From e74f72a7e21782332bb7b9541634199278f3461b Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Tue, 27 Jan 2026 10:45:04 -0800
Subject: [PATCH] perf jevents: Add mesh bandwidth saturation metric for Intel

Memory bandwidth saturation from CBOX/CHA events present in
broadwellde, broadwellx, cascadelakex, haswellx, icelakex, skylakex
and snowridgex.

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>
---
 tools/perf/pmu-events/intel_metrics.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index f6bb691dc5bb..d56bab7337df 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -1033,6 +1033,22 @@ def UncoreMemBw() -> Optional[MetricGroup]:
     ], description="Memory Bandwidth")
 
 
+def UncoreMemSat() -> Optional[Metric]:
+    try:
+        clocks = Event("UNC_CHA_CLOCKTICKS", "UNC_C_CLOCKTICKS")
+        sat = Event("UNC_CHA_DISTRESS_ASSERTED.VERT", "UNC_CHA_FAST_ASSERTED.VERT",
+                    "UNC_C_FAST_ASSERTED")
+    except:
+        return None
+
+    desc = ("Mesh Bandwidth saturation (% CBOX cycles with FAST signal asserted, "
+            "include QPI bandwidth saturation), lower is better")
+    if "UNC_CHA_" in sat.name:
+        desc = ("Mesh Bandwidth saturation (% CHA cycles with FAST signal asserted, "
+                "include UPI bandwidth saturation), lower is better")
+    return Metric("lpm_mem_sat", desc, d_ratio(sat, clocks), "100%")
+
+
 def UncoreUpiBw() -> Optional[MetricGroup]:
     try:
         upi_rds = Event("UNC_UPI_RxL_FLITS.ALL_DATA")
@@ -1097,6 +1113,7 @@ def main() -> None:
         UncoreDir(),
         UncoreMem(),
         UncoreMemBw(),
+        UncoreMemSat(),
         UncoreUpiBw(),
     ])
 
-- 
2.47.3