perf report: Show group description when event group is enabled

When using event group viewer, it's better to show the group description
rather than the leader information alone.

If a leader did not contain any member, it's a non-group event.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1358845787-1350-17-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 33 insertions, 0 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index baa26ddbcc7b..94e74043ded8 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -434,6 +434,31 @@ const char *perf_evsel__name(struct perf_evsel *evsel)
         return evsel->name ?: "unknown";
 }
 
+const char *perf_evsel__group_name(struct perf_evsel *evsel)
+{
+        return evsel->group_name ?: "anon group";
+}
+
+int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
+{
+        int ret;
+        struct perf_evsel *pos;
+        const char *group_name = perf_evsel__group_name(evsel);
+
+        ret = scnprintf(buf, size, "%s", group_name);
+
+        ret += scnprintf(buf + ret, size - ret, " { %s",
+                         perf_evsel__name(evsel));
+
+        for_each_group_member(pos, evsel)
+                ret += scnprintf(buf + ret, size - ret, ", %s",
+                                 perf_evsel__name(pos));
+
+        ret += scnprintf(buf + ret, size - ret, " }");
+
+        return ret;
+}
+
 /*
  * The enable_on_exec/disabled value strategy:
  *
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 371713977888..8512f6a8a6ea 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -114,6 +114,8 @@ extern const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX];
 int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
                                             char *bf, size_t size);
 const char *perf_evsel__name(struct perf_evsel *evsel);
+const char *perf_evsel__group_name(struct perf_evsel *evsel);
+int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size);
 
 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads);
@@ -267,4 +269,10 @@ static inline int perf_evsel__group_idx(struct perf_evsel *evsel)
 {
         return evsel->idx - evsel->leader->idx;
 }
+
+#define for_each_group_member(_evsel, _leader)                                  \
+for ((_evsel) = list_entry((_leader)->node.next, struct perf_evsel, node);      \
+     (_evsel) && (_evsel)->leader == (_leader);                                 \
+     (_evsel) = list_entry((_evsel)->node.next, struct perf_evsel, node))
+
 #endif /* __PERF_EVSEL_H */