From 130f4245af99e140cc5dc93bdf8e59ffd9cc9d6f Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Tue, 27 Jan 2026 10:44:58 -0800
Subject: [PATCH] perf jevents: Add mem_bw metric for Intel

Break down memory bandwidth using uncore counters. For many models
this matches the memory_bandwidth_* metrics, but these metrics aren't
made available on all models.

Add support for free running counters.  Query the event JSON when
determining which what events/counters are available.

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 | 62 ++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index dddeae35e4b4..f671d6e4fd67 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -815,6 +815,67 @@ def IntelLdSt() -> Optional[MetricGroup]:
     ], description="Breakdown of load/store instructions")
 
 
+def UncoreMemBw() -> Optional[MetricGroup]:
+    mem_events = []
+    try:
+        mem_events = json.load(open(f"{os.path.dirname(os.path.realpath(__file__))}"
+                                    f"/arch/x86/{args.model}/uncore-memory.json"))
+    except:
+        pass
+
+    ddr_rds = 0
+    ddr_wrs = 0
+    ddr_total = 0
+    for x in mem_events:
+        if "EventName" in x:
+            name = x["EventName"]
+            if re.search("^UNC_MC[0-9]+_RDCAS_COUNT_FREERUN", name):
+                ddr_rds += Event(name)
+            elif re.search("^UNC_MC[0-9]+_WRCAS_COUNT_FREERUN", name):
+                ddr_wrs += Event(name)
+            # elif re.search("^UNC_MC[0-9]+_TOTAL_REQCOUNT_FREERUN", name):
+            #  ddr_total += Event(name)
+
+    if ddr_rds == 0:
+        try:
+            ddr_rds = Event("UNC_M_CAS_COUNT.RD")
+            ddr_wrs = Event("UNC_M_CAS_COUNT.WR")
+        except:
+            return None
+
+    ddr_total = ddr_rds + ddr_wrs
+
+    pmm_rds = 0
+    pmm_wrs = 0
+    try:
+        pmm_rds = Event("UNC_M_PMM_RPQ_INSERTS")
+        pmm_wrs = Event("UNC_M_PMM_WPQ_INSERTS")
+    except:
+        pass
+
+    pmm_total = pmm_rds + pmm_wrs
+
+    scale = 64 / 1_000_000
+    return MetricGroup("lpm_mem_bw", [
+        MetricGroup("lpm_mem_bw_ddr", [
+            Metric("lpm_mem_bw_ddr_read", "DDR memory read bandwidth",
+                   d_ratio(ddr_rds, interval_sec), f"{scale}MB/s"),
+            Metric("lpm_mem_bw_ddr_write", "DDR memory write bandwidth",
+                   d_ratio(ddr_wrs, interval_sec), f"{scale}MB/s"),
+            Metric("lpm_mem_bw_ddr_total", "DDR memory write bandwidth",
+                   d_ratio(ddr_total, interval_sec), f"{scale}MB/s"),
+        ], description="DDR Memory Bandwidth"),
+        MetricGroup("lpm_mem_bw_pmm", [
+            Metric("lpm_mem_bw_pmm_read", "PMM memory read bandwidth",
+                   d_ratio(pmm_rds, interval_sec), f"{scale}MB/s"),
+            Metric("lpm_mem_bw_pmm_write", "PMM memory write bandwidth",
+                   d_ratio(pmm_wrs, interval_sec), f"{scale}MB/s"),
+            Metric("lpm_mem_bw_pmm_total", "PMM memory write bandwidth",
+                   d_ratio(pmm_total, interval_sec), f"{scale}MB/s"),
+        ], description="PMM Memory Bandwidth") if pmm_rds != 0 else None,
+    ], description="Memory Bandwidth")
+
+
 def main() -> None:
     global _args
 
@@ -853,6 +914,7 @@ def main() -> None:
         IntelMlp(),
         IntelPorts(),
         IntelSwpf(),
+        UncoreMemBw(),
     ])
 
     if _args.metricgroups:
-- 
2.47.3