perf jevents: Update metric constraint support

Previous metric constraints were binary, either none or don't group
when the NMI watchdog is present. Update to match the definitions in
'enum metric_event_groups' in pmu-events.h.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/pmu-events/metric.py

@@ -4,8 +4,14 @@ import ast
 import decimal
 import json
 import re
+from enum import Enum
 from typing import Dict, List, Optional, Set, Tuple, Union
 
+class MetricConstraint(Enum):
+  GROUPED_EVENTS = 0
+  NO_GROUP_EVENTS = 1
+  NO_GROUP_EVENTS_NMI = 2
+  NO_GROUP_EVENTS_SMT = 3
 
 class Expression:
   """Abstract base class of elements in a metric expression."""
@@ -423,14 +429,14 @@ class Metric:
   groups: Set[str]
   expr: Expression
   scale_unit: str
-  constraint: bool
+  constraint: MetricConstraint
 
   def __init__(self,
                name: str,
                description: str,
                expr: Expression,
                scale_unit: str,
-               constraint: bool = False):
+               constraint: MetricConstraint = MetricConstraint.GROUPED_EVENTS):
     self.name = name
     self.description = description
     self.expr = expr.Simplify()
@@ -464,8 +470,8 @@ class Metric:
         'MetricExpr': self.expr.ToPerfJson(),
         'ScaleUnit': self.scale_unit
     }
-    if self.constraint:
-      result['MetricConstraint'] = 'NO_NMI_WATCHDOG'
+    if self.constraint != MetricConstraint.GROUPED_EVENTS:
+      result['MetricConstraint'] = self.constraint.name
 
     return result