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 <Yd3bbelDA1qGPodk@kernel.org>
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From:   Ian Rogers <irogers@google.com>
Date:   Tue, 11 Jan 2022 11:36:02 -0800
Message-ID: <CAP-5=fVSuF-BCKuv6dutwLaAEKOctNYPtHzGYYDzZ7cm0110GQ@mail.gmail.com>
Subject: Re: [PATCH v4 02/48] perf stat: Add aggr creators that are passed a cpu.
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Andi Kleen <ak@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        John Garry <john.garry@huawei.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        "Paul A . Clarke" <pc@us.ibm.com>,
        Riccardo Mancini <rickyman7@gmail.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        Vineet Singh <vineet.singh@intel.com>,
        James Clark <james.clark@arm.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org, zhengjun.xing@intel.com,
        eranian@google.com
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On Tue, Jan 11, 2022 at 11:33 AM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Tue, Jan 04, 2022 at 10:13:05PM -0800, Ian Rogers escreveu:
> > The cpu_map and index can get confused. Add variants of the cpu_map__get
> > routines that are passed a cpu. Make the existing cpu_map__get routines
> > use the new functions with a view to remove them when no longer used.
> >
> > Reviewed-by: James Clark <james.clark@arm.com>
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >  tools/perf/util/cpumap.c | 79 +++++++++++++++++++++++-----------------
> >  tools/perf/util/cpumap.h |  6 ++-
> >  2 files changed, 51 insertions(+), 34 deletions(-)
> >
> > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> > index 87d3eca9b872..49fba2c53822 100644
> > --- a/tools/perf/util/cpumap.c
> > +++ b/tools/perf/util/cpumap.c
> > @@ -128,21 +128,23 @@ int cpu_map__get_socket_id(int cpu)
> >       return ret ?: value;
> >  }
> >
> > -struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx,
> > -                                     void *data __maybe_unused)
> > +struct aggr_cpu_id cpu_map__get_socket_aggr_by_cpu(int cpu, void *data __maybe_unused)
> >  {
> > -     int cpu;
> >       struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> >
> > -     if (idx > map->nr)
> > -             return id;
> > -
> > -     cpu = map->map[idx];
> > -
> >       id.socket = cpu_map__get_socket_id(cpu);
> >       return id;
> >  }
> >
> > +struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx,
> > +                                    void *data)
> > +{
> > +     if (idx < 0 || idx > map->nr)
> > +             return cpu_map__empty_aggr_cpu_id();
> > +
> > +     return cpu_map__get_socket_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
>
>
> This 'idx < 0' wasn't in the original code nor is described in the
> comment log message, please avoid doing this, this may be harmless or
> even a good hardening, but either way would be interesting to have it in
> a separate patch. This eases review as in the end this code is just a
> refactoring, moving things around but in the end should be equivalent code.
>
> There are a few more, please consider this and if you agree, to speed
> things up I can make the changes here, if I think this won't fallout in
> changes to subsequent patches touching this area.
>
> - Arnaldo

Fwiw, there's the same issue in cpu_map__get_die that's also in
cpu_map__get_core, but weirdly not copied into cpu_map__get_node. As
these functions are removed later I think doing nothing is best here.

Thanks,
Ian

> >  static int cmp_aggr_cpu_id(const void *a_pointer, const void *b_pointer)
> >  {
> >       struct aggr_cpu_id *a = (struct aggr_cpu_id *)a_pointer;
> > @@ -200,15 +202,10 @@ int cpu_map__get_die_id(int cpu)
> >       return ret ?: value;
> >  }
> >
> > -struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *data)
> > +struct aggr_cpu_id cpu_map__get_die_aggr_by_cpu(int cpu, void *data)
> >  {
> > -     int cpu, die;
> > -     struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> > -
> > -     if (idx > map->nr)
> > -             return id;
> > -
> > -     cpu = map->map[idx];
> > +     struct aggr_cpu_id id;
> > +     int die;
> >
> >       die = cpu_map__get_die_id(cpu);
> >       /* There is no die_id on legacy system. */
> > @@ -220,7 +217,7 @@ struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *dat
> >        * with the socket ID and then add die to
> >        * make a unique ID.
> >        */
> > -     id = cpu_map__get_socket(map, idx, data);
> > +     id = cpu_map__get_socket_aggr_by_cpu(cpu, data);
> >       if (cpu_map__aggr_cpu_id_is_empty(id))
> >               return id;
> >
> > @@ -228,6 +225,15 @@ struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *dat
> >       return id;
> >  }
> >
> > +struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx,
> > +                                 void *data)
> > +{
> > +     if (idx < 0 || idx > map->nr)
> > +             return cpu_map__empty_aggr_cpu_id();
>
> Ditto
>
> > +
> > +     return cpu_map__get_die_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
> >  int cpu_map__get_core_id(int cpu)
> >  {
> >       int value, ret = cpu__get_topology_int(cpu, "core_id", &value);
> > @@ -239,20 +245,13 @@ int cpu_map__get_node_id(int cpu)
> >       return cpu__get_node(cpu);
> >  }
> >
> > -struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data)
> > +struct aggr_cpu_id cpu_map__get_core_aggr_by_cpu(int cpu, void *data)
> >  {
> > -     int cpu;
> > -     struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> > -
> > -     if (idx > map->nr)
> > -             return id;
> > -
> > -     cpu = map->map[idx];
> > -
> > -     cpu = cpu_map__get_core_id(cpu);
> > +     struct aggr_cpu_id id;
> > +     int core = cpu_map__get_core_id(cpu);
> >
> >       /* cpu_map__get_die returns a struct with socket and die set*/
> > -     id = cpu_map__get_die(map, idx, data);
> > +     id = cpu_map__get_die_aggr_by_cpu(cpu, data);
> >       if (cpu_map__aggr_cpu_id_is_empty(id))
> >               return id;
> >
> > @@ -260,19 +259,33 @@ struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *da
> >        * core_id is relative to socket and die, we need a global id.
> >        * So we combine the result from cpu_map__get_die with the core id
> >        */
> > -     id.core = cpu;
> > +     id.core = core;
> >       return id;
> > +
> >  }
> >
> > -struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data __maybe_unused)
> > +struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data)
> > +{
> > +     if (idx < 0 || idx > map->nr)
> > +             return cpu_map__empty_aggr_cpu_id();
>
> Ditto
>
> > +
> > +     return cpu_map__get_core_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
> > +struct aggr_cpu_id cpu_map__get_node_aggr_by_cpu(int cpu, void *data __maybe_unused)
> >  {
> >       struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> >
> > +     id.node = cpu_map__get_node_id(cpu);
> > +     return id;
> > +}
> > +
> > +struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data)
> > +{
> >       if (idx < 0 || idx >= map->nr)
> > -             return id;
> > +             return cpu_map__empty_aggr_cpu_id();
> >
> > -     id.node = cpu_map__get_node_id(map->map[idx]);
> > -     return id;
> > +     return cpu_map__get_node_aggr_by_cpu(map->map[idx], data);
> >  }
> >
> >  int cpu_map__build_socket_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **sockp)
> > diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
> > index a27eeaf086e8..c62d67704425 100644
> > --- a/tools/perf/util/cpumap.h
> > +++ b/tools/perf/util/cpumap.h
> > @@ -31,13 +31,17 @@ size_t cpu_map__snprint(struct perf_cpu_map *map, char *buf, size_t size);
> >  size_t cpu_map__snprint_mask(struct perf_cpu_map *map, char *buf, size_t size);
> >  size_t cpu_map__fprintf(struct perf_cpu_map *map, FILE *fp);
> >  int cpu_map__get_socket_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_socket_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_die_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_die_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_core_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_core_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_node_id(int cpu);
> > -struct aggr_cpu_id  cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data);
> > +struct aggr_cpu_id cpu_map__get_node_aggr_by_cpu(int cpu, void *data);
> > +struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__build_socket_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **sockp);
> >  int cpu_map__build_die_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **diep);
> >  int cpu_map__build_core_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **corep);
> > --
> > 2.34.1.448.ga2b2bfdf31-goog
>
> --
>
> - Arnaldo