[v4,32/35] perf pmus: Ensure all PMUs are read for find_by_type

Commit Message

Ian Rogers May 26, 2023, 9:54 p.m. UTC

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 <[e-mail]>
Reviewed-by: Kan Liang <[e-mail]>
---
 tools/perf/util/pmus.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Patch

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 2c512345191d..6ecccb5ad03e 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.