RE: [RFC PATCH v4 03/15] perf pmu-events: Add functions in jevent.py to parse counter and event info for hardware aware grouping

[Wang, Weilin]

> -----Original Message-----
> From: Ian Rogers <irogers@xxxxxxxxxx>
> Sent: Saturday, March 23, 2024 9:49 PM
> To: Wang, Weilin <weilin.wang@xxxxxxxxx>
> Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>; Namhyung Kim
> <namhyung@xxxxxxxxxx>; Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>;
> Peter Zijlstra <peterz@xxxxxxxxxxxxx>; Ingo Molnar <mingo@xxxxxxxxxx>;
> Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>; Jiri Olsa
> <jolsa@xxxxxxxxxx>; Hunter, Adrian <adrian.hunter@xxxxxxxxx>; linux-perf-
> users@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Taylor, Perry
> <perry.taylor@xxxxxxxxx>; Alt, Samantha <samantha.alt@xxxxxxxxx>; Biggers,
> Caleb <caleb.biggers@xxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>
> Subject: Re: [RFC PATCH v4 03/15] perf pmu-events: Add functions in
> jevent.py to parse counter and event info for hardware aware grouping
> 
> On Thu, Feb 8, 2024 at 7:14 PM <weilin.wang@xxxxxxxxx> wrote:
> >
> > From: Weilin Wang <weilin.wang@xxxxxxxxx>
> >
> > These functions are added to parse event counter restrictions and counter
> > availability info from json files so that the metric grouping method could
> > do grouping based on the counter restriction of events and the counters
> > that are available on the system.
> >
> > Signed-off-by: Weilin Wang <weilin.wang@xxxxxxxxx>
> > ---
> >  tools/perf/pmu-events/jevents.py   | 185
> +++++++++++++++++++++++++++--
> >  tools/perf/pmu-events/pmu-events.h |  34 +++++-
> >  2 files changed, 207 insertions(+), 12 deletions(-)
> >
> > diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-
> events/jevents.py
> > index 2c7e5d61ce92..bc91b7efa49a 100755
> > --- a/tools/perf/pmu-events/jevents.py
> > +++ b/tools/perf/pmu-events/jevents.py
> > @@ -23,6 +23,8 @@ _metric_tables = []
> >  _sys_metric_tables = []
> >  # Mapping between sys event table names and sys metric table names.
> >  _sys_event_table_to_metric_table_mapping = {}
> > +# List of regular PMU counter layout tables.
> > +_pmu_layouts_tables = []
> >  # 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.
> > @@ -31,6 +33,10 @@ _arch_std_events = {}
> >  _pending_events = []
> >  # Name of events table to be written out
> >  _pending_events_tblname = None
> > +# PMU counter layout to write out when the layout table is closed
> > +_pending_pmu_counts = []
> > +# Name of PMU counter layout table to be written out
> > +_pending_pmu_counts_tblname = None
> >  # Metrics to write out when the table is closed
> >  _pending_metrics = []
> >  # Name of metrics table to be written out
> > @@ -47,10 +53,17 @@ _json_event_attributes = [
> >      'event',
> >      # Short things in alphabetical order.
> >      'compat', 'deprecated', 'perpkg', 'unit',
> > +    # The list of counter(s) this event could use
> > +    'counters',
> >      # Longer things (the last won't be iterated over during decompress).
> >      'long_desc'
> >  ]
> >
> > +# Attributes that are in pmu_unit_layout.
> > +_json_layout_attributes = [
> > +    'pmu', 'desc', 'num_counters', 'num_fixed_counters'
> > +]
> > +
> >  # Attributes that are in pmu_metric rather than pmu_event.
> >  _json_metric_attributes = [
> >      'metric_name', 'metric_group', 'metric_expr', 'metric_threshold',
> > @@ -58,7 +71,9 @@ _json_metric_attributes = [
> >      'default_metricgroup_name', 'aggr_mode', 'event_grouping'
> >  ]
> >  # Attributes that are bools or enum int values, encoded as '0', '1',...
> > -_json_enum_attributes = ['aggr_mode', 'deprecated', 'event_grouping',
> 'perpkg']
> > +_json_enum_attributes = ['aggr_mode', 'deprecated', 'event_grouping',
> 'perpkg',
> > +    'num_counters', 'num_fixed_counters'
> > +]
> >
> >  def removesuffix(s: str, suffix: str) -> str:
> >    """Remove the suffix from a string
> > @@ -334,6 +349,12 @@ class JsonEvent:
> >      if 'Errata' in jd:
> >        extra_desc += '  Spec update: ' + jd['Errata']
> >      self.pmu = unit_to_pmu(jd.get('Unit'))
> > +    # The list of counter(s) the event could be collected with
> > +    self.counters = jd.get('Counter')
> > +    # Number of generic counter
> > +    self.num_counters = jd.get('NumCounters')
> > +    # Number of fixed counter
> > +    self.num_fixed_counters = jd.get('NumFixedCounters')
> 
> I'm not a fan of counters vs fixed_counters, perhaps in the python:
> 
> self.counters['generic'].list = jd.get('Counter')
> self.counters['generic'].num = jd.get('NumCounters')
> self.counters['fixed'].num = jd.get('NumFixedCounters')
> 

At this point of time, we cannot tell the content in 'Counter' would be for 
generic counter or fixed counter. Maybe we could do something like: 
self.counters['list'] = jd.get('Counter')
self.counters['num'].gp = jd.get('NumCounters')
self.counters['num'].fixed = jd.get('NumFixedCounters')

One difficulty I still have is to get getattr() work with this type of attribute. 
Do you have some suggestion?

Thanks,
Weilin

> Would make things a bit more intention revealing. Fwiw, the json name
> is worse as Counter is really for a plural of things. I don't think we
> can update this in the Intel perfmon events, but maybe we can do it in
> the create_perf_json.py converter script and its generated json.
> 
> This is pretty trivial as clean up so I'd prefer it before my
> Reviewed-by unless there's something I'm overlooking.
> 
> Thanks,
> Ian
> 
> >      filter = jd.get('Filter')
> >      self.unit = jd.get('ScaleUnit')
> >      self.perpkg = jd.get('PerPkg')
> > @@ -405,8 +426,16 @@ class JsonEvent:
> >          s += f'\t{attr} = {value},\n'
> >      return s + '}'
> >
> > -  def build_c_string(self, metric: bool) -> str:
> > +  def build_c_string(self, metric: bool, layout: bool) -> str:
> >      s = ''
> > +    if layout:
> > +      for attr in _json_layout_attributes:
> > +        x = getattr(self, attr)
> > +        if attr in _json_enum_attributes:
> > +          s += x if x else '0'
> > +        else:
> > +          s += f'{x}\\000' if x else '\\000'
> > +      return s
> >      for attr in _json_metric_attributes if metric else _json_event_attributes:
> >        x = getattr(self, attr)
> >        if metric and x and attr == 'metric_expr':
> > @@ -421,10 +450,10 @@ class JsonEvent:
> >          s += f'{x}\\000' if x else '\\000'
> >      return s
> >
> > -  def to_c_string(self, metric: bool) -> str:
> > +  def to_c_string(self, metric: bool, layout: bool) -> str:
> >      """Representation of the event as a C struct initializer."""
> >
> > -    s = self.build_c_string(metric)
> > +    s = self.build_c_string(metric, layout)
> >      return f'{{ { _bcs.offsets[s] } }}, /* {s} */\n'
> >
> >
> > @@ -461,6 +490,8 @@ def preprocess_arch_std_files(archpath: str) ->
> None:
> >            _arch_std_events[event.name.lower()] = event
> >          if event.metric_name:
> >            _arch_std_events[event.metric_name.lower()] = event
> > +        if event.num_counters:
> > +          _arch_std_events[event.pmu.lower()] = event
> >
> >
> >  def add_events_table_entries(item: os.DirEntry, topic: str) -> None:
> > @@ -470,6 +501,8 @@ def add_events_table_entries(item: os.DirEntry,
> topic: str) -> None:
> >        _pending_events.append(e)
> >      if e.metric_name:
> >        _pending_metrics.append(e)
> > +    if e.num_counters:
> > +      _pending_pmu_counts.append(e)
> >
> >
> >  def print_pending_events() -> None:
> > @@ -510,7 +543,7 @@ def print_pending_events() -> None:
> >        last_pmu = event.pmu
> >        pmus.add((event.pmu, pmu_name))
> >
> > -    _args.output_file.write(event.to_c_string(metric=False))
> > +    _args.output_file.write(event.to_c_string(metric=False, layout=False))
> >    _pending_events = []
> >
> >    _args.output_file.write(f"""
> > @@ -565,7 +598,7 @@ def print_pending_metrics() -> None:
> >        last_pmu = metric.pmu
> >        pmus.add((metric.pmu, pmu_name))
> >
> > -    _args.output_file.write(metric.to_c_string(metric=True))
> > +    _args.output_file.write(metric.to_c_string(metric=True, layout=False))
> >    _pending_metrics = []
> >
> >    _args.output_file.write(f"""
> > @@ -583,6 +616,35 @@ const struct pmu_table_entry
> {_pending_metrics_tblname}[] = {{
> >  """)
> >    _args.output_file.write('};\n\n')
> >
> > +def print_pending_pmu_counter_layout_table() -> None:
> > +  '''Print counter layout data from counter.json file to counter layout table in
> > +    c-string'''
> > +
> > +  def pmu_counts_cmp_key(j: JsonEvent) -> Tuple[bool, str, str]:
> > +    def fix_none(s: Optional[str]) -> str:
> > +      if s is None:
> > +        return ''
> > +      return s
> > +
> > +    return (j.desc is not None, fix_none(j.pmu), fix_none(j.num_counters))
> > +
> > +  global _pending_pmu_counts
> > +  if not _pending_pmu_counts:
> > +    return
> > +
> > +  global _pending_pmu_counts_tblname
> > +  global pmu_layouts_tables
> > +  _pmu_layouts_tables.append(_pending_pmu_counts_tblname)
> > +
> > +  _args.output_file.write(
> > +      f'static const struct compact_pmu_event
> {_pending_pmu_counts_tblname}[] = {{\n')
> > +
> > +  for pmu_layout in sorted(_pending_pmu_counts,
> key=pmu_counts_cmp_key):
> > +    _args.output_file.write(pmu_layout.to_c_string(metric=False,
> layout=True))
> > +    _pending_pmu_counts = []
> > +
> > +  _args.output_file.write('};\n\n')
> > +
> >  def get_topic(topic: str) -> str:
> >    if topic.endswith('metrics.json'):
> >      return 'metrics'
> > @@ -619,10 +681,12 @@ def preprocess_one_file(parents: Sequence[str],
> item: os.DirEntry) -> None:
> >      pmu_name = f"{event.pmu}\\000"
> >      if event.name:
> >        _bcs.add(pmu_name, metric=False)
> > -      _bcs.add(event.build_c_string(metric=False), metric=False)
> > +      _bcs.add(event.build_c_string(metric=False, layout=False), metric=False)
> >      if event.metric_name:
> >        _bcs.add(pmu_name, metric=True)
> > -      _bcs.add(event.build_c_string(metric=True), metric=True)
> > +      _bcs.add(event.build_c_string(metric=True, layout=False), metric=True)
> > +    if event.num_counters:
> > +      _bcs.add(event.build_c_string(metric=False, layout=True), metric=False)
> >
> >  def process_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
> >    """Process a JSON file during the main walk."""
> > @@ -636,11 +700,14 @@ def process_one_file(parents: Sequence[str],
> item: os.DirEntry) -> None:
> >    if item.is_dir() and is_leaf_dir(item.path):
> >      print_pending_events()
> >      print_pending_metrics()
> > +    print_pending_pmu_counter_layout_table()
> >
> >      global _pending_events_tblname
> >      _pending_events_tblname = file_name_to_table_name('pmu_events_',
> parents, item.name)
> >      global _pending_metrics_tblname
> >      _pending_metrics_tblname = file_name_to_table_name('pmu_metrics_',
> parents, item.name)
> > +    global _pending_pmu_counts_tblname
> > +    _pending_pmu_counts_tblname =
> file_name_to_table_name('pmu_layouts_', parents, item.name)
> >
> >      if item.name == 'sys':
> >        _sys_event_table_to_metric_table_mapping[_pending_events_tblname]
> = _pending_metrics_tblname
> > @@ -674,6 +741,12 @@ struct pmu_metrics_table {
> >          uint32_t num_pmus;
> >  };
> >
> > +/* Struct used to make the PMU counter layout table implementation
> opaque to callers. */
> > +struct pmu_layouts_table {
> > +        const struct compact_pmu_event *entries;
> > +        size_t length;
> > +};
> > +
> >  /*
> >   * Map a CPU to its table of PMU events. The CPU is identified by the
> >   * cpuid field, which is an arch-specific identifier for the CPU.
> > @@ -687,6 +760,7 @@ struct pmu_events_map {
> >          const char *cpuid;
> >          struct pmu_events_table event_table;
> >          struct pmu_metrics_table metric_table;
> > +        struct pmu_layouts_table layout_table;
> >  };
> >
> >  /*
> > @@ -731,6 +805,12 @@ const struct pmu_events_map
> pmu_events_map[] = {
> >                metric_size = '0'
> >              if event_size == '0' and metric_size == '0':
> >                continue
> > +            layout_tblname = file_name_to_table_name('pmu_layouts_', [],
> row[2].replace('/', '_'))
> > +            if layout_tblname in _pmu_layouts_tables:
> > +              layout_size = f'ARRAY_SIZE({layout_tblname})'
> > +            else:
> > +              layout_tblname = 'NULL'
> > +              layout_size = '0'
> >              cpuid = row[0].replace('\\', '\\\\')
> >              _args.output_file.write(f"""{{
> >  \t.arch = "{arch}",
> > @@ -742,6 +822,10 @@ const struct pmu_events_map
> pmu_events_map[] = {
> >  \t.metric_table = {{
> >  \t\t.pmus = {metric_tblname},
> >  \t\t.num_pmus = {metric_size}
> > +\t}},
> > +\t.layout_table = {{
> > +\t\t.entries = {layout_tblname},
> > +\t\t.length = {layout_size}
> >  \t}}
> >  }},
> >  """)
> > @@ -752,6 +836,7 @@ const struct pmu_events_map pmu_events_map[]
> = {
> >  \t.cpuid = 0,
> >  \t.event_table = { 0, 0 },
> >  \t.metric_table = { 0, 0 },
> > +\t.layout_table = { 0, 0 },
> >  }
> >  };
> >  """)
> > @@ -840,6 +925,24 @@ static void decompress_metric(int offset, struct
> pmu_metric *pm)
> >        _args.output_file.write('\twhile (*p++);')
> >    _args.output_file.write("""}
> >
> > +static void decompress_layout(int offset, struct pmu_layout *pm)
> > +{
> > +\tconst char *p = &big_c_string[offset];
> > +""")
> > +  for attr in _json_layout_attributes:
> > +    _args.output_file.write(f'\n\tpm->{attr} = ')
> > +    if attr in _json_enum_attributes:
> > +      _args.output_file.write("*p - '0';\n")
> > +    else:
> > +      _args.output_file.write("(*p == '\\0' ? NULL : p);\n")
> > +    if attr == _json_layout_attributes[-1]:
> > +      continue
> > +    if attr in _json_enum_attributes:
> > +      _args.output_file.write('\tp++;')
> > +    else:
> > +      _args.output_file.write('\twhile (*p++);')
> > +  _args.output_file.write("""}
> > +
> >  static int pmu_events_table__for_each_event_pmu(const struct
> pmu_events_table *table,
> >                                                  const struct pmu_table_entry *pmu,
> >                                                  pmu_event_iter_fn fn,
> > @@ -995,6 +1098,21 @@ int pmu_metrics_table__for_each_metric(const
> struct pmu_metrics_table *table,
> >          return 0;
> >  }
> >
> > +int pmu_layouts_table__for_each_layout(const struct pmu_layouts_table
> *table,
> > +                                     pmu_layout_iter_fn fn,
> > +                                     void *data) {
> > +        for (size_t i = 0; i < table->length; i++) {
> > +                struct pmu_layout pm;
> > +                int ret;
> > +
> > +                decompress_layout(table->entries[i].offset, &pm);
> > +                ret = fn(&pm, data);
> > +                if (ret)
> > +                        return ret;
> > +        }
> > +        return 0;
> > +}
> > +
> >  static const struct pmu_events_map *map_for_pmu(struct perf_pmu
> *pmu)
> >  {
> >          static struct {
> > @@ -1090,6 +1208,33 @@ const struct pmu_metrics_table
> *perf_pmu__find_metrics_table(struct perf_pmu *pm
> >          return NULL;
> >  }
> >
> > +const struct pmu_layouts_table *perf_pmu__find_layouts_table(struct
> perf_pmu *pmu)
> > +{
> > +        const struct pmu_layouts_table *table = NULL;
> > +        char *cpuid = perf_pmu__getcpuid(pmu);
> > +        int i;
> > +
> > +        /* on some platforms which uses cpus map, cpuid can be NULL for
> > +         * PMUs other than CORE PMUs.
> > +         */
> > +        if (!cpuid)
> > +                return NULL;
> > +
> > +        i = 0;
> > +        for (;;) {
> > +                const struct pmu_events_map *map = &pmu_events_map[i++];
> > +                if (!map->arch)
> > +                        break;
> > +
> > +                if (!strcmp_cpuid_str(map->cpuid, cpuid)) {
> > +                        table = &map->layout_table;
> > +                        break;
> > +                }
> > +        }
> > +        free(cpuid);
> > +        return table;
> > +}
> > +
> >  const struct pmu_events_table *find_core_events_table(const char *arch,
> const char *cpuid)
> >  {
> >          for (const struct pmu_events_map *tables = &pmu_events_map[0];
> > @@ -1111,6 +1256,16 @@ const struct pmu_metrics_table
> *find_core_metrics_table(const char *arch, const
> >          }
> >          return NULL;
> >  }
> > +const struct pmu_layouts_table *find_core_layouts_table(const char *arch,
> const char *cpuid)
> > +{
> > +        for (const struct pmu_events_map *tables = &pmu_events_map[0];
> > +             tables->arch;
> > +             tables++) {
> > +                if (!strcmp(tables->arch, arch) && !strcmp_cpuid_str(tables-
> >cpuid, cpuid))
> > +                        return &tables->layout_table;
> > +        }
> > +        return NULL;
> > +}
> >
> >  int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
> >  {
> > @@ -1139,6 +1294,19 @@ int
> pmu_for_each_core_metric(pmu_metric_iter_fn fn, void *data)
> >          return 0;
> >  }
> >
> > +int pmu_for_each_core_layout(pmu_layout_iter_fn fn, void *data)
> > +{
> > +        for (const struct pmu_events_map *tables = &pmu_events_map[0];
> > +             tables->arch;
> > +             tables++) {
> > +                int ret = pmu_layouts_table__for_each_layout(&tables-
> >layout_table, fn, data);
> > +
> > +                if (ret)
> > +                        return ret;
> > +        }
> > +        return 0;
> > +}
> > +
> >  const struct pmu_events_table *find_sys_events_table(const char *name)
> >  {
> >          for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
> > @@ -1295,6 +1463,7 @@ struct pmu_table_entry {
> >      ftw(arch_path, [], process_one_file)
> >      print_pending_events()
> >      print_pending_metrics()
> > +    print_pending_pmu_counter_layout_table()
> >
> >    print_mapping_table(archs)
> >    print_system_mapping_table()
> > diff --git a/tools/perf/pmu-events/pmu-events.h b/tools/perf/pmu-
> events/pmu-events.h
> > index f5aa96f1685c..e245e4738970 100644
> > --- a/tools/perf/pmu-events/pmu-events.h
> > +++ b/tools/perf/pmu-events/pmu-events.h
> > @@ -45,6 +45,11 @@ struct pmu_event {
> >         const char *desc;
> >         const char *topic;
> >         const char *long_desc;
> > +       /**
> > +        * The list of counter(s) the event could be collected on.
> > +        * eg., "0,1,2,3,4,5,6,7".
> > +        */
> > +       const char *counters;
> >         const char *pmu;
> >         const char *unit;
> >         bool perpkg;
> > @@ -67,8 +72,20 @@ struct pmu_metric {
> >         enum metric_event_groups event_grouping;
> >  };
> >
> > +struct pmu_layout {
> > +       const char *pmu;
> > +       const char *desc;
> > +       /** Total number of generic counters*/
> > +       int num_counters;
> > +       /**
> > +        * Total number of fixed counters.
> > +        * Set to zero if no fixed counter on the unit.*/
> > +       int num_fixed_counters;
> > +};
> > +
> >  struct pmu_events_table;
> >  struct pmu_metrics_table;
> > +struct pmu_layouts_table;
> >
> >  typedef int (*pmu_event_iter_fn)(const struct pmu_event *pe,
> >                                  const struct pmu_events_table *table,
> > @@ -78,15 +95,21 @@ typedef int (*pmu_metric_iter_fn)(const struct
> pmu_metric *pm,
> >                                   const struct pmu_metrics_table *table,
> >                                   void *data);
> >
> > +typedef int (*pmu_layout_iter_fn)(const struct pmu_layout *pm,
> > +                                 void *data);
> > +
> >  int pmu_events_table__for_each_event(const struct pmu_events_table
> *table,
> >                                     struct perf_pmu *pmu,
> >                                     pmu_event_iter_fn fn,
> >                                     void *data);
> >  int pmu_events_table__find_event(const struct pmu_events_table *table,
> > -                                 struct perf_pmu *pmu,
> > -                                 const char *name,
> > -                                 pmu_event_iter_fn fn,
> > -                                void *data);
> > +                               struct perf_pmu *pmu,
> > +                               const char *name,
> > +                               pmu_event_iter_fn fn,
> > +                               void *data);
> > +int pmu_layouts_table__for_each_layout(const struct pmu_layouts_table
> *table,
> > +                                       pmu_layout_iter_fn fn,
> > +                                       void *data);
> >  size_t pmu_events_table__num_events(const struct pmu_events_table
> *table,
> >                                     struct perf_pmu *pmu);
> >
> > @@ -95,10 +118,13 @@ int pmu_metrics_table__for_each_metric(const
> struct pmu_metrics_table *table, pm
> >
> >  const struct pmu_events_table *perf_pmu__find_events_table(struct
> perf_pmu *pmu);
> >  const struct pmu_metrics_table *perf_pmu__find_metrics_table(struct
> perf_pmu *pmu);
> > +const struct pmu_layouts_table *perf_pmu__find_layouts_table(struct
> perf_pmu *pmu);
> >  const struct pmu_events_table *find_core_events_table(const char *arch,
> const char *cpuid);
> >  const struct pmu_metrics_table *find_core_metrics_table(const char *arch,
> const char *cpuid);
> > +const struct pmu_layouts_table *find_core_layouts_table(const char *arch,
> const char *cpuid);
> >  int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data);
> >  int pmu_for_each_core_metric(pmu_metric_iter_fn fn, void *data);
> > +int pmu_for_each_core_layout(pmu_layout_iter_fn fn, void *data);
> >
> >  const struct pmu_events_table *find_sys_events_table(const char *name);
> >  const struct pmu_metrics_table *find_sys_metrics_table(const char
> *name);
> > --
> > 2.42.0
> >