Re: [PATCH v1] perf pmu: Recognize default_core as a core PMU in more places

[Qinxin Xia]

On 2026/6/12 09:24:13, Ian Rogers <irogers@xxxxxxxxxx> wrote:
> The python metrics code used in places like ilist.py passes a
> pmu-filter of "default_core" on non-hybrid x86/ARM/.. systems. As a
> PMU like "cpu" isn't a literal name match then no PMU matches
> "default_core" and the events fail to parse for the metric. Fix the
> name matching and PMU lookup for "default_core" and check that it
> fixes ilist.py.
>
> Fixes: 74e2dbe7be50 ("perf tools: Add --pmu-filter option for filtering PMUs")
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> Note: this bug is in 7.1 but it is a little too late to send for the
>        release. It should get picked up via the fixes tag.
> ---
>   tools/perf/util/pmu.c  | 6 +++++-
>   tools/perf/util/pmus.c | 2 ++
>   2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index a550f030b85d..836e3b5615cd 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -2660,8 +2660,12 @@ bool perf_pmu__wildcard_match(const struct perf_pmu *pmu, const char *wildcard_t
>   		pmu->name,
>   		pmu->alias_name,
>   	};
> -	bool need_fnmatch = strisglob(wildcard_to_match);
> +	bool need_fnmatch;
>   
> +	if (pmu->is_core && !strcmp(wildcard_to_match, "default_core"))
> +		return true;
> +
> +	need_fnmatch = strisglob(wildcard_to_match);
>   	if (!strncmp(wildcard_to_match, "uncore_", 7))
>   		wildcard_to_match += 7;
>   
> diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> index 5e3f571450fe..e0a4cb2428ca 100644
> --- a/tools/perf/util/pmus.c
> +++ b/tools/perf/util/pmus.c
> @@ -150,6 +150,8 @@ struct perf_pmu *perf_pmus__find(const char *name)
>   	bool core_pmu;
>   	unsigned int to_read_pmus = 0;
>   
> +	if (!strcmp(name, "default_core"))
> +		return perf_pmus__find_core_pmu();
>   	/*
>   	 * Once PMU is loaded it stays in the list,
>   	 * so we keep us from multiple reading/parsing

Thank you for the fix, Ian.
In the previous patch, I overlooked the handling of the "default_core"
alias. Also, perhaps we can leave need_fnmatch as-is, since it doesn't
seem to affect anything here.

--
Thanks,
Qinxin