[PATCH v4 4/7] perf evsel x86: Make evsel__has_perf_metrics work for legacy events

James Clark james.clark at linaro.org
Thu Aug 22 06:24:48 PDT 2024


From: Ian Rogers <irogers at google.com>

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.

Signed-off-by: Ian Rogers <irogers at google.com>
Signed-off-by: James Clark <james.clark at linaro.org>
---
 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




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