perf pmu: Change aliases from list to hashmap

Finding an alias for things like perf_pmu__have_event() would need to
search the aliases list, whilst this happens relatively infrequently it
can be a significant overhead in testing.

Switch to using a hashmap. Move common initialization code to
perf_pmu__init(). Refactor the test 'struct perf_pmu_test_pmu' to not
have perf pmu within it to better support the perf_pmu__init() function.

Before:
```
$ time perf test "Parsing of PMU event table metrics"
 10.3: Parsing of PMU event table metrics                            : Ok
 10.4: Parsing of PMU event table metrics with fake PMUs             : Ok

real    0m13.287s
user    0m13.026s
sys     0m0.532s
```

After:
```
$ time perf test "Parsing of PMU event table metrics"
 10.3: Parsing of PMU event table metrics                            : Ok
 10.4: Parsing of PMU event table metrics with fake PMUs             : Ok

real    0m13.011s
user    0m12.885s
sys     0m0.485s
```

Committer testing:

  root@number:~# grep -m1 'model name' /proc/cpuinfo
  model name	: AMD Ryzen 9 9950X3D 16-Core Processor
  root@number:~#

Before:

  root@number:~# time perf test "Parsing of PMU event table metrics"
   10.3: Parsing of PMU event table metrics                            : Ok
   10.4: Parsing of PMU event table metrics with fake PMUs             : Ok

  real	0m9.296s
  user	0m9.361s
  sys	0m0.063s
  root@number:~#

After:

  root@number:~# time perf test "Parsing of PMU event table metrics"
   10.3: Parsing of PMU event table metrics                            : Ok
   10.4: Parsing of PMU event table metrics with fake PMUs             : Ok

  real	0m9.286s
  user	0m9.354s
  sys	0m0.062s
  root@number:~#

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20250512194622.33258-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 22 insertions, 21 deletions

diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c
index 3cce77fc8004..c25e7296f1c1 100644
--- a/tools/perf/util/hwmon_pmu.c
+++ b/tools/perf/util/hwmon_pmu.c
@@ -346,42 +346,43 @@ struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir, const cha
 {
 	char buf[32];
 	struct hwmon_pmu *hwm;
+	__u32 type = PERF_PMU_TYPE_HWMON_START + strtoul(sysfs_name + 5, NULL, 10);
+
+	if (type > PERF_PMU_TYPE_HWMON_END) {
+		pr_err("Unable to encode hwmon type from %s in valid PMU type\n", sysfs_name);
+		return NULL;
+	}
+
+	snprintf(buf, sizeof(buf), "hwmon_%s", name);
+	fix_name(buf + 6);
 
 	hwm = zalloc(sizeof(*hwm));
 	if (!hwm)
 		return NULL;
 
-	hwm->hwmon_dir_fd = hwmon_dir;
-	hwm->pmu.type = PERF_PMU_TYPE_HWMON_START + strtoul(sysfs_name + 5, NULL, 10);
-	if (hwm->pmu.type > PERF_PMU_TYPE_HWMON_END) {
-		pr_err("Unable to encode hwmon type from %s in valid PMU type\n", sysfs_name);
-		goto err_out;
+	if (perf_pmu__init(&hwm->pmu, type, buf) != 0) {
+		perf_pmu__delete(&hwm->pmu);
+		return NULL;
 	}
-	snprintf(buf, sizeof(buf), "hwmon_%s", name);
-	fix_name(buf + 6);
-	hwm->pmu.name = strdup(buf);
-	if (!hwm->pmu.name)
-		goto err_out;
+
+	hwm->hwmon_dir_fd = hwmon_dir;
 	hwm->pmu.alias_name = strdup(sysfs_name);
-	if (!hwm->pmu.alias_name)
-		goto err_out;
+	if (!hwm->pmu.alias_name) {
+		perf_pmu__delete(&hwm->pmu);
+		return NULL;
+	}
 	hwm->pmu.cpus = perf_cpu_map__new("0");
-	if (!hwm->pmu.cpus)
-		goto err_out;
+	if (!hwm->pmu.cpus) {
+		perf_pmu__delete(&hwm->pmu);
+		return NULL;
+	}
 	INIT_LIST_HEAD(&hwm->pmu.format);
-	INIT_LIST_HEAD(&hwm->pmu.aliases);
 	INIT_LIST_HEAD(&hwm->pmu.caps);
 	hashmap__init(&hwm->events, hwmon_pmu__event_hashmap_hash,
 		      hwmon_pmu__event_hashmap_equal, /*ctx=*/NULL);
 
 	list_add_tail(&hwm->pmu.list, pmus);
 	return &hwm->pmu;
-err_out:
-	free((char *)hwm->pmu.name);
-	free(hwm->pmu.alias_name);
-	free(hwm);
-	close(hwmon_dir);
-	return NULL;
 }
 
 void hwmon_pmu__exit(struct perf_pmu *pmu)