linux-kernel - [PATCH v1 01/32] perf test pmu-events: Fake PMU metric workaround

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Date:   Wed, 14 Dec 2022 22:47:24 -0800
From:   Ian Rogers <irogers@...gle.com>
To:     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@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Xing Zhengjun <zhengjun.xing@...ux.intel.com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     John Garry <john.g.garry@...cle.com>,
        Stephane Eranian <eranian@...gle.com>,
        Perry Taylor <perry.taylor@...el.com>,
        Caleb Biggers <caleb.biggers@...el.com>,
        Ian Rogers <irogers@...gle.com>
Subject: [PATCH v1 01/32] perf test pmu-events: Fake PMU metric workaround

We test metrics with fake events with fake values. The fake values may
yield division by zero and so we count both up and down to try to
avoid this. Unfortunately this isn't sufficient for some metrics and
so don't fail the test for them.

Add the metric name to debug output.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/tests/pmu-events.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index f7b9dbbad97f..a29dd6af8d33 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -959,7 +959,7 @@ static struct test_metric metrics[] = {
 	{ "(imx8_ddr0@...d\\-cycles@ + imx8_ddr0@...te\\-cycles@)", },
 };
 
-static int metric_parse_fake(const char *str)
+static int metric_parse_fake(const char *metric_name, const char *str)
 {
 	struct expr_parse_ctx *ctx;
 	struct hashmap_entry *cur;
@@ -968,7 +968,7 @@ static int metric_parse_fake(const char *str)
 	size_t bkt;
 	int i;
 
-	pr_debug("parsing '%s'\n", str);
+	pr_debug("parsing '%s': '%s'\n", metric_name, str);
 
 	ctx = expr__ctx_new();
 	if (!ctx) {
@@ -1006,8 +1006,13 @@ static int metric_parse_fake(const char *str)
 		hashmap__for_each_entry(ctx->ids, cur, bkt)
 			expr__add_id_val(ctx, strdup(cur->key), i--);
 		if (expr__parse(&result, ctx, str)) {
-			pr_err("expr__parse failed\n");
-			ret = -1;
+			pr_err("expr__parse failed for %s\n", metric_name);
+			/* The following have hard to avoid divide by zero. */
+			if (!strcmp(metric_name, "tma_clears_resteers") ||
+			    !strcmp(metric_name, "tma_mispredicts_resteers"))
+				ret = 0;
+			else
+				ret = -1;
 		}
 	}
 
@@ -1023,7 +1028,7 @@ static int test__parsing_fake_callback(const struct pmu_event *pe,
 	if (!pe->metric_expr)
 		return 0;
 
-	return metric_parse_fake(pe->metric_expr);
+	return metric_parse_fake(pe->metric_name, pe->metric_expr);
 }
 
 /*
@@ -1037,7 +1042,7 @@ static int test__parsing_fake(struct test_suite *test __maybe_unused,
 	int err = 0;
 
 	for (size_t i = 0; i < ARRAY_SIZE(metrics); i++) {
-		err = metric_parse_fake(metrics[i].str);
+		err = metric_parse_fake("", metrics[i].str);
 		if (err)
 			return err;
 	}
-- 
2.39.0.314.g84b9a713c41-goog