Re: [PATCH v1 4/9] perf list: Generalize limiting to a PMU name

[Ian Rogers <irogers@google.com>]

On Mon, Nov 14, 2022 at 12:51 AM Xing Zhengjun
<zhengjun.xing@linux.intel.com> wrote:
>
>
>
> On 11/14/2022 3:51 PM, Ian Rogers wrote:
> > Deprecate the --cputype option and add a --unit option where '--unit
> > cpu_atom' behaves like '--cputype atom'. The --unit option can be used
> > with arbitrary PMUs, for example:
> >
> > ```
> > $ perf list --unit msr pmu
> >
> > List of pre-defined events (to be used in -e or -M):
> >
> >    msr/aperf/                                         [Kernel PMU event]
> >    msr/cpu_thermal_margin/                            [Kernel PMU event]
> >    msr/mperf/                                         [Kernel PMU event]
> >    msr/pperf/                                         [Kernel PMU event]
> >    msr/smi/                                           [Kernel PMU event]
> >    msr/tsc/                                           [Kernel PMU event]
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >   tools/perf/Documentation/perf-list.txt |  6 +++---
> >   tools/perf/builtin-list.c              | 18 ++++++++++++------
> >   tools/perf/util/metricgroup.c          |  3 ++-
> >   tools/perf/util/pmu.c                  |  4 +---
> >   4 files changed, 18 insertions(+), 13 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt
> > index 57384a97c04f..44a819af573d 100644
> > --- a/tools/perf/Documentation/perf-list.txt
> > +++ b/tools/perf/Documentation/perf-list.txt
> > @@ -39,9 +39,9 @@ any extra expressions computed by perf stat.
> >   --deprecated::
> >   Print deprecated events. By default the deprecated events are hidden.
> >
> > ---cputype::
> > -Print events applying cpu with this type for hybrid platform
> > -(e.g. --cputype core or --cputype atom)
> > +--unit::
> > +Print PMU events and metrics limited to the specific PMU name.
> > +(e.g. --unit cpu, --unit msr, --unit cpu_core, --unit cpu_atom)
> >
> >   [[EVENT_MODIFIERS]]
> >   EVENT MODIFIERS
> > diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
> > index 58e1ec1654ef..cc84ced6da26 100644
> > --- a/tools/perf/builtin-list.c
> > +++ b/tools/perf/builtin-list.c
> > @@ -21,7 +21,6 @@
> >
> >   static bool desc_flag = true;
> >   static bool details_flag;
> > -static const char *hybrid_type;
> >
> >   int cmd_list(int argc, const char **argv)
> >   {
> > @@ -30,6 +29,8 @@ int cmd_list(int argc, const char **argv)
> >       bool long_desc_flag = false;
> >       bool deprecated = false;
> >       char *pmu_name = NULL;
> > +     const char *hybrid_name = NULL;
> > +     const char *unit_name = NULL;
> >       struct option list_options[] = {
> >               OPT_BOOLEAN(0, "raw-dump", &raw_dump, "Dump raw events"),
> >               OPT_BOOLEAN('d', "desc", &desc_flag,
> > @@ -40,9 +41,10 @@ int cmd_list(int argc, const char **argv)
> >                           "Print information on the perf event names and expressions used internally by events."),
> >               OPT_BOOLEAN(0, "deprecated", &deprecated,
> >                           "Print deprecated events."),
> > -             OPT_STRING(0, "cputype", &hybrid_type, "hybrid cpu type",
> > -                        "Print events applying cpu with this type for hybrid platform "
> > -                        "(e.g. core or atom)"),
> > +             OPT_STRING(0, "cputype", &hybrid_name, "hybrid cpu type",
> > +                        "Limit PMU or metric printing to the given hybrid PMU (e.g. core or atom)."),
> > +             OPT_STRING(0, "unit", &unit_name, "PMU name",
> > +                        "Limit PMU or metric printing to the specified PMU."),
> >               OPT_INCR(0, "debug", &verbose,
> >                            "Enable debugging output"),
> >               OPT_END()
> > @@ -53,6 +55,8 @@ int cmd_list(int argc, const char **argv)
> >       };
> >
> >       set_option_flag(list_options, 0, "raw-dump", PARSE_OPT_HIDDEN);
> > +     /* Hide hybrid flag for the more generic 'unit' flag. */
> > +     set_option_flag(list_options, 0, "cputype", PARSE_OPT_HIDDEN);
> >
> >       argc = parse_options(argc, argv, list_options, list_usage,
> >                            PARSE_OPT_STOP_AT_NON_OPTION);
> > @@ -62,8 +66,10 @@ int cmd_list(int argc, const char **argv)
> >       if (!raw_dump && pager_in_use())
> >               printf("\nList of pre-defined events (to be used in -e or -M):\n\n");
> >
> > -     if (hybrid_type) {
> > -             pmu_name = perf_pmu__hybrid_type_to_pmu(hybrid_type);
> > +     if (unit_name)
> > +             pmu_name = strdup(unit_name);
> > +     else if (hybrid_name) {
> > +             pmu_name = perf_pmu__hybrid_type_to_pmu(hybrid_name);
> >               if (!pmu_name)
> >                       pr_warning("WARNING: hybrid cputype is not supported!\n");
> >       }
> > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > index 4c98ac29ee13..1943fed9b6d9 100644
> > --- a/tools/perf/util/metricgroup.c
> > +++ b/tools/perf/util/metricgroup.c
> > @@ -556,11 +556,12 @@ static int metricgroup__print_callback(const struct pmu_event *pe,
> >                                      void *vdata)
> >   {
> >       struct metricgroup_print_data *data = vdata;
> > +     const char *pmu = pe->pmu ?: "cpu";
> >
> >       if (!pe->metric_expr)
> >               return 0;
> >
> > -     if (data->pmu_name && perf_pmu__is_hybrid(pe->pmu) && strcmp(data->pmu_name, pe->pmu))
> > +     if (data->pmu_name && strcmp(data->pmu_name, pmu))
> >               return 0;
> >
> >       return metricgroup__print_pmu_event(pe, data->metricgroups, data->filter,
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index a8f9f47c6ed9..9c771f136b81 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -1694,10 +1694,8 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
> >       pmu = NULL;
> >       j = 0;
> >       while ((pmu = perf_pmu__scan(pmu)) != NULL) {
> > -             if (pmu_name && perf_pmu__is_hybrid(pmu->name) &&
> > -                 strcmp(pmu_name, pmu->name)) {
> > +             if (pmu_name && pmu->name && strcmp(pmu_name, pmu->name))
>
> Why remove perf_pmu__is_hybrid check?

Thanks for checking! If you have the perf_pmu__is_hybrid check then
the filter only applies PMUs that are hybrid. Firstly, why have
is_hybrid in struct perf_pmu if you use this function that searches a
list?  Secondly, the point of this change is to make the PMU name
filtering a generic feature rather than one limited to specifically
PMUs called cpu_core and cpu_atom.

Thanks,
Ian

>
> >                       continue;
> > -             }
> >
> >               list_for_each_entry(alias, &pmu->aliases, list) {
> >                       char *name = alias->desc ? alias->name :
>
> --
> Zhengjun Xing