perf stat: Handle partially bad results with merging

When any result that is being merged is bad, mark them all bad to give
consistent output in interval mode.

No before/after, because the issue was only found in theoretical review
and it is hard to reproduce

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170320201711.14142-4-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a4da10a506dd533acea6682d7054a0c0561ba3a1..cd7dc3b648cafa08eafae178495fc44918b61fa9 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1237,6 +1237,16 @@ static void aggr_cb(struct perf_evsel *counter, void *data, bool first)
                if (first)
                        ad->nr++;
                counts = perf_counts(counter->counts, cpu, 0);
+               /*
+                * When any result is bad, make them all to give
+                * consistent output in interval mode.
+                */
+               if (counts->ena == 0 || counts->run == 0 ||
+                   counter->counts->scaled == -1) {
+                       ad->ena = 0;
+                       ad->run = 0;
+                       break;
+               }
                ad->val += counts->val;
                ad->ena += counts->ena;
                ad->run += counts->run;