Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Wed, 18 Mar 2020 16:49:37 -0300 | Subject | Re: [PATCH V3 02/17] perf header: Support CPU PMU capabilities |
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Em Fri, Mar 13, 2020 at 11:33:04AM -0700, kan.liang@linux.intel.com escreveu: > 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. > > 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/util/env.h | 3 + > tools/perf/util/header.c | 110 ++++++++++++++++++ > tools/perf/util/header.h | 1 + > 4 files changed, 130 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/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");
please combine decl + assign:
+ struct perf_pmu *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))) {
Why can't you play use list_for_each_entry() here and remove that perf_pmu__scan_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;
ditto
> + 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 >
--
- Arnaldo
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