From 78067ae26815f8432f8648657ea14c0e3c4f93ad Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 27 Jan 2026 10:44:37 -0800 Subject: [PATCH] perf jevents: Add br metric group for branch statistics on AMD 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. Reviewed-by: Sandipan Das Signed-off-by: Ian Rogers 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: Thomas Falcon Cc: Weilin Wang Cc: Xu Yang Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/pmu-events/amd_metrics.py | 105 +++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) diff --git a/tools/perf/pmu-events/amd_metrics.py b/tools/perf/pmu-events/amd_metrics.py index 42e46b33334d..38948f63cb52 100755 --- a/tools/perf/pmu-events/amd_metrics.py +++ b/tools/perf/pmu-events/amd_metrics.py @@ -18,6 +18,110 @@ cycles = Event("cycles") 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_brn_cond_misp", + "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("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") + ]) + + 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("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%"), + 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]: + global _zen_model + br = Event("ex_ret_brn_cond", "ex_ret_cond") + br_r = d_ratio(br, interval_sec) + ins_r = d_ratio(ins, br) + + 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"), + ] + if _zen_model == 2: + br_m_cond = Event("ex_ret_cond_misp") + misp_r = d_ratio(br_m_cond, br) + metrics += [ + Metric("lpm_br_cond_mispred", + "Retired conditional branch instructions mispredicted as a " + "percentage of all conditional branches.", misp_r, "100%"), + ] + + return MetricGroup("lpm_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("lpm_br_cond", [ + Metric("lpm_br_fused_retired", + "Retired fused branch instructions per second.", br_r, "insn/s"), + Metric( + "lpm_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("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(), 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) @@ -83,6 +187,7 @@ def main() -> None: _zen_model = int(_args.model[6:]) all_metrics = MetricGroup("", [ + AmdBr(), AmdUpc(), Idle(), Rapl(), -- 2.47.3