[PATCH v1 04/13] perf jevents: Add br metric group for branch statistics on AMD

Ian Rogers
2024-02-29T00:15:52Z

The br metric group for branches itself comprises metric groups for
total, taken, conditional, fused and far metric groups using json
events. The lack of conditional events on anything but zen2 means this
category is lacking on zen1, zen3 and zen4.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/pmu-events/amd_metrics.py | 104 +++++++++++++++++++++++++++
1 file changed, 104 insertions(+)

diff --git a/tools/perf/pmu-events/amd_metrics.py b/tools/perf/pmu-events/amd_metrics.py
index ce3d1535483a..f8d5ba2861ee 100755
--- a/tools/perf/pmu-events/amd_metrics.py
+++ b/tools/perf/pmu-events/amd_metrics.py
@@ -7,6 +7,7 @@ import argparse
import json
import math
import os
+from typing import Optional

parser = argparse.ArgumentParser(description="AMD perf json generator")
parser.add_argument("-metricgroups", help="Generate metricgroups data", action='store_true')
@@ -18,10 +19,112 @@ LoadEvents(directory)

zen_model = int(args.model[6:])
interval_sec = Event("duration_time")
+ins = Event("instructions")
cycles = Event("cycles")
# Number of CPU cycles scaled for SMT.
smt_cycles = Select(cycles / 2, Literal("#smt_on"), cycles)

+def AmdBr():
+ def Total() -> MetricGroup:
+ br = Event("ex_ret_brn")
+ br_m_all = Event("ex_ret_brn_misp")
+ br_clr = Event("ex_ret_msprd_brnch_instr_dir_msmtch", "ex_ret_brn_resync")
+
+ br_r = d_ratio(br, interval_sec)
+ ins_r = d_ratio(ins, br)
+ misp_r = d_ratio(br_m_all, br)
+ clr_r = d_ratio(br_clr, interval_sec)
+
+ 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")
+ ])
+
+ def Taken() -> MetricGroup:
+ br = Event("ex_ret_brn_tkn")
+ br_m_tk = Event("ex_ret_brn_tkn_misp")
+ br_r = d_ratio(br, interval_sec)
+ ins_r = d_ratio(ins, br)
+ misp_r = d_ratio(br_m_tk, br)
+ 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%"),
+ Metric(
+ "br_taken_insn_between_branches",
+ "The number of instructions divided by the number of taken branches.",
+ ins_r, "insn"),
+ ])
+
+ def Conditional() -> Optional[MetricGroup]:
+ br = Event("ex_ret_cond")
+ br_r = d_ratio(br, interval_sec)
+ ins_r = d_ratio(ins, br)
+
+ 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"),
+ ]
+ if zen_model == 2:
+ br_m_cond = Event("ex_ret_cond_misp")
+ misp_r = d_ratio(br_m_cond, br)
+ metrics += [
+ Metric("br_cond_mispred",
+ "Retired conditional branch instructions mispredicted as a "
+ "percentage of all conditional branches.", misp_r, "100%"),
+ ]
+
+ return MetricGroup("br_cond", metrics)
+
+ def Fused() -> MetricGroup:
+ br = Event("ex_ret_fused_instr", "ex_ret_fus_brnch_inst")
+ br_r = d_ratio(br, interval_sec)
+ ins_r = d_ratio(ins, br)
+ return MetricGroup("br_cond", [
+ Metric("br_fused_retired",
+ "Retired fused branch instructions per second.", br_r, "insn/s"),
+ Metric(
+ "br_fused_insn_between_branches",
+ "The number of instructions divided by the number of fused "
+ "branches.", ins_r, "insn"),
+ ])
+
+ def Far() -> MetricGroup:
+ br = Event("ex_ret_brn_far")
+ br_r = d_ratio(br, interval_sec)
+ ins_r = d_ratio(ins, br)
+ 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(), Fused(), Far()],
+ description="breakdown of retired branch instructions")
+
+
def AmdUpc() -> Metric:
ops = Event("ex_ret_ops", "ex_ret_cops")
upc = d_ratio(ops, smt_cycles)
@@ -58,6 +161,7 @@ def Rapl() -> MetricGroup:
description="Processor socket power consumption estimates")

all_metrics = MetricGroup("", [
+ AmdBr(),
AmdUpc(),
Idle(),
Rapl(),
--
2.44.0.278.ge034bb2e1d-goog