[RFC PATCH 10/25] perf stat: Add helper functions to hardware-grouping method

[weilin . wang]

From: Weilin Wang <weilin.wang@xxxxxxxxx>

Add struct metricgroup__pmu_group_list to hold the lists of groups from
different PMUs. Each PMU has one separate list.

Add struct metricgroup__group as one node (one group in the grouping
result) of the metricgroup__pmu_group_list. It uses two bitmaps to log
counter availabilities(gp counters and fixed counters).

Add functions to create group and assign event into the groups based on the
event restrictions (struct metricgroup__event_info) and counter
availability (pmu_info_list and bitmaps). New group is inserted into the
list groups.

Signed-off-by: Weilin Wang <weilin.wang@xxxxxxxxx>
---
 tools/perf/util/metricgroup.c | 72 +++++++++++++++++++++++++++++++++++
 tools/perf/util/metricgroup.h | 37 ++++++++++++++++++
 2 files changed, 109 insertions(+)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 0ca885a42..de6a6a1d7 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1681,6 +1681,76 @@ static int get_pmu_counter_layouts(struct list_head *pmu_info_list,
 	return ret;
 }
 
+/**
+ * assign_event_grouping - Assign an event into a group. If existing group
+ * cannot include it, create a new group and insert the event to it.
+ */
+static int assign_event_grouping(struct metricgroup__event_info *e,
+				struct list_head *pmu_info_list __maybe_unused,
+				struct list_head *groups)
+{
+	int ret = 0;
+
+	struct metricgroup__pmu_group_list *g = NULL;
+	struct metricgroup__pmu_group_list *pmu_group_head = NULL;
+
+	list_for_each_entry(g, groups, nd) {
+		if (!strcasecmp(g->pmu_name, e->pmu_name)) {
+			pr_debug("found group for event %s in pmu %s\n", e->name, g->pmu_name);
+			pmu_group_head = g;
+			break;
+		}
+	}
+	if (!pmu_group_head) {
+		struct metricgroup__pmu_counters *p;
+
+		pmu_group_head = malloc(sizeof(struct metricgroup__pmu_group_list));
+		INIT_LIST_HEAD(&pmu_group_head->group_head);
+		pr_debug("create new group for event %s in pmu %s ", e->name, e->pmu_name);
+		pmu_group_head->pmu_name = e->pmu_name;
+		list_for_each_entry(p, pmu_info_list, nd) {
+			if (!strcasecmp(p->name, e->pmu_name)) {
+				pmu_group_head->size = p->size;
+				pmu_group_head->fixed_size = p->fixed_size;
+			}
+		}
+		list_add_tail(&pmu_group_head->nd, groups);
+	}
+
+	//ret = insert_event_to_group(e, pmu_group_head, pmu_info_list);
+	return ret;
+}
+
+/**
+ * create_grouping - Create a list of groups and place all the events of
+ * event_info_list into these groups.
+ * @pmu_info_list: the list of PMU units info based on pmu-events data, used for
+ * creating new groups.
+ * @event_info_list: the list of events to be grouped.
+ * @groupings: the list of groups with events placed in.
+ * @modifier: any modifiers added to the events.
+ */
+static int create_grouping(struct list_head *pmu_info_list,
+			  struct list_head *event_info_list,
+			  struct list_head *groupings __maybe_unused,
+			  const char *modifier __maybe_unused)
+{
+	int ret = 0;
+	struct metricgroup__event_info *e;
+	LIST_HEAD(groups);
+	char *bit_buf = malloc(NR_COUNTERS);
+
+	//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);
+		ret = assign_event_grouping(e, pmu_info_list, &groups);
+	}
+
+	return ret;
+};
+
 /**
  * hw_aware_build_grouping - Build event groupings by reading counter
  * requirement of the events and counter available on the system from
@@ -1714,6 +1784,8 @@ static int hw_aware_build_grouping(struct expr_parse_ctx *ctx __maybe_unused,
 	ret = get_pmu_counter_layouts(&pmu_info_list, ltable);
 	if (ret)
 		goto err_out;
+	ret = create_grouping(&pmu_info_list, &event_info_list, groupings,
+			     modifier);
 
 err_out:
 	metricgroup__free_event_info(&event_info_list);
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 8ee7b434e..f9f8b7498 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -100,6 +100,43 @@ struct metricgroup__pmu_counters {
 	size_t fixed_size;
 };
 
+/**
+ * A list of groups for this pmu.
+ * This is updated during the grouping.
+ */
+struct metricgroup__pmu_group_list {
+	struct list_head nd;
+	/** The name of the pmu(/core) the events collected on. */
+	const char *pmu_name;
+	/** The number of gp counters in the pmu(/core). */
+	size_t size;
+	/** The number of fixed counters in the pmu(/core) if applicable. */
+	size_t fixed_size;
+	/** Head to the list of groups using this pmu(/core)*/
+	struct list_head group_head;
+};
+
+/**
+ * This is one node in the metricgroup__pmu_group_list.
+ * It represents on group.
+ */
+struct metricgroup__group {
+	struct list_head nd;
+	/** The bitmaps represent availability of the counters.
+	 *  They are updated once the corresponding counter is used by
+	 *  an event (event inserted into the group).
+	 */
+	DECLARE_BITMAP(gp_counters, NR_COUNTERS);
+	DECLARE_BITMAP(fixed_counters, NR_COUNTERS);
+	/** Head to the list of event names in this group*/
+	struct list_head event_head;
+};
+
+struct metricgroup__group_events {
+	struct list_head nd;
+	const char *event_name;
+};
+
 /**
  * Each group is one node in the group string list.
  */
-- 
2.39.3