[PATCH v1 11/20] perf jevents: Add context switch metrics for Intel

Ian Rogers
2024-02-29T00:18:49Z

Metrics break down context switches for different kinds of
instruction.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/pmu-events/intel_metrics.py | 55 ++++++++++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 0ca72aeec1ea..6ee708e84863 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -271,6 +271,60 @@ def IntelBr():
description="breakdown of retired branch instructions")

+def IntelCtxSw() -> MetricGroup:
+ cs = Event("context\-switches")
+ metrics = [
+ Metric("cs_rate", "Context switches per second", d_ratio(cs, interval_sec), "ctxsw/s")
+ ]
+
+ ev = Event("instructions")
+ metrics.append(Metric("cs_instr", "Instructions per context switch",
+ d_ratio(ev, cs), "instr/cs"))
+
+ ev = Event("cycles")
+ metrics.append(Metric("cs_cycles", "Cycles per context switch",
+ d_ratio(ev, cs), "cycles/cs"))
+
+ try:
+ ev = Event("MEM_INST_RETIRED.ALL_LOADS", "MEM_UOPS_RETIRED.ALL_LOADS")
+ metrics.append(Metric("cs_loads", "Loads per context switch",
+ d_ratio(ev, cs), "loads/cs"))
+ except:
+ pass
+
+ try:
+ ev = Event("MEM_INST_RETIRED.ALL_STORES", "MEM_UOPS_RETIRED.ALL_STORES")
+ metrics.append(Metric("cs_stores", "Stores per context switch",
+ d_ratio(ev, cs), "stores/cs"))
+ except:
+ pass
+
+ try:
+ ev = Event("BR_INST_RETIRED.NEAR_TAKEN", "BR_INST_RETIRED.TAKEN_JCC")
+ metrics.append(Metric("cs_br_taken", "Branches taken per context switch",
+ d_ratio(ev, cs), "br_taken/cs"))
+ except:
+ pass
+
+ try:
+ l2_misses = (Event("L2_RQSTS.DEMAND_DATA_RD_MISS") +
+ Event("L2_RQSTS.RFO_MISS") +
+ Event("L2_RQSTS.CODE_RD_MISS"))
+ try:
+ l2_misses += Event("L2_RQSTS.HWPF_MISS", "L2_RQSTS.L2_PF_MISS", "L2_RQSTS.PF_MISS")
+ except:
+ pass
+
+ metrics.append(Metric("cs_l2_misses", "L2 misses per context switch",
+ d_ratio(l2_misses, cs), "l2_misses/cs"))
+ except:
+ pass
+
+ return MetricGroup("cs", metrics,
+ description = ("Number of context switches per second, instructions "
+ "retired & core cycles between context switches"))
+
+
def IntelIlp() -> MetricGroup:
tsc = Event("msr/tsc/")
c0 = Event("msr/mperf/")
@@ -632,6 +686,7 @@ all_metrics = MetricGroup("", [
Smi(),
Tsx(),
IntelBr(),
+ IntelCtxSw(),
IntelIlp(),
IntelL2(),
IntelLdSt(),
--
2.44.0.278.ge034bb2e1d-goog