Re: [PATCH v1 2/2] perf arch x86 tests: Add test for topdown event sorting

[Namhyung Kim]

On Mon, Mar 30, 2026 at 02:53:45PM -0700, Chen, Zide wrote:
> 
> 
> On 3/25/2026 11:30 AM, Ian Rogers wrote:
> > Add a test to capture the comment in
> > tools/perf/arch/x86/util/evlist.c. Test that slots and
> > topdown-retiring get appropriately sorted with respect to instructions
> > when they're all specified together. When the PMU requires topdown
> > event grouping (indicated by the pressence of the slots event) metric
> > events should be after slots, which should be the group leader.
> > 
> > Add a related test that when the slots event isn't given it is
> > injected into the appropriate group.
> > 
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/arch/x86/tests/topdown.c | 137 +++++++++++++++++++++++++++-
> >  1 file changed, 136 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/arch/x86/tests/topdown.c b/tools/perf/arch/x86/tests/topdown.c
> > index 3ee4e5e71be3..aca7faa16fc7 100644
> > --- a/tools/perf/arch/x86/tests/topdown.c
> > +++ b/tools/perf/arch/x86/tests/topdown.c
> > @@ -75,4 +75,139 @@ static int test__x86_topdown(struct test_suite *test __maybe_unused, int subtest
> >  	return ret;
> >  }
> >  
> > -DEFINE_SUITE("x86 topdown", x86_topdown);
> > +static int test_sort(const char *str, int expected_slots_group_size,
> > +		     int expected_instructions_group_size)
> > +{
> > +	struct evlist *evlist;
> > +	struct parse_events_error err;
> > +	struct evsel *evsel;
> > +	int ret;
> > +
> > +	evlist = evlist__new();
> > +	if (!evlist)
> > +		return TEST_FAIL;
> > +
> > +	parse_events_error__init(&err);
> > +	ret = parse_events(evlist, str, &err);
> > +	if (ret) {
> > +		pr_debug("parse_events failed for %s\n", str);
> > +		goto out_err;
> > +	}
> > +
> > +	evlist__for_each_entry(evlist, evsel) {
> > +		if (evsel__is_group_leader(evsel)) {

Same thing.  Please reduce the indentation.


> > +			if (strstr(evsel->name, "slots")) {
> > +				/*
> > +				 * Slots as a leader means the PMU is for a perf
> > +				 * metric group as the slots event isn't present
> > +				 * when not.
> > +				 */
> > +				TEST_ASSERT_EQUAL("slots group size", evsel->core.nr_members,
> > +						  expected_slots_group_size);
> > +				if (expected_slots_group_size == 3) {
> > +					struct evsel *next = evsel__next(evsel);
> > +					struct evsel *next2 = evsel__next(next);
> > +
> > +					TEST_ASSERT_VAL("slots second event is instructions",
> > +							strstr(next->name, "instructions")
> > +							!= NULL);
> > +					TEST_ASSERT_VAL("slots third event is topdown-retiring",
> > +							strstr(next2->name, "topdown-retiring")
> > +							!= NULL);
> > +				} else if (expected_slots_group_size == 2) {
> > +					struct evsel *next = evsel__next(evsel);
> > +
> > +					TEST_ASSERT_VAL("slots second event is topdown-retiring",
> > +							strstr(next->name, "topdown-retiring")
> > +							!= NULL);
> > +				}
> > +			} else if (strstr(evsel->name, "instructions")) {
> > +				TEST_ASSERT_EQUAL("instructions group size", evsel->core.nr_members,
> > +						  expected_instructions_group_size);
> > +				if (expected_instructions_group_size == 2) {
> > +					/*
> > +					 * The instructions event leads a group
> > +					 * with a topdown-retiring event,
> > +					 * neither of which need reordering for
> > +					 * perf metric event support.
> > +					 */
> > +					struct evsel *next = evsel__next(evsel);
> > +
> > +					TEST_ASSERT_VAL("instructions second event is topdown-retiring",
> > +							strstr(next->name, "topdown-retiring")
> > +							!= NULL);
> > +				}
> > +			} else if (strstr(evsel->name, "topdown-retiring")) {
> > +				/*
> > +				 * A perf metric event where the PMU doesn't
> > +				 * require slots as a leader.
> > +				 */
> > +				TEST_ASSERT_EQUAL("topdown-retiring group size",
> > +						  evsel->core.nr_members, 1);
> > +			} else if (strstr(evsel->name, "cycles")) {
> > +				TEST_ASSERT_EQUAL("cycles group size", evsel->core.nr_members, 1);
> > +			}
> > +		}
> > +	}
> > +
> > +	evlist__delete(evlist);
> > +	parse_events_error__exit(&err);
> > +	return TEST_OK;
> > +
> > +out_err:
> > +	evlist__delete(evlist);
> > +	parse_events_error__exit(&err);
> > +	return TEST_FAIL;

Also, please share the code and use a different return value.

> > +}
> > +
> > +static int test__x86_topdown_sorting(struct test_suite *test __maybe_unused,
> > +				     int subtest __maybe_unused)
> > +{
> > +	if (!topdown_sys_has_perf_metrics())
> > +		return TEST_OK;
> 
> I'm wondering if it makes more sense to return TEST_SKIP? As well as for
> other calls to topdown_sys_has_perf_metrics().

Makes sense.

Thanks,
Namhyung

> 
> Other than that, Tested-by: Zide Chen <zide.chen@xxxxxxxxx>
> 
> 
> 
> > +	TEST_ASSERT_EQUAL("all events in a group",
> > +			  test_sort("{instructions,topdown-retiring,slots}", 3, 2), TEST_OK);
> > +	TEST_ASSERT_EQUAL("all events not in a group",
> > +			  test_sort("instructions,topdown-retiring,slots", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("slots event in a group but topdown metrics events outside the group",
> > +			  test_sort("{instructions,slots},topdown-retiring", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("slots event and topdown metrics events in two groups",
> > +			  test_sort("{instructions,slots},{topdown-retiring}", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("slots event and metrics event are not in a group and not adjacent",
> > +			  test_sort("{instructions,slots},cycles,topdown-retiring", 2, 1), TEST_OK);
> > +
> > +	return TEST_OK;
> > +}
> > +
> > +static int test__x86_topdown_slots_injection(struct test_suite *test __maybe_unused,
> > +					     int subtest __maybe_unused)
> > +{
> > +	if (!topdown_sys_has_perf_metrics())
> > +		return TEST_OK;
> > +
> > +	TEST_ASSERT_EQUAL("all events in a group",
> > +			  test_sort("{instructions,topdown-retiring}", 3, 2), TEST_OK);
> > +	TEST_ASSERT_EQUAL("all events not in a group",
> > +			  test_sort("instructions,topdown-retiring", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("event in a group but topdown metrics events outside the group",
> > +			  test_sort("{instructions},topdown-retiring", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("event and topdown metrics events in two groups",
> > +			  test_sort("{instructions},{topdown-retiring}", 2, 1), TEST_OK);
> > +	TEST_ASSERT_EQUAL("event and metrics event are not in a group and not adjacent",
> > +			  test_sort("{instructions},cycles,topdown-retiring", 2, 1), TEST_OK);
> > +
> > +	return TEST_OK;
> > +}
> > +
> > +static struct test_case x86_topdown_tests[] = {
> > +	TEST_CASE("topdown events", x86_topdown),
> > +	TEST_CASE("topdown sorting", x86_topdown_sorting),
> > +	TEST_CASE("topdown slots injection", x86_topdown_slots_injection),
> > +	{ .name = NULL, }
> > +};
> > +
> > +struct test_suite suite__x86_topdown = {
> > +	.desc = "x86 topdown",
> > +	.test_cases = x86_topdown_tests,
> > +};
>