Re: [PATCH v1 2/3] perf jevents: Add python type annotations

[Ian Rogers]

On Thu, Jul 16, 2026 at 9:56 AM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Mon, Jul 06, 2026 at 08:40:18PM -0700, Ian Rogers wrote:
> > Make mypy clean.
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/pmu-events/jevents.py | 77 +++++++++++++++++++-------------
> >  1 file changed, 45 insertions(+), 32 deletions(-)
> >
> > diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> > index 3c6cfeefbd5d..83a239dd69f5 100755
> > --- a/tools/perf/pmu-events/jevents.py
> > +++ b/tools/perf/pmu-events/jevents.py
> > @@ -14,27 +14,27 @@ import collections
> >  # Global command line arguments.
> >  _args = None
> >  # List of regular event tables.
> > -_event_tables = []
> > +_event_tables: list[str] = []
>
> I got this from one of my test setup.
>
>     GEN     /build/pmu-events/test-empty-pmu-events.c
>   Traceback (most recent call last):
>     File "pmu-events/jevents.py", line 17, in <module>
>       _event_tables: list[str] = []
>   TypeError: 'type' object is not subscriptable
>   make[3]: *** [pmu-events/Build:176: /build/pmu-events/test-empty-pmu-events.c] Error 1
>   make[2]: *** [Makefile.perf:550: /build/pmu-events/pmu-events-in.o] Error 2
>   make[2]: *** Waiting for unfinished jobs....
>   make[1]: *** [Makefile.perf:288: sub-make] Error 2
>   make: *** [Makefile:76: all] Error 2
>
> Python version was 3.6.15.

I believe the minimum Python version should be 3.9.x:
https://docs.kernel.org/process/changes.html
That version will resolve this issue.

Thanks,
Ian

> I'll process patch 1 for now.
>
> Thanks,
> Namhyung
>
>
> >  # List of event tables generated from "/sys" directories.
> > -_sys_event_tables = []
> > +_sys_event_tables: list[str] = []
> >  # List of regular metric tables.
> > -_metric_tables = []
> > +_metric_tables: list[str] = []
> >  # List of metric tables generated from "/sys" directories.
> > -_sys_metric_tables = []
> > +_sys_metric_tables: list[str] = []
> >  # Mapping between sys event table names and sys metric table names.
> >  _sys_event_table_to_metric_table_mapping = {}
> >  # Map from an event name to an architecture standard
> >  # JsonEvent. Architecture standard events are in json files in the top
> >  # f'{_args.starting_dir}/{_args.arch}' directory.
> > -_arch_std_events = {}
> > +_arch_std_events: Dict[str, "JsonEvent"] = {}
> >  # Events to write out when the table is closed
> > -_pending_events = []
> > +_pending_events: list["JsonEvent"] = []
> >  # Name of events table to be written out
> > -_pending_events_tblname = None
> > +_pending_events_tblname: Optional[str] = None
> >  # Metrics to write out when the table is closed
> > -_pending_metrics = []
> > +_pending_metrics: list["JsonEvent"] = []
> >  # Name of metrics table to be written out
> > -_pending_metrics_tblname = None
> > +_pending_metrics_tblname: Optional[str] = None
> >  # Global BigCString shared by all structures.
> >  _bcs = None
> >  # Map from the name of a metric group to a description of the group.
> > @@ -210,7 +210,7 @@ class JsonEvent:
> >        """Convert an int to a string similar to a printf modifier of %#llx."""
> >        return str(x) if x >= 0 and x < 10 else hex(x)
> >
> > -    def fixdesc(s: str) -> str:
> > +    def fixdesc(s: Optional[str]) -> Optional[str]:
> >        """Fix formatting issue for the desc string."""
> >        if s is None:
> >          return None
> > @@ -218,7 +218,7 @@ class JsonEvent:
> >                                         '. '), '.').replace('\n', '\\n').replace(
> >                                             '\"', '\\"').replace('\r', '\\r')
> >
> > -    def convert_aggr_mode(aggr_mode: str) -> Optional[str]:
> > +    def convert_aggr_mode(aggr_mode: Optional[str]) -> Optional[str]:
> >        """Returns the aggr_mode_class enum value associated with the JSON string."""
> >        if not aggr_mode:
> >          return None
> > @@ -228,7 +228,7 @@ class JsonEvent:
> >        }
> >        return aggr_mode_to_enum[aggr_mode]
> >
> > -    def convert_metric_constraint(metric_constraint: str) -> Optional[str]:
> > +    def convert_metric_constraint(metric_constraint: Optional[str]) -> Optional[str]:
> >        """Returns the metric_event_groups enum value associated with the JSON string."""
> >        if not metric_constraint:
> >          return None
> > @@ -241,7 +241,7 @@ class JsonEvent:
> >        }
> >        return metric_constraint_to_enum[metric_constraint]
> >
> > -    def lookup_msr(num: str) -> Optional[str]:
> > +    def lookup_msr(num: Optional[str]) -> Optional[str]:
> >        """Converts the msr number, or first in a list to the appropriate event field."""
> >        if not num:
> >          return None
> > @@ -253,7 +253,7 @@ class JsonEvent:
> >        }
> >        return msrmap[int(num.split(',', 1)[0], 0)]
> >
> > -    def real_event(name: str, event: str) -> Optional[str]:
> > +    def real_event(name: Optional[str], event: Optional[str]) -> Optional[str]:
> >        """Convert well known event names to an event string otherwise use the event argument."""
> >        fixed = {
> >            'inst_retired.any': 'event=0xc0,period=2000003',
> > @@ -269,7 +269,7 @@ class JsonEvent:
> >          return fixed[name.lower()]
> >        return event
> >
> > -    def unit_to_pmu(unit: str) -> Optional[str]:
> > +    def unit_to_pmu(unit: Optional[str]) -> Optional[str]:
> >        """Convert a JSON Unit to Linux PMU name."""
> >        if not unit:
> >          return 'default_core'
> > @@ -304,21 +304,21 @@ class JsonEvent:
> >        return table[unit] if unit in table else f'uncore_{unit.lower()}'
> >
> >      def is_zero(val: str) -> bool:
> > -        try:
> > -            if val.startswith('0x'):
> > -                return int(val, 16) == 0
> > -            else:
> > -                return int(val) == 0
> > -        except e:
> > -            return False
> > +      try:
> > +        if val.startswith('0x'):
> > +          return int(val, 16) == 0
> > +        else:
> > +          return int(val) == 0
> > +      except:
> > +        return False
> >
> >      def canonicalize_value(val: str) -> str:
> > -        try:
> > -            if val.startswith('0x'):
> > -                return llx(int(val, 16))
> > -            return str(int(val))
> > -        except e:
> > -            return val
> > +      try:
> > +        if val.startswith('0x'):
> > +          return llx(int(val, 16))
> > +        return str(int(val))
> > +      except:
> > +        return val
> >
> >      eventcode = 0
> >      if 'EventCode' in jd:
> > @@ -370,7 +370,8 @@ class JsonEvent:
> >      if precise and self.desc and '(Precise Event)' not in self.desc:
> >        extra_desc += ' (Must be precise)' if precise == '2' else (' (Precise '
> >                                                                   'event)')
> > -    event = None
> > +    self.event: Optional[str] = None
> > +    event: Optional[str] = None
> >      if configcode is not None:
> >        event = f'config={llx(configcode)}'
> >      elif eventidcode is not None:
> > @@ -455,6 +456,7 @@ class JsonEvent:
> >          return f'\t/* {s} */\n' if len(s) < 80 else f'\t/* {s[0:80]}... */\n'
> >
> >      s = self.build_c_string(metric)
> > +    assert _bcs is not None
> >      return f'{make_comment(s)}\t{{ { _bcs.offsets[s] } }},\n'
> >
> >
> > @@ -524,6 +526,7 @@ def print_pending_events() -> None:
> >      return
> >
> >    global _pending_events_tblname
> > +  assert _pending_events_tblname is not None
> >    if _pending_events_tblname.endswith('_sys'):
> >      global _sys_event_tables
> >      _sys_event_tables.append(_pending_events_tblname)
> > @@ -534,7 +537,8 @@ def print_pending_events() -> None:
> >    first = True
> >    last_pmu = None
> >    last_name = None
> > -  pmus = set()
> > +  pmus: Set[Tuple[str, str]] = set()
> > +  assert _args is not None
> >    for event in sorted(_pending_events, key=event_cmp_key):
> >      if last_pmu and last_pmu == event.pmu:
> >        assert event.name != last_name, f"Duplicate event: {last_pmu}/{last_name}/ in {_pending_events_tblname}"
> > @@ -576,6 +580,7 @@ def print_pending_metrics() -> None:
> >          return ''
> >        return s
> >
> > +    assert j.metric_expr is not None
> >      return (fix_none(j.pmu), fix_none(j.metric_name), j.metric_expr.ToPerfJson(),
> >              fix_none(j.desc))
> >
> > @@ -584,6 +589,7 @@ def print_pending_metrics() -> None:
> >      return
> >
> >    global _pending_metrics_tblname
> > +  assert _pending_metrics_tblname is not None
> >    if _pending_metrics_tblname.endswith('_sys'):
> >      global _sys_metric_tables
> >      _sys_metric_tables.append(_pending_metrics_tblname)
> > @@ -593,7 +599,8 @@ def print_pending_metrics() -> None:
> >
> >    first = True
> >    last_pmu = None
> > -  pmus = set()
> > +  pmus: Set[Tuple[str, str]] = set()
> > +  assert _args is not None
> >    for metric in sorted(_pending_metrics, key=metric_cmp_key):
> >      if metric.pmu != last_pmu:
> >        if not first:
> > @@ -629,7 +636,6 @@ def get_topic(topic: str) -> str:
> >    return removesuffix(topic, '.json').replace('-', ' ')
> >
> >  def preprocess_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
> > -
> >    if item.is_dir():
> >      return
> >
> > @@ -643,6 +649,7 @@ def preprocess_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
> >    if not item.is_file() or not item.name.endswith('.json'):
> >      return
> >
> > +  assert _bcs is not None
> >    if item.name.endswith('metricgroups.json'):
> >      metricgroup_descriptions = json.load(open(item.path))
> >      for mgroup in metricgroup_descriptions:
> > @@ -704,6 +711,7 @@ def process_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
> >
> >  def print_mapping_table(archs: Sequence[str]) -> None:
> >    """Read the mapfile and generate the struct from cpuid string to event table."""
> > +  assert _args is not None
> >    _args.output_file.write("""
> >  /* Struct used to make the PMU event table implementation opaque to callers. */
> >  struct pmu_events_table {
> > @@ -821,6 +829,7 @@ static const struct pmu_events_map pmu_events_map[] = {
> >
> >
> >  def print_metric_table_functions() -> None:
> > +  assert _args is not None
> >    _args.output_file.write("""
> >  const char *pmu_metrics_table__name(const struct pmu_metrics_table *table)
> >  {
> > @@ -864,6 +873,7 @@ int pmu_metrics_table__iterate_tables(pmu_metrics_table_iter_t fn, void *data)
> >
> >
> >  def print_system_mapping_table() -> None:
> > +  assert _args is not None
> >    """C struct mapping table array for tables from /sys directories."""
> >    _args.output_file.write("""
> >  struct pmu_sys_events {
> > @@ -1400,6 +1410,7 @@ int pmu_for_each_sys_metric(pmu_metric_iter_fn fn, void *data)
> >  """)
> >
> >  def print_metricgroups() -> None:
> > +  assert _args is not None
> >    _args.output_file.write("""
> >  static const int metricgroups[][2] = {
> >  """)
> > @@ -1443,6 +1454,7 @@ def main() -> None:
> >    def ftw(path: str, parents: Sequence[str],
> >            action: Callable[[Sequence[str], os.DirEntry], None]) -> None:
> >      """Replicate the directory/file walking behavior of C's file tree walk."""
> > +    assert _args is not None
> >      for item in sorted(os.scandir(path), key=lambda e: e.name):
> >        if _args.model != 'all' and item.is_dir():
> >          # Check if the model matches one in _args.model.
> > @@ -1513,6 +1525,7 @@ struct pmu_table_entry {
> >      preprocess_arch_std_files(arch_path)
> >      ftw(arch_path, [], preprocess_one_file)
> >
> > +  assert _bcs is not None
> >    _bcs.compute()
> >    _args.output_file.write('/* clang-format off */\n')
> >    if not _args.output_string_file:
> > --
> > 2.55.0.795.g602f6c329a-goog
> >