[RFC PATCH 11/25] perf stat: Add utility functions to hardware-grouping method

weilin.wang
2023-09-25T06:20:24Z

Add functions to handle counter bitmaps. Add functions do find and insert
operations to handle inserting event into groups.

Signed-off-by: Weilin Wang <weilin.wang@intel.com>
---
tools/lib/bitmap.c | 20 ++++++
tools/perf/util/metricgroup.c | 115 +++++++++++++++++++++++++++++++++-
2 files changed, 133 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index c3e487196..a96dbf001 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -100,3 +100,23 @@ bool __bitmap_intersects(const unsigned long *bitmap1,
return true;
return false;
}
+
+void bitmap_clear(unsigned long *map, unsigned int start, int len)
+{
+ unsigned long *p = map + BIT_WORD(start);
+ const unsigned int size = start + len;
+ int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+ unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+ while (len - bits_to_clear >= 0) {
+ *p &= ~mask_to_clear;
+ len -= bits_to_clear;
+ bits_to_clear = BITS_PER_LONG;
+ mask_to_clear = ~0UL;
+ p++;
+ }
+ if (len) {
+ mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+ *p &= ~mask_to_clear;
+ }
+}
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index de6a6a1d7..68d56087b 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1450,6 +1450,27 @@ static int set_counter_bitmap(int pos, unsigned long *bitmap)
return 0;
}

+static int find_counter_bitmap(unsigned long *addr1,
+ unsigned long *addr2,
+ unsigned long *bit)
+{
+ unsigned long find_bit = find_next_and_bit(addr1, addr2, NR_COUNTERS, 0);
+
+ if (find_bit == NR_COUNTERS)
+ return -ERANGE;
+ *bit = find_bit;
+ return 0;
+}
+
+static int use_counter_bitmap(unsigned long *bitmap,
+ unsigned long find_bit)
+{
+ if (find_bit >= NR_COUNTERS)
+ return -EINVAL;
+ bitmap_clear(bitmap, find_bit, 1);
+ return 0;
+}
+
static int parse_fixed_counter(const char *counter,
unsigned long *bitmap,
bool *fixed)
@@ -1681,12 +1702,102 @@ static int get_pmu_counter_layouts(struct list_head *pmu_info_list,
return ret;
}

+/**
+ * Find if there is a counter available for event e in current_group. If a
+ * counter is available, use this counter by fill the bit in the correct counter
+ * bitmap. Otherwise, return error (-ERANGE).
+ */
+static int find_and_set_counters(struct metricgroup__event_info *e,
+ struct metricgroup__group *current_group)
+{
+ int ret;
+ unsigned long find_bit = 0;
+
+ if (e->free_counter)
+ return 0;
+ if (e->fixed_counter) {
+ ret = find_counter_bitmap(current_group->fixed_counters, e->counters,
+ &find_bit);
+ if (ret)
+ return ret;
+ pr_debug("found counter for [event]=%s [e->fixed_counters]=%lu\n",
+ e->name, *current_group->fixed_counters);
+ ret = use_counter_bitmap(current_group->fixed_counters, find_bit);
+ } else {
+ ret = find_counter_bitmap(current_group->gp_counters, e->counters,
+ &find_bit);
+ if (ret)
+ return ret;
+ pr_debug("found counter for [event]=%s [e->gp_counters]=%lu\n",
+ e->name, *current_group->gp_counters);
+ ret = use_counter_bitmap(current_group->gp_counters, find_bit);
+ }
+ return ret;
+}
+
+static int _insert_event(struct metricgroup__event_info *e,
+ struct metricgroup__group *group)
+{
+ struct metricgroup__group_events *event = malloc(sizeof(struct metricgroup__group_events));
+
+ if (!event)
+ return -ENOMEM;
+ event->event_name = e->name;
+ if (e->fixed_counter)
+ list_add(&event->nd, &group->event_head);
+ else
+ list_add_tail(&event->nd, &group->event_head);
+ return 0;
+}
+
+/**
+ * Insert event e into a group capable to include it
+ *
+ */
+static int insert_event_to_group(struct metricgroup__event_info *e,
+ struct metricgroup__pmu_group_list *pmu_group_head)
+{
+ struct metricgroup__group *g;
+ int ret;
+ //struct list_head *head;
+
+ list_for_each_entry(g, &pmu_group_head->group_head, nd) {
+ ret = find_and_set_counters(e, g);
+ if (!ret) { /* return if successfully find and set counter*/
+ ret = _insert_event(e, g);
+ return ret;
+ }
+ }
+ /*
+ * We were not able to find an existing group to insert this event.
+ * Continue to create a new group and insert the event in it.
+ */
+ {
+ struct metricgroup__group *current_group = malloc(sizeof(struct metricgroup__group));
+ if (!current_group)
+ return -ENOMEM;
+ pr_debug("create_new_group for [event] %s\n", e->name);
+
+ //head = &pmu_group_head->group_head;
+ //ret = create_new_group(head, current_group, pmu_group_head->size,
+ // pmu_group_head->fixed_size);
+ if (ret)
+ return ret;
+ ret = find_and_set_counters(e, current_group);
+ if (ret)
+ return ret;
+ ret = _insert_event(e, current_group);
+ }
+
+ 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 *pmu_info_list,
struct list_head *groups)
{
int ret = 0;
@@ -1717,7 +1828,7 @@ static int assign_event_grouping(struct metricgroup__event_info *e,
list_add_tail(&pmu_group_head->nd, groups);
}

- //ret = insert_event_to_group(e, pmu_group_head, pmu_info_list);
+ ret = insert_event_to_group(e, pmu_group_head);
return ret;
}

--
2.39.3