[PATCH v3 3/4] perf stat: Copy counts from prev_raw_counts to evsel->counts

[Jin Yao]

It would be useful to support the overall statistics for perf-stat
interval mode. For example, report the summary at the end of
"perf-stat -I" output.

But since perf-stat can support many aggregation modes, such as
--per-thread, --per-socket, -M and etc, we need a solution which
doesn't bring much complexity.

The idea is to use 'evsel->prev_raw_counts' which is updated in
each interval and it's saved with the latest counts. Before reporting
the summary, we copy the counts from evsel->prev_raw_counts to
evsel->counts, and next we just follow non-interval processing.

In evsel__compute_deltas, this patch saves counts to the position
of [cpu0,thread0] for AGGR_GLOBAL. After copying counts from
evsel->prev_raw_counts to evsel->counts, we don't need to
modify process_counter_maps in perf_stat_process_counter to let it
work well.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/util/evsel.c |  1 +
 tools/perf/util/stat.c  | 24 ++++++++++++++++++++++++
 tools/perf/util/stat.h  |  1 +
 3 files changed, 26 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f3e60c45d59a..898a697c7cdd 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1288,6 +1288,7 @@ void evsel__compute_deltas(struct evsel *evsel, int cpu, int thread,
 	if (cpu == -1) {
 		tmp = evsel->prev_raw_counts->aggr;
 		evsel->prev_raw_counts->aggr = *count;
+		*perf_counts(evsel->prev_raw_counts, 0, 0) = *count;
 	} else {
 		tmp = *perf_counts(evsel->prev_raw_counts, cpu, thread);
 		*perf_counts(evsel->prev_raw_counts, cpu, thread) = *count;
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 89e541564ed5..ede113805ecd 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -230,6 +230,30 @@ void perf_evlist__reset_prev_raw_counts(struct evlist *evlist)
 		perf_evsel__reset_prev_raw_counts(evsel);
 }
 
+static void perf_evsel__copy_prev_raw_counts(struct evsel *evsel)
+{
+	int ncpus = evsel__nr_cpus(evsel);
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
+
+	for (int thread = 0; thread < nthreads; thread++) {
+		for (int cpu = 0; cpu < ncpus; cpu++) {
+			*perf_counts(evsel->counts, cpu, thread) =
+				*perf_counts(evsel->prev_raw_counts, cpu,
+					     thread);
+		}
+	}
+
+	evsel->counts->aggr = evsel->prev_raw_counts->aggr;
+}
+
+void perf_evlist__copy_prev_raw_counts(struct evlist *evlist)
+{
+	struct evsel *evsel;
+
+	evlist__for_each_entry(evlist, evsel)
+		perf_evsel__copy_prev_raw_counts(evsel);
+}
+
 static void zero_per_pkg(struct evsel *counter)
 {
 	if (counter->per_pkg_mask)
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index b4fdfaa7f2c0..62cf72c71869 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -198,6 +198,7 @@ int perf_evlist__alloc_stats(struct evlist *evlist, bool alloc_raw);
 void perf_evlist__free_stats(struct evlist *evlist);
 void perf_evlist__reset_stats(struct evlist *evlist);
 void perf_evlist__reset_prev_raw_counts(struct evlist *evlist);
+void perf_evlist__copy_prev_raw_counts(struct evlist *evlist);
 
 int perf_stat_process_counter(struct perf_stat_config *config,
 			      struct evsel *counter);
-- 
2.17.1