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Date:   Sun, 21 May 2023 23:43:30 -0700
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Subject: [PATCH v2 23/23] perf pmus: Ensure all PMUs are read for find_by_type
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
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

perf_pmus__find_by_type may be called for something like a raw event,
in which case the PMU isn't guaranteed to have been looked up. Add a
second check to make sure all PMUs are loaded.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmus.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 22e9e46ab765..ce75c7adca84 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -142,7 +142,7 @@ static void pmu_read_sysfs(bool core_only)
 	}
 }
 
-struct perf_pmu *perf_pmus__find_by_type(unsigned int type)
+static struct perf_pmu *__perf_pmus__find_by_type(unsigned int type)
 {
 	struct perf_pmu *pmu;
 
@@ -150,6 +150,7 @@ struct perf_pmu *perf_pmus__find_by_type(unsigned int type)
 		if (pmu->type == type)
 			return pmu;
 	}
+
 	list_for_each_entry(pmu, &other_pmus, list) {
 		if (pmu->type == type)
 			return pmu;
@@ -157,6 +158,18 @@ struct perf_pmu *perf_pmus__find_by_type(unsigned int type)
 	return NULL;
 }
 
+struct perf_pmu *perf_pmus__find_by_type(unsigned int type)
+{
+	struct perf_pmu *pmu = __perf_pmus__find_by_type(type);
+
+	if (pmu || read_sysfs_all_pmus)
+		return pmu;
+
+	pmu_read_sysfs(/*core_only=*/false);
+	pmu = __perf_pmus__find_by_type(type);
+	return pmu;
+}
+
 /*
  * pmu iterator: If pmu is NULL, we start at the begin, otherwise return the
  * next pmu. Returns NULL on end.
-- 
2.40.1.698.g37aff9b760-goog