Re: [PATCH v2] perf tools: report initial event parsing error

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

Em Fri, Nov 15, 2019 at 11:46:52PM -0800, Ian Rogers escreveu:
> Record the first event parsing error and report. Implementing feedback
> from Jiri Olsa:
> https://lkml.org/lkml/2019/10/28/680
> 
> An example error is:
> 
> $ tools/perf/perf stat -e c/c/
> WARNING: multiple event parsing errors
> event syntax error: 'c/c/'
>                        \___ unknown term
> 
> valid terms: event,filter_rem,filter_opc0,edge,filter_isoc,filter_tid,filter_loc,filter_nc,inv,umask,filter_opc1,tid_en,thresh,filter_all_op,filter_not_nm,filter_state,filter_nm,config,config1,config2,name,period,percore
> 
> Initial error:
> event syntax error: 'c/c/'
>                     \___ Cannot find PMU `c'. Missing kernel support?
> Run 'perf list' for a list of valid events
> 
>  Usage: perf stat [<options>] [<command>]
> 
>     -e, --event <event>   event selector. use 'perf list' to list available events

Thanks, tested and applied.

Jiri, please holler if something is still problematic,

- Arnaldo
 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/arch/powerpc/util/kvm-stat.c |  4 +-
>  tools/perf/builtin-stat.c               |  2 +
>  tools/perf/builtin-trace.c              | 16 +++--
>  tools/perf/tests/parse-events.c         |  3 +-
>  tools/perf/util/metricgroup.c           |  2 +-
>  tools/perf/util/parse-events.c          | 78 ++++++++++++++++++-------
>  tools/perf/util/parse-events.h          |  4 ++
>  7 files changed, 80 insertions(+), 29 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
> index 9cc1c4a9dec4..16807269317c 100644
> --- a/tools/perf/arch/powerpc/util/kvm-stat.c
> +++ b/tools/perf/arch/powerpc/util/kvm-stat.c
> @@ -113,10 +113,10 @@ static int is_tracepoint_available(const char *str, struct evlist *evlist)
>  	struct parse_events_error err;
>  	int ret;
>  
> -	err.str = NULL;
> +	bzero(&err, sizeof(err));
>  	ret = parse_events(evlist, str, &err);
>  	if (err.str)
> -		pr_err("%s : %s\n", str, err.str);
> +		parse_events_print_error(&err, "tracepoint");
>  	return ret;
>  }
>  
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 5964e808d73d..0a15253b438c 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -1307,6 +1307,7 @@ static int add_default_attributes(void)
>  	if (stat_config.null_run)
>  		return 0;
>  
> +	bzero(&errinfo, sizeof(errinfo));
>  	if (transaction_run) {
>  		/* Handle -T as -M transaction. Once platform specific metrics
>  		 * support has been added to the json files, all archictures
> @@ -1364,6 +1365,7 @@ static int add_default_attributes(void)
>  			return -1;
>  		}
>  		if (err) {
> +			parse_events_print_error(&errinfo, smi_cost_attrs);
>  			fprintf(stderr, "Cannot set up SMI cost events\n");
>  			return -1;
>  		}
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 43c05eae1768..46a72ecac427 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -3016,11 +3016,18 @@ static bool evlist__add_vfs_getname(struct evlist *evlist)
>  {
>  	bool found = false;
>  	struct evsel *evsel, *tmp;
> -	struct parse_events_error err = { .idx = 0, };
> -	int ret = parse_events(evlist, "probe:vfs_getname*", &err);
> +	struct parse_events_error err;
> +	int ret;
>  
> -	if (ret)
> +	bzero(&err, sizeof(err));
> +	ret = parse_events(evlist, "probe:vfs_getname*", &err);
> +	if (ret) {
> +		free(err.str);
> +		free(err.help);
> +		free(err.first_str);
> +		free(err.first_help);
>  		return false;
> +	}
>  
>  	evlist__for_each_entry_safe(evlist, evsel, tmp) {
>  		if (!strstarts(perf_evsel__name(evsel), "probe:vfs_getname"))
> @@ -4832,8 +4839,9 @@ int cmd_trace(int argc, const char **argv)
>  	 * wrong in more detail.
>  	 */
>  	if (trace.perfconfig_events != NULL) {
> -		struct parse_events_error parse_err = { .idx = 0, };
> +		struct parse_events_error parse_err;
>  
> +		bzero(&parse_err, sizeof(parse_err));
>  		err = parse_events(trace.evlist, trace.perfconfig_events, &parse_err);
>  		if (err) {
>  			parse_events_print_error(&parse_err, trace.perfconfig_events);
> diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
> index 25e0ed2eedfc..091c3aeccc27 100644
> --- a/tools/perf/tests/parse-events.c
> +++ b/tools/perf/tests/parse-events.c
> @@ -1768,10 +1768,11 @@ static struct terms_test test__terms[] = {
>  
>  static int test_event(struct evlist_test *e)
>  {
> -	struct parse_events_error err = { .idx = 0, };
> +	struct parse_events_error err;
>  	struct evlist *evlist;
>  	int ret;
>  
> +	bzero(&err, sizeof(err));
>  	if (e->valid && !e->valid()) {
>  		pr_debug("... SKIP");
>  		return 0;
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index a7c0424dbda3..6a4d350d5cdb 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -523,7 +523,7 @@ int metricgroup__parse_groups(const struct option *opt,
>  	if (ret)
>  		return ret;
>  	pr_debug("adding %s\n", extra_events.buf);
> -	memset(&parse_error, 0, sizeof(struct parse_events_error));
> +	bzero(&parse_error, sizeof(parse_error));
>  	ret = parse_events(perf_evlist, extra_events.buf, &parse_error);
>  	if (ret) {
>  		parse_events_print_error(&parse_error, extra_events.buf);
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 6d18ff9bce49..6bae9d6edc12 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -189,12 +189,29 @@ void parse_events__handle_error(struct parse_events_error *err, int idx,
>  		free(help);
>  		return;
>  	}
> -	WARN_ONCE(err->str, "WARNING: multiple event parsing errors\n");
> -	err->idx = idx;
> -	free(err->str);
> -	err->str = str;
> -	free(err->help);
> -	err->help = help;
> +	switch (err->num_errors) {
> +	case 0:
> +		err->idx = idx;
> +		err->str = str;
> +		err->help = help;
> +		break;
> +	case 1:
> +		err->first_idx = err->idx;
> +		err->idx = idx;
> +		err->first_str = err->str;
> +		err->str = str;
> +		err->first_help = err->help;
> +		err->help = help;
> +		break;
> +	default:
> +		WARN_ONCE(1, "WARNING: multiple event parsing errors\n");
> +		free(err->str);
> +		err->str = str;
> +		free(err->help);
> +		err->help = help;
> +		break;
> +	}
> +	err->num_errors++;
>  }
>  
>  struct tracepoint_path *tracepoint_id_to_path(u64 config)
> @@ -1349,7 +1366,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>  		if (asprintf(&err_str,
>  				"Cannot find PMU `%s'. Missing kernel support?",
>  				name) >= 0)
> -			parse_events__handle_error(err, -1, err_str, NULL);
> +			parse_events__handle_error(err, 0, err_str, NULL);
>  		return -EINVAL;
>  	}
>  
> @@ -2007,15 +2024,14 @@ static int get_term_width(void)
>  	return ws.ws_col > MAX_WIDTH ? MAX_WIDTH : ws.ws_col;
>  }
>  
> -void parse_events_print_error(struct parse_events_error *err,
> -			      const char *event)
> +static void __parse_events_print_error(int err_idx, const char *err_str,
> +				const char *err_help, const char *event)
>  {
>  	const char *str = "invalid or unsupported event: ";
>  	char _buf[MAX_WIDTH];
>  	char *buf = (char *) event;
>  	int idx = 0;
> -
> -	if (err->str) {
> +	if (err_str) {
>  		/* -2 for extra '' in the final fprintf */
>  		int width       = get_term_width() - 2;
>  		int len_event   = strlen(event);
> @@ -2038,8 +2054,8 @@ void parse_events_print_error(struct parse_events_error *err,
>  		buf = _buf;
>  
>  		/* We're cutting from the beginning. */
> -		if (err->idx > max_err_idx)
> -			cut = err->idx - max_err_idx;
> +		if (err_idx > max_err_idx)
> +			cut = err_idx - max_err_idx;
>  
>  		strncpy(buf, event + cut, max_len);
>  
> @@ -2052,16 +2068,33 @@ void parse_events_print_error(struct parse_events_error *err,
>  			buf[max_len] = 0;
>  		}
>  
> -		idx = len_str + err->idx - cut;
> +		idx = len_str + err_idx - cut;
>  	}
>  
>  	fprintf(stderr, "%s'%s'\n", str, buf);
>  	if (idx) {
> -		fprintf(stderr, "%*s\\___ %s\n", idx + 1, "", err->str);
> -		if (err->help)
> -			fprintf(stderr, "\n%s\n", err->help);
> -		zfree(&err->str);
> -		zfree(&err->help);
> +		fprintf(stderr, "%*s\\___ %s\n", idx + 1, "", err_str);
> +		if (err_help)
> +			fprintf(stderr, "\n%s\n", err_help);
> +	}
> +}
> +
> +void parse_events_print_error(struct parse_events_error *err,
> +			      const char *event)
> +{
> +	if (!err->num_errors)
> +		return;
> +
> +	__parse_events_print_error(err->idx, err->str, err->help, event);
> +	zfree(&err->str);
> +	zfree(&err->help);
> +
> +	if (err->num_errors > 1) {
> +		fputs("\nInitial error:\n", stderr);
> +		__parse_events_print_error(err->first_idx, err->first_str,
> +					err->first_help, event);
> +		zfree(&err->first_str);
> +		zfree(&err->first_help);
>  	}
>  }
>  
> @@ -2071,8 +2104,11 @@ int parse_events_option(const struct option *opt, const char *str,
>  			int unset __maybe_unused)
>  {
>  	struct evlist *evlist = *(struct evlist **)opt->value;
> -	struct parse_events_error err = { .idx = 0, };
> -	int ret = parse_events(evlist, str, &err);
> +	struct parse_events_error err;
> +	int ret;
> +
> +	bzero(&err, sizeof(err));
> +	ret = parse_events(evlist, str, &err);
>  
>  	if (ret) {
>  		parse_events_print_error(&err, str);
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index 5ee8ac93840c..ff367f248fe8 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -110,9 +110,13 @@ struct parse_events_term {
>  };
>  
>  struct parse_events_error {
> +	int   num_errors;       /* number of errors encountered */
>  	int   idx;	/* index in the parsed string */
>  	char *str;      /* string to display at the index */
>  	char *help;	/* optional help string */
> +	int   first_idx;/* as above, but for the first encountered error */
> +	char *first_str;
> +	char *first_help;
>  };
>  
>  struct parse_events_state {
> -- 
> 2.24.0.432.g9d3f5f5b63-goog

-- 

- Arnaldo