[RFC PATCH v4 11/15] perf stat: Handle taken alone in hardware-grouping

[weilin . wang]

From: Weilin Wang <weilin.wang@xxxxxxxxx>

Add taken alone into consideration when grouping. Only one taken
alone event is supported per group.

Signed-off-by: Weilin Wang <weilin.wang@xxxxxxxxx>
---
 tools/perf/pmu-events/jevents.py   |  7 ++++++-
 tools/perf/pmu-events/pmu-events.h |  1 +
 tools/perf/util/metricgroup.c      | 20 +++++++++++++++-----
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index bc91b7efa49a..4fbb367a3228 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -56,7 +56,9 @@ _json_event_attributes = [
     # The list of counter(s) this event could use
     'counters',
     # Longer things (the last won't be iterated over during decompress).
-    'long_desc'
+    'long_desc',
+    # Taken alone event could not be collected in the same group with other taken alone event
+    'taken_alone'
 ]
 
 # Attributes that are in pmu_unit_layout.
@@ -355,6 +357,9 @@ class JsonEvent:
     self.num_counters = jd.get('NumCounters')
     # Number of fixed counter
     self.num_fixed_counters = jd.get('NumFixedCounters')
+    # If the event is taken alone event, which cannot be grouped with any other
+    # taken alone event.
+    self.taken_alone = jd.get('TakenAlone')
     filter = jd.get('Filter')
     self.unit = jd.get('ScaleUnit')
     self.perpkg = jd.get('PerPkg')
diff --git a/tools/perf/pmu-events/pmu-events.h b/tools/perf/pmu-events/pmu-events.h
index e245e4738970..837edfeb676a 100644
--- a/tools/perf/pmu-events/pmu-events.h
+++ b/tools/perf/pmu-events/pmu-events.h
@@ -54,6 +54,7 @@ struct pmu_event {
 	const char *unit;
 	bool perpkg;
 	bool deprecated;
+	bool taken_alone;
 };
 
 struct pmu_metric {
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index fe115f0880f9..95d3868819e3 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -189,6 +189,7 @@ struct metricgroup__event_info {
 	/** The event uses special counters that we consider that as free counter
 	 *  during the event grouping*/
 	bool free_counter;
+	bool taken_alone;
 	/** The counters the event allowed to be collected on. */
 	DECLARE_BITMAP(counters, NR_COUNTERS);
 };
@@ -235,6 +236,7 @@ struct metricgroup__group {
 	DECLARE_BITMAP(fixed_counters, NR_COUNTERS);
 	/** Head to the list of event names in this group*/
 	struct list_head event_head;
+	bool taken_alone;
 };
 
 struct metricgroup__group_events {
@@ -1717,6 +1719,7 @@ static void metricgroup__free_pmu_info(struct list_head *pmu_info_list)
 static struct metricgroup__event_info *event_info__new(const char *name,
 						      const char *pmu_name,
 						      const char *counter,
+						      bool taken_alone,
 						      bool free_counter)
 {
 	int ret = 0;
@@ -1731,6 +1734,7 @@ static struct metricgroup__event_info *event_info__new(const char *name,
 		pmu_name = "core";
 
 	e->name = name;
+	e->taken_alone = taken_alone;
 	e->free_counter = free_counter;
 	e->pmu_name = pmu_name;
 	if (free_counter) {
@@ -1769,7 +1773,8 @@ static int metricgroup__add_metric_event_callback(const struct pmu_event *pe,
 	if (!strcasecmp(pe->name, d->event_name)) {
 		if (!pe->counters)
 			return -EINVAL;
-		event = event_info__new(d->event_id, pe->pmu, pe->counters, /*free_counter=*/false);
+		event = event_info__new(d->event_id, pe->pmu, pe->counters,
+					pe->taken_alone, /*free_counter=*/false);
 		if (!event)
 			return -ENOMEM;
 		list_add(&event->nd, d->list);
@@ -1892,6 +1897,8 @@ static int find_and_set_counters(struct metricgroup__event_info *e,
 	int ret;
 	unsigned long find_bit = 0;
 
+	if (e->taken_alone && current_group->taken_alone)
+		return -ENOSPC;
 	if (e->free_counter)
 		return 0;
 	if (e->fixed_counter) {
@@ -1926,11 +1933,13 @@ static int _insert_event(struct metricgroup__event_info *e,
 		list_add(&event->nd, &group->event_head);
 	else
 		list_add_tail(&event->nd, &group->event_head);
+	if (e->taken_alone)
+		group->taken_alone = true;
 	return 0;
 }
 
 /**
- * Insert the new_group node at the end of the group list.
+ * Initialize the new group and insert it to the end of the group list.
  */
 static int insert_new_group(struct list_head *head,
 			   struct metricgroup__group *new_group,
@@ -1940,6 +1949,7 @@ static int insert_new_group(struct list_head *head,
 	INIT_LIST_HEAD(&new_group->event_head);
 	fill_counter_bitmap(new_group->gp_counters, 0, num_counters);
 	fill_counter_bitmap(new_group->fixed_counters, 0, num_fixed_counters);
+	new_group->taken_alone = false;
 	list_add_tail(&new_group->nd, head);
 	return 0;
 }
@@ -2143,8 +2153,8 @@ static int create_grouping(struct list_head *pmu_info_list,
 	//TODO: for each new core group, we should consider to add events that uses fixed counters
 	list_for_each_entry(e, event_info_list, nd) {
 		bitmap_scnprintf(e->counters, NR_COUNTERS, bit_buf, NR_COUNTERS);
-		pr_debug("Event name %s, [pmu]=%s, [counters]=%s\n", e->name,
-			e->pmu_name, bit_buf);
+		pr_debug("Event name %s, [pmu]=%s, [counters]=%s, [taken_alone]=%d\n",
+			e->name, e->pmu_name, bit_buf, e->taken_alone);
 		ret = assign_event_grouping(e, pmu_info_list, &groups);
 		if (ret)
 			goto out;
@@ -2191,7 +2201,7 @@ static int hw_aware_build_grouping(struct expr_parse_ctx *ctx __maybe_unused,
 		if (is_special_event(id)) {
 			struct metricgroup__event_info *event;
 
-			event = event_info__new(id, "default_core", "0",
+			event = event_info__new(id, "default_core", "0", false,
 						/*free_counter=*/true);
 			if (!event)
 				goto err_out;
-- 
2.42.0