perf annotate-data: Support --skip-empty option

The --skip-empty option is to hide dummy events in a group.  Like other
output mode in 'perf report' and 'perf annotate', the data-type
profiling output should support the option.

Committer testing:

With dummy:

  root@number:~# perf annotate --stdio --group --data-type --skip-empty | head -24
  Annotate type: 'pthread_mutex_t' in /usr/lib64/libc.so.6 (50 samples):
   event[0] = cpu_atom/mem-loads,ldlat=30/P
   event[1] = cpu_atom/mem-stores/P
   event[2] = dummy:u
  ============================================================================
                   Percent     offset       size  field
    100.00  100.00    0.00          0         40  pthread_mutex_t	 {
    100.00  100.00    0.00          0         40      struct __pthread_mutex_s	__data {
     45.21   84.54    0.00          0          4          int	__lock;
      0.00    0.00    0.00          4          4          unsigned int	__count;
      0.00    1.83    0.00          8          4          int	__owner;
      5.19   10.65    0.00         12          4          unsigned int	__nusers;
     49.61    2.97    0.00         16          4          int	__kind;
      0.00    0.00    0.00         20          2          short int	__spins;
      0.00    0.00    0.00         22          2          short int	__elision;
      0.00    0.00    0.00         24         16          __pthread_list_t	__list {
      0.00    0.00    0.00         24          8              struct __pthread_internal_list*	__prev;
      0.00    0.00    0.00         32          8              struct __pthread_internal_list*	__next;
                                                          };
                                                      };
      0.00    0.00    0.00          0          0      char[]	__size;
     45.21   84.54    0.00          0          8      long int	__align;
                                                };
Skipping it:

  root@number:~# perf annotate --stdio --group --data-type --skip-empty | head -24
  Annotate type: 'pthread_mutex_t' in /usr/lib64/libc.so.6 (50 samples):
   event[0] = cpu_atom/mem-loads,ldlat=30/P
   event[1] = cpu_atom/mem-stores/P
  ============================================================================
           Percent     offset       size  field
    100.00  100.00          0         40  pthread_mutex_t	 {
    100.00  100.00          0         40      struct __pthread_mutex_s	__data {
     45.21   84.54          0          4          int	__lock;
      0.00    0.00          4          4          unsigned int	__count;
      0.00    1.83          8          4          int	__owner;
      5.19   10.65         12          4          unsigned int	__nusers;
     49.61    2.97         16          4          int	__kind;
      0.00    0.00         20          2          short int	__spins;
      0.00    0.00         22          2          short int	__elision;
      0.00    0.00         24         16          __pthread_list_t	__list {
      0.00    0.00         24          8              struct __pthread_internal_list*	__prev;
      0.00    0.00         32          8              struct __pthread_internal_list*	__next;
                                                  };
                                              };
      0.00    0.00          0          0      char[]	__size;
     45.21   84.54          0          8      long int	__align;
                                          };

  Annotate type: 'pthread_mutexattr_t' in /usr/lib64/libc.so.6 (1 samples):
  root@number:~#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240807061713.1642924-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/browsers/annotate-data.c

@@ -46,15 +46,18 @@ static int get_member_overhead(struct annotated_data_type *adt,
 	struct annotated_member *member = entry->data;
 	int i, k;
 
-	for (i = 0; i < member->size; i++) {
+	for (i = 0, k = 0; i < member->size; i++) {
 		struct type_hist *h;
 		struct evsel *evsel;
 		int offset = member->offset + i;
 
 		for_each_group_evsel(evsel, leader) {
+			if (symbol_conf.skip_empty &&
+			    evsel__hists(evsel)->stats.nr_samples == 0)
+				continue;
+
 			h = adt->histograms[evsel->core.idx];
-			k = evsel__group_idx(evsel);
-			update_hist_entry(&entry->hists[k], &h->addr[offset]);
+			update_hist_entry(&entry->hists[k++], &h->addr[offset]);
 		}
 	}
 	return 0;
@@ -203,6 +206,7 @@ static void browser__write(struct ui_browser *uib, void *entry, int row)
 	struct annotated_data_type *adt = he->mem_type;
 	struct evsel *leader = hists_to_evsel(he->hists);
 	struct evsel *evsel;
+	int idx = 0;
 
 	if (member == NULL) {
 		bool current = ui_browser__is_current_entry(uib, row);
@@ -219,9 +223,12 @@ static void browser__write(struct ui_browser *uib, void *entry, int row)
 	/* print the number */
 	for_each_group_evsel(evsel, leader) {
 		struct type_hist *h = adt->histograms[evsel->core.idx];
-		int idx = evsel__group_idx(evsel);
 
-		browser__write_overhead(uib, h, &be->hists[idx], row);
+		if (symbol_conf.skip_empty &&
+		    evsel__hists(evsel)->stats.nr_samples == 0)
+			continue;
+
+		browser__write_overhead(uib, h, &be->hists[idx++], row);
 	}
 
 	/* print type info */
@@ -300,8 +307,17 @@ int hist_entry__annotate_data_tui(struct hist_entry *he, struct evsel *evsel,
 
 	ui_helpline__push("Press ESC to exit");
 
-	if (evsel__is_group_event(evsel))
-		browser.nr_events = evsel->core.nr_members;
+	if (evsel__is_group_event(evsel)) {
+		struct evsel *pos;
+		int nr = 0;
+
+		for_each_group_evsel(pos, evsel) {
+			if (!symbol_conf.skip_empty ||
+			    evsel__hists(pos)->stats.nr_samples)
+				nr++;
+		}
+		browser.nr_events = nr;
+	}
 
 	ret = annotated_data_browser__collect_entries(&browser);
 	if (ret == 0)

tools/perf/util/annotate-data.c

@@ -1502,10 +1502,15 @@ static void print_annotated_data_header(struct hist_entry *he, struct evsel *evs
 		struct evsel *pos;
 		int i = 0;
 
-		for_each_group_evsel(pos, evsel)
-			printf(" event[%d] = %s\n", i++, pos->name);
+		nr_members = 0;
+		for_each_group_evsel(pos, evsel) {
+			if (symbol_conf.skip_empty &&
+			    evsel__hists(pos)->stats.nr_samples == 0)
+				continue;
 
-		nr_members = evsel->core.nr_members;
+			printf(" event[%d] = %s\n", i++, pos->name);
+			nr_members++;
+		}
 	}
 
 	if (symbol_conf.show_total_period) {
@@ -1540,31 +1545,26 @@ static void print_annotated_data_type(struct annotated_data_type *mem_type,
 {
 	struct annotated_member *child;
 	struct type_hist *h = mem_type->histograms[evsel->core.idx];
-	int i, nr_events = 1, samples = 0;
+	int i, nr_events = 0, samples = 0;
 	u64 period = 0;
 	int width = symbol_conf.show_total_period ? 11 : 7;
+	struct evsel *pos;
 
-	for (i = 0; i < member->size; i++) {
-		samples += h->addr[member->offset + i].nr_samples;
-		period += h->addr[member->offset + i].period;
-	}
-	print_annotated_data_value(h, period, samples);
-
-	if (evsel__is_group_event(evsel)) {
-		struct evsel *pos;
+	for_each_group_evsel(pos, evsel) {
+		h = mem_type->histograms[pos->core.idx];
 
-		for_each_group_member(pos, evsel) {
-			h = mem_type->histograms[pos->core.idx];
+		if (symbol_conf.skip_empty &&
+		    evsel__hists(pos)->stats.nr_samples == 0)
+			continue;
 
-			samples = 0;
-			period = 0;
-			for (i = 0; i < member->size; i++) {
-				samples += h->addr[member->offset + i].nr_samples;
-				period += h->addr[member->offset + i].period;
-			}
-			print_annotated_data_value(h, period, samples);
+		samples = 0;
+		period = 0;
+		for (i = 0; i < member->size; i++) {
+			samples += h->addr[member->offset + i].nr_samples;
+			period += h->addr[member->offset + i].period;
 		}
-		nr_events = evsel->core.nr_members;
+		print_annotated_data_value(h, period, samples);
+		nr_events++;
 	}
 
 	printf(" %10d %10d  %*s%s\t%s",