perf tools: Add event_update user level event

It'll serve as a base event for additional event attributes details,
that are not part of the attr event.

At the moment this event is just a dummy one without any specific
functionality. The type value will distinguish the update event details.
It'll come in the following patches.

The idea for this event is to be extensible for any update that the
event might need in the future.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-21-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -44,6 +44,7 @@ static const char *perf_event__names[] = {
 	[PERF_RECORD_STAT_CONFIG]		= "STAT_CONFIG",
 	[PERF_RECORD_STAT]			= "STAT",
 	[PERF_RECORD_STAT_ROUND]		= "STAT_ROUND",
+	[PERF_RECORD_EVENT_UPDATE]		= "EVENT_UPDATE",
 };
 
 const char *perf_event__name(unsigned int id)

tools/perf/util/event.h

@@ -231,6 +231,7 @@ enum perf_user_event_type { /* above any possible kernel type */
 	PERF_RECORD_STAT_CONFIG			= 75,
 	PERF_RECORD_STAT			= 76,
 	PERF_RECORD_STAT_ROUND			= 77,
+	PERF_RECORD_EVENT_UPDATE		= 78,
 	PERF_RECORD_HEADER_MAX
 };
 
@@ -307,6 +308,14 @@ struct attr_event {
 	u64 id[];
 };
 
+struct event_update_event {
+	struct perf_event_header header;
+	u64 type;
+	u64 id;
+
+	char data[];
+};
+
 #define MAX_EVENT_NAME 64
 
 struct perf_trace_event_type {
@@ -456,6 +465,7 @@ union perf_event {
 	struct throttle_event		throttle;
 	struct sample_event		sample;
 	struct attr_event		attr;
+	struct event_update_event	event_update;
 	struct event_type_event		event_type;
 	struct tracing_data_event	tracing_data;
 	struct build_id_event		build_id;

tools/perf/util/header.c

@@ -2745,6 +2745,26 @@ int perf_event__process_attr(struct perf_tool *tool __maybe_unused,
 	return 0;
 }
 
+int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,
+				     union perf_event *event,
+				     struct perf_evlist **pevlist)
+{
+	struct event_update_event *ev = &event->event_update;
+	struct perf_evlist *evlist;
+	struct perf_evsel *evsel;
+
+	if (!pevlist || *pevlist == NULL)
+		return -EINVAL;
+
+	evlist = *pevlist;
+
+	evsel = perf_evlist__id2evsel(evlist, ev->id);
+	if (evsel == NULL)
+		return -EINVAL;
+
+	return 0;
+}
+
 int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
 					struct perf_evlist *evlist,
 					perf_event__handler_t process)

tools/perf/util/header.h

@@ -107,6 +107,9 @@ int perf_event__synthesize_attrs(struct perf_tool *tool,
 				 perf_event__handler_t process);
 int perf_event__process_attr(struct perf_tool *tool, union perf_event *event,
 			     struct perf_evlist **pevlist);
+int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,
+				     union perf_event *event,
+				     struct perf_evlist **pevlist);
 
 int perf_event__synthesize_tracing_data(struct perf_tool *tool,
 					int fd, struct perf_evlist *evlist,

tools/perf/util/session.c

@@ -205,6 +205,15 @@ static int process_event_synth_attr_stub(struct perf_tool *tool __maybe_unused,
 	return 0;
 }
 
+static int process_event_synth_event_update_stub(struct perf_tool *tool __maybe_unused,
+						 union perf_event *event __maybe_unused,
+						 struct perf_evlist **pevlist
+						 __maybe_unused)
+{
+	dump_printf(": unhandled!\n");
+	return 0;
+}
+
 static int process_event_sample_stub(struct perf_tool *tool __maybe_unused,
 				     union perf_event *event __maybe_unused,
 				     struct perf_sample *sample __maybe_unused,
@@ -374,6 +383,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->unthrottle = process_event_stub;
 	if (tool->attr == NULL)
 		tool->attr = process_event_synth_attr_stub;
+	if (tool->event_update == NULL)
+		tool->event_update = process_event_synth_event_update_stub;
 	if (tool->tracing_data == NULL)
 		tool->tracing_data = process_event_synth_tracing_data_stub;
 	if (tool->build_id == NULL)
@@ -625,6 +636,13 @@ static void perf_event__hdr_attr_swap(union perf_event *event,
 	mem_bswap_64(event->attr.id, size);
 }
 
+static void perf_event__event_update_swap(union perf_event *event,
+					  bool sample_id_all __maybe_unused)
+{
+	event->event_update.type = bswap_64(event->event_update.type);
+	event->event_update.id   = bswap_64(event->event_update.id);
+}
+
 static void perf_event__event_type_swap(union perf_event *event,
 					bool sample_id_all __maybe_unused)
 {
@@ -779,6 +797,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
 	[PERF_RECORD_STAT_CONFIG]	  = perf_event__stat_config_swap,
 	[PERF_RECORD_STAT]		  = perf_event__stat_swap,
 	[PERF_RECORD_STAT_ROUND]	  = perf_event__stat_round_swap,
+	[PERF_RECORD_EVENT_UPDATE]	  = perf_event__event_update_swap,
 	[PERF_RECORD_HEADER_MAX]	  = NULL,
 };
 
@@ -1290,6 +1309,8 @@ static s64 perf_session__process_user_event(struct perf_session *session,
 			perf_session__set_comm_exec(session);
 		}
 		return err;
+	case PERF_RECORD_EVENT_UPDATE:
+		return tool->event_update(tool, event, &session->evlist);
 	case PERF_RECORD_HEADER_EVENT_TYPE:
 		/*
 		 * Depreceated, but we need to handle it for sake

tools/perf/util/tool.h

@@ -50,6 +50,7 @@ struct perf_tool {
 			throttle,
 			unthrottle;
 	event_attr_op	attr;
+	event_attr_op	event_update;
 	event_op2	tracing_data;
 	event_oe	finished_round;
 	event_op2	build_id,