Messages in this thread Patch in this message | | | From | kan.liang@linux ... | Subject | [PATCH 05/12] perf header: Support CPU PMU capabilities | Date | Fri, 28 Feb 2020 08:30:04 -0800 |
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From: Kan Liang <kan.liang@linux.intel.com>
To stitch LBR call stack, the max LBR information is required. So the CPU PMU capabilities information has to be stored in perf header.
Add a new feature HEADER_CPU_PMU_CAPS for CPU PMU capabilities. Retrieve all CPU PMU capabilities, not just max LBR information.
Add variable max_branches to facilitate future usage.
The CPU PMU capabilities information is only useful for LBR call stack mode. Clear the feature for perf stat and other perf record mode.
Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> --- .../Documentation/perf.data-file-format.txt | 16 +++ tools/perf/builtin-record.c | 3 + tools/perf/builtin-stat.c | 1 + tools/perf/util/env.h | 3 + tools/perf/util/header.c | 110 ++++++++++++++++++ tools/perf/util/header.h | 1 + 6 files changed, 134 insertions(+)
diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt index b0152e1095c5..b6472e463284 100644 --- a/tools/perf/Documentation/perf.data-file-format.txt +++ b/tools/perf/Documentation/perf.data-file-format.txt @@ -373,6 +373,22 @@ struct { Indicates that trace contains records of PERF_RECORD_COMPRESSED type that have perf_events records in compressed form. + HEADER_CPU_PMU_CAPS = 28, + + A list of cpu PMU capabilities. The format of data is as below. + +struct { + u32 nr_cpu_pmu_caps; + { + char name[]; + char value[]; + } [nr_cpu_pmu_caps] +}; + + +Example: + cpu pmu capabilities: branches=32, max_precise=3, pmu_name=icelake + other bits are reserved and should ignored for now HEADER_FEAT_BITS = 256, diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 4c301466101b..428f7f5b8e48 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1120,6 +1120,9 @@ static void record__init_features(struct record *rec) if (!record__comp_enabled(rec)) perf_header__clear_feat(&session->header, HEADER_COMPRESSED); + if (!callchain_param.enabled || (callchain_param.record_mode != CALLCHAIN_LBR)) + perf_header__clear_feat(&session->header, HEADER_CPU_PMU_CAPS); + perf_header__clear_feat(&session->header, HEADER_STAT); } diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index a098c2ebf4ea..6d6979b8317a 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -1591,6 +1591,7 @@ static void init_features(struct perf_session *session) perf_header__clear_feat(&session->header, HEADER_TRACING_DATA); perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK); perf_header__clear_feat(&session->header, HEADER_AUXTRACE); + perf_header__clear_feat(&session->header, HEADER_CPU_PMU_CAPS); } static int __cmd_record(int argc, const char **argv) diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h index 11d05ae3606a..d286d478b4d8 100644 --- a/tools/perf/util/env.h +++ b/tools/perf/util/env.h @@ -48,6 +48,7 @@ struct perf_env { char *cpuid; unsigned long long total_mem; unsigned int msr_pmu_type; + unsigned int max_branches; int nr_cmdline; int nr_sibling_cores; @@ -57,12 +58,14 @@ struct perf_env { int nr_memory_nodes; int nr_pmu_mappings; int nr_groups; + int nr_cpu_pmu_caps; char *cmdline; const char **cmdline_argv; char *sibling_cores; char *sibling_dies; char *sibling_threads; char *pmu_mappings; + char *cpu_pmu_caps; struct cpu_topology_map *cpu; struct cpu_cache_level *caches; int caches_cnt; diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index acbd046bf95c..ce29321a4e1d 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1395,6 +1395,39 @@ static int write_compressed(struct feat_fd *ff __maybe_unused, return do_write(ff, &(ff->ph->env.comp_mmap_len), sizeof(ff->ph->env.comp_mmap_len)); } +static int write_cpu_pmu_caps(struct feat_fd *ff, + struct evlist *evlist __maybe_unused) +{ + struct perf_pmu_caps *caps = NULL; + struct perf_pmu *cpu_pmu; + int nr_caps; + int ret; + + cpu_pmu = perf_pmu__find("cpu"); + if (!cpu_pmu) + return -ENOENT; + + nr_caps = perf_pmu__caps_parse(cpu_pmu); + if (nr_caps < 0) + return nr_caps; + + ret = do_write(ff, &nr_caps, sizeof(nr_caps)); + if (ret < 0) + return ret; + + while ((caps = perf_pmu__scan_caps(cpu_pmu, caps))) { + ret = do_write_string(ff, caps->name); + if (ret < 0) + return ret; + + ret = do_write_string(ff, caps->value); + if (ret < 0) + return ret; + } + + return ret; +} + static void print_hostname(struct feat_fd *ff, FILE *fp) { fprintf(fp, "# hostname : %s\n", ff->ph->env.hostname); @@ -1809,6 +1842,28 @@ static void print_compressed(struct feat_fd *ff, FILE *fp) ff->ph->env.comp_level, ff->ph->env.comp_ratio); } +static void print_cpu_pmu_caps(struct feat_fd *ff, FILE *fp) +{ + const char *delimiter = "# cpu pmu capabilities: "; + char *str; + u32 nr_caps; + + nr_caps = ff->ph->env.nr_cpu_pmu_caps; + if (!nr_caps) { + fprintf(fp, "# cpu pmu capabilities: not available\n"); + return; + } + + str = ff->ph->env.cpu_pmu_caps; + while (nr_caps--) { + fprintf(fp, "%s%s", delimiter, str); + delimiter = ", "; + str += strlen(str) + 1; + } + + fprintf(fp, "\n"); +} + static void print_pmu_mappings(struct feat_fd *ff, FILE *fp) { const char *delimiter = "# pmu mappings: "; @@ -2846,6 +2901,60 @@ static int process_compressed(struct feat_fd *ff, return 0; } +static int process_cpu_pmu_caps(struct feat_fd *ff, + void *data __maybe_unused) +{ + char *name, *value; + struct strbuf sb; + u32 nr_caps; + + if (do_read_u32(ff, &nr_caps)) + return -1; + + if (!nr_caps) { + pr_debug("cpu pmu capabilities not available\n"); + return 0; + } + + ff->ph->env.nr_cpu_pmu_caps = nr_caps; + + if (strbuf_init(&sb, 128) < 0) + return -1; + + while (nr_caps--) { + name = do_read_string(ff); + if (!name) + goto error; + + value = do_read_string(ff); + if (!value) + goto free_name; + + if (strbuf_addf(&sb, "%s=%s", name, value) < 0) + goto free_value; + + /* include a NULL character at the end */ + if (strbuf_add(&sb, "", 1) < 0) + goto free_value; + + if (!strcmp(name, "branches")) + ff->ph->env.max_branches = atoi(value); + + free(value); + free(name); + } + ff->ph->env.cpu_pmu_caps = strbuf_detach(&sb, NULL); + return 0; + +free_value: + free(value); +free_name: + free(name); +error: + strbuf_release(&sb); + return -1; +} + #define FEAT_OPR(n, func, __full_only) \ [HEADER_##n] = { \ .name = __stringify(n), \ @@ -2903,6 +3012,7 @@ const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE] = { FEAT_OPR(BPF_PROG_INFO, bpf_prog_info, false), FEAT_OPR(BPF_BTF, bpf_btf, false), FEAT_OPR(COMPRESSED, compressed, false), + FEAT_OPR(CPU_PMU_CAPS, cpu_pmu_caps, false), }; struct header_print_data { diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 840f95cee349..650bd1c7a99b 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -43,6 +43,7 @@ enum { HEADER_BPF_PROG_INFO, HEADER_BPF_BTF, HEADER_COMPRESSED, + HEADER_CPU_PMU_CAPS, HEADER_LAST_FEATURE, HEADER_FEAT_BITS = 256, }; -- 2.17.1
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