perf tools: Add event_update event unit type

Adding unit type 'event update' event, that stores/transfer events unit
name. The unit name is part of the perf stat output data.

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/1445784728-21732-22-git-send-email-jolsa@kernel.org
[ Rename __alloc() to __new() for consistency ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 51 insertions, 0 deletions

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 6966a4b7c0f0..64c4cdf5aada 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -308,6 +308,10 @@ struct attr_event {
 	u64 id[];
 };
 
+enum {
+	PERF_EVENT_UPDATE__UNIT  = 0,
+};
+
 struct event_update_event {
 	struct perf_event_header header;
 	u64 type;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 6b4e00220a5a..5759ebfde666 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2686,6 +2686,43 @@ int perf_event__synthesize_attr(struct perf_tool *tool,
 	return err;
 }
 
+static struct event_update_event *
+event_update_event__new(size_t size, u64 type, u64 id)
+{
+	struct event_update_event *ev;
+
+	size += sizeof(*ev);
+	size  = PERF_ALIGN(size, sizeof(u64));
+
+	ev = zalloc(size);
+	if (ev) {
+		ev->header.type = PERF_RECORD_EVENT_UPDATE;
+		ev->header.size = (u16)size;
+		ev->type = type;
+		ev->id = id;
+	}
+	return ev;
+}
+
+int
+perf_event__synthesize_event_update_unit(struct perf_tool *tool,
+					 struct perf_evsel *evsel,
+					 perf_event__handler_t process)
+{
+	struct event_update_event *ev;
+	size_t size = strlen(evsel->unit);
+	int err;
+
+	ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->id[0]);
+	if (ev == NULL)
+		return -ENOMEM;
+
+	strncpy(ev->data, evsel->unit, size);
+	err = process(tool, (union perf_event *)ev, NULL, NULL);
+	free(ev);
+	return err;
+}
+
 int perf_event__synthesize_attrs(struct perf_tool *tool,
 				   struct perf_session *session,
 				   perf_event__handler_t process)
@@ -2762,6 +2799,13 @@ int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,
 	if (evsel == NULL)
 		return -EINVAL;
 
+	switch (ev->type) {
+	case PERF_EVENT_UPDATE__UNIT:
+		evsel->unit = strdup(ev->data);
+	default:
+		break;
+	}
+
 	return 0;
 }
 
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 1e843c67a4ff..6aa2b9242fc1 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -105,6 +105,9 @@ int perf_event__synthesize_attr(struct perf_tool *tool,
 int perf_event__synthesize_attrs(struct perf_tool *tool,
 				 struct perf_session *session,
 				 perf_event__handler_t process);
+int perf_event__synthesize_event_update_unit(struct perf_tool *tool,
+					     struct perf_evsel *evsel,
+					     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,