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, 3 insertions, 1 deletions

diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index a1fdd6d50c53..71b8636fd07d 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -14,6 +14,7 @@
 #include "mem-events.h"
 
 struct evsel_config_term;
+struct hashmap;
 struct perf_cpu_map;
 struct print_callbacks;
 
@@ -125,7 +126,7 @@ struct perf_pmu {
 	 * event read from <sysfs>/bus/event_source/devices/<name>/events/ or
 	 * from json events in pmu-events.c.
 	 */
-	struct list_head aliases;
+	struct hashmap *aliases;
 	/**
 	 * @events_table: The events table for json events in pmu-events.c.
 	 */
@@ -294,6 +295,7 @@ int perf_pmu__pathname_scnprintf(char *buf, size_t size,
 int perf_pmu__event_source_devices_fd(void);
 int perf_pmu__pathname_fd(int dirfd, const char *pmu_name, const char *filename, int flags);
 
+int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name);
 struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char *lookup_name,
 				  bool eager_load);
 struct perf_pmu *perf_pmu__create_placeholder_core_pmu(struct list_head *core_pmus);