perf annotate: Support event group display

When events are grouped together, it'd be natural to show them at once
like in other mode.  Handle group leaders with members to collect the
number of samples together and display like below:

  $ perf annotate --data-type --group
  ...
  Annotate type: 'struct page' in vmlinux (1 samples):
   event[0] = cpu/mem-loads,ldlat=30/P
   event[1] = cpu/mem-stores/P
   event[2] = dummy:u
  ============================================================================
                            samples     offset       size  field
            1          0          0          0         64  struct page     {
            0          0          0          0          8      long unsigned int  flags;
            0          0          0          8         40      union       {
            0          0          0          8         40          struct          {
            0          0          0          8         16              union       {
            0          0          0          8         16                  struct list_head       lru {
            0          0          0          8          8                      struct list_head*  next;
            0          0          0         16          8                      struct list_head*  prev;
                                                                           };
            0          0          0          8         16                  struct          {
            0          0          0          8          8                      void*      __filler;
            0          0          0         16          4                      unsigned int       mlock_count;
                                                                           };
            0          0          0          8         16                  struct list_head       buddy_list {
            0          0          0          8          8                      struct list_head*  next;
            0          0          0         16          8                      struct list_head*  prev;
                                                                           };

Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: namhyung

tools/perf/builtin-annotate.c

@@ -325,19 +325,64 @@ static int hist_entry__tty_annotate(struct hist_entry *he,
 	return symbol__tty_annotate2(&he->ms, evsel);
 }
 
+static void print_annotated_data_header(struct hist_entry *he, struct evsel *evsel)
+{
+	struct dso *dso = map__dso(he->ms.map);
+	int nr_members = 1;
+	int nr_samples = he->stat.nr_events;
+
+	if (evsel__is_group_event(evsel)) {
+		struct hist_entry *pair;
+
+		list_for_each_entry(pair, &he->pairs.head, pairs.node)
+			nr_samples += pair->stat.nr_events;
+	}
+
+	printf("Annotate type: '%s' in %s (%d samples):\n",
+	       he->mem_type->self.type_name, dso->name, nr_samples);
+
+	if (evsel__is_group_event(evsel)) {
+		struct evsel *pos;
+		int i = 0;
+
+		for_each_group_evsel(pos, evsel)
+			printf(" event[%d] = %s\n", i++, pos->name);
+
+		nr_members = evsel->core.nr_members;
+	}
+
+	printf("============================================================================\n");
+	printf("%*s %10s %10s  %s\n", 11 * nr_members, "samples", "offset", "size", "field");
+}
+
 static void print_annotated_data_type(struct annotated_data_type *mem_type,
 				      struct annotated_member *member,
 				      struct evsel *evsel, int indent)
 {
 	struct annotated_member *child;
 	struct type_hist *h = mem_type->histograms[evsel->core.idx];
-	int i, samples = 0;
+	int i, nr_events = 1, samples = 0;
 
 	for (i = 0; i < member->size; i++)
 		samples += h->addr[member->offset + i].nr_samples;
+	printf(" %10d", samples);
+
+	if (evsel__is_group_event(evsel)) {
+		struct evsel *pos;
+
+		for_each_group_member(pos, evsel) {
+			h = mem_type->histograms[pos->core.idx];
+
+			samples = 0;
+			for (i = 0; i < member->size; i++)
+				samples += h->addr[member->offset + i].nr_samples;
+			printf(" %10d", samples);
+		}
+		nr_events = evsel->core.nr_members;
+	}
 
-	printf(" %10d %10d %10d  %*s%s\t%s",
-	       samples, member->offset, member->size, indent, "", member->type_name,
+	printf(" %10d %10d  %*s%s\t%s",
+	       member->offset, member->size, indent, "", member->type_name,
 	       member->var_name ?: "");
 
 	if (!list_empty(&member->children))
@@ -347,7 +392,7 @@ static void print_annotated_data_type(struct annotated_data_type *mem_type,
 		print_annotated_data_type(mem_type, child, evsel, indent + 4);
 
 	if (!list_empty(&member->children))
-		printf("%*s}", 35 + indent, "");
+		printf("%*s}", 11 * nr_events + 24 + indent, "");
 	printf(";\n");
 }
 
@@ -391,8 +436,6 @@ static void hists__find_annotations(struct hists *hists,
 		}
 
 		if (ann->data_type) {
-			struct dso *dso = map__dso(he->ms.map);
-
 			/* skip unknown type */
 			if (he->mem_type->histograms == NULL)
 				goto find_next;
@@ -414,11 +457,7 @@ static void hists__find_annotations(struct hists *hists,
 					goto find_next;
 			}
 
-			printf("Annotate type: '%s' in %s (%d samples):\n",
-				he->mem_type->self.type_name, dso->name, he->stat.nr_events);
-			printf("============================================================================\n");
-			printf(" %10s %10s %10s  %s\n", "samples", "offset", "size", "field");
-
+			print_annotated_data_header(he, evsel);
 			print_annotated_data_type(he->mem_type, &he->mem_type->self, evsel, 0);
 			printf("\n");
 			goto find_next;
@@ -521,8 +560,20 @@ static int __cmd_annotate(struct perf_annotate *ann)
 			evsel__reset_sample_bit(pos, CALLCHAIN);
 			evsel__output_resort(pos, NULL);
 
-			if (symbol_conf.event_group && !evsel__is_group_leader(pos))
+			/*
+			 * An event group needs to display other events too.
+			 * Let's delay printing until other events are processed.
+			 */
+			if (symbol_conf.event_group) {
+				if (!evsel__is_group_leader(pos)) {
+					struct hists *leader_hists;
+
+					leader_hists = evsel__hists(evsel__leader(pos));
+					hists__match(leader_hists, hists);
+					hists__link(leader_hists, hists);
+				}
 				continue;
+			}
 
 			hists__find_annotations(hists, pos, ann);
 		}
@@ -533,6 +584,20 @@ static int __cmd_annotate(struct perf_annotate *ann)
 		goto out;
 	}
 
+	/* Display group events together */
+	evlist__for_each_entry(session->evlist, pos) {
+		struct hists *hists = evsel__hists(pos);
+		u32 nr_samples = hists->stats.nr_samples;
+
+		if (nr_samples == 0)
+			continue;
+
+		if (!symbol_conf.event_group || !evsel__is_group_leader(pos))
+			continue;
+
+		hists__find_annotations(hists, pos, ann);
+	}
+
 	if (use_browser == 2) {
 		void (*show_annotations)(void);