[PATCH v1 2/3] perf pmus: Add scan that ignores duplicates, use for perf list

[Ian Rogers]

When there are multiple PMUs that differ only by suffix, just list the
first one and skip all others. As the PMUs are sorted, the scan
routine checks that the PMU names match and the numbers are
consecutive.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/pmus.c | 48 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 3581710667b0..87e5fb74e121 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -275,6 +275,50 @@ struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu)
 	return NULL;
 }
 
+static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
+{
+	bool use_core_pmus = !pmu || pmu->is_core;
+	int last_pmu_name_len = 0;
+	unsigned long last_pmu_num = 0;
+	const char *last_pmu_name = (pmu && pmu->name) ? pmu->name : "";
+
+	if (!pmu) {
+		pmu_read_sysfs(/*core_only=*/false);
+		pmu = list_prepare_entry(pmu, &core_pmus, list);
+	} else
+		last_pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", &last_pmu_num);
+
+	if (use_core_pmus) {
+		list_for_each_entry_continue(pmu, &core_pmus, list) {
+			unsigned long pmu_num = 0;
+			int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", &pmu_num);
+
+			if (last_pmu_name_len == pmu_name_len &&
+			    (last_pmu_num + 1 == pmu_num) &&
+			    !strncmp(last_pmu_name, pmu->name ?: "", pmu_name_len)) {
+				last_pmu_num++;
+				continue;
+			}
+			return pmu;
+		}
+		pmu = NULL;
+		pmu = list_prepare_entry(pmu, &other_pmus, list);
+	}
+	list_for_each_entry_continue(pmu, &other_pmus, list) {
+		unsigned long pmu_num = 0;
+		int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", &pmu_num);
+
+		if (last_pmu_name_len == pmu_name_len &&
+		    (last_pmu_num + 1 == pmu_num) &&
+		    !strncmp(last_pmu_name, pmu->name ?: "", pmu_name_len)) {
+			last_pmu_num++;
+			continue;
+		}
+		return pmu;
+	}
+	return NULL;
+}
+
 const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
 {
 	struct perf_pmu *pmu = NULL;
@@ -432,7 +476,7 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 
 	pmu = NULL;
 	len = 0;
-	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
+	while ((pmu = perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
 		list_for_each_entry(event, &pmu->aliases, list)
 			len++;
 		if (pmu->selectable)
@@ -445,7 +489,7 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 	}
 	pmu = NULL;
 	j = 0;
-	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
+	while ((pmu = perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
 		bool is_cpu = pmu->is_core;
 
 		list_for_each_entry(event, &pmu->aliases, list) {
-- 
2.41.0.390.g38632f3daf-goog