[PATCH v3 18/20] perf jevents: Add C-State metrics from the PCU PMU for Intel

[Ian Rogers <irogers@google.com>]

Use occupancy events fixed in:
https://lore.kernel.org/lkml/20240226201517.3540187-1-irogers@google.com/

Metrics are at the socket level referring to cores, not hyperthreads.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/pmu-events/intel_metrics.py | 27 ++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 0e3ead0fa0b1..6fd45350395f 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -777,6 +777,32 @@ def IntelLdSt() -> Optional[MetricGroup]:
   ], description = "Breakdown of load/store instructions")
 
 
+def UncoreCState() -> Optional[MetricGroup]:
+  try:
+    pcu_ticks = Event("UNC_P_CLOCKTICKS")
+    c0 = Event("UNC_P_POWER_STATE_OCCUPANCY.CORES_C0")
+    c3 = Event("UNC_P_POWER_STATE_OCCUPANCY.CORES_C3")
+    c6 = Event("UNC_P_POWER_STATE_OCCUPANCY.CORES_C6")
+  except:
+    return None
+
+  num_cores = Literal("#num_cores") / Literal("#num_packages")
+
+  max_cycles   = pcu_ticks * num_cores;
+  total_cycles = c0 + c3 + c6
+
+  # remove fused-off cores which show up in C6/C7.
+  c6 = Select(max(c6 - (total_cycles - max_cycles), 0),
+              total_cycles > max_cycles,
+              c6)
+
+  return MetricGroup("cstate", [
+      Metric("cstate_c0", "C-State cores in C0/C1", d_ratio(c0, pcu_ticks), "cores"),
+      Metric("cstate_c3", "C-State cores in C3", d_ratio(c3, pcu_ticks), "cores"),
+      Metric("cstate_c6", "C-State cores in C6/C7", d_ratio(c6, pcu_ticks), "cores"),
+  ])
+
+
 def UncoreDir() -> Optional[MetricGroup]:
   try:
     m2m_upd = Event("UNC_M2M_DIRECTORY_UPDATE.ANY")
@@ -935,6 +961,7 @@ def main() -> None:
       IntelMlp(),
       IntelPorts(),
       IntelSwpf(),
+      UncoreCState(),
       UncoreDir(),
       UncoreMem(),
       UncoreMemBw(),
-- 
2.44.0.278.ge034bb2e1d-goog