perf hist: Introduce hists class and move lots of methods to it

In cbbc79a we introduced support for multiple events by introducing a
new "event_stat_id" struct and then made several perf_session methods
receive a point to it instead of a pointer to perf_session, and kept the
event_stats and hists rb_tree in perf_session.

While working on the new newt based browser, I realised that it would be
better to introduce a new class, "hists" (short for "histograms"),
renaming the "event_stat_id" struct and the perf_session methods that
were really "hists" methods, as they manipulate only struct hists
members, not touching anything in the other perf_session members.

Other optimizations, such as calculating the maximum lenght of a symbol
name present in an hists instance will be possible as we add them,
avoiding a re-traversal just for finding that information.

The rationale for the name "hists" to replace "event_stat_id" is that we
may have multiple sets of hists for the same event_stat id, as, for
instance, the 'perf diff' tool has, so event stat id is not what
characterizes what this struct and the functions that manipulate it do.

Cc: Eric B Munson <ebmunson@us.ibm.com>
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-annotate.c

@@ -96,8 +96,7 @@ static int annotate__hist_hit(struct hist_entry *he, u64 ip)
 	return 0;
 }
 
-static int perf_session__add_hist_entry(struct perf_session *self,
-					struct addr_location *al)
+static int hists__add_entry(struct hists *self, struct addr_location *al)
 {
 	struct hist_entry *he;
 
@@ -112,7 +111,7 @@ static int perf_session__add_hist_entry(struct perf_session *self,
 		return 0;
 	}
 
-	he = __perf_session__add_hist_entry(&self->hists, al, NULL, 1);
+	he = __hists__add_entry(self, al, NULL, 1);
 	if (he == NULL)
 		return -ENOMEM;
 
@@ -132,7 +131,7 @@ static int process_sample_event(event_t *event, struct perf_session *session)
 		return -1;
 	}
 
-	if (!al.filtered && perf_session__add_hist_entry(session, &al)) {
+	if (!al.filtered && hists__add_entry(&session->hists, &al)) {
 		pr_warning("problem incrementing symbol count, "
 			   "skipping event\n");
 		return -1;
@@ -514,11 +513,11 @@ static void annotate_sym(struct hist_entry *he)
 		free_source_line(he, len);
 }
 
-static void perf_session__find_annotations(struct perf_session *self)
+static void hists__find_annotations(struct hists *self)
 {
 	struct rb_node *nd;
 
-	for (nd = rb_first(&self->hists); nd; nd = rb_next(nd)) {
+	for (nd = rb_first(&self->entries); nd; nd = rb_next(nd)) {
 		struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);
 		struct sym_priv *priv;
 
@@ -570,9 +569,9 @@ static int __cmd_annotate(void)
 	if (verbose > 2)
 		perf_session__fprintf_dsos(session, stdout);
 
-	perf_session__collapse_resort(&session->hists);
-	perf_session__output_resort(&session->hists, session->event_total[0]);
-	perf_session__find_annotations(session);
+	hists__collapse_resort(&session->hists);
+	hists__output_resort(&session->hists);
+	hists__find_annotations(&session->hists);
 out_delete:
 	perf_session__delete(session);
 

tools/perf/builtin-diff.c

@@ -22,10 +22,10 @@ static char	  diff__default_sort_order[] = "dso,symbol";
 static bool  force;
 static bool show_displacement;
 
-static int perf_session__add_hist_entry(struct perf_session *self,
-					struct addr_location *al, u64 count)
+static int hists__add_entry(struct hists *self,
+			    struct addr_location *al, u64 count)
 {
-	if (__perf_session__add_hist_entry(&self->hists, al, NULL, count) != NULL)
+	if (__hists__add_entry(self, al, NULL, count) != NULL)
 		return 0;
 	return -ENOMEM;
 }
@@ -49,12 +49,12 @@ static int diff__process_sample_event(event_t *event, struct perf_session *sessi
 
 	event__parse_sample(event, session->sample_type, &data);
 
-	if (perf_session__add_hist_entry(session, &al, data.period)) {
+	if (hists__add_entry(&session->hists, &al, data.period)) {
 		pr_warning("problem incrementing symbol count, skipping event\n");
 		return -1;
 	}
 
-	session->events_stats.total += data.period;
+	session->hists.stats.total += data.period;
 	return 0;
 }
 
@@ -87,35 +87,34 @@ static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
 	rb_insert_color(&he->rb_node, root);
 }
 
-static void perf_session__resort_hist_entries(struct perf_session *self)
+static void hists__resort_entries(struct hists *self)
 {
 	unsigned long position = 1;
 	struct rb_root tmp = RB_ROOT;
-	struct rb_node *next = rb_first(&self->hists);
+	struct rb_node *next = rb_first(&self->entries);
 
 	while (next != NULL) {
 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
 
 		next = rb_next(&n->rb_node);
-		rb_erase(&n->rb_node, &self->hists);
+		rb_erase(&n->rb_node, &self->entries);
 		n->position = position++;
 		perf_session__insert_hist_entry_by_name(&tmp, n);
 	}
 
-	self->hists = tmp;
+	self->entries = tmp;
 }
 
-static void perf_session__set_hist_entries_positions(struct perf_session *self)
+static void hists__set_positions(struct hists *self)
 {
-	perf_session__output_resort(&self->hists, self->events_stats.total);
-	perf_session__resort_hist_entries(self);
+	hists__output_resort(self);
+	hists__resort_entries(self);
 }
 
-static struct hist_entry *
-perf_session__find_hist_entry(struct perf_session *self,
-			      struct hist_entry *he)
+static struct hist_entry *hists__find_entry(struct hists *self,
+					    struct hist_entry *he)
 {
-	struct rb_node *n = self->hists.rb_node;
+	struct rb_node *n = self->entries.rb_node;
 
 	while (n) {
 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
@@ -132,14 +131,13 @@ perf_session__find_hist_entry(struct perf_session *self,
 	return NULL;
 }
 
-static void perf_session__match_hists(struct perf_session *old_session,
-				      struct perf_session *new_session)
+static void hists__match(struct hists *older, struct hists *newer)
 {
 	struct rb_node *nd;
 
-	for (nd = rb_first(&new_session->hists); nd; nd = rb_next(nd)) {
+	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
-		pos->pair = perf_session__find_hist_entry(old_session, pos);
+		pos->pair = hists__find_entry(older, pos);
 	}
 }
 
@@ -159,15 +157,13 @@ static int __cmd_diff(void)
 			goto out_delete;
 	}
 
-	perf_session__output_resort(&session[1]->hists,
-				    session[1]->events_stats.total);
+	hists__output_resort(&session[1]->hists);
 	if (show_displacement)
-		perf_session__set_hist_entries_positions(session[0]);
+		hists__set_positions(&session[0]->hists);
 
-	perf_session__match_hists(session[0], session[1]);
-	perf_session__fprintf_hists(&session[1]->hists, session[0],
-				    show_displacement, stdout,
-				    session[1]->events_stats.total);
+	hists__match(&session[0]->hists, &session[1]->hists);
+	hists__fprintf(&session[1]->hists, &session[0]->hists,
+		       show_displacement, stdout);
 out_delete:
 	for (i = 0; i < 2; ++i)
 		perf_session__delete(session[i]);

tools/perf/builtin-report.c

@@ -44,16 +44,17 @@ static char		*pretty_printing_style = default_pretty_printing_style;
 
 static char		callchain_default_opt[] = "fractal,0.5";
 
-static struct event_stat_id *get_stats(struct perf_session *self,
-				       u64 event_stream, u32 type, u64 config)
+static struct hists *perf_session__hists_findnew(struct perf_session *self,
+						 u64 event_stream, u32 type,
+						 u64 config)
 {
-	struct rb_node **p = &self->stats_by_id.rb_node;
+	struct rb_node **p = &self->hists_tree.rb_node;
 	struct rb_node *parent = NULL;
-	struct event_stat_id *iter, *new;
+	struct hists *iter, *new;
 
 	while (*p != NULL) {
 		parent = *p;
-		iter = rb_entry(parent, struct event_stat_id, rb_node);
+		iter = rb_entry(parent, struct hists, rb_node);
 		if (iter->config == config)
 			return iter;
 
@@ -64,15 +65,15 @@ static struct event_stat_id *get_stats(struct perf_session *self,
 			p = &(*p)->rb_left;
 	}
 
-	new = malloc(sizeof(struct event_stat_id));
+	new = malloc(sizeof(struct hists));
 	if (new == NULL)
 		return NULL;
-	memset(new, 0, sizeof(struct event_stat_id));
+	memset(new, 0, sizeof(struct hists));
 	new->event_stream = event_stream;
 	new->config = config;
 	new->type = type;
 	rb_link_node(&new->rb_node, parent, p);
-	rb_insert_color(&new->rb_node, &self->stats_by_id);
+	rb_insert_color(&new->rb_node, &self->hists_tree);
 	return new;
 }
 
@@ -84,7 +85,7 @@ static int perf_session__add_hist_entry(struct perf_session *self,
 	struct symbol *parent = NULL;
 	int err = -ENOMEM;
 	struct hist_entry *he;
-	struct event_stat_id *stats;
+	struct hists *hists;
 	struct perf_event_attr *attr;
 
 	if ((sort__has_parent || symbol_conf.use_callchain) && data->callchain) {
@@ -96,13 +97,12 @@ static int perf_session__add_hist_entry(struct perf_session *self,
 
 	attr = perf_header__find_attr(data->id, &self->header);
 	if (attr)
-		stats = get_stats(self, data->id, attr->type, attr->config);
+		hists = perf_session__hists_findnew(self, data->id, attr->type, attr->config);
 	else
-		stats = get_stats(self, data->id, 0, 0);
-	if (stats == NULL)
+		hists = perf_session__hists_findnew(self, data->id, 0, 0);
+	if (hists == NULL)
 		goto out_free_syms;
-	he = __perf_session__add_hist_entry(&stats->hists, al, parent,
-					    data->period);
+	he = __hists__add_entry(hists, al, parent, data->period);
 	if (he == NULL)
 		goto out_free_syms;
 	err = 0;
@@ -117,18 +117,19 @@ static int add_event_total(struct perf_session *session,
 			   struct sample_data *data,
 			   struct perf_event_attr *attr)
 {
-	struct event_stat_id *stats;
+	struct hists *hists;
 
 	if (attr)
-		stats = get_stats(session, data->id, attr->type, attr->config);
+		hists = perf_session__hists_findnew(session, data->id,
+						    attr->type, attr->config);
 	else
-		stats = get_stats(session, data->id, 0, 0);
+		hists = perf_session__hists_findnew(session, data->id, 0, 0);
 
-	if (!stats)
+	if (!hists)
 		return -ENOMEM;
 
-	stats->stats.total += data->period;
-	session->events_stats.total += data->period;
+	hists->stats.total += data->period;
+	session->hists.stats.total += data->period;
 	return 0;
 }
 
@@ -292,35 +293,33 @@ static int __cmd_report(void)
 	if (verbose > 2)
 		perf_session__fprintf_dsos(session, stdout);
 
-	next = rb_first(&session->stats_by_id);
+	next = rb_first(&session->hists_tree);
 	while (next) {
-		struct event_stat_id *stats;
+		struct hists *hists;
 		u64 nr_hists;
 
-		stats = rb_entry(next, struct event_stat_id, rb_node);
-		perf_session__collapse_resort(&stats->hists);
-		nr_hists = perf_session__output_resort(&stats->hists,
-						       stats->stats.total);
+		hists = rb_entry(next, struct hists, rb_node);
+		hists__collapse_resort(hists);
+		nr_hists = hists__output_resort(hists);
 		if (use_browser)
-			perf_session__browse_hists(&stats->hists, nr_hists,
-						   stats->stats.total, help,
+			perf_session__browse_hists(&hists->entries, nr_hists,
+						   hists->stats.total, help,
 						   input_name);
 		else {
-			if (rb_first(&session->stats_by_id) ==
-			    rb_last(&session->stats_by_id))
+			if (rb_first(&session->hists.entries) ==
+			    rb_last(&session->hists.entries))
 				fprintf(stdout, "# Samples: %Ld\n#\n",
-					stats->stats.total);
+					hists->stats.total);
 			else
 				fprintf(stdout, "# Samples: %Ld %s\n#\n",
-					stats->stats.total,
-					__event_name(stats->type, stats->config));
+					hists->stats.total,
+					__event_name(hists->type, hists->config));
 
-			perf_session__fprintf_hists(&stats->hists, NULL, false, stdout,
-					    stats->stats.total);
+			hists__fprintf(hists, NULL, false, stdout);
 			fprintf(stdout, "\n\n");
 		}
 
-		next = rb_next(&stats->rb_node);
+		next = rb_next(&hists->rb_node);
 	}
 
 	if (!use_browser && sort_order == default_sort_order &&

tools/perf/builtin-trace.c

@@ -107,7 +107,7 @@ static int process_sample_event(event_t *event, struct perf_session *session)
 					     data.time, thread->comm);
 	}
 
-	session->events_stats.total += data.period;
+	session->hists.stats.total += data.period;
 	return 0;
 }
 

tools/perf/util/event.c

@@ -368,7 +368,7 @@ int event__process_comm(event_t *self, struct perf_session *session)
 int event__process_lost(event_t *self, struct perf_session *session)
 {
 	dump_printf(": id:%Ld: lost:%Ld\n", self->lost.id, self->lost.lost);
-	session->events_stats.lost += self->lost.lost;
+	session->hists.stats.lost += self->lost.lost;
 	return 0;
 }
 

tools/perf/util/event.h

@@ -131,20 +131,6 @@ typedef union event_union {
 	struct build_id_event		build_id;
 } event_t;
 
-struct events_stats {
-	u64 total;
-	u64 lost;
-};
-
-struct event_stat_id {
-	struct rb_node		rb_node;
-	struct rb_root		hists;
-	struct events_stats	stats;
-	u64			config;
-	u64			event_stream;
-	u32			type;
-};
-
 void event__print_totals(void);
 
 struct perf_session;