linux-kernel - Re: [PATCH 2/2] perf test: Improve pmu event metric testing

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Date:   Wed, 13 May 2020 19:48:19 +0200
From:   Jiri Olsa <jolsa@...hat.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>,
        Namhyung Kim <namhyung@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        Jin Yao <yao.jin@...ux.intel.com>,
        Leo Yan <leo.yan@...aro.org>,
        John Garry <john.garry@...wei.com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Kajol Jain <kjain@...ux.ibm.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Paul Clarke <pc@...ibm.com>, linux-kernel@...r.kernel.org,
        Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH 2/2] perf test: Improve pmu event metric testing

On Tue, May 12, 2020 at 11:22:36PM -0700, Ian Rogers wrote:

SNIP

> +
> +static int check_parse_id(const char *id, bool same_cpu, struct pmu_event *pe)
> +{
> +	struct parse_events_error error;
> +	struct evlist *evlist;
> +	int ret;
> +
> +	/* Numbers are always valid. */
> +	if (is_number(id))
> +		return 0;
> +
> +	evlist = evlist__new();
> +	memset(&error, 0, sizeof(error));
> +	ret = parse_events(evlist, id, &error);
> +	if (ret && same_cpu) {
> +		fprintf(stderr,
> +			"\nWARNING: Parse event failed metric '%s' id '%s' expr '%s'\n",
> +			pe->metric_name, id, pe->metric_expr);
> +		fprintf(stderr, "Error string '%s' help '%s'\n",
> +			error.str, error.help);
> +	} else if (ret) {
> +		pr_debug3("Parse event failed, but for an event that may not be supported by this CPU.\nid '%s' metric '%s' expr '%s'\n",
> +			id, pe->metric_name, pe->metric_expr);
> +	}

I wonder if we could add 'fake pmu' that would be used for tests
and use it parse_events_add_pmu to add 'fake' evsel but the name
would be correct.. we could add parse_events_state::fake_pmu bool
for that

rest of the event types (other than pmu syntax) might be ok


> +	evlist__delete(evlist);
> +	free(error.str);
> +	free(error.help);
> +	free(error.first_str);
> +	free(error.first_help);
> +	/* TODO: too many metrics are broken to fail on this test currently. */
> +	return 0;
> +}
> +
> +static int test_parsing(void)
> +{
> +	struct pmu_events_map *cpus_map = perf_pmu__find_map(NULL);
> +	struct pmu_events_map *map;
> +	struct pmu_event *pe;
> +	int i, j, k;
> +	const char **ids;
> +	int idnum;
> +	int ret = 0;
> +	struct expr_parse_ctx ctx;
> +	double result;
> +
> +	i = 0;
> +	for (;;) {
> +		map = &pmu_events_map[i++];
> +		if (!map->table) {
> +			map = NULL;

hum, what's the map = NULL for in here?

thanks,
jirka

> +			break;
> +		}
> +		j = 0;
> +		for (;;) {
> +			pe = &map->table[j++];
> +			if (!pe->name && !pe->metric_group && !pe->metric_name)
> +				break;
> +			if (!pe->metric_expr)
> +				continue;
> +			if (expr__find_other(pe->metric_expr, NULL,
> +						&ids, &idnum, 0) < 0) {
> +				pr_debug("Parse other failed for map %s %s %s\n",
> +					map->cpuid, map->version, map->type);
> +				pr_debug("On metric %s\n", pe->metric_name);
> +				pr_debug("On expression %s\n", pe->metric_expr);
> +				ret++;
> +				continue;
> +			}
> +			expr__ctx_init(&ctx);
> +
> +			/*
> +			 * Add all ids with a made up value. The value may
> +			 * trigger divide by zero when subtracted and so try to
> +			 * make them unique.
> +			 */
> +			for (k = 0; k < idnum; k++)
> +				expr__add_id(&ctx, ids[k], k + 1);
> +
> +			for (k = 0; k < idnum; k++) {
> +				if (check_parse_id(ids[k], map == cpus_map, pe))
> +					ret++;
> +			}
> +
> +			if (expr__parse(&result, &ctx, pe->metric_expr, 0)) {
> +				pr_debug("Parse failed for map %s %s %s\n",
> +					map->cpuid, map->version, map->type);
> +				pr_debug("On metric %s\n", pe->metric_name);
> +				pr_debug("On expression %s\n", pe->metric_expr);
> +				ret++;
> +			}
> +			for (k = 0; k < idnum; k++)
> +				zfree(&ids[k]);
> +			free(ids);
> +		}
> +	}
> +	return ret;

SNIP