linux-kernel - Re: [PATCH] perf metricgroup: Fix for metrics containing duration

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Date:   Thu, 21 Jan 2021 17:14:07 +0000
From:   John Garry <john.garry@...wei.com>
To:     Ian Rogers <irogers@...gle.com>
CC:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        "Namhyung Kim" <namhyung@...nel.org>,
        kajoljain <kjain@...ux.ibm.com>,
        LKML <linux-kernel@...r.kernel.org>, <linuxarm@...neuler.org>,
        Joakim Zhang <qiangqing.zhang@....com>
Subject: Re: [PATCH] perf metricgroup: Fix for metrics containing
 duration_time


>      >
>      >
>      > Thanks for this, it should be fairly easy to add a test. Could we
>     do this?
> 
>     I don't mind following up with that.

How about this:

---- >8 ----

 From 38e9d5aa07588d552378d97760b6b79f19d59bbd Mon Sep 17 00:00:00 2001
From: John Garry <john.garry@...wei.com>
Date: Thu, 21 Jan 2021 16:55:17 +0000
Subject: [PATCH] perf test: Add parse-metric memory bandwidth testcase

Event duration_time in a metric expression requires special handling.

Improve test coverage by including a metric whose expression includes
duration_time. The actual metric is copied from the L1D_Cache_Fill_BW
metric on my broadwell machine.

Signed-off-by: John Garry <john.garry@...wei.com>

diff --git a/tools/perf/tests/parse-metric.c 
b/tools/perf/tests/parse-metric.c
index ce7be37f0d88..98b9570c6194 100644
--- a/tools/perf/tests/parse-metric.c
+++ b/tools/perf/tests/parse-metric.c
@@ -11,6 +11,7 @@
  #include "debug.h"
  #include "expr.h"
  #include "stat.h"
+#include <math.h>

  static struct pmu_event pme_test[] = {
  {
@@ -69,6 +70,10 @@ static struct pmu_event pme_test[] = {
  	.metric_expr	= "1/m3",
  	.metric_name	= "M3",
  },
+{
+	.metric_expr	= "64 * l1d.replacement / 1000000000 / duration_time",
+	.metric_name	= "L1D_Cache_Fill_BW",
+},
  {
  	.name	= NULL,
  }
@@ -107,6 +112,8 @@ static void load_runtime_stat(struct runtime_stat 
*st, struct evlist *evlist,
  	evlist__for_each_entry(evlist, evsel) {
  		count = find_value(evsel->name, vals);
  		perf_stat__update_shadow_stats(evsel, count, 0, st);
+		if (!strcmp(evsel->name, "duration_time"))
+			update_stats(&walltime_nsecs_stats, count);
  	}
  }

@@ -321,6 +328,24 @@ static int test_recursion_fail(void)
  	return 0;
  }

+static int test_memory_bandwidth(void)
+{
+	double ratio;
+	struct value vals[] = {
+		{ .event = "l1d.replacement", .val = 304334545 },
+		{ .event = "duration_time",  .val = 1001057587 },
+		{ .event = NULL, },
+	};
+
+	TEST_ASSERT_VAL("failed to compute metric",
+			compute_metric("L1D_Cache_Fill_BW", vals, &ratio) == 0);
+
+	TEST_ASSERT_VAL("L1D_Cache_Fill_BW, wrong ratio",
+			fabs(ratio - 19.45) < 0.01);
+
+	return 0;
+}
+
  static int test_metric_group(void)
  {
  	double ratio1, ratio2;
@@ -353,5 +378,6 @@ int test__parse_metric(struct test *test 
__maybe_unused, int subtest __maybe_unu
  	TEST_ASSERT_VAL("DCache_L2 failed", test_dcache_l2() == 0);
  	TEST_ASSERT_VAL("recursion fail failed", test_recursion_fail() == 0);
  	TEST_ASSERT_VAL("test metric group", test_metric_group() == 0);
+	TEST_ASSERT_VAL("Memory bandwidth", test_memory_bandwidth() == 0);
  	return 0;
  }
-- 
2.26.2

Cheers,
John