[RFC PATCH v2 13/17] 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      | 18 +++++++++++++-----
 tools/perf/util/metricgroup.h      |  2 ++
 4 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 1b3776c92..8566ea225 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -55,7 +55,9 @@ _json_event_attributes = [
     # Counter this event could use
     'counter',
     # 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.
@@ -71,7 +73,7 @@ _json_metric_attributes = [
 ]
 # Attributes that are bools or enum int values, encoded as '0', '1',...
 _json_enum_attributes = ['aggr_mode', 'deprecated', 'event_grouping', 'perpkg',
-    'size', 'fixed_size'
+    'size', 'fixed_size', 'taken_alone'
 ]
 
 def removesuffix(s: str, suffix: str) -> str:
@@ -330,6 +332,7 @@ class JsonEvent:
       extra_desc += '  Spec update: ' + jd['Errata']
     self.pmu = unit_to_pmu(jd.get('Unit'))
     self.counter = jd.get('Counter')
+    self.taken_alone = jd.get('TakenAlone')
     self.size = jd.get('Size')
     self.fixed_size = jd.get('FixedSize')
     filter = jd.get('Filter')
diff --git a/tools/perf/pmu-events/pmu-events.h b/tools/perf/pmu-events/pmu-events.h
index 65e0c5dd8..ce10356e9 100644
--- a/tools/perf/pmu-events/pmu-events.h
+++ b/tools/perf/pmu-events/pmu-events.h
@@ -50,6 +50,7 @@ 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 9211e8c09..100c9d948 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1624,6 +1624,7 @@ 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;
@@ -1638,6 +1639,7 @@ 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) {
@@ -1676,7 +1678,8 @@ static int metricgroup__add_metric_event_callback(const struct pmu_event *pe,
 	if (!strcasecmp(pe->name, d->event_name)) {
 		if (!pe->counter)
 			return -EINVAL;
-		event = event_info__new(d->event_id, pe->pmu, pe->counter, /*free_counter=*/false);
+		event = event_info__new(d->event_id, pe->pmu, pe->counter,
+					pe->taken_alone, /*free_counter=*/false);
 		if (!event)
 			return -ENOMEM;
 		list_add(&event->nd, d->list);
@@ -1799,6 +1802,8 @@ 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) {
@@ -1833,11 +1838,13 @@ 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,
@@ -1847,6 +1854,7 @@ static int insert_new_group(struct list_head *head,
 	INIT_LIST_HEAD(&new_group->event_head);
 	fill_counter_bitmap(new_group->gp_counters, 0, size);
 	fill_counter_bitmap(new_group->fixed_counters, 0, fixed_size);
+	new_group->taken_alone = false;
 	list_add_tail(&new_group->nd, head);
 	return 0;
 }
@@ -2050,8 +2058,8 @@ 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;
@@ -2098,7 +2106,7 @@ 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;
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 37fdf8c5b..8f6a1bb9d 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -105,6 +105,7 @@ struct metricgroup__event_info {
 	const char *pmu_name;
 	bool fixed_counter;
 	bool free_counter;
+	bool taken_alone;
 	/** The counters the event allowed to be collected on. */
 	DECLARE_BITMAP(counters, NR_COUNTERS);
 };
@@ -154,6 +155,7 @@ 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 {
-- 
2.39.3