From: Ian Rogers <irogers@google.com>
Date: Tue, 27 Jan 2026 18:45:01 +0000 (-0800)
Subject: perf jevents: Add C-State metrics from the PCU PMU for Intel
X-Git-Tag: v7.0-rc1~16^2~61
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1fee2701a7d35fa7285479c5c2ee6c2d9bd99526;p=thirdparty%2Flinux.git

perf jevents: Add C-State metrics from the PCU PMU for Intel

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>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Benjamin Gray <bgray@linux.ibm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Xu Yang <xu.yang_2@nxp.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 24ceb7f8719b..118fe0fc05a3 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -815,6 +815,35 @@ 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("lpm_cstate", [
+        Metric("lpm_cstate_c0", "C-State cores in C0/C1",
+               d_ratio(c0, pcu_ticks), "cores"),
+        Metric("lpm_cstate_c3", "C-State cores in C3",
+               d_ratio(c3, pcu_ticks), "cores"),
+        Metric("lpm_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")
@@ -979,6 +1008,7 @@ def main() -> None:
         IntelMlp(),
         IntelPorts(),
         IntelSwpf(),
+        UncoreCState(),
         UncoreDir(),
         UncoreMem(),
         UncoreMemBw(),