perf report: Report number of events, not samples

Number of samples is meaningless after we switched to auto-freq, so
report the number of events, i.e. not the sum of the different periods,
but the number PERF_RECORD_SAMPLE emitted by the kernel.

While doing this I noticed that naming "count" to the sum of all the
event periods can be confusing, so rename it to .period, just like in
struct sample.data, so that we become more consistent.

This helps with the next step, that was to record in struct hist_entry
the number of sample events for each instance, we need that because we
use it to generate the number of events when applying filters to the
tree of hist entries like it is being done in the TUI report browser.

Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-diff.c

@@ -23,9 +23,9 @@ static bool  force;
 static bool show_displacement;
 
 static int hists__add_entry(struct hists *self,
-			    struct addr_location *al, u64 count)
+			    struct addr_location *al, u64 period)
 {
-	if (__hists__add_entry(self, al, NULL, count) != NULL)
+	if (__hists__add_entry(self, al, NULL, period) != NULL)
 		return 0;
 	return -ENOMEM;
 }
@@ -50,7 +50,7 @@ static int diff__process_sample_event(event_t *event, struct perf_session *sessi
 	event__parse_sample(event, session->sample_type, &data);
 
 	if (hists__add_entry(&session->hists, &al, data.period)) {
-		pr_warning("problem incrementing symbol count, skipping event\n");
+		pr_warning("problem incrementing symbol period, skipping event\n");
 		return -1;
 	}
 

tools/perf/builtin-report.c

@@ -188,14 +188,14 @@ static int process_sample_event(event_t *event, struct perf_session *session)
 		return 0;
 
 	if (perf_session__add_hist_entry(session, &al, &data)) {
-		pr_debug("problem incrementing symbol count, skipping event\n");
+		pr_debug("problem incrementing symbol period, skipping event\n");
 		return -1;
 	}
 
 	attr = perf_header__find_attr(data.id, &session->header);
 
 	if (add_event_total(session, &data, attr)) {
-		pr_debug("problem adding event count\n");
+		pr_debug("problem adding event period\n");
 		return -1;
 	}
 
@@ -269,11 +269,25 @@ static struct perf_event_ops event_ops = {
 
 extern volatile int session_done;
 
-static void sig_handler(int sig __attribute__((__unused__)))
+static void sig_handler(int sig __used)
 {
 	session_done = 1;
 }
 
+static size_t hists__fprintf_nr_sample_events(struct hists *self,
+					      const char *evname, FILE *fp)
+{
+	size_t ret;
+	char unit;
+	unsigned long nr_events = self->stats.nr_events[PERF_RECORD_SAMPLE];
+
+	nr_events = convert_unit(nr_events, &unit);
+	ret = fprintf(fp, "# Events: %lu%c", nr_events, unit);
+	if (evname != NULL)
+		ret += fprintf(fp, " %s", evname);
+	return ret + fprintf(fp, "\n#\n");
+}
+
 static int __cmd_report(void)
 {
 	int ret = -EINVAL;
@@ -319,14 +333,12 @@ static int __cmd_report(void)
 		if (use_browser)
 			hists__browse(hists, help, input_name);
 		else {
-			if (rb_first(&session->hists.entries) ==
+			const char *evname = NULL;
+			if (rb_first(&session->hists.entries) !=
 			    rb_last(&session->hists.entries))
-				fprintf(stdout, "# Samples: %Ld\n#\n",
-					hists->stats.total_period);
-			else
-				fprintf(stdout, "# Samples: %Ld %s\n#\n",
-					hists->stats.total_period,
-					__event_name(hists->type, hists->config));
+				evname = __event_name(hists->type, hists->config);
+
+			hists__fprintf_nr_sample_events(hists, evname, stdout);
 
 			hists__fprintf(hists, NULL, false, stdout);
 			fprintf(stdout, "\n\n");

tools/perf/util/hist.c

@@ -9,29 +9,29 @@ struct callchain_param	callchain_param = {
 	.min_percent = 0.5
 };
 
-static void hist_entry__add_cpumode_count(struct hist_entry *self,
-					  unsigned int cpumode, u64 count)
+static void hist_entry__add_cpumode_period(struct hist_entry *self,
+					   unsigned int cpumode, u64 period)
 {
 	switch (cpumode) {
 	case PERF_RECORD_MISC_KERNEL:
-		self->count_sys += count;
+		self->period_sys += period;
 		break;
 	case PERF_RECORD_MISC_USER:
-		self->count_us += count;
+		self->period_us += period;
 		break;
 	case PERF_RECORD_MISC_GUEST_KERNEL:
-		self->count_guest_sys += count;
+		self->period_guest_sys += period;
 		break;
 	case PERF_RECORD_MISC_GUEST_USER:
-		self->count_guest_us += count;
+		self->period_guest_us += period;
 		break;
 	default:
 		break;
 	}
 }
 
 /*
- * histogram, sorted on item, collects counts
+ * histogram, sorted on item, collects periods
  */
 
 static struct hist_entry *hist_entry__new(struct hist_entry *template)
@@ -41,6 +41,7 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template)
 
 	if (self != NULL) {
 		*self = *template;
+		self->nr_events = 1;
 		if (symbol_conf.use_callchain)
 			callchain_init(self->callchain);
 	}
@@ -57,7 +58,7 @@ static void hists__inc_nr_entries(struct hists *self, struct hist_entry *entry)
 
 struct hist_entry *__hists__add_entry(struct hists *self,
 				      struct addr_location *al,
-				      struct symbol *sym_parent, u64 count)
+				      struct symbol *sym_parent, u64 period)
 {
 	struct rb_node **p = &self->entries.rb_node;
 	struct rb_node *parent = NULL;
@@ -70,7 +71,7 @@ struct hist_entry *__hists__add_entry(struct hists *self,
 		},
 		.ip	= al->addr,
 		.level	= al->level,
-		.count	= count,
+		.period	= period,
 		.parent = sym_parent,
 	};
 	int cmp;
@@ -82,7 +83,8 @@ struct hist_entry *__hists__add_entry(struct hists *self,
 		cmp = hist_entry__cmp(&entry, he);
 
 		if (!cmp) {
-			he->count += count;
+			he->period += period;
+			++he->nr_events;
 			goto out;
 		}
 
@@ -99,7 +101,7 @@ struct hist_entry *__hists__add_entry(struct hists *self,
 	rb_insert_color(&he->rb_node, &self->entries);
 	hists__inc_nr_entries(self, he);
 out:
-	hist_entry__add_cpumode_count(he, al->cpumode, count);
+	hist_entry__add_cpumode_period(he, al->cpumode, period);
 	return he;
 }
 
@@ -160,7 +162,7 @@ static bool collapse__insert_entry(struct rb_root *root, struct hist_entry *he)
 		cmp = hist_entry__collapse(iter, he);
 
 		if (!cmp) {
-			iter->count += he->count;
+			iter->period += he->period;
 			hist_entry__free(he);
 			return false;
 		}
@@ -203,7 +205,7 @@ void hists__collapse_resort(struct hists *self)
 }
 
 /*
- * reverse the map, sort on count.
+ * reverse the map, sort on period.
  */
 
 static void __hists__insert_output_entry(struct rb_root *entries,
@@ -222,7 +224,7 @@ static void __hists__insert_output_entry(struct rb_root *entries,
 		parent = *p;
 		iter = rb_entry(parent, struct hist_entry, rb_node);
 
-		if (he->count > iter->count)
+		if (he->period > iter->period)
 			p = &(*p)->rb_left;
 		else
 			p = &(*p)->rb_right;
@@ -288,7 +290,7 @@ static size_t ipchain__fprintf_graph_line(FILE *fp, int depth, int depth_mask,
 }
 
 static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_list *chain,
-				     int depth, int depth_mask, int count,
+				     int depth, int depth_mask, int period,
 				     u64 total_samples, int hits,
 				     int left_margin)
 {
@@ -301,7 +303,7 @@ static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_list *chain,
 			ret += fprintf(fp, "|");
 		else
 			ret += fprintf(fp, " ");
-		if (!count && i == depth - 1) {
+		if (!period && i == depth - 1) {
 			double percent;
 
 			percent = hits * 100.0 / total_samples;
@@ -516,75 +518,75 @@ int hist_entry__snprintf(struct hist_entry *self, char *s, size_t size,
 			 long displacement, bool color, u64 session_total)
 {
 	struct sort_entry *se;
-	u64 count, total, count_sys, count_us, count_guest_sys, count_guest_us;
+	u64 period, total, period_sys, period_us, period_guest_sys, period_guest_us;
 	const char *sep = symbol_conf.field_sep;
 	int ret;
 
 	if (symbol_conf.exclude_other && !self->parent)
 		return 0;
 
 	if (pair_hists) {
-		count = self->pair ? self->pair->count : 0;
+		period = self->pair ? self->pair->period : 0;
 		total = pair_hists->stats.total_period;
-		count_sys = self->pair ? self->pair->count_sys : 0;
-		count_us = self->pair ? self->pair->count_us : 0;
-		count_guest_sys = self->pair ? self->pair->count_guest_sys : 0;
-		count_guest_us = self->pair ? self->pair->count_guest_us : 0;
+		period_sys = self->pair ? self->pair->period_sys : 0;
+		period_us = self->pair ? self->pair->period_us : 0;
+		period_guest_sys = self->pair ? self->pair->period_guest_sys : 0;
+		period_guest_us = self->pair ? self->pair->period_guest_us : 0;
 	} else {
-		count = self->count;
+		period = self->period;
 		total = session_total;
-		count_sys = self->count_sys;
-		count_us = self->count_us;
-		count_guest_sys = self->count_guest_sys;
-		count_guest_us = self->count_guest_us;
+		period_sys = self->period_sys;
+		period_us = self->period_us;
+		period_guest_sys = self->period_guest_sys;
+		period_guest_us = self->period_guest_us;
 	}
 
 	if (total) {
 		if (color)
 			ret = percent_color_snprintf(s, size,
 						     sep ? "%.2f" : "   %6.2f%%",
-						     (count * 100.0) / total);
+						     (period * 100.0) / total);
 		else
 			ret = snprintf(s, size, sep ? "%.2f" : "   %6.2f%%",
-				       (count * 100.0) / total);
+				       (period * 100.0) / total);
 		if (symbol_conf.show_cpu_utilization) {
 			ret += percent_color_snprintf(s + ret, size - ret,
 					sep ? "%.2f" : "   %6.2f%%",
-					(count_sys * 100.0) / total);
+					(period_sys * 100.0) / total);
 			ret += percent_color_snprintf(s + ret, size - ret,
 					sep ? "%.2f" : "   %6.2f%%",
-					(count_us * 100.0) / total);
+					(period_us * 100.0) / total);
 			if (perf_guest) {
 				ret += percent_color_snprintf(s + ret,
 						size - ret,
 						sep ? "%.2f" : "   %6.2f%%",
-						(count_guest_sys * 100.0) /
+						(period_guest_sys * 100.0) /
 								total);
 				ret += percent_color_snprintf(s + ret,
 						size - ret,
 						sep ? "%.2f" : "   %6.2f%%",
-						(count_guest_us * 100.0) /
+						(period_guest_us * 100.0) /
 								total);
 			}
 		}
 	} else
-		ret = snprintf(s, size, sep ? "%lld" : "%12lld ", count);
+		ret = snprintf(s, size, sep ? "%lld" : "%12lld ", period);
 
 	if (symbol_conf.show_nr_samples) {
 		if (sep)
-			ret += snprintf(s + ret, size - ret, "%c%lld", *sep, count);
+			ret += snprintf(s + ret, size - ret, "%c%lld", *sep, period);
 		else
-			ret += snprintf(s + ret, size - ret, "%11lld", count);
+			ret += snprintf(s + ret, size - ret, "%11lld", period);
 	}
 
 	if (pair_hists) {
 		char bf[32];
 		double old_percent = 0, new_percent = 0, diff;
 
 		if (total > 0)
-			old_percent = (count * 100.0) / total;
+			old_percent = (period * 100.0) / total;
 		if (session_total > 0)
-			new_percent = (self->count * 100.0) / session_total;
+			new_percent = (self->period * 100.0) / session_total;
 
 		diff = new_percent - old_percent;
 
@@ -796,6 +798,7 @@ void hists__filter_by_dso(struct hists *self, const struct dso *dso)
 	struct rb_node *nd;
 
 	self->nr_entries = self->stats.total_period = 0;
+	self->stats.nr_events[PERF_RECORD_SAMPLE] = 0;
 	self->max_sym_namelen = 0;
 
 	for (nd = rb_first(&self->entries); nd; nd = rb_next(nd)) {
@@ -812,7 +815,8 @@ void hists__filter_by_dso(struct hists *self, const struct dso *dso)
 		h->filtered &= ~(1 << HIST_FILTER__DSO);
 		if (!h->filtered) {
 			++self->nr_entries;
-			self->stats.total_period += h->count;
+			self->stats.total_period += h->period;
+			self->stats.nr_events[PERF_RECORD_SAMPLE] += h->nr_events;
 			if (h->ms.sym &&
 			    self->max_sym_namelen < h->ms.sym->namelen)
 				self->max_sym_namelen = h->ms.sym->namelen;
@@ -825,6 +829,7 @@ void hists__filter_by_thread(struct hists *self, const struct thread *thread)
 	struct rb_node *nd;
 
 	self->nr_entries = self->stats.total_period = 0;
+	self->stats.nr_events[PERF_RECORD_SAMPLE] = 0;
 	self->max_sym_namelen = 0;
 
 	for (nd = rb_first(&self->entries); nd; nd = rb_next(nd)) {
@@ -837,7 +842,8 @@ void hists__filter_by_thread(struct hists *self, const struct thread *thread)
 		h->filtered &= ~(1 << HIST_FILTER__THREAD);
 		if (!h->filtered) {
 			++self->nr_entries;
-			self->stats.total_period += h->count;
+			self->stats.total_period += h->period;
+			self->stats.nr_events[PERF_RECORD_SAMPLE] += h->nr_events;
 			if (h->ms.sym &&
 			    self->max_sym_namelen < h->ms.sym->namelen)
 				self->max_sym_namelen = h->ms.sym->namelen;
@@ -881,7 +887,7 @@ int hist_entry__inc_addr_samples(struct hist_entry *self, u64 ip)
 	h->sum++;
 	h->ip[offset]++;
 
-	pr_debug3("%#Lx %s: count++ [ip: %#Lx, %#Lx] => %Ld\n", self->ms.sym->start,
+	pr_debug3("%#Lx %s: period++ [ip: %#Lx, %#Lx] => %Ld\n", self->ms.sym->start,
 		  self->ms.sym->name, ip, ip - self->ms.sym->start, h->ip[offset]);
 	return 0;
 }

tools/perf/util/hist.h

@@ -69,7 +69,7 @@ struct hists {
 
 struct hist_entry *__hists__add_entry(struct hists *self,
 				      struct addr_location *al,
-				      struct symbol *parent, u64 count);
+				      struct symbol *parent, u64 period);
 extern int64_t hist_entry__cmp(struct hist_entry *, struct hist_entry *);
 extern int64_t hist_entry__collapse(struct hist_entry *, struct hist_entry *);
 int hist_entry__fprintf(struct hist_entry *self, struct hists *pair_hists,

tools/perf/util/newt.c

@@ -680,16 +680,18 @@ static int hist_browser__populate(struct hist_browser *self, struct hists *hists
 	struct ui_progress *progress;
 	struct rb_node *nd;
 	u64 curr_hist = 0;
-	char seq[] = ".";
+	char seq[] = ".", unit;
 	char str[256];
+	unsigned long nr_events = hists->stats.nr_events[PERF_RECORD_SAMPLE];
 
 	if (self->form) {
 		newtFormDestroy(self->form);
 		newtPopWindow();
 	}
 
-	snprintf(str, sizeof(str), "Samples: %Ld                            ",
-		 hists->stats.total_period);
+	nr_events = convert_unit(nr_events, &unit);
+	snprintf(str, sizeof(str), "Events: %lu%c                            ",
+		 nr_events, unit);
 	newtDrawRootText(0, 0, str);
 
 	newtGetScreenSize(NULL, &rows);