Calling perf_pmu__find_map(NULL) returns the cpumap for the common CPU
PMU. However arm64 supports heterogeneous-CPU based systems, and so there
may be no common CPU PMU. As such, perf_pmu__find_map(NULL) returns NULL
for arm64.
To support printing metrics for arm64, iterate through all PMUs, looking
for a CPU PMU, and use the cpumap there for determining supported metrics.
For heterogeneous systems (like arm big.LITTLE), supporting metrics has
potential challenges, like not all CPUs in a system not supporting a
specific metric event. So just don't support it for now.
Signed-off-by: John Garry <john.ga...@huawei.com>
---
tools/perf/util/metricgroup.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 26c990e32378..9a2a23093961 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -6,6 +6,7 @@
/* Manage metrics and groups of metrics from JSON files */
#include "metricgroup.h"
+#include "cpumap.h"
#include "debug.h"
#include "evlist.h"
#include "evsel.h"
@@ -615,10 +616,31 @@ static int metricgroup__print_sys_event_iter(struct
pmu_event *pe, void *data)
d->details, d->groups, d->metriclist);
}
+static struct pmu_events_map *find_cpumap(void)
+{
+ struct perf_pmu *pmu = NULL;
+
+ while ((pmu = perf_pmu__scan(pmu))) {
+ if (!is_pmu_core(pmu->name))
+ continue;
+
+ /*
+ * The cpumap should cover all CPUs. Otherwise, some CPUs may
+ * not support some events or have different event IDs.
+ */
+ if (pmu->cpus && pmu->cpus->nr != cpu__max_cpu())
+ return NULL;
+
+ return perf_pmu__find_map(pmu);
+ }
+
+ return NULL;
+}
+
void metricgroup__print(bool metrics, bool metricgroups, char *filter,
bool raw, bool details)
{
- struct pmu_events_map *map = perf_pmu__find_map(NULL);
+ struct pmu_events_map *map = find_cpumap();
struct pmu_event *pe;
int i;
struct rblist groups;
--
2.26.2
