Make groups visible in output:

Before:
{cycles,instructions} ->
cpu_atom/cycles/,cpu_atom/instructions/,cpu_core/cycles/,cpu_core/instructions/

After:
{cycles,instructions} ->
{cpu_atom/cycles/,cpu_atom/instructions/},{cpu_core/cycles/,cpu_core/instructions/}

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/evlist.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index ffb5be41a465..6ebe0795e1c9 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2471,13 +2471,18 @@ struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
 
 void evlist__format_evsels(struct evlist *evlist, struct strbuf *sb, size_t max_length)
 {
-	struct evsel *evsel;
+	struct evsel *evsel, *leader = NULL;
 	bool first = true;
 
 	evlist__for_each_entry(evlist, evsel) {
+		struct evsel *new_leader = evsel__leader(evsel);
+
 		if (evsel__is_dummy_event(evsel))
 			continue;
 
+		if (leader != new_leader && leader && leader->core.nr_members > 1)
+			strbuf_addch(sb, '}');
+
 		if (!first)
 			strbuf_addch(sb, ',');
 
@@ -2485,9 +2490,15 @@ void evlist__format_evsels(struct evlist *evlist, struct strbuf *sb, size_t max_
 			strbuf_addstr(sb, "...");
 			return;
 		}
+		if (leader != new_leader && new_leader->core.nr_members > 1)
+			strbuf_addch(sb, '{');
+
 		strbuf_addstr(sb, evsel__name(evsel));
 		first = false;
+		leader = new_leader;
 	}
+	if (leader && leader->core.nr_members > 1)
+		strbuf_addch(sb, '}');
 }
 
 void evlist__check_mem_load_aux(struct evlist *evlist)
-- 
2.49.0.504.g3bcea36a83-goog