[PATCH v11 17/35] 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.

Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/pmu-events/intel_metrics.py | 50 ++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 94604b1b07d8..05f3d94ec5d5 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -3,6 +3,7 @@
 import argparse
 import math
 import os
+from typing import Optional
 from metric import (d_ratio, has_event, max, CheckPmu, Event, JsonEncodeMetric,
                     JsonEncodeMetricGroupDescriptions, LoadEvents, Metric,
                     MetricGroup, MetricRef, Select)
@@ -75,6 +76,54 @@ 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
 
@@ -103,6 +152,7 @@ def main() -> None:
         Idle(),
         Rapl(),
         Smi(),
+        Tsx(),
     ])
 
     if _args.metricgroups:
-- 
2.52.0.457.g6b5491de43-goog