Re: [PATCH] tools/perf: Fix ratio_to_prev event parsing test

[Mi, Dapeng]

On 3/25/2026 6:25 AM, thomas.falcon@xxxxxxxxx wrote:
> From: Thomas Falcon <thomas.falcon@xxxxxxxxx>
>
> test__ratio_to_prev() assumed the first event in a group is the leader,
> which is not the case when the event is expanded into two event groups
> on hybrid PMU's with auto counter reload support. This patch updates the
> test to iterate over the event group generated for each core PMU. Also
> update "wrong leader" test to check that the subordinate event has the
> correct leader instead of checking that it is not the group leader.
>
> Signed-off-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
> Fixes: 56be0fe5f62c ("perf record: Add auto counter reload parse and regression tests")
> ---
>  tools/perf/tests/parse-events.c | 45 +++++++++++++++++++--------------
>  1 file changed, 26 insertions(+), 19 deletions(-)
>
> diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
> index 1d3cc224fbc2..cd48e6b2bb57 100644
> --- a/tools/perf/tests/parse-events.c
> +++ b/tools/perf/tests/parse-events.c
> @@ -1796,31 +1796,38 @@ static bool test__acr_valid(void)
>  
>  static int test__ratio_to_prev(struct evlist *evlist)
>  {
> -	struct evsel *evsel;
> +	struct evsel *evsel, *leader;
>  
>  	TEST_ASSERT_VAL("wrong number of entries", 2 * perf_pmus__num_core_pmus() == evlist->core.nr_entries);
>  
> -	 evlist__for_each_entry(evlist, evsel) {
> +	for (int i = 0; i < num_core_entries(evlist); i++) {
> +		evsel = leader = (i == 0 ? evlist__first(evlist) : evsel__next(evsel));

could we use the "leader" to replace "evsel" for all the "TEST_ASSERT_VAL"
of cycles event? That make code look more clearer. Then the above sentence
can be simplified to this,

```
leader = (i == 0 ? evlist__first(evlist) : evsel__next(evsel));

```


>  		if (!perf_pmu__has_format(evsel->pmu, "acr_mask"))
>  			return TEST_OK;
>  
> -		if (evsel == evlist__first(evlist)) {
> -			TEST_ASSERT_VAL("wrong config2", 0 == evsel->core.attr.config2);
> -			TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));
> -			TEST_ASSERT_VAL("wrong core.nr_members", evsel->core.nr_members == 2);
> -			TEST_ASSERT_VAL("wrong group_idx", evsel__group_idx(evsel) == 0);
> -			TEST_ASSERT_EVSEL("unexpected event",
> -					evsel__match(evsel, HARDWARE, HW_CPU_CYCLES),
> -					evsel);
> -		} else {
> -			TEST_ASSERT_VAL("wrong config2", 0 == evsel->core.attr.config2);
> -			TEST_ASSERT_VAL("wrong leader", !evsel__is_group_leader(evsel));
> -			TEST_ASSERT_VAL("wrong core.nr_members", evsel->core.nr_members == 0);
> -			TEST_ASSERT_VAL("wrong group_idx", evsel__group_idx(evsel) == 1);
> -			TEST_ASSERT_EVSEL("unexpected event",
> -					evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS),
> -					evsel);
> -		}
> +		/* cycles */
> +		TEST_ASSERT_VAL("wrong config2", 0 == evsel->core.attr.config2);
> +		TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));
> +		TEST_ASSERT_VAL("wrong core.nr_members", evsel->core.nr_members == 2);
> +		TEST_ASSERT_VAL("wrong group_idx", evsel__group_idx(evsel) == 0);
> +		TEST_ASSERT_EVSEL("unexpected event",
> +				  evsel__match(evsel, HARDWARE, HW_CPU_CYCLES),
> +				  evsel);
> +		/*
> +		 * The period value gets configured within evlist__config,
> +		 * while this test executes only parse events method.
> +		 */
> +		TEST_ASSERT_VAL("wrong period", 0 == evsel->core.attr.sample_period);
> +
> +		 /* instructions/period=200000,ratio-to-prev=2.0/ */
> +		evsel = evsel__next(evsel);

and here, the code needs to be changed to

```

evsel = evsel__next(leader);

```


> +		TEST_ASSERT_VAL("wrong config2", 0 == evsel->core.attr.config2);
> +		TEST_ASSERT_VAL("wrong leader", evsel__has_leader(evsel, leader));
> +		TEST_ASSERT_VAL("wrong core.nr_members", evsel->core.nr_members == 0);
> +		TEST_ASSERT_VAL("wrong group_idx", evsel__group_idx(evsel) == 1);
> +		TEST_ASSERT_EVSEL("unexpected event",
> +				  evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS),
> +				  evsel);
>  		/*
>  		 * The period value gets configured within evlist__config,
>  		 * while this test executes only parse events method.