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

Ian Rogers
2022-11-14T14:03:32Z

On Mon, Nov 14, 2022 at 5:58 AM Liang, Kan <kan.liang@linux.intel.com> wrote:
>
>
>
> On 2022-11-14 2:51 a.m., 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)
>
> The "--cputype" is removed from the documentation, but the code is still
> available. It sounds weird.
>
> Can we still keep the "--cputype" in the documentation? Just say that
> it's a deprecated option, please use the --unit cpu_atom instead. I
> think even better if we can throw a warning and point to --unit when the
> "--cputype" is used.

I think we want to remove --cputype widely in the code and replace
what it does with specifying a PMU name. Advertising a flag but then
warning seems strange and is a behavioral change from what is
currently done. For raw-dump we don't document it in the man page and
hide the flag, this is the pattern being followed here.

Thanks,
Ian

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