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

[Falcon, Thomas]

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?

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():