Re: [PATCH 07/19] perf stat: Add struct perf_stat_aggr to perf_stat_evsel

[Ian Rogers <irogers@google.com>]

On Sun, Oct 9, 2022 at 10:36 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> The perf_stat_aggr struct is to keep aggregated counter values and the
> states according to the aggregation mode.  The number of entries is
> depends on the mode and this is a preparation for the later use.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/stat.c | 34 +++++++++++++++++++++++++++-------
>  tools/perf/util/stat.h |  9 +++++++++
>  2 files changed, 36 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index 8ec8bb4a9912..c9d5aa295b54 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -133,15 +133,33 @@ static void perf_stat_evsel_id_init(struct evsel *evsel)
>  static void evsel__reset_stat_priv(struct evsel *evsel)
>  {
>         struct perf_stat_evsel *ps = evsel->stats;
> +       struct perf_stat_aggr *aggr = ps->aggr;
>
>         init_stats(&ps->res_stats);
> +
> +       if (aggr)
> +               memset(aggr, 0, sizeof(*aggr) * ps->nr_aggr);
>  }
>
> -static int evsel__alloc_stat_priv(struct evsel *evsel)
> +
> +static int evsel__alloc_stat_priv(struct evsel *evsel, int nr_aggr)
>  {
> -       evsel->stats = zalloc(sizeof(struct perf_stat_evsel));
> -       if (evsel->stats == NULL)
> +       struct perf_stat_evsel *ps;
> +
> +       ps = zalloc(sizeof(*ps));
> +       if (ps == NULL)
>                 return -ENOMEM;
> +
> +       if (nr_aggr) {
> +               ps->nr_aggr = nr_aggr;
> +               ps->aggr = calloc(nr_aggr, sizeof(*ps->aggr));
> +               if (ps->aggr == NULL) {
> +                       free(ps);
> +                       return -ENOMEM;
> +               }
> +       }
> +
> +       evsel->stats = ps;
>         perf_stat_evsel_id_init(evsel);
>         evsel__reset_stat_priv(evsel);
>         return 0;
> @@ -151,8 +169,10 @@ static void evsel__free_stat_priv(struct evsel *evsel)
>  {
>         struct perf_stat_evsel *ps = evsel->stats;
>
> -       if (ps)
> +       if (ps) {
> +               zfree(&ps->aggr);
>                 zfree(&ps->group_data);
> +       }
>         zfree(&evsel->stats);
>  }
>
> @@ -181,9 +201,9 @@ static void evsel__reset_prev_raw_counts(struct evsel *evsel)
>                 perf_counts__reset(evsel->prev_raw_counts);
>  }
>
> -static int evsel__alloc_stats(struct evsel *evsel, bool alloc_raw)
> +static int evsel__alloc_stats(struct evsel *evsel, int nr_aggr, bool alloc_raw)
>  {
> -       if (evsel__alloc_stat_priv(evsel) < 0 ||
> +       if (evsel__alloc_stat_priv(evsel, nr_aggr) < 0 ||
>             evsel__alloc_counts(evsel) < 0 ||
>             (alloc_raw && evsel__alloc_prev_raw_counts(evsel) < 0))
>                 return -ENOMEM;
> @@ -196,7 +216,7 @@ int evlist__alloc_stats(struct evlist *evlist, bool alloc_raw)
>         struct evsel *evsel;
>
>         evlist__for_each_entry(evlist, evsel) {
> -               if (evsel__alloc_stats(evsel, alloc_raw))
> +               if (evsel__alloc_stats(evsel, 0, alloc_raw))
>                         goto out_free;
>         }
>
> diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
> index b0899c6e002f..ea356e5aa351 100644
> --- a/tools/perf/util/stat.h
> +++ b/tools/perf/util/stat.h
> @@ -8,6 +8,7 @@
>  #include <sys/resource.h>
>  #include "cpumap.h"
>  #include "rblist.h"
> +#include "counts.h"
>
>  struct perf_cpu_map;
>  struct perf_stat_config;
> @@ -42,9 +43,17 @@ enum perf_stat_evsel_id {
>         PERF_STAT_EVSEL_ID__MAX,
>  };
>

The new struct variables below are all worth comments.

> +struct perf_stat_aggr {
> +       struct perf_counts_values       counts;
> +       int                             nr;

Could this value be derived from counts.values.size ?

> +       bool                            failed;
> +};
> +
>  struct perf_stat_evsel {
>         struct stats             res_stats;
>         enum perf_stat_evsel_id  id;
> +       int                      nr_aggr;
> +       struct perf_stat_aggr   *aggr;
>         u64                     *group_data;
>  };
>
> --
> 2.38.0.rc1.362.ged0d419d3c-goog
>