[PATCH v2 04/20] perf jevents: Add tsx metric group for Intel models

[Ian Rogers]

Allow duplicated metric to be dropped from json files. Detect when TSX
is supported by a model by using the json events, use sysfs events at
runtime as hypervisors, etc. may disable TSX.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/pmu-events/intel_metrics.py | 52 +++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 81879e68da96..3d80b555fac9 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -1,12 +1,13 @@
 #!/usr/bin/env python3
 # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
-from metric import (d_ratio, has_event, max, Event, JsonEncodeMetric,
+from metric import (d_ratio, has_event, max, CheckPmu, Event, JsonEncodeMetric,
                     JsonEncodeMetricGroupDescriptions, LoadEvents, Metric,
                     MetricGroup, MetricRef, Select)
 import argparse
 import json
 import math
 import os
+from typing import Optional
 
 parser = argparse.ArgumentParser(description="Intel perf json generator")
 parser.add_argument("-metricgroups", help="Generate metricgroups data", action='store_true')
@@ -80,10 +81,59 @@ def Smi() -> MetricGroup:
     ], description = 'System Management Interrupt metrics')
 
 
+def Tsx() -> Optional[MetricGroup]:
+  pmu = "cpu_core" if CheckPmu("cpu_core") else "cpu"
+  cycles = Event('cycles')
+  cycles_in_tx = Event(f'{pmu}/cycles\-t/')
+  cycles_in_tx_cp = Event(f'{pmu}/cycles\-ct/')
+  try:
+    # Test if the tsx event is present in the json, prefer the
+    # sysfs version so that we can detect its presence at runtime.
+    transaction_start = Event("RTM_RETIRED.START")
+    transaction_start = Event(f'{pmu}/tx\-start/')
+  except:
+    return None
+
+  elision_start = None
+  try:
+    # Elision start isn't supported by all models, but we'll not
+    # generate the tsx_cycles_per_elision metric in that
+    # case. Again, prefer the sysfs encoding of the event.
+    elision_start = Event("HLE_RETIRED.START")
+    elision_start = Event(f'{pmu}/el\-start/')
+  except:
+    pass
+
+  return MetricGroup('transaction', [
+      Metric('tsx_transactional_cycles',
+             'Percentage of cycles within a transaction region.',
+             Select(cycles_in_tx / cycles, has_event(cycles_in_tx), 0),
+             '100%'),
+      Metric('tsx_aborted_cycles', 'Percentage of cycles in aborted transactions.',
+             Select(max(cycles_in_tx - cycles_in_tx_cp, 0) / cycles,
+                    has_event(cycles_in_tx),
+                    0),
+             '100%'),
+      Metric('tsx_cycles_per_transaction',
+             'Number of cycles within a transaction divided by the number of transactions.',
+             Select(cycles_in_tx / transaction_start,
+                    has_event(cycles_in_tx),
+                    0),
+             "cycles / transaction"),
+      Metric('tsx_cycles_per_elision',
+             'Number of cycles within a transaction divided by the number of elisions.',
+             Select(cycles_in_tx / elision_start,
+                    has_event(elision_start),
+                    0),
+             "cycles / elision") if elision_start else None,
+  ], description="Breakdown of transactional memory statistics")
+
+
 all_metrics = MetricGroup("", [
     Idle(),
     Rapl(),
     Smi(),
+    Tsx(),
 ])
 
 if args.metricgroups:
-- 
2.44.0.278.ge034bb2e1d-goog