[PATCH v7 4/7] perf evsel x86: Make evsel__has_perf_metrics work for legacy events

From: James Clark
Date: Tue Sep 10 2024 - 11:19:00 EST


From: Ian Rogers <irogers@xxxxxxxxxx>

Use PMU interface to better detect core PMU for legacy events. Look
for slots event on core PMU if it is appropriate for the event.

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
---
tools/perf/arch/x86/util/evsel.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
index 090d0f371891..1eaae8819c5e 100644
--- a/tools/perf/arch/x86/util/evsel.c
+++ b/tools/perf/arch/x86/util/evsel.c
@@ -21,7 +21,8 @@ void arch_evsel__set_sample_weight(struct evsel *evsel)
/* Check whether the evsel's PMU supports the perf metrics */
bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
{
- const char *pmu_name = evsel->pmu_name ? evsel->pmu_name : "cpu";
+ struct perf_pmu *pmu;
+ u32 type = evsel->core.attr.type;

/*
* The PERF_TYPE_RAW type is the core PMU type, e.g., "cpu" PMU
@@ -31,11 +32,31 @@ bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
* Checking both the PERF_TYPE_RAW type and the slots event
* should be good enough to detect the perf metrics feature.
*/
- if ((evsel->core.attr.type == PERF_TYPE_RAW) &&
- perf_pmus__have_event(pmu_name, "slots"))
- return true;
+again:
+ switch (type) {
+ case PERF_TYPE_HARDWARE:
+ case PERF_TYPE_HW_CACHE:
+ type = evsel->core.attr.config >> PERF_PMU_TYPE_SHIFT;
+ if (type)
+ goto again;
+ break;
+ case PERF_TYPE_RAW:
+ break;
+ default:
+ return false;
+ }
+
+ pmu = evsel->pmu;
+ if (pmu == &perf_pmu__fake)
+ pmu = NULL;

- return false;
+ if (!pmu) {
+ while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
+ if (pmu->type == PERF_TYPE_RAW)
+ break;
+ }
+ }
+ return pmu && perf_pmu__have_event(pmu, "slots");
}

bool arch_evsel__must_be_in_group(const struct evsel *evsel)
--
2.34.1