From: Ian Rogers <irogers@google.com>
Date: Tue, 27 Jan 2026 18:44:42 +0000 (-0800)
Subject: perf jevents: Add context switch metrics for AMD
X-Git-Tag: v7.0-rc1~16^2~80
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3563030d4f77856bd0a32492fbe9edc3d36248ec;p=thirdparty%2Flinux.git

perf jevents: Add context switch metrics for AMD

Metrics break down context switches for different kinds of
instruction.

Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Ian Rogers <irogers@google.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: Thomas Falcon <thomas.falcon@intel.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/amd_metrics.py b/tools/perf/pmu-events/amd_metrics.py
index b3de74babe40..83e77ccc059e 100755
--- a/tools/perf/pmu-events/amd_metrics.py
+++ b/tools/perf/pmu-events/amd_metrics.py
@@ -122,6 +122,38 @@ def AmdBr():
                        description="breakdown of retired branch instructions")
 
 
+def AmdCtxSw() -> MetricGroup:
+    cs = Event("context\\-switches")
+    metrics = [
+        Metric("lpm_cs_rate", "Context switches per second",
+               d_ratio(cs, interval_sec), "ctxsw/s")
+    ]
+
+    ev = Event("instructions")
+    metrics.append(Metric("lpm_cs_instr", "Instructions per context switch",
+                          d_ratio(ev, cs), "instr/cs"))
+
+    ev = Event("cycles")
+    metrics.append(Metric("lpm_cs_cycles", "Cycles per context switch",
+                          d_ratio(ev, cs), "cycles/cs"))
+
+    ev = Event("ls_dispatch.pure_ld", "ls_dispatch.ld_dispatch")
+    metrics.append(Metric("lpm_cs_loads", "Loads per context switch",
+                          d_ratio(ev, cs), "loads/cs"))
+
+    ev = Event("ls_dispatch.pure_st", "ls_dispatch.store_dispatch")
+    metrics.append(Metric("lpm_cs_stores", "Stores per context switch",
+                          d_ratio(ev, cs), "stores/cs"))
+
+    ev = Event("ex_ret_brn_tkn")
+    metrics.append(Metric("lpm_cs_br_taken", "Branches taken per context switch",
+                          d_ratio(ev, cs), "br_taken/cs"))
+
+    return MetricGroup("lpm_cs", metrics,
+                       description=("Number of context switches per second, instructions "
+                                    "retired & core cycles between context switches"))
+
+
 def AmdDtlb() -> Optional[MetricGroup]:
     global _zen_model
     if _zen_model >= 4:
@@ -438,6 +470,7 @@ def main() -> None:
 
     all_metrics = MetricGroup("", [
         AmdBr(),
+        AmdCtxSw(),
         AmdDtlb(),
         AmdItlb(),
         AmdLdSt(),