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

From: Arnaldo Carvalho de Melo
Date: Tue Sep 27 2016 - 13:41:17 EST


Em Thu, Sep 15, 2016 at 03:24:43PM -0700, Sukadev Bhattiprolu escreveu:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> 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 <ak@xxxxxxxxxxxxxxx>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
>
> 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