perf stat: Save aggr value to first member of prev_raw_counts

To collect the overall statistics for interval mode, we copy the counts
from evsel->prev_raw_counts to evsel->counts.

For AGGR_GLOBAL mode, because the perf_stat_process_counter creates aggr
values from per cpu values, but the per cpu values are 0, so the
calculated aggr values will be always 0.

This patch uses a trick that saves the previous aggr value to the first
member of perf_counts, then aggr calculation in process_counter_values
can work correctly for AGGR_GLOBAL.

 v6:
 ---
 Add comments in perf_evlist__save_aggr_prev_raw_counts.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200520042737.24160-5-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index aadc723..d23109c 100644 (file)
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -249,6 +249,26 @@ void perf_evlist__copy_prev_raw_counts(struct evlist *evlist)
                perf_evsel__copy_prev_raw_counts(evsel);
 }
 
+void perf_evlist__save_aggr_prev_raw_counts(struct evlist *evlist)
+{
+       struct evsel *evsel;
+
+       /*
+        * To collect the overall statistics for interval mode,
+        * we copy the counts from evsel->prev_raw_counts to
+        * evsel->counts. The perf_stat_process_counter creates
+        * aggr values from per cpu values, but the per cpu values
+        * are 0 for AGGR_GLOBAL. So we use a trick that saves the
+        * previous aggr value to the first member of perf_counts,
+        * then aggr calculation in process_counter_values can work
+        * correctly.
+        */
+       evlist__for_each_entry(evlist, evsel) {
+               *perf_counts(evsel->prev_raw_counts, 0, 0) =
+                       evsel->prev_raw_counts->aggr;
+       }
+}
+
 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 62cf72c..18ead55 100644 (file)
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -199,6 +199,7 @@ 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);
+void perf_evlist__save_aggr_prev_raw_counts(struct evlist *evlist);
 
 int perf_stat_process_counter(struct perf_stat_config *config,
                              struct evsel *counter);