perf jevents: Group events by PMU

Prior to this change a cpuid would map to a list of events where the PMU
would be encoded alongside the event information. This change breaks
apart each group of events so that there is a group per PMU. A new table
is added with the PMU's name and the list of events, the original table
now holding an array of these per PMU tables.

These changes are to make it easier to get per PMU information about
events, rather than the current approach of scanning all events. The
perf binary size with BPF skeletons on x86 is reduced by about 1%. The
unidentified PMU is now always expanded to "cpu".

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230824041330.266337-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 136 insertions, 45 deletions

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index aae5334099b1..1ad20140114c 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -42,7 +42,7 @@ _metricgroups = {}
 # Order specific JsonEvent attributes will be visited.
 _json_event_attributes = [
     # cmp_sevent related attributes.
-    'name', 'pmu', 'topic', 'desc',
+    'name', 'topic', 'desc',
     # Seems useful, put it early.
     'event',
     # Short things in alphabetical order.
@@ -53,7 +53,7 @@ _json_event_attributes = [
 
 # Attributes that are in pmu_metric rather than pmu_event.
 _json_metric_attributes = [
-    'pmu', 'metric_name', 'metric_group', 'metric_expr', 'metric_threshold',
+    'metric_name', 'metric_group', 'metric_expr', 'metric_threshold',
     'desc', 'long_desc', 'unit', 'compat', 'metricgroup_no_group',
     'default_metricgroup_name', 'aggr_mode', 'event_grouping'
 ]
@@ -252,7 +252,7 @@ class JsonEvent:
     def unit_to_pmu(unit: str) -> Optional[str]:
       """Convert a JSON Unit to Linux PMU name."""
       if not unit:
-        return None
+        return 'cpu'
       # Comment brought over from jevents.c:
       # it's not realistic to keep adding these, we need something more scalable ...
       table = {
@@ -343,10 +343,13 @@ class JsonEvent:
       self.desc += extra_desc
     if self.long_desc and extra_desc:
       self.long_desc += extra_desc
-    if self.pmu:
-      if self.desc and not self.desc.endswith('. '):
-        self.desc += '. '
-      self.desc = (self.desc if self.desc else '') + ('Unit: ' + self.pmu + ' ')
+    if self.pmu and self.pmu != 'cpu':
+      if not self.desc:
+        self.desc = 'Unit: ' + self.pmu
+      else:
+        if not self.desc.endswith('. '):
+          self.desc += '. '
+      self.desc += 'Unit: ' + self.pmu
     if arch_std:
       if arch_std.lower() in _arch_std_events:
         event = _arch_std_events[arch_std.lower()].event
@@ -437,13 +440,13 @@ def add_events_table_entries(item: os.DirEntry, topic: str) -> None:
 def print_pending_events() -> None:
   """Optionally close events table."""
 
-  def event_cmp_key(j: JsonEvent) -> Tuple[bool, str, str, str, str]:
+  def event_cmp_key(j: JsonEvent) -> Tuple[str, str, 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.topic), fix_none(j.name), fix_none(j.pmu),
+    return (fix_none(j.pmu).replace(',','_'), fix_none(j.name), j.desc is not None, fix_none(j.topic),
             fix_none(j.metric_name))
 
   global _pending_events
@@ -458,13 +461,36 @@ def print_pending_events() -> None:
     global event_tables
     _event_tables.append(_pending_events_tblname)
 
-  _args.output_file.write(
-      f'static const struct compact_pmu_event {_pending_events_tblname}[] = {{\n')
-
+  first = True
+  last_pmu = None
+  pmus = set()
   for event in sorted(_pending_events, key=event_cmp_key):
+    if event.pmu != last_pmu:
+      if not first:
+        _args.output_file.write('};\n')
+      pmu_name = event.pmu.replace(',', '_')
+      _args.output_file.write(
+          f'static const struct compact_pmu_event {_pending_events_tblname}_{pmu_name}[] = {{\n')
+      first = False
+      last_pmu = event.pmu
+      pmus.add((event.pmu, pmu_name))
+
     _args.output_file.write(event.to_c_string(metric=False))
   _pending_events = []
 
+  _args.output_file.write(f"""
+}};
+
+const struct pmu_table_entry {_pending_events_tblname}[] = {{
+""")
+  for (pmu, tbl_pmu) in sorted(pmus):
+    pmu_name = f"{pmu}\\000"
+    _args.output_file.write(f"""{{
+     .entries = {_pending_events_tblname}_{tbl_pmu},
+     .num_entries = ARRAY_SIZE({_pending_events_tblname}_{tbl_pmu}),
+     .pmu_name = {{ {_bcs.offsets[pmu_name]} /* {pmu_name} */ }},
+}},
+""")
   _args.output_file.write('};\n\n')
 
 def print_pending_metrics() -> None:
@@ -490,13 +516,36 @@ def print_pending_metrics() -> None:
     global metric_tables
     _metric_tables.append(_pending_metrics_tblname)
 
-  _args.output_file.write(
-      f'static const struct compact_pmu_event {_pending_metrics_tblname}[] = {{\n')
-
+  first = True
+  last_pmu = None
+  pmus = set()
   for metric in sorted(_pending_metrics, key=metric_cmp_key):
+    if metric.pmu != last_pmu:
+      if not first:
+        _args.output_file.write('};\n')
+      pmu_name = metric.pmu.replace(',', '_')
+      _args.output_file.write(
+          f'static const struct compact_pmu_event {_pending_metrics_tblname}_{pmu_name}[] = {{\n')
+      first = False
+      last_pmu = metric.pmu
+      pmus.add((metric.pmu, pmu_name))
+
     _args.output_file.write(metric.to_c_string(metric=True))
   _pending_metrics = []
 
+  _args.output_file.write(f"""
+}};
+
+const struct pmu_table_entry {_pending_metrics_tblname}[] = {{
+""")
+  for (pmu, tbl_pmu) in sorted(pmus):
+    pmu_name = f"{pmu}\\000"
+    _args.output_file.write(f"""{{
+     .entries = {_pending_metrics_tblname}_{tbl_pmu},
+     .num_entries = ARRAY_SIZE({_pending_metrics_tblname}_{tbl_pmu}),
+     .pmu_name = {{ {_bcs.offsets[pmu_name]} /* {pmu_name} */ }},
+}},
+""")
   _args.output_file.write('};\n\n')
 
 def get_topic(topic: str) -> str:
@@ -532,6 +581,8 @@ def preprocess_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
 
   topic = get_topic(item.name)
   for event in read_json_events(item.path, topic):
+    pmu_name = f"{event.pmu}\\000"
+    _bcs.add(pmu_name)
     if event.name:
       _bcs.add(event.build_c_string(metric=False))
     if event.metric_name:
@@ -577,14 +628,14 @@ def print_mapping_table(archs: Sequence[str]) -> None:
   _args.output_file.write("""
 /* Struct used to make the PMU event table implementation opaque to callers. */
 struct pmu_events_table {
-        const struct compact_pmu_event *entries;
-        size_t length;
+        const struct pmu_table_entry *pmus;
+        uint32_t num_pmus;
 };
 
 /* Struct used to make the PMU metric table implementation opaque to callers. */
 struct pmu_metrics_table {
-        const struct compact_pmu_event *entries;
-        size_t length;
+        const struct pmu_table_entry *pmus;
+        uint32_t num_pmus;
 };
 
 /*
@@ -614,12 +665,12 @@ const struct pmu_events_map pmu_events_map[] = {
 \t.arch = "testarch",
 \t.cpuid = "testcpu",
 \t.event_table = {
-\t\t.entries = pmu_events__test_soc_cpu,
-\t\t.length = ARRAY_SIZE(pmu_events__test_soc_cpu),
+\t\t.pmus = pmu_events__test_soc_cpu,
+\t\t.num_pmus = ARRAY_SIZE(pmu_events__test_soc_cpu),
 \t},
 \t.metric_table = {
-\t\t.entries = pmu_metrics__test_soc_cpu,
-\t\t.length = ARRAY_SIZE(pmu_metrics__test_soc_cpu),
+\t\t.pmus = pmu_metrics__test_soc_cpu,
+\t\t.num_pmus = ARRAY_SIZE(pmu_metrics__test_soc_cpu),
 \t}
 },
 """)
@@ -649,12 +700,12 @@ const struct pmu_events_map pmu_events_map[] = {
 \t.arch = "{arch}",
 \t.cpuid = "{cpuid}",
 \t.event_table = {{
-\t\t.entries = {event_tblname},
-\t\t.length = {event_size}
+\t\t.pmus = {event_tblname},
+\t\t.num_pmus = {event_size}
 \t}},
 \t.metric_table = {{
-\t\t.entries = {metric_tblname},
-\t\t.length = {metric_size}
+\t\t.pmus = {metric_tblname},
+\t\t.num_pmus = {metric_size}
 \t}}
 }},
 """)
@@ -685,15 +736,15 @@ static const struct pmu_sys_events pmu_sys_event_tables[] = {
   for tblname in _sys_event_tables:
     _args.output_file.write(f"""\t{{
 \t\t.event_table = {{
-\t\t\t.entries = {tblname},
-\t\t\t.length = ARRAY_SIZE({tblname})
+\t\t\t.pmus = {tblname},
+\t\t\t.num_pmus = ARRAY_SIZE({tblname})
 \t\t}},""")
     metric_tblname = _sys_event_table_to_metric_table_mapping[tblname]
     if metric_tblname in _sys_metric_tables:
       _args.output_file.write(f"""
 \t\t.metric_table = {{
-\t\t\t.entries = {metric_tblname},
-\t\t\t.length = ARRAY_SIZE({metric_tblname})
+\t\t\t.pmus = {metric_tblname},
+\t\t\t.num_pmus = ARRAY_SIZE({metric_tblname})
 \t\t}},""")
       printed_metric_tables.append(metric_tblname)
     _args.output_file.write(f"""
@@ -753,18 +804,56 @@ static void decompress_metric(int offset, struct pmu_metric *pm)
       _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,
+                                                void *data)
+{
+        int ret;
+        struct pmu_event pe = {
+                .pmu = &big_c_string[pmu->pmu_name.offset],
+        };
+
+        for (uint32_t i = 0; i < pmu->num_entries; i++) {
+                decompress_event(pmu->entries[i].offset, &pe);
+                if (!pe.name)
+                        continue;
+                ret = fn(&pe, table, data);
+                if (ret)
+                        return ret;
+        }
+        return 0;
+ }
+
 int pmu_events_table__for_each_event(const struct pmu_events_table *table,
                                     pmu_event_iter_fn fn,
                                     void *data)
 {
-        for (size_t i = 0; i < table->length; i++) {
-                struct pmu_event pe;
-                int ret;
+        for (size_t i = 0; i < table->num_pmus; i++) {
+                int ret = pmu_events_table__for_each_event_pmu(table, &table->pmus[i],
+                                                               fn, data);
 
-                decompress_event(table->entries[i].offset, &pe);
-                if (!pe.name)
+                if (ret)
+                        return ret;
+        }
+        return 0;
+}
+
+static int pmu_metrics_table__for_each_metric_pmu(const struct pmu_metrics_table *table,
+                                                const struct pmu_table_entry *pmu,
+                                                pmu_metric_iter_fn fn,
+                                                void *data)
+{
+        int ret;
+        struct pmu_metric pm = {
+                .pmu = &big_c_string[pmu->pmu_name.offset],
+        };
+
+        for (uint32_t i = 0; i < pmu->num_entries; i++) {
+                decompress_metric(pmu->entries[i].offset, &pm);
+                if (!pm.metric_expr)
                         continue;
-                ret = fn(&pe, table, data);
+                ret = fn(&pm, table, data);
                 if (ret)
                         return ret;
         }
@@ -775,14 +864,10 @@ int pmu_metrics_table__for_each_metric(const struct pmu_metrics_table *table,
                                      pmu_metric_iter_fn fn,
                                      void *data)
 {
-        for (size_t i = 0; i < table->length; i++) {
-                struct pmu_metric pm;
-                int ret;
+        for (size_t i = 0; i < table->num_pmus; i++) {
+                int ret = pmu_metrics_table__for_each_metric_pmu(table, &table->pmus[i],
+                                                                 fn, data);
 
-                decompress_metric(table->entries[i].offset, &pm);
-                if (!pm.metric_expr)
-                        continue;
-                ret = fn(&pm, table, data);
                 if (ret)
                         return ret;
         }
@@ -1010,7 +1095,13 @@ such as "arm/cortex-a34".''',
 #include <stddef.h>
 
 struct compact_pmu_event {
-  int offset;
+        int offset;
+};
+
+struct pmu_table_entry {
+        const struct compact_pmu_event *entries;
+        uint32_t num_entries;
+        struct compact_pmu_event pmu_name;
 };
 
 """)