Re: [PATCH v4 1/2] perf pmu: Add PMU alias support

[Jin, Yao]

Hi Jiri,

On 8/12/2021 3:23 AM, Jiri Olsa wrote:
> On Wed, Aug 11, 2021 at 10:48:26AM +0800, Jin Yao wrote:
>
> SNIP
>
> >   				if (!parse_events_add_pmu(_parse_state, list, pmu->name, terms, true, false))
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index fc683bc41715..796a4be752f4 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -946,6 +946,18 @@ perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
> >   	return NULL;
> >   }
> >   
> > +char * __weak
> > +pmu_find_real_name(const char *name)
> > +{
> > +	return strdup(name);
> > +}
> hm, why does this need to return already strdup? it forces you
> to add all those goto below.. could just return name and keep
> the 'pmu->name = strdup(name);' below?
>
> that should make the change simpler
>
> jirka

In x86 specific __pmu_find_real_name,

static char *__pmu_find_real_name(const char *name)
{
	struct perf_pmu_alias_name *pmu;

	list_for_each_entry(pmu, &pmu_alias_name_list, list) {
		if (!strcmp(name, pmu->alias))
			return strdup(pmu->name);
	}

	return strdup(name);
}

We have returned with strdup(name).

OK, I will change the code to:

static char *__pmu_find_real_name(const char *name)
{
	struct perf_pmu_alias_name *pmu;

	list_for_each_entry(pmu, &pmu_alias_name_list, list) {
		if (!strcmp(name, pmu->alias))
			return pmu->name;
	}

	return name;
}

And keep 'pmu->name = strdup(name);' in pmu_lookup().

Thanks
Jin Yao