Re: [PATCH V4 6/7] perf mem: Clean up perf_mem_events__record_args()

[Ian Rogers]

On Tue, Jan 23, 2024 at 10:51 AM <kan.liang@xxxxxxxxxxxxxxx> wrote:
>
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> The current code iterates all memory PMUs. It doesn't matter if the
> system has only one memory PMU or multiple PMUs. The check of
> perf_pmus__num_mem_pmus() is not required anymore.
>
> The rec_tmp is not used in c2c and mem. Removing them as well.
>
> Suggested-by: Leo Yan <leo.yan@xxxxxxxxxx>
> Tested-by: Leo Yan <leo.yan@xxxxxxxxxx>
> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks for the cleanup!
Ian

> ---
>  tools/perf/builtin-c2c.c     | 15 ++-------------
>  tools/perf/builtin-mem.c     | 18 ++----------------
>  tools/perf/util/mem-events.c | 34 ++++++++++++----------------------
>  tools/perf/util/mem-events.h |  3 +--
>  4 files changed, 17 insertions(+), 53 deletions(-)
>
> diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> index 838481505e08..3bcb903b6b38 100644
> --- a/tools/perf/builtin-c2c.c
> +++ b/tools/perf/builtin-c2c.c
> @@ -3245,9 +3245,8 @@ static const char * const *record_mem_usage = __usage_record;
>
>  static int perf_c2c__record(int argc, const char **argv)
>  {
> -       int rec_argc, i = 0, j, rec_tmp_nr = 0;
> +       int rec_argc, i = 0, j;
>         const char **rec_argv;
> -       char **rec_tmp;
>         int ret;
>         bool all_user = false, all_kernel = false;
>         bool event_set = false;
> @@ -3285,12 +3284,6 @@ static int perf_c2c__record(int argc, const char **argv)
>         if (!rec_argv)
>                 return -1;
>
> -       rec_tmp = calloc(rec_argc + 1, sizeof(char *));
> -       if (!rec_tmp) {
> -               free(rec_argv);
> -               return -1;
> -       }
> -
>         rec_argv[i++] = "record";
>
>         if (!event_set) {
> @@ -3319,7 +3312,7 @@ static int perf_c2c__record(int argc, const char **argv)
>         rec_argv[i++] = "--phys-data";
>         rec_argv[i++] = "--sample-cpu";
>
> -       ret = perf_mem_events__record_args(rec_argv, &i, rec_tmp, &rec_tmp_nr);
> +       ret = perf_mem_events__record_args(rec_argv, &i);
>         if (ret)
>                 goto out;
>
> @@ -3346,10 +3339,6 @@ static int perf_c2c__record(int argc, const char **argv)
>
>         ret = cmd_record(i, rec_argv);
>  out:
> -       for (i = 0; i < rec_tmp_nr; i++)
> -               free(rec_tmp[i]);
> -
> -       free(rec_tmp);
>         free(rec_argv);
>         return ret;
>  }
> diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
> index ef64bae77ca7..1d92e309c97c 100644
> --- a/tools/perf/builtin-mem.c
> +++ b/tools/perf/builtin-mem.c
> @@ -72,10 +72,9 @@ static const char * const *record_mem_usage = __usage;
>
>  static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
>  {
> -       int rec_argc, i = 0, j, tmp_nr = 0;
> +       int rec_argc, i = 0, j;
>         int start, end;
>         const char **rec_argv;
> -       char **rec_tmp;
>         int ret;
>         bool all_user = false, all_kernel = false;
>         struct perf_mem_event *e;
> @@ -116,15 +115,6 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
>         if (!rec_argv)
>                 return -1;
>
> -       /*
> -        * Save the allocated event name strings.
> -        */
> -       rec_tmp = calloc(rec_argc + 1, sizeof(char *));
> -       if (!rec_tmp) {
> -               free(rec_argv);
> -               return -1;
> -       }
> -
>         rec_argv[i++] = "record";
>
>         e = perf_pmu__mem_events_ptr(pmu, PERF_MEM_EVENTS__LOAD_STORE);
> @@ -163,7 +153,7 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
>                 rec_argv[i++] = "--data-page-size";
>
>         start = i;
> -       ret = perf_mem_events__record_args(rec_argv, &i, rec_tmp, &tmp_nr);
> +       ret = perf_mem_events__record_args(rec_argv, &i);
>         if (ret)
>                 goto out;
>         end = i;
> @@ -193,10 +183,6 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
>
>         ret = cmd_record(i, rec_argv);
>  out:
> -       for (i = 0; i < tmp_nr; i++)
> -               free(rec_tmp[i]);
> -
> -       free(rec_tmp);
>         free(rec_argv);
>         return ret;
>  }
> diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
> index 7d7df3d0b2b9..a20611b4fb1b 100644
> --- a/tools/perf/util/mem-events.c
> +++ b/tools/perf/util/mem-events.c
> @@ -218,14 +218,14 @@ void perf_pmu__mem_events_list(struct perf_pmu *pmu)
>         }
>  }
>
> -int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
> -                                char **rec_tmp, int *tmp_nr)
> +int perf_mem_events__record_args(const char **rec_argv, int *argv_nr)
>  {
>         const char *mnt = sysfs__mount();
>         struct perf_pmu *pmu = NULL;
> -       int i = *argv_nr, k = 0;
>         struct perf_mem_event *e;
> -
> +       int i = *argv_nr;
> +       const char *s;
> +       char *copy;
>
>         while ((pmu = perf_pmus__scan_mem(pmu)) != NULL) {
>                 for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
> @@ -240,30 +240,20 @@ int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
>                                 return -1;
>                         }
>
> -                       if (perf_pmus__num_mem_pmus() == 1) {
> -                               rec_argv[i++] = "-e";
> -                               rec_argv[i++] = perf_pmu__mem_events_name(j, pmu);
> -                       } else {
> -                               const char *s = perf_pmu__mem_events_name(j, pmu);
> -
> -                               if (!perf_pmu__mem_events_supported(mnt, pmu, e))
> -                                       continue;
> +                       s = perf_pmu__mem_events_name(j, pmu);
> +                       if (!s || !perf_pmu__mem_events_supported(mnt, pmu, e))
> +                               continue;
>
> -                               rec_argv[i++] = "-e";
> -                               if (s) {
> -                                       char *copy = strdup(s);
> -                                       if (!copy)
> -                                               return -1;
> +                       copy = strdup(s);
> +                       if (!copy)
> +                               return -1;
>
> -                                       rec_argv[i++] = copy;
> -                                       rec_tmp[k++] = copy;
> -                               }
> -                       }
> +                       rec_argv[i++] = "-e";
> +                       rec_argv[i++] = copy;
>                 }
>         }
>
>         *argv_nr = i;
> -       *tmp_nr = k;
>         return 0;
>  }
>
> diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
> index f817a507b106..c97cd3caa766 100644
> --- a/tools/perf/util/mem-events.h
> +++ b/tools/perf/util/mem-events.h
> @@ -46,8 +46,7 @@ struct perf_pmu *perf_mem_events_find_pmu(void);
>  bool is_mem_loads_aux_event(struct evsel *leader);
>
>  void perf_pmu__mem_events_list(struct perf_pmu *pmu);
> -int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
> -                                char **rec_tmp, int *tmp_nr);
> +int perf_mem_events__record_args(const char **rec_argv, int *argv_nr);
>
>  int perf_mem__tlb_scnprintf(char *out, size_t sz, struct mem_info *mem_info);
>  int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info);
> --
> 2.35.1
>