diff mbox series

[v2,4/7] perf metricgroup: Order event groups by size

Message ID 20200520182011.32236-5-irogers@google.com
State Not Applicable
Delegated to: BPF Maintainers
Headers show
Series Share events between metrics | expand

Commit Message

Ian Rogers May 20, 2020, 6:20 p.m. UTC 
When adding event groups to the group list, insert them in size order.
This performs an insertion sort on the group list. By placing the
largest groups at the front of the group list it is possible to see if a
larger group contains the same events as a later group. This can make
the later group redundant - it can reuse the events from the large group.
A later patch will add this sharing.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/metricgroup.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index dca433520b92..bac63524d12f 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -508,7 +508,21 @@  static int __metricgroup__add_metric(struct list_head *group_list,
 		return -EINVAL;
 	}
 
-	list_add_tail(&eg->nd, group_list);
+	if (list_empty(group_list))
+		list_add(&eg->nd, group_list);
+	else {
+		struct list_head *pos;
+
+		/* Place the largest groups at the front. */
+		list_for_each_prev(pos, group_list) {
+			struct egroup *old = list_entry(pos, struct egroup, nd);
+
+			if (hashmap__size(&eg->pctx.ids) <=
+			    hashmap__size(&old->pctx.ids))
+				break;
+		}
+		list_add(&eg->nd, pos);
+	}
 
 	return 0;
 }