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SUSE:SLE-15-SP5:Update
perf.23962
perf-stat-support-new-per-thread-topdown-metric...
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File perf-stat-support-new-per-thread-topdown-metrics.patch of Package perf.23962
From: Andi Kleen <ak@linux.intel.com> Date: Fri, 11 Sep 2020 07:48:07 -0700 Subject: perf stat: Support new per thread TopDown metrics Git-commit: 55c36a9fc2aaac6a0c77eeaeefd8d8f691c98e19 Patch-mainline: v5.10-rc1 References: jsc#SLE-13346 X-Info: adjust for context, np c754c382c9a7a546087d3f52f5fcf1e1a8c3ee01 no fc393839c11bbe2c7f1a44ab34e5f2a219d8366e no 5f09ca5a1484632d1d3dc533d626d12c4370dbbc Icelake has support for reporting per thread TopDown metrics. These are reported differently than the previous TopDown support, each metric is standalone, but scaled to pipeline "slots". We don't need to do anything special for HyperThreading anymore. Teach perf stat --topdown to handle these new metrics and print them in the same way as the previous TopDown metrics. The restrictions of only being able to report information per core is gone. Signed-off-by: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kan Liang <kan.liang@linux.intel.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200911144808.27603-4-kan.liang@linux.intel.com Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Tony Jones <tonyj@suse.de> --- tools/perf/Documentation/perf-stat.txt | 7 ++- tools/perf/builtin-stat.c | 30 +++++++++++- tools/perf/util/stat-shadow.c | 89 ++++++++++++++++++++++++++++++++++ tools/perf/util/stat.c | 4 ++ tools/perf/util/stat.h | 8 +++ 5 files changed, 134 insertions(+), 4 deletions(-) diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 7d18694e592a..5bf3d7ae4660 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -363,6 +363,11 @@ if the workload is actually bound by the CPU and not by something else. For best results it is usually a good idea to use it with interval mode like -I 1000, as the bottleneck of workloads can change often. +This enables --metric-only, unless overridden with --no-metric-only. + +The following restrictions only apply to older Intel CPUs and Atom, +on newer CPUs (IceLake and later) TopDown can be collected for any thread: + The top down metrics are collected per core instead of per CPU thread. Per core mode is automatically enabled and -a (global monitoring) is needed, requiring root rights or @@ -374,8 +379,6 @@ echo 0 > /proc/sys/kernel/nmi_watchdog for best results. Otherwise the bottlenecks may be inconsistent on workload with changing phases. -This enables --metric-only, unless overridden with --no-metric-only. - To interpret the results it is usually needed to know on which CPUs the workload runs on. If needed the CPUs can be forced using taskset. diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index a39bb28b44f9..17fbbd03e154 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -128,6 +128,15 @@ static const char * topdown_attrs[] = { NULL, }; +static const char *topdown_metric_attrs[] = { + "slots", + "topdown-retiring", + "topdown-bad-spec", + "topdown-fe-bound", + "topdown-be-bound", + NULL, +}; + static const char *smi_cost_attrs = { "{" "msr/aperf/," @@ -1677,6 +1686,24 @@ static int add_default_attributes(void) char *str = NULL; bool warn = false; + if (!force_metric_only) + stat_config.metric_only = true; + + if (topdown_filter_events(topdown_metric_attrs, &str, 1) < 0) { + pr_err("Out of memory\n"); + return -1; + } + if (topdown_metric_attrs[0] && str) { + if (!stat_config.interval && !stat_config.metric_only) { + fprintf(stat_config.output, + "Topdown accuracy may decrease when measuring long periods.\n" + "Please print the result regularly, e.g. -I1000\n"); + } + goto setup_metrics; + } + + zfree(&str); + if (stat_config.aggr_mode != AGGR_GLOBAL && stat_config.aggr_mode != AGGR_CORE) { pr_err("top down event configuration requires --per-core mode\n"); @@ -1688,8 +1715,6 @@ static int add_default_attributes(void) return -1; } - if (!force_metric_only) - stat_config.metric_only = true; if (topdown_filter_events(topdown_attrs, &str, arch_topdown_check_group(&warn)) < 0) { pr_err("Out of memory\n"); @@ -1698,6 +1723,7 @@ static int add_default_attributes(void) if (topdown_attrs[0] && str) { if (warn) arch_topdown_group_warn(); +setup_metrics: err = parse_events(evsel_list, str, &errinfo); if (err) { fprintf(stderr, diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c index 924b54d15d54..901265127e36 100644 --- a/tools/perf/util/stat-shadow.c +++ b/tools/perf/util/stat-shadow.c @@ -241,6 +241,18 @@ void perf_stat__update_shadow_stats(struct evsel *counter, u64 count, else if (perf_stat_evsel__is(counter, TOPDOWN_RECOVERY_BUBBLES)) update_runtime_stat(st, STAT_TOPDOWN_RECOVERY_BUBBLES, ctx, cpu, count); + else if (perf_stat_evsel__is(counter, TOPDOWN_RETIRING)) + update_runtime_stat(st, STAT_TOPDOWN_RETIRING, + ctx, cpu, count); + else if (perf_stat_evsel__is(counter, TOPDOWN_BAD_SPEC)) + update_runtime_stat(st, STAT_TOPDOWN_BAD_SPEC, + ctx, cpu, count); + else if (perf_stat_evsel__is(counter, TOPDOWN_FE_BOUND)) + update_runtime_stat(st, STAT_TOPDOWN_FE_BOUND, + ctx, cpu, count); + else if (perf_stat_evsel__is(counter, TOPDOWN_BE_BOUND)) + update_runtime_stat(st, STAT_TOPDOWN_BE_BOUND, + ctx, cpu, count); else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND)) update_runtime_stat(st, STAT_STALLED_CYCLES_FRONT, ctx, cpu, count); @@ -705,6 +717,47 @@ static double td_be_bound(int ctx, int cpu, struct runtime_stat *st) return sanitize_val(1.0 - sum); } +/* + * Kernel reports metrics multiplied with slots. To get back + * the ratios we need to recreate the sum. + */ + +static double td_metric_ratio(int ctx, int cpu, + enum stat_type type, + struct runtime_stat *stat) +{ + double sum = runtime_stat_avg(stat, STAT_TOPDOWN_RETIRING, ctx, cpu) + + runtime_stat_avg(stat, STAT_TOPDOWN_FE_BOUND, ctx, cpu) + + runtime_stat_avg(stat, STAT_TOPDOWN_BE_BOUND, ctx, cpu) + + runtime_stat_avg(stat, STAT_TOPDOWN_BAD_SPEC, ctx, cpu); + double d = runtime_stat_avg(stat, type, ctx, cpu); + + if (sum) + return d / sum; + return 0; +} + +/* + * ... but only if most of the values are actually available. + * We allow two missing. + */ + +static bool full_td(int ctx, int cpu, + struct runtime_stat *stat) +{ + int c = 0; + + if (runtime_stat_avg(stat, STAT_TOPDOWN_RETIRING, ctx, cpu) > 0) + c++; + if (runtime_stat_avg(stat, STAT_TOPDOWN_BE_BOUND, ctx, cpu) > 0) + c++; + if (runtime_stat_avg(stat, STAT_TOPDOWN_FE_BOUND, ctx, cpu) > 0) + c++; + if (runtime_stat_avg(stat, STAT_TOPDOWN_BAD_SPEC, ctx, cpu) > 0) + c++; + return c >= 2; +} + static void print_smi_cost(struct perf_stat_config *config, int cpu, struct evsel *evsel, struct perf_stat_output_ctx *out, @@ -1073,6 +1126,42 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config, be_bound * 100.); else print_metric(config, ctxp, NULL, NULL, name, 0); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_RETIRING) && + full_td(ctx, cpu, st)) { + double retiring = td_metric_ratio(ctx, cpu, + STAT_TOPDOWN_RETIRING, st); + + if (retiring > 0.7) + color = PERF_COLOR_GREEN; + print_metric(config, ctxp, color, "%8.1f%%", "retiring", + retiring * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_FE_BOUND) && + full_td(ctx, cpu, st)) { + double fe_bound = td_metric_ratio(ctx, cpu, + STAT_TOPDOWN_FE_BOUND, st); + + if (fe_bound > 0.2) + color = PERF_COLOR_RED; + print_metric(config, ctxp, color, "%8.1f%%", "frontend bound", + fe_bound * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_BE_BOUND) && + full_td(ctx, cpu, st)) { + double be_bound = td_metric_ratio(ctx, cpu, + STAT_TOPDOWN_BE_BOUND, st); + + if (be_bound > 0.2) + color = PERF_COLOR_RED; + print_metric(config, ctxp, color, "%8.1f%%", "backend bound", + be_bound * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_BAD_SPEC) && + full_td(ctx, cpu, st)) { + double bad_spec = td_metric_ratio(ctx, cpu, + STAT_TOPDOWN_BAD_SPEC, st); + + if (bad_spec > 0.1) + color = PERF_COLOR_RED; + print_metric(config, ctxp, color, "%8.1f%%", "bad speculation", + bad_spec * 100.); } else if (evsel->metric_expr) { generic_metric(config, evsel->metric_expr, evsel->metric_events, evsel->name, evsel->metric_name, NULL, 1, avg, cpu, out, st); diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c index cdb154381a87..bd0decd6d753 100644 --- a/tools/perf/util/stat.c +++ b/tools/perf/util/stat.c @@ -95,6 +95,10 @@ static const char *id_str[PERF_STAT_EVSEL_ID__MAX] = { ID(TOPDOWN_SLOTS_RETIRED, topdown-slots-retired), ID(TOPDOWN_FETCH_BUBBLES, topdown-fetch-bubbles), ID(TOPDOWN_RECOVERY_BUBBLES, topdown-recovery-bubbles), + ID(TOPDOWN_RETIRING, topdown-retiring), + ID(TOPDOWN_BAD_SPEC, topdown-bad-spec), + ID(TOPDOWN_FE_BOUND, topdown-fe-bound), + ID(TOPDOWN_BE_BOUND, topdown-be-bound), ID(SMI_NUM, msr/smi/), ID(APERF, msr/aperf/), }; diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h index 9911fc6adbfd..f36c8c92efa0 100644 --- a/tools/perf/util/stat.h +++ b/tools/perf/util/stat.h @@ -28,6 +28,10 @@ enum perf_stat_evsel_id { PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_RETIRED, PERF_STAT_EVSEL_ID__TOPDOWN_FETCH_BUBBLES, PERF_STAT_EVSEL_ID__TOPDOWN_RECOVERY_BUBBLES, + PERF_STAT_EVSEL_ID__TOPDOWN_RETIRING, + PERF_STAT_EVSEL_ID__TOPDOWN_BAD_SPEC, + PERF_STAT_EVSEL_ID__TOPDOWN_FE_BOUND, + PERF_STAT_EVSEL_ID__TOPDOWN_BE_BOUND, PERF_STAT_EVSEL_ID__SMI_NUM, PERF_STAT_EVSEL_ID__APERF, PERF_STAT_EVSEL_ID__MAX, @@ -82,6 +86,10 @@ enum stat_type { STAT_TOPDOWN_SLOTS_RETIRED, STAT_TOPDOWN_FETCH_BUBBLES, STAT_TOPDOWN_RECOVERY_BUBBLES, + STAT_TOPDOWN_RETIRING, + STAT_TOPDOWN_BAD_SPEC, + STAT_TOPDOWN_FE_BOUND, + STAT_TOPDOWN_BE_BOUND, STAT_SMI_NUM, STAT_APERF, STAT_MAX
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