Subject: Re: [PATCH v21 06/19] perf, tools: Support alias descriptions

From: Arnaldo Carvalho de Melo <[email-masked]>
Date: Tue, 27 Sep 2016 14:41:00 -0300

Em Thu, Sep 15, 2016 at 03:24:43PM -0700, Sukadev Bhattiprolu escreveu:
> From: Andi Kleen <[email-masked]>
> 
> Add support to print alias descriptions in perf list, which
> are taken from the generated event files.
> 
> The sorting code is changed to put the events with descriptions
> at the end. The descriptions are printed as possibly multiple word
> wrapped lines.

So, now I'm trying to reproduce the results below, but I couldn't find a
tarball with those .json files for me to use, can you provide me with
one?

I've put what I have at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tmp.perf/json

Now testing Jiri's cross compiling patch...

Thanks,

- Arnaldo
 
> Example output:
> 
> % perf list
> ...
>   arith.fpu_div
>        [Divide operations executed]
>   arith.fpu_div_active
>        [Cycles when divider is busy executing divide operations]
> 
> Signed-off-by: Andi Kleen <[email-masked]>
> Signed-off-by: Sukadev Bhattiprolu <[email-masked]>
> Acked-by: Jiri Olsa <[email-masked]>
> Acked-by: Ingo Molnar <[email-masked]>
> ---
> 
> Changelog
> 	- Delete a redundant free()
> 
> Changelog[v14]
> 	- [Jiri Olsa] Fail, rather than continue if strdup() returns NULL;
> 	  remove unnecessary __maybe_unused.
> ---
>  tools/perf/util/pmu.c | 83 +++++++++++++++++++++++++++++++++++++++++----------
>  tools/perf/util/pmu.h |  1 +
>  2 files changed, 68 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index c842886..af1a612 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -222,7 +222,7 @@ static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
>  }
>  
>  static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
> -				 char *desc __maybe_unused, char *val)
> +				 char *desc, char *val)
>  {
>  	struct perf_pmu_alias *alias;
>  	int ret;
> @@ -255,6 +255,8 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
>  		perf_pmu__parse_snapshot(alias, dir, name);
>  	}
>  
> +	alias->desc = desc ? strdup(desc) : NULL;
> +
>  	list_add_tail(&alias->list, list);
>  
>  	return 0;
> @@ -1044,11 +1046,42 @@ static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
>  	return buf;
>  }
>  
> -static int cmp_string(const void *a, const void *b)
> +struct pair {
> +	char *name;
> +	char *desc;
> +};
> +
> +static int cmp_pair(const void *a, const void *b)
> +{
> +	const struct pair *as = a;
> +	const struct pair *bs = b;
> +
> +	/* Put extra events last */
> +	if (!!as->desc != !!bs->desc)
> +		return !!as->desc - !!bs->desc;
> +	return strcmp(as->name, bs->name);
> +}
> +
> +static void wordwrap(char *s, int start, int max, int corr)
>  {
> -	const char * const *as = a;
> -	const char * const *bs = b;
> -	return strcmp(*as, *bs);
> +	int column = start;
> +	int n;
> +
> +	while (*s) {
> +		int wlen = strcspn(s, " \t");
> +
> +		if (column + wlen >= max && column > start) {
> +			printf("\n%*s", start, "");
> +			column = start + corr;
> +		}
> +		n = printf("%s%.*s", column > start ? " " : "", wlen, s);
> +		if (n <= 0)
> +			break;
> +		s += wlen;
> +		column += n;
> +		while (isspace(*s))
> +			s++;
> +	}
>  }
>  
>  void print_pmu_events(const char *event_glob, bool name_only)
> @@ -1058,7 +1091,9 @@ void print_pmu_events(const char *event_glob, bool name_only)
>  	char buf[1024];
>  	int printed = 0;
>  	int len, j;
> -	char **aliases;
> +	struct pair *aliases;
> +	int numdesc = 0;
> +	int columns = 78;
>  
>  	pmu = NULL;
>  	len = 0;
> @@ -1068,14 +1103,15 @@ void print_pmu_events(const char *event_glob, bool name_only)
>  		if (pmu->selectable)
>  			len++;
>  	}
> -	aliases = zalloc(sizeof(char *) * len);
> +	aliases = zalloc(sizeof(struct pair) * len);
>  	if (!aliases)
>  		goto out_enomem;
>  	pmu = NULL;
>  	j = 0;
>  	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
>  		list_for_each_entry(alias, &pmu->aliases, list) {
> -			char *name = format_alias(buf, sizeof(buf), pmu, alias);
> +			char *name = alias->desc ? alias->name :
> +				format_alias(buf, sizeof(buf), pmu, alias);
>  			bool is_cpu = !strcmp(pmu->name, "cpu");
>  
>  			if (event_glob != NULL &&
> @@ -1084,12 +1120,19 @@ void print_pmu_events(const char *event_glob, bool name_only)
>  						       event_glob))))
>  				continue;
>  
> -			if (is_cpu && !name_only)
> +			if (is_cpu && !name_only && !alias->desc)
>  				name = format_alias_or(buf, sizeof(buf), pmu, alias);
>  
> -			aliases[j] = strdup(name);
> -			if (aliases[j] == NULL)
> +			aliases[j].name = name;
> +			if (is_cpu && !name_only && !alias->desc)
> +				aliases[j].name = format_alias_or(buf,
> +								  sizeof(buf),
> +								  pmu, alias);
> +			aliases[j].name = strdup(aliases[j].name);
> +			if (!aliases[j].name)
>  				goto out_enomem;
> +
> +			aliases[j].desc = alias->desc;
>  			j++;
>  		}
>  		if (pmu->selectable &&
> @@ -1097,25 +1140,33 @@ void print_pmu_events(const char *event_glob, bool name_only)
>  			char *s;
>  			if (asprintf(&s, "%s//", pmu->name) < 0)
>  				goto out_enomem;
> -			aliases[j] = s;
> +			aliases[j].name = s;
>  			j++;
>  		}
>  	}
>  	len = j;
> -	qsort(aliases, len, sizeof(char *), cmp_string);
> +	qsort(aliases, len, sizeof(struct pair), cmp_pair);
>  	for (j = 0; j < len; j++) {
>  		if (name_only) {
> -			printf("%s ", aliases[j]);
> +			printf("%s ", aliases[j].name);
>  			continue;
>  		}
> -		printf("  %-50s [Kernel PMU event]\n", aliases[j]);
> +		if (aliases[j].desc) {
> +			if (numdesc++ == 0)
> +				printf("\n");
> +			printf("  %-50s\n", aliases[j].name);
> +			printf("%*s", 8, "[");
> +			wordwrap(aliases[j].desc, 8, columns, 0);
> +			printf("]\n");
> +		} else
> +			printf("  %-50s [Kernel PMU event]\n", aliases[j].name);
>  		printed++;
>  	}
>  	if (printed && pager_in_use())
>  		printf("\n");
>  out_free:
>  	for (j = 0; j < len; j++)
> -		zfree(&aliases[j]);
> +		zfree(&aliases[j].name);
>  	zfree(&aliases);
>  	return;
>  
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 5d7e844..11bda57 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -38,6 +38,7 @@ struct perf_pmu_info {
>  
>  struct perf_pmu_alias {
>  	char *name;
> +	char *desc;
>  	struct list_head terms; /* HEAD struct parse_events_term -> list */
>  	struct list_head list;  /* ELEM */
>  	char unit[UNIT_MAX_LEN+1];
> -- 
> 1.8.3.1