[PATCH v2 1/2] libperf: Add perf_evlist__reset_id_hash()

[Namhyung Kim]

Add the perf_evlist__reset_id_hash() function as an internal function
so that it can be called by perf to reset the hash table.  This is
necessary for perf stat to run the workload multiple times.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/lib/perf/evlist.c                  | 13 +++++++++----
 tools/lib/perf/include/internal/evlist.h |  2 ++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 17465d454a0e..a0aaf385cbb5 100644
--- a/tools/lib/perf/evlist.c
+++ b/tools/lib/perf/evlist.c
@@ -26,13 +26,10 @@
 
 void perf_evlist__init(struct perf_evlist *evlist)
 {
-	int i;
-
-	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
-		INIT_HLIST_HEAD(&evlist->heads[i]);
 	INIT_LIST_HEAD(&evlist->entries);
 	evlist->nr_entries = 0;
 	fdarray__init(&evlist->pollfd, 64);
+	perf_evlist__reset_id_hash(evlist);
 }
 
 static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
@@ -237,6 +234,14 @@ static void perf_evlist__id_hash(struct perf_evlist *evlist,
 	hlist_add_head(&sid->node, &evlist->heads[hash]);
 }
 
+void perf_evlist__reset_id_hash(struct perf_evlist *evlist)
+{
+	int i;
+
+	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
+		INIT_HLIST_HEAD(&evlist->heads[i]);
+}
+
 void perf_evlist__id_add(struct perf_evlist *evlist,
 			 struct perf_evsel *evsel,
 			 int cpu, int thread, u64 id)
diff --git a/tools/lib/perf/include/internal/evlist.h b/tools/lib/perf/include/internal/evlist.h
index 2d0fa02b036f..212c29063ad4 100644
--- a/tools/lib/perf/include/internal/evlist.h
+++ b/tools/lib/perf/include/internal/evlist.h
@@ -124,4 +124,6 @@ int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 			   struct perf_evsel *evsel,
 			   int cpu, int thread, int fd);
 
+void perf_evlist__reset_id_hash(struct perf_evlist *evlist);
+
 #endif /* __LIBPERF_INTERNAL_EVLIST_H */
-- 
2.30.0.617.g56c4b15f3c-goog