[PATCH v1 05/20] perf jevents: Add br metric group for branch statistics on Intel

Ian Rogers
2024-02-29T00:18:36Z

The br metric group for branches itself comprises metric groups for
total, taken, conditional, fused and far metric groups using json
events. Condtional taken and not taken metrics are specific to Icelake
and later generations, so a model to generation look up is added.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/pmu-events/intel_metrics.py | 139 +++++++++++++++++++++++++
1 file changed, 139 insertions(+)

diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
index 1096accea2aa..bee5da19d19d 100755
--- a/tools/perf/pmu-events/intel_metrics.py
+++ b/tools/perf/pmu-events/intel_metrics.py
@@ -19,6 +19,7 @@ LoadEvents(directory)

interval_sec = Event("duration_time")

+
def Idle() -> Metric:
cyc = Event("msr/mperf/")
tsc = Event("msr/tsc/")
@@ -127,11 +128,149 @@ def Tsx() -> Optional[MetricGroup]:
return MetricGroup('transaction', metrics)

+def IntelBr():
+ ins = Event("instructions")
+
+ def Total() -> MetricGroup:
+ br_all = Event ("BR_INST_RETIRED.ALL_BRANCHES", "BR_INST_RETIRED.ANY")
+ br_m_all = Event("BR_MISP_RETIRED.ALL_BRANCHES",
+ "BR_INST_RETIRED.MISPRED",
+ "BR_MISP_EXEC.ANY")
+ br_clr = None
+ try:
+ br_clr = Event("BACLEARS.ANY", "BACLEARS.ALL")
+ except:
+ pass
+
+ br_r = d_ratio(br_all, interval_sec)
+ ins_r = d_ratio(ins, br_all)
+ misp_r = d_ratio(br_m_all, br_all)
+ clr_r = d_ratio(br_clr, interval_sec) if br_clr else None
+
+ return MetricGroup("br_total", [
+ Metric("br_total_retired",
+ "The number of branch instructions retired per second.", br_r,
+ "insn/s"),
+ Metric(
+ "br_total_mispred",
+ "The number of branch instructions retired, of any type, that were "
+ "not correctly predicted as a percentage of all branch instrucions.",
+ misp_r, "100%"),
+ Metric("br_total_insn_between_branches",
+ "The number of instructions divided by the number of branches.",
+ ins_r, "insn"),
+ Metric("br_total_insn_fe_resteers",
+ "The number of resync branches per second.", clr_r, "req/s"
+ ) if clr_r else None
+ ])
+
+ def Taken() -> MetricGroup:
+ br_all = Event("BR_INST_RETIRED.ALL_BRANCHES", "BR_INST_RETIRED.ANY")
+ br_m_tk = None
+ try:
+ br_m_tk = Event("BR_MISP_RETIRED.NEAR_TAKEN",
+ "BR_MISP_RETIRED.TAKEN_JCC",
+ "BR_INST_RETIRED.MISPRED_TAKEN")
+ except:
+ pass
+ br_r = d_ratio(br_all, interval_sec)
+ ins_r = d_ratio(ins, br_all)
+ misp_r = d_ratio(br_m_tk, br_all) if br_m_tk else None
+ return MetricGroup("br_taken", [
+ Metric("br_taken_retired",
+ "The number of taken branches that were retired per second.",
+ br_r, "insn/s"),
+ Metric(
+ "br_taken_mispred",
+ "The number of retired taken branch instructions that were "
+ "mispredicted as a percentage of all taken branches.", misp_r,
+ "100%") if misp_r else None,
+ Metric(
+ "br_taken_insn_between_branches",
+ "The number of instructions divided by the number of taken branches.",
+ ins_r, "insn"),
+ ])
+
+ def Conditional() -> Optional[MetricGroup]:
+ try:
+ br_cond = Event("BR_INST_RETIRED.COND",
+ "BR_INST_RETIRED.CONDITIONAL",
+ "BR_INST_RETIRED.TAKEN_JCC")
+ br_m_cond = Event("BR_MISP_RETIRED.COND",
+ "BR_MISP_RETIRED.CONDITIONAL",
+ "BR_MISP_RETIRED.TAKEN_JCC")
+ except:
+ return None
+
+ br_cond_nt = None
+ br_m_cond_nt = None
+ try:
+ br_cond_nt = Event("BR_INST_RETIRED.COND_NTAKEN")
+ br_m_cond_nt = Event("BR_MISP_RETIRED.COND_NTAKEN")
+ except:
+ pass
+ br_r = d_ratio(br_cond, interval_sec)
+ ins_r = d_ratio(ins, br_cond)
+ misp_r = d_ratio(br_m_cond, br_cond)
+ taken_metrics = [
+ Metric("br_cond_retired", "Retired conditional branch instructions.",
+ br_r, "insn/s"),
+ Metric("br_cond_insn_between_branches",
+ "The number of instructions divided by the number of conditional "
+ "branches.", ins_r, "insn"),
+ Metric("br_cond_mispred",
+ "Retired conditional branch instructions mispredicted as a "
+ "percentage of all conditional branches.", misp_r, "100%"),
+ ]
+ if not br_m_cond_nt:
+ return MetricGroup("br_cond", taken_metrics)
+
+ br_r = d_ratio(br_cond_nt, interval_sec)
+ ins_r = d_ratio(ins, br_cond_nt)
+ misp_r = d_ratio(br_m_cond_nt, br_cond_nt)
+
+ not_taken_metrics = [
+ Metric("br_cond_retired", "Retired conditional not taken branch instructions.",
+ br_r, "insn/s"),
+ Metric("br_cond_insn_between_branches",
+ "The number of instructions divided by the number of not taken conditional "
+ "branches.", ins_r, "insn"),
+ Metric("br_cond_mispred",
+ "Retired not taken conditional branch instructions mispredicted as a "
+ "percentage of all not taken conditional branches.", misp_r, "100%"),
+ ]
+ return MetricGroup("br_cond", [
+ MetricGroup("br_cond_nt", not_taken_metrics),
+ MetricGroup("br_cond_tkn", taken_metrics),
+ ])
+
+ def Far() -> Optional[MetricGroup]:
+ try:
+ br_far = Event("BR_INST_RETIRED.FAR_BRANCH")
+ except:
+ return None
+
+ br_r = d_ratio(br_far, interval_sec)
+ ins_r = d_ratio(ins, br_far)
+ return MetricGroup("br_far", [
+ Metric("br_far_retired", "Retired far control transfers per second.",
+ br_r, "insn/s"),
+ Metric(
+ "br_far_insn_between_branches",
+ "The number of instructions divided by the number of far branches.",
+ ins_r, "insn"),
+ ])
+
+ return MetricGroup("br", [Total(), Taken(), Conditional(), Far()],
+ description="breakdown of retired branch instructions")
+
+
all_metrics = MetricGroup("", [
Idle(),
Rapl(),
Smi(),
Tsx(),
+ IntelBr(),
])

if args.metricgroups:
--
2.44.0.278.ge034bb2e1d-goog