), "%s", "process_event");
+
+ handler = get_handler(handler_name);
+ if (!handler)
+ return;
+
/*
* Use the MAX_FIELDS to make the function expandable, though
* currently there is only one item for the tuple.
@@ -815,12 +827,6 @@
if (!dict_sample)
Py_FatalError("couldn't create Python dictionary");
- snprintf(handler_name, sizeof(handler_name), "%s", "process_event");
-
- handler = get_handler(handler_name);
- if (!handler)
- goto exit;
-
pydict_set_item_string_decref(dict, "ev_name", PyString_FromString(perf_evsel__name(evsel)));
pydict_set_item_string_decref(dict, "attr", PyString_FromStringAndSize(
(const char *)&evsel->attr, sizeof(evsel->attr)));
@@ -861,7 +867,7 @@
Py_FatalError("error resizing Python tuple");
call_object(handler, t, handler_name);
-exit:
+
Py_DECREF(dict);
Py_DECREF(t);
}