linux-kernel - [PATCH] perf pmu: Fix event list for uncore PMUs

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Date:   Thu, 16 Dec 2021 23:53:37 +0800
From:   John Garry <john.garry@...wei.com>
To:     <peterz@...radead.org>, <mingo@...hat.com>, <acme@...nel.org>,
        <mark.rutland@....com>, <alexander.shishkin@...ux.intel.com>,
        <jolsa@...hat.com>, <namhyung@...nel.org>, <irogers@...gle.com>,
        <kan.liang@...ux.intel.com>
CC:     <linux-perf-users@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        "John Garry" <john.garry@...wei.com>
Subject: [PATCH] perf pmu: Fix event list for uncore PMUs

Commit 0e0ae8742207 ("perf list: Display hybrid PMU events with cpu type")
changed the list for uncore PMUs, such that duplicate aliases are now
listed per PMU (which they should not be), like:

./perf list
...
unc_cbo_cache_lookup.any_es
[Unit: uncore_cbox L3 Lookup any request that access cache and found
line in E or S-state]
unc_cbo_cache_lookup.any_es
[Unit: uncore_cbox L3 Lookup any request that access cache and found
line in E or S-state]
unc_cbo_cache_lookup.any_i
[Unit: uncore_cbox L3 Lookup any request that access cache and found
line in I-state]
unc_cbo_cache_lookup.any_i
[Unit: uncore_cbox L3 Lookup any request that access cache and found
line in I-state]
...

Notice how the events are listed twice.

The named commit changed how we remove duplicate events, in that events
for different PMUs are not treated as duplicates. I suppose this is to
handle how "Each hybrid pmu event has been assigned with a pmu name".

Fix uncore PMU alias list by also checking if events with PMU name are not
cpu PMUs.

Fixes: 0e0ae8742207 ("perf list: Display hybrid PMU events with cpu type")
Signed-off-by: John Garry <john.garry@...wei.com>
---
It would be helpful if someone with some of these hybrid CPU systems could
test this change, thanks!

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 6ae58406f4fc..392f6a36418b 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1659,6 +1659,24 @@ bool is_pmu_core(const char *name)
 	return !strcmp(name, "cpu") || is_arm_pmu_core(name);
 }
 
+static bool pmu_alias_is_duplicate(struct sevent *alias_a,
+				   struct sevent *alias_b)
+{
+	/* Different names -> never duplicates */
+	if (strcmp(alias_a->name, alias_b->name))
+		return false;
+	if (!alias_a->pmu)
+		return true;
+	if (!alias_b->pmu)
+		return true;
+	if (!strcmp(alias_a->pmu, alias_b->pmu))
+		return true;
+	/* uncore PMUs */
+	if (!alias_a->is_cpu && !alias_b->is_cpu)
+		return true;
+	return false;
+}
+
 void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 			bool long_desc, bool details_flag, bool deprecated,
 			const char *pmu_name)
@@ -1744,12 +1762,8 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 	qsort(aliases, len, sizeof(struct sevent), cmp_sevent);
 	for (j = 0; j < len; j++) {
 		/* Skip duplicates */
-		if (j > 0 && !strcmp(aliases[j].name, aliases[j - 1].name)) {
-			if (!aliases[j].pmu || !aliases[j - 1].pmu ||
-			    !strcmp(aliases[j].pmu, aliases[j - 1].pmu)) {
-				continue;
-			}
-		}
+		if (j > 0 && pmu_alias_is_duplicate(&aliases[j], &aliases[j - 1]))
+			continue;
 
 		if (name_only) {
 			printf("%s ", aliases[j].name);
-- 
2.26.2