perf hists: Split hists_stats from events_stats

Each struct hists have events_stats but most of the fields were not
used. It's to count number of samples and periods whether filtered or
not. And other fields are used only by evlist.

So it'd be better to split hists_stats and events_stats to reduce
wasted memory in the struct hists. This makes the output of event
statistics in the perf report compact by skipping 0 events in each
evsel/hists.

Reviewed-by: Andi Kleen <[e-mail]>
Signed-off-by: Namhyung Kim <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-annotate.c

···
 	total_nr_samples = 0;
 	evlist__for_each_entry(session->evlist, pos) {
 		struct hists *hists = evsel__hists(pos);
-		u32 nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+		u32 nr_samples = hists->stats.nr_samples;
 
 		if (nr_samples > 0) {
 			total_nr_samples += nr_samples;

tools/perf/builtin-report.c

···
 {
 	size_t ret;
 	char unit;
-	unsigned long nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	unsigned long nr_samples = hists->stats.nr_samples;
 	u64 nr_events = hists->stats.total_period;
 	struct evsel *evsel = hists_to_evsel(hists);
 	char buf[512];
···
 				nr_samples += pos_hists->stats.nr_non_filtered_samples;
 				nr_events += pos_hists->stats.total_non_filtered_period;
 			} else {
-				nr_samples += pos_hists->stats.nr_events[PERF_RECORD_SAMPLE];
+				nr_samples += pos_hists->stats.nr_samples;
 				nr_events += pos_hists->stats.total_period;
 			}
 		}

tools/perf/tests/hists_filter.c

···
 		}
 
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",
 				hists->stats.total_period == 1000);
 		TEST_ASSERT_VAL("Unmatched nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] ==
+				hists->stats.nr_samples ==
 				hists->stats.nr_non_filtered_samples);
 		TEST_ASSERT_VAL("Unmatched nr hist entries",
 				hists->nr_entries == hists->nr_non_filtered_entries);
···
 
 		/* normal stats should be invariant */
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",
···
 
 		/* normal stats should be invariant */
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",
···
 
 		/* normal stats should be invariant */
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",
···
 
 		/* normal stats should be invariant */
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",
···
 
 		/* normal stats should be invariant */
 		TEST_ASSERT_VAL("Invalid nr samples",
-				hists->stats.nr_events[PERF_RECORD_SAMPLE] == 10);
+				hists->stats.nr_samples == 10);
 		TEST_ASSERT_VAL("Invalid nr hist entries",
 				hists->nr_entries == 9);
 		TEST_ASSERT_VAL("Invalid total period",

tools/perf/ui/browsers/hists.c

···
 	switch (key) {
 	case K_TIMER: {
 		struct hist_browser_timer *hbt = browser->hbt;
+		struct evsel *evsel = hists_to_evsel(browser->hists);
 		u64 nr_entries;
 
 		WARN_ON_ONCE(!hbt);
···
 		ui_browser__update_nr_entries(&browser->b, nr_entries);
 
 		if (warn_lost_event &&
-		    (browser->hists->stats.nr_lost_warned !=
-		    browser->hists->stats.nr_events[PERF_RECORD_LOST])) {
-			browser->hists->stats.nr_lost_warned =
-				browser->hists->stats.nr_events[PERF_RECORD_LOST];
+		    (evsel->evlist->stats.nr_lost_warned !=
+		     evsel->evlist->stats.nr_events[PERF_RECORD_LOST])) {
+			evsel->evlist->stats.nr_lost_warned =
+				evsel->evlist->stats.nr_events[PERF_RECORD_LOST];
 			ui_browser__warn_lost_events(&browser->b);
 		}
 
···
 	struct evsel *evsel = list_entry(entry, struct evsel, core.node);
 	struct hists *hists = evsel__hists(evsel);
 	bool current_entry = ui_browser__is_current_entry(browser, row);
-	unsigned long nr_events = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	unsigned long nr_events = hists->stats.nr_samples;
 	const char *ev_name = evsel__name(evsel);
 	char bf[256], unit;
 	const char *warn = " ";
···
 
 		for_each_group_member(pos, evsel) {
 			struct hists *pos_hists = evsel__hists(pos);
-			nr_events += pos_hists->stats.nr_events[PERF_RECORD_SAMPLE];
+			nr_events += pos_hists->stats.nr_samples;
 		}
 	}
 
···
 			   unit, unit == ' ' ? "" : " ", ev_name);
 	ui_browser__printf(browser, "%s", bf);
 
-	nr_events = hists->stats.nr_events[PERF_RECORD_LOST];
+	nr_events = evsel->evlist->stats.nr_events[PERF_RECORD_LOST];
 	if (nr_events != 0) {
 		menu->lost_events = true;
 		if (!current_entry)
···
 {
 	struct hists *hists = evsel__hists(browser->block_evsel);
 	const char *evname = evsel__name(browser->block_evsel);
-	unsigned long nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	unsigned long nr_samples = hists->stats.nr_samples;
 	int ret;
 
 	ret = scnprintf(bf, size, "# Samples: %lu", nr_samples);

tools/perf/util/events_stats.h

···
  * perf_record_sample.period and stash the result in total_period.
  */
 struct events_stats {
-	u64 total_period;
-	u64 total_non_filtered_period;
 	u64 total_lost;
 	u64 total_lost_samples;
 	u64 total_aux_lost;
 	u64 total_aux_partial;
 	u64 total_invalid_chains;
 	u32 nr_events[PERF_RECORD_HEADER_MAX];
-	u32 nr_non_filtered_samples;
 	u32 nr_lost_warned;
 	u32 nr_unknown_events;
 	u32 nr_invalid_chains;
···
 	u32 nr_unprocessable_samples;
 	u32 nr_auxtrace_errors[PERF_AUXTRACE_ERROR_MAX];
 	u32 nr_proc_map_timeout;
+};
+
+struct hists_stats {
+	u64 total_period;
+	u64 total_non_filtered_period;
+	u32 nr_samples;
+	u32 nr_non_filtered_samples;
 };
 
 void events_stats__inc(struct events_stats *stats, u32 type);

tools/perf/util/hist.c

···
 	++stats->nr_events[type];
 }
 
-void hists__inc_nr_events(struct hists *hists, u32 type)
+static void hists_stats__inc(struct hists_stats *stats)
 {
-	events_stats__inc(&hists->stats, type);
+	++stats->nr_samples;
+}
+
+void hists__inc_nr_events(struct hists *hists)
+{
+	hists_stats__inc(&hists->stats);
 }
 
 void hists__inc_nr_samples(struct hists *hists, bool filtered)
 {
-	events_stats__inc(&hists->stats, PERF_RECORD_SAMPLE);
+	hists_stats__inc(&hists->stats);
 	if (!filtered)
 		hists->stats.nr_non_filtered_samples++;
 }
···
 	size_t ret = 0;
 
 	evlist__for_each_entry(evlist, pos) {
+		struct hists *hists = evsel__hists(pos);
+
 		ret += fprintf(fp, "%s stats:\n", evsel__name(pos));
-		ret += events_stats__fprintf(&evsel__hists(pos)->stats, fp);
+		ret += fprintf(fp, "%16s events: %10d\n",
+			       "SAMPLE", hists->stats.nr_samples);
 	}
 
 	return ret;
···
 	const struct dso *dso = hists->dso_filter;
 	struct thread *thread = hists->thread_filter;
 	int socket_id = hists->socket_filter;
-	unsigned long nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	unsigned long nr_samples = hists->stats.nr_samples;
 	u64 nr_events = hists->stats.total_period;
 	struct evsel *evsel = hists_to_evsel(hists);
 	const char *ev_name = evsel__name(evsel);
···
 				nr_samples += pos_hists->stats.nr_non_filtered_samples;
 				nr_events += pos_hists->stats.total_non_filtered_period;
 			} else {
-				nr_samples += pos_hists->stats.nr_events[PERF_RECORD_SAMPLE];
+				nr_samples += pos_hists->stats.nr_samples;
 				nr_events += pos_hists->stats.total_period;
 			}
 		}

tools/perf/util/hist.h

···
 	const char		*uid_filter_str;
 	const char		*symbol_filter_str;
 	pthread_mutex_t		lock;
-	struct events_stats	stats;
+	struct hists_stats	stats;
 	u64			event_stream;
 	u16			col_len[HISTC_NR_COLS];
 	bool			has_callchains;
···
 u64 hists__total_period(struct hists *hists);
 void hists__reset_stats(struct hists *hists);
 void hists__inc_stats(struct hists *hists, struct hist_entry *h);
-void hists__inc_nr_events(struct hists *hists, u32 type);
+void hists__inc_nr_events(struct hists *hists);
 void hists__inc_nr_samples(struct hists *hists, bool filtered);
 
 size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,