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

Ian Rogers
2024-03-01T01:02:38Z

On Thu, Feb 29, 2024 at 1:17 PM Liang, Kan <kan.liang@linux.intel.com> wrote:
>
>
>
> On 2024-02-28 7:17 p.m., Ian Rogers wrote:
> > 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")
> >
> > +
>
> Unnecessary empty line.

Ack. Will fix in v2.

Thanks,
Ian

> Thanks,
> Kan
>
> > 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(),
> > ])
> >