linux-kernel - [PATCH v8 26/52] perf jevents: Add context switch metrics for AMD

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251113032040.1994090-27-irogers@google.com>
Date: Wed, 12 Nov 2025 19:20:14 -0800
From: Ian Rogers <irogers@...gle.com>
To: Adrian Hunter <adrian.hunter@...el.com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Benjamin Gray <bgray@...ux.ibm.com>, 
	Caleb Biggers <caleb.biggers@...el.com>, Edward Baker <edward.baker@...el.com>, 
	Ian Rogers <irogers@...gle.com>, Ingo Molnar <mingo@...hat.com>, 
	James Clark <james.clark@...aro.org>, Jing Zhang <renyu.zj@...ux.alibaba.com>, 
	Jiri Olsa <jolsa@...nel.org>, John Garry <john.g.garry@...cle.com>, Leo Yan <leo.yan@....com>, 
	Namhyung Kim <namhyung@...nel.org>, Perry Taylor <perry.taylor@...el.com>, 
	Peter Zijlstra <peterz@...radead.org>, Samantha Alt <samantha.alt@...el.com>, 
	Sandipan Das <sandipan.das@....com>, Thomas Falcon <thomas.falcon@...el.com>, 
	Weilin Wang <weilin.wang@...el.com>, Xu Yang <xu.yang_2@....com>, linux-kernel@...r.kernel.org, 
	linux-perf-users@...r.kernel.org
Subject: [PATCH v8 26/52] perf jevents: Add context switch metrics for AMD

Metrics break down context switches for different kinds of
instruction.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/pmu-events/amd_metrics.py | 33 ++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/tools/perf/pmu-events/amd_metrics.py b/tools/perf/pmu-events/amd_metrics.py
index 9a39e23075b8..da50337557f5 100755
--- a/tools/perf/pmu-events/amd_metrics.py
+++ b/tools/perf/pmu-events/amd_metrics.py
@@ -121,6 +121,38 @@ 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.ld_dispatch")
+    metrics.append(Metric("lpm_cs_loads", "Loads per context switch",
+                          d_ratio(ev, cs), "loads/cs"))
+
+    ev = Event("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 AmdIlp() -> MetricGroup:
     tsc = Event("msr/tsc/")
     c0 = Event("msr/mperf/")
@@ -636,6 +668,7 @@ def main() -> None:
 
     all_metrics = MetricGroup("", [
         AmdBr(),
+        AmdCtxSw(),
         AmdIlp(),
         AmdDtlb(),
         AmdItlb(),
-- 
2.51.2.1041.gc1ab5b90ca-goog