Re: [PATCH v6 05/22] perf jevents: Mark metrics with experimental events as experimental

[Ian Rogers]

On Wed, Sep 17, 2025 at 11:02 AM Falcon, Thomas <thomas.falcon@xxxxxxxxx> wrote:
>
> On Wed, 2025-09-03 at 21:46 -0700, Ian Rogers wrote:
> > When metrics are made with experimental events it is desirable the
> > metric description also carries this information in case of metric
> > inaccuracies.
> >
> > Suggested-by: Perry Taylor <perry.taylor@xxxxxxxxx>
>
> Does this need a Signed-off-by?

It does, I'll fix in v7.

Thanks,
Ian

> Thanks,
> Tom
>
> > ---
> >  tools/perf/pmu-events/metric.py | 44 +++++++++++++++++++++++++++++++++
> >  1 file changed, 44 insertions(+)
> >
> > diff --git a/tools/perf/pmu-events/metric.py b/tools/perf/pmu-events/metric.py
> > index 62d1a1e1d458..2029b6e28365 100644
> > --- a/tools/perf/pmu-events/metric.py
> > +++ b/tools/perf/pmu-events/metric.py
> > @@ -10,11 +10,13 @@ from typing import Dict, List, Optional, Set, Tuple, Union
> >
> >  all_pmus = set()
> >  all_events = set()
> > +experimental_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
> > +  global experimental_events
> >    all_events = {
> >        "context\\-switches",
> >        "cpu\\-cycles",
> > @@ -32,6 +34,8 @@ def LoadEvents(directory: str) -> None:
> >              all_pmus.add(x["Unit"])
> >            if "EventName" in x:
> >              all_events.add(x["EventName"])
> > +            if "Experimental" in x and x["Experimental"] == "1":
> > +              experimental_events.add(x["EventName"])
> >            elif "ArchStdEvent" in x:
> >              all_events.add(x["ArchStdEvent"])
> >        except json.decoder.JSONDecodeError:
> > @@ -61,6 +65,18 @@ def CheckEvent(name: str) -> bool:
> >    return name in all_events
> >
> >
> > +def IsExperimentalEvent(name: str) -> bool:
> > +  global experimental_events
> > +  if ':' in name:
> > +    # Remove trailing modifier.
> > +    name = name[:name.find(':')]
> > +  elif '/' in name:
> > +    # Name could begin with a PMU or an event, for now assume it is not experimental.
> > +    return False
> > +
> > +  return name in experimental_events
> > +
> > +
> >  class MetricConstraint(Enum):
> >    GROUPED_EVENTS = 0
> >    NO_GROUP_EVENTS = 1
> > @@ -82,6 +98,10 @@ class Expression:
> >      """Returns a simplified version of self."""
> >      raise NotImplementedError()
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    """Are experimental events used in the expression?"""
> > +    raise NotImplementedError()
> > +
> >    def Equals(self, other) -> bool:
> >      """Returns true when two expressions are the same."""
> >      raise NotImplementedError()
> > @@ -249,6 +269,9 @@ class Operator(Expression):
> >
> >      return Operator(self.operator, lhs, rhs)
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return self.lhs.HasExperimentalEvents() or self.rhs.HasExperimentalEvents()
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      if isinstance(other, Operator):
> >        return self.operator == other.operator and self.lhs.Equals(
> > @@ -297,6 +320,10 @@ class Select(Expression):
> >
> >      return Select(true_val, cond, false_val)
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return (self.cond.HasExperimentalEvents() or self.true_val.HasExperimentalEvents() or
> > +            self.false_val.HasExperimentalEvents())
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      if isinstance(other, Select):
> >        return self.cond.Equals(other.cond) and self.false_val.Equals(
> > @@ -345,6 +372,9 @@ class Function(Expression):
> >
> >      return Function(self.fn, lhs, rhs)
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return self.lhs.HasExperimentalEvents() or (self.rhs and self.rhs.HasExperimentalEvents())
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      if isinstance(other, Function):
> >        result = self.fn == other.fn and self.lhs.Equals(other.lhs)
> > @@ -384,6 +414,9 @@ class Event(Expression):
> >      global all_events
> >      raise Exception(f"No event {error} in:\n{all_events}")
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return IsExperimentalEvent(self.name)
> > +
> >    def ToPerfJson(self):
> >      result = re.sub('/', '@', self.name)
> >      return result
> > @@ -416,6 +449,9 @@ class MetricRef(Expression):
> >    def Simplify(self) -> Expression:
> >      return self
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return False
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      return isinstance(other, MetricRef) and self.name == other.name
> >
> > @@ -443,6 +479,9 @@ class Constant(Expression):
> >    def Simplify(self) -> Expression:
> >      return self
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return False
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      return isinstance(other, Constant) and self.value == other.value
> >
> > @@ -465,6 +504,9 @@ class Literal(Expression):
> >    def Simplify(self) -> Expression:
> >      return self
> >
> > +  def HasExperimentalEvents(self) -> bool:
> > +    return False
> > +
> >    def Equals(self, other: Expression) -> bool:
> >      return isinstance(other, Literal) and self.value == other.value
> >
> > @@ -527,6 +569,8 @@ class Metric:
> >      self.name = name
> >      self.description = description
> >      self.expr = expr.Simplify()
> > +    if self.expr.HasExperimentalEvents():
> > +      self.description += " (metric should be considered experimental as it contains experimental events)."
> >      # Workraound valid_only_metric hiding certain metrics based on unit.
> >      scale_unit = scale_unit.replace('/sec', ' per sec')
> >      if scale_unit[0].isdigit():