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Date:   Wed, 24 May 2023 15:18:29 -0700
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Subject: [PATCH v3 33/35] perf pmus: Add function to return count of core PMUs
From:   Ian Rogers <irogers@google.com>
To:     Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        John Garry <john.g.garry@oracle.com>,
        Will Deacon <will@kernel.org>,
        James Clark <james.clark@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Jing Zhang <renyu.zj@linux.alibaba.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Zhengjun Xing <zhengjun.xing@linux.intel.com>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        Madhavan Srinivasan <maddy@linux.ibm.com>,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        Ming Wang <wangming01@loongson.cn>,
        Huacai Chen <chenhuacai@kernel.org>,
        Sandipan Das <sandipan.das@amd.com>,
        Dmitrii Dolgov <9erthalion6@gmail.com>,
        Sean Christopherson <seanjc@google.com>,
        Ali Saidi <alisaidi@amazon.com>, Rob Herring <robh@kernel.org>,
        Thomas Richter <tmricht@linux.ibm.com>,
        Kang Minchul <tegongkang@gmail.com>,
        linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org,
        linux-perf-users@vger.kernel.org
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Precedence: bulk

Add perf_pmus__num_core_pmus that will count core PMUs holding the
result in a static. Reuse for perf_pmus__num_mem_pmus.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmus.c | 21 ++++++++++++++-------
 tools/perf/util/pmus.h |  1 +
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 6ecccb5ad03e..bf927aed162e 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -229,14 +229,8 @@ const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
 
 int perf_pmus__num_mem_pmus(void)
 {
-	struct perf_pmu *pmu = NULL;
-	int count = 0;
-
 	/* All core PMUs are for mem events. */
-	while ((pmu = perf_pmus__scan_core(pmu)) != NULL)
-		count++;
-
-	return count;
+	return perf_pmus__num_core_pmus();
 }
 
 /** Struct for ordering events as output in perf list. */
@@ -488,6 +482,19 @@ bool perf_pmus__has_hybrid(void)
 	return has_hybrid;
 }
 
+int perf_pmus__num_core_pmus(void)
+{
+	static int count;
+
+	if (!count) {
+		struct perf_pmu *pmu = NULL;
+
+		while ((pmu = perf_pmus__scan_core(pmu)) != NULL)
+			count++;
+	}
+	return count;
+}
+
 struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
 {
 	struct perf_pmu *pmu = evsel->pmu;
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index 9de0222ed52b..27400a027d41 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -19,5 +19,6 @@ int perf_pmus__num_mem_pmus(void);
 void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *print_state);
 bool perf_pmus__have_event(const char *pname, const char *name);
 bool perf_pmus__has_hybrid(void);
+int perf_pmus__num_core_pmus(void);
 
 #endif /* __PMUS_H */
-- 
2.40.1.698.g37aff9b760-goog