perf jevents: Add CheckPmu to see if a PMU is in loaded JSON events

CheckPmu can be used to determine if hybrid events are present,
allowing for hybrid conditional metrics/events/pmus to be premised on
the JSON files rather than hard coded tables.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Benjamin Gray <bgray@linux.ibm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Xu Yang <xu.yang_2@nxp.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/metric.py

@@ -8,10 +8,12 @@ import re
 from enum import Enum
 from typing import Dict, List, Optional, Set, Tuple, Union
 
+all_pmus = set()
 all_events = set()
 
 def LoadEvents(directory: str) -> None:
   """Populate a global set of all known events for the purpose of validating Event names"""
+  global all_pmus
   global all_events
   all_events = {
       "context\\-switches",
@@ -26,6 +28,8 @@ def LoadEvents(directory: str) -> None:
     if filename.endswith(".json"):
       try:
         for x in json.load(open(f"{directory}/{filename}")):
+          if "Unit" in x:
+            all_pmus.add(x["Unit"])
           if "EventName" in x:
             all_events.add(x["EventName"])
           elif "ArchStdEvent" in x:
@@ -36,6 +40,10 @@ def LoadEvents(directory: str) -> None:
         pass
 
 
+def CheckPmu(name: str) -> bool:
+  return name in all_pmus
+
+
 def CheckEvent(name: str) -> bool:
   """Check the event name exists in the set of all loaded events"""
   global all_events