From: Ian Rogers Date: Tue, 27 Jan 2026 18:44:49 +0000 (-0800) Subject: perf jevents: Add br metric group for branch statistics on Intel X-Git-Tag: v7.0-rc1~16^2~73 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=37d0b00a1ac85309e63700153049bc16fc446b19;p=thirdparty%2Flinux.git perf jevents: Add br metric group for branch statistics on Intel The br metric group for branches itself comprises metric groups for total, taken, conditional, fused and far metric groups using JSON events. Conditional taken and not taken metrics are specific to Icelake and later generations, so the presence of the event is used to determine whether the metric should exist. Signed-off-by: Ian Rogers Tested-by: Thomas Falcon Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Benjamin Gray Cc: Caleb Biggers Cc: Edward Baker Cc: Ingo Molnar Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Namhyung Kim Cc: Perry Taylor Cc: Peter Zijlstra Cc: Sandipan Das Cc: Weilin Wang Cc: Xu Yang Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py index 05f3d94ec5d5..e1944d821248 100755 --- a/tools/perf/pmu-events/intel_metrics.py +++ b/tools/perf/pmu-events/intel_metrics.py @@ -124,6 +124,143 @@ def Tsx() -> Optional[MetricGroup]: ], description="Breakdown of transactional memory statistics") +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("lpm_br_total", [ + Metric("lpm_br_total_retired", + "The number of branch instructions retired per second.", br_r, + "insn/s"), + Metric( + "lpm_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("lpm_br_total_insn_between_branches", + "The number of instructions divided by the number of branches.", + ins_r, "insn"), + Metric("lpm_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("lpm_br_taken", [ + Metric("lpm_br_taken_retired", + "The number of taken branches that were retired per second.", + br_r, "insn/s"), + Metric( + "lpm_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( + "lpm_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("lpm_br_cond_retired", "Retired conditional branch instructions.", + br_r, "insn/s"), + Metric("lpm_br_cond_insn_between_branches", + "The number of instructions divided by the number of conditional " + "branches.", ins_r, "insn"), + Metric("lpm_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("lpm_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("lpm_br_cond_retired", "Retired conditional not taken branch instructions.", + br_r, "insn/s"), + Metric("lpm_br_cond_insn_between_branches", + "The number of instructions divided by the number of not taken conditional " + "branches.", ins_r, "insn"), + Metric("lpm_br_cond_mispred", + "Retired not taken conditional branch instructions mispredicted as a " + "percentage of all not taken conditional branches.", misp_r, "100%"), + ] + return MetricGroup("lpm_br_cond", [ + MetricGroup("lpm_br_cond_nt", not_taken_metrics), + MetricGroup("lpm_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("lpm_br_far", [ + Metric("lpm_br_far_retired", "Retired far control transfers per second.", + br_r, "insn/s"), + Metric( + "lpm_br_far_insn_between_branches", + "The number of instructions divided by the number of far branches.", + ins_r, "insn"), + ]) + + return MetricGroup("lpm_br", [Total(), Taken(), Conditional(), Far()], + description="breakdown of retired branch instructions") + + def main() -> None: global _args @@ -153,6 +290,7 @@ def main() -> None: Rapl(), Smi(), Tsx(), + IntelBr(), ]) if _args.metricgroups: