[PATCH v2 3/3] perf pmus: Don't print duplicate PMU suffix in list by default

[Ian Rogers <irogers@google.com>]

Duplicate PMUs are no longer printed by default but the suffix of the
first is printed. When duplicate PMUs are being skipped avoid printing
the suffix.

Before:
```
$ perf list
...
  uncore_imc_free_running_0/data_read/               [Kernel PMU event]
  uncore_imc_free_running_0/data_total/              [Kernel PMU event]
  uncore_imc_free_running_0/data_write/              [Kernel PMU event]
```

After:
```
$ perf list
...
  uncore_imc_free_running/data_read/                 [Kernel PMU event]
  uncore_imc_free_running/data_total/                [Kernel PMU event]
  uncore_imc_free_running/data_write/                [Kernel PMU event]
...
$ perf list -v
  uncore_imc_free_running_0/data_read/               [Kernel PMU event]
  uncore_imc_free_running_0/data_total/              [Kernel PMU event]
  uncore_imc_free_running_0/data_write/              [Kernel PMU event]
  uncore_imc_free_running_1/data_read/               [Kernel PMU event]
  uncore_imc_free_running_1/data_total/              [Kernel PMU event]
  uncore_imc_free_running_1/data_write/              [Kernel PMU event]
...
```

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmus.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 5073843aca19..b0ecb2e5bdcc 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -440,10 +440,13 @@ static int sub_non_neg(int a, int b)
 }
 
 static char *format_alias(char *buf, int len, const struct perf_pmu *pmu,
-			  const struct perf_pmu_alias *alias)
+			  const struct perf_pmu_alias *alias, bool skip_duplicate_pmus)
 {
 	struct parse_events_term *term;
-	int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
+	int pmu_name_len = skip_duplicate_pmus
+		? pmu_name_len_no_suffix(pmu->name, /*num=*/NULL)
+		: (int)strlen(pmu->name);
+	int used = snprintf(buf, len, "%.*s/%s", pmu_name_len, pmu->name, alias->name);
 
 	list_for_each_entry(term, &alias->terms, list) {
 		if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
@@ -473,9 +476,10 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 	int printed = 0;
 	int len, j;
 	struct sevent *aliases;
+	bool skip_duplicate_pmus = print_cb->skip_duplicate_pmus(print_state);
 	struct perf_pmu *(*scan_fn)(struct perf_pmu *);
 
-	if (print_cb->skip_duplicate_pmus(print_state))
+	if (skip_duplicate_pmus)
 		scan_fn = perf_pmus__scan_skip_duplicates;
 	else
 		scan_fn = perf_pmus__scan;
@@ -518,6 +522,7 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 			*desc = NULL, *long_desc = NULL,
 			*encoding_desc = NULL, *topic = NULL,
 			*pmu_name = NULL;
+		int pmu_name_len;
 		bool deprecated = false;
 		size_t buf_used;
 
@@ -528,7 +533,8 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 		if (!aliases[j].event) {
 			/* A selectable event. */
 			pmu_name = aliases[j].pmu->name;
-			buf_used = snprintf(buf, sizeof(buf), "%s//", pmu_name) + 1;
+			pmu_name_len = pmu_name_len_no_suffix(pmu_name, /*num=*/NULL);
+			buf_used = snprintf(buf, sizeof(buf), "%.*s//", pmu_name_len, pmu_name) + 1;
 			name = buf;
 		} else {
 			if (aliases[j].event->desc) {
@@ -536,7 +542,7 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 				buf_used = 0;
 			} else {
 				name = format_alias(buf, sizeof(buf), aliases[j].pmu,
-						    aliases[j].event);
+						    aliases[j].event, skip_duplicate_pmus);
 				if (aliases[j].is_cpu) {
 					alias = name;
 					name = aliases[j].event->name;
@@ -554,8 +560,10 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 			long_desc = aliases[j].event->long_desc;
 			topic = aliases[j].event->topic;
 			encoding_desc = buf + buf_used;
+			pmu_name_len = pmu_name_len_no_suffix(pmu_name, /*num=*/NULL);
 			buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
-					"%s/%s/", pmu_name, aliases[j].event->str) + 1;
+					"%.*s/%s/", pmu_name_len, pmu_name,
+					aliases[j].event->str) + 1;
 			deprecated = aliases[j].event->deprecated;
 		}
 		print_cb->print_event(print_state,
-- 
2.41.0.640.ga95def55d0-goog