[PATCH v3 05/20] perf jevents: Add tsx metric group for Intel models

[Ian Rogers <irogers@google.com>]

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.

Add CheckPmu to metric to determine if which PMUs have been associated
with the loaded events.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 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 f34b4230a4ee..58e243695f0a 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
 
 # Global command line arguments.
 _args = None
@@ -74,6 +75,54 @@ 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")
+
+
 def main() -> None:
   global _args
 
@@ -100,6 +149,7 @@ def main() -> None:
       Idle(),
       Rapl(),
       Smi(),
+      Tsx(),
   ])
 
 
-- 
2.44.0.278.ge034bb2e1d-goog