perf tools: Stop using a global trace events description list

The pevent thing is per perf.data file, so I made it stop being static
and become a perf_session member, so tools processing perf.data files
use perf_session and _there_ we read the trace events description into
session->pevent and then change everywhere to stop using that single
global pevent variable and use the per session one.

Note that it _doesn't_ fall backs to trace__event_id, as we're not
interested at all in what is present in the
/sys/kernel/debug/tracing/events in the workstation doing the analysis,
just in what is in the perf.data file.

This patch also introduces perf_session__set_tracepoints_handlers that
is the perf perf.data/session way to associate handlers to tracepoint
events by resolving their IDs using the events descriptions stored in a
perf.data file. Make 'perf sched' use it.

Reported-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Tested-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linaro-dev@lists.linaro.org
Cc: patches@linaro.org
Link: http://lkml.kernel.org/r/20120625232016.GA28525@infradead.org
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 acb9795..a8ca2f8 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -190,7 +190,8 @@
 		define_event_symbols(event, ev_name, args->next);
 }
 
-static inline struct event_format *find_cache_event(int type)
+static inline
+struct event_format *find_cache_event(struct pevent *pevent, int type)
 {
 	static char ev_name[256];
 	struct event_format *event;
@@ -198,7 +199,7 @@
 	if (events[type])
 		return events[type];
 
-	events[type] = event = trace_find_event(type);
+	events[type] = event = pevent_find_event(pevent, type);
 	if (!event)
 		return NULL;
 
@@ -209,7 +210,8 @@
 	return event;
 }
 
-static void python_process_event(union perf_event *pevent __unused,
+static void python_process_event(union perf_event *perf_event __unused,
+				 struct pevent *pevent,
 				 struct perf_sample *sample,
 				 struct perf_evsel *evsel __unused,
 				 struct machine *machine __unused,
@@ -233,13 +235,13 @@
 	if (!t)
 		Py_FatalError("couldn't create Python tuple");
 
-	type = trace_parse_common_type(data);
+	type = trace_parse_common_type(pevent, data);
 
-	event = find_cache_event(type);
+	event = find_cache_event(pevent, type);
 	if (!event)
 		die("ug! no event found for type %d", type);
 
-	pid = trace_parse_common_pid(data);
+	pid = trace_parse_common_pid(pevent, data);
 
 	sprintf(handler_name, "%s__%s", event->system, event->name);
 
@@ -284,7 +286,8 @@
 				offset = field->offset;
 			obj = PyString_FromString((char *)data + offset);
 		} else { /* FIELD_IS_NUMERIC */
-			val = read_size(data + field->offset, field->size);
+			val = read_size(pevent, data + field->offset,
+					field->size);
 			if (field->flags & FIELD_IS_SIGNED) {
 				if ((long long)val >= LONG_MIN &&
 				    (long long)val <= LONG_MAX)
@@ -438,7 +441,7 @@
 	return err;
 }
 
-static int python_generate_script(const char *outfile)
+static int python_generate_script(struct pevent *pevent, const char *outfile)
 {
 	struct event_format *event = NULL;
 	struct format_field *f;
@@ -487,7 +490,7 @@
 	fprintf(ofp, "def trace_end():\n");
 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
 
-	while ((event = trace_find_next_event(event))) {
+	while ((event = trace_find_next_event(pevent, event))) {
 		fprintf(ofp, "def %s__%s(", event->system, event->name);
 		fprintf(ofp, "event_name, ");
 		fprintf(ofp, "context, ");