releases/4.9.231/perf-stat-zero-all-the-ena-and-run-array-slot-stats-for-interval-mode.patch

From 0e0bf1ea1147fcf74eab19c2d3c853cc3740a72f Mon Sep 17 00:00:00 2001
From: Jin Yao <yao.jin@linux.intel.com>
Date: Thu, 9 Apr 2020 15:07:55 +0800
Subject: perf stat: Zero all the 'ena' and 'run' array slot stats for interval mode

From: Jin Yao <yao.jin@linux.intel.com>

commit 0e0bf1ea1147fcf74eab19c2d3c853cc3740a72f upstream.

As the code comments in perf_stat_process_counter() say, we calculate
counter's data every interval, and the display code shows ps->res_stats
avg value. We need to zero the stats for interval mode.

But the current code only zeros the res_stats[0], it doesn't zero the
res_stats[1] and res_stats[2], which are for ena and run of counter.

This patch zeros the whole res_stats[] for interval mode.

Fixes: 51fd2df1e882 ("perf stat: Fix interval output values")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200409070755.17261-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/perf/util/stat.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -341,8 +341,10 @@ int perf_stat_process_counter(struct per
 	 * interval mode, otherwise overall avg running
 	 * averages will be shown for each interval.
 	 */
-	if (config->interval)
-		init_stats(ps->res_stats);
+	if (config->interval) {
+		for (i = 0; i < 3; i++)
+			init_stats(&ps->res_stats[i]);
+	}
 
 	if (counter->per_pkg)
 		zero_per_pkg(counter);