libperf: Add perf_evlist__reset_id_hash()

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@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210225035148.778569-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 17465d454a0e31d912f7d0782d3f0bc19b6bfcdd..a0aaf385cbb5855e48a46d37c49209a23c0c162e 100644 (file)
--- 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 2d0fa02b036f604646663ca5703bd13c12a00ae2..212c29063ad42ccc7891e5e17446ef6ab1827ef9 100644 (file)
--- 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 */