Re: [PATCH v2 6/8] perf header: Parse non-cpu pmu capabilities

Arnaldo Carvalho de Melo
2022-05-16T13:28:23Z

Em Mon, May 09, 2022 at 10:19:12AM +0530, Ravi Bangoria escreveu:
> Pmus advertise their capabilities via sysfs attribute files but
> perf tool currently parses only core(cpu) pmu capabilities. Add
> support for parsing non-cpu pmu capabilities.
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
> ---
> .../Documentation/perf.data-file-format.txt | 18 ++
> tools/perf/util/env.c | 48 +++-
> tools/perf/util/env.h | 11 +
> tools/perf/util/header.c | 211 ++++++++++++++++++
> tools/perf/util/header.h | 1 +
> tools/perf/util/pmu.c | 15 +-
> tools/perf/util/pmu.h | 2 +
> 7 files changed, 301 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
> index f56d0e0fbff6..dea3acb36558 100644
> --- a/tools/perf/Documentation/perf.data-file-format.txt
> +++ b/tools/perf/Documentation/perf.data-file-format.txt
> @@ -435,6 +435,24 @@ struct {
> } [nr_pmu];
> };
>
> + HEADER_PMU_CAPS = 32,
> +
> + List of pmu capabilities (except cpu pmu which is already
> + covered by HEADER_CPU_PMU_CAPS)
> +
> +struct {
> + u32 nr_pmus;
> + struct {
> + u8 core_type; /* For hybrid topology */

Humm, I'd say use u32 here and..

> + char pmu_name[];
> + u16 nr_caps;

Here, no need to save space here, I guess.

> + struct {
> + char name[];
> + char value[];
> + } [nr_caps];
> + } [nr_pmus];
> +};
> +
> other bits are reserved and should ignored for now
> HEADER_FEAT_BITS = 256,
>
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index 579e44c59914..928633f07086 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -179,7 +179,7 @@ static void perf_env__purge_bpf(struct perf_env *env __maybe_unused)
>
> void perf_env__exit(struct perf_env *env)
> {
> - int i;
> + int i, j;
>
> perf_env__purge_bpf(env);
> perf_env__purge_cgroups(env);
> @@ -222,6 +222,14 @@ void perf_env__exit(struct perf_env *env)
> zfree(&env->hybrid_cpc_nodes[i].pmu_name);
> }
> zfree(&env->hybrid_cpc_nodes);
> +
> + for (i = 0; i < env->nr_pmus_with_caps; i++) {
> + zfree(&env->env_pmu_caps[i].pmu_name);
> + for (j = 0; j < env->env_pmu_caps[i].nr_caps; j++)
> + zfree(&env->env_pmu_caps[i].pmu_caps[j]);
> + zfree(&env->env_pmu_caps[i].pmu_caps);
> + }
> + zfree(&env->env_pmu_caps);
> }
>
> void perf_env__init(struct perf_env *env)
> @@ -527,3 +535,41 @@ int perf_env__numa_node(struct perf_env *env, struct perf_cpu cpu)
>
> return cpu.cpu >= 0 && cpu.cpu < env->nr_numa_map ? env->numa_map[cpu.cpu] : -1;
> }
> +
> +char *perf_env__find_pmu_cap(struct perf_env *env, u8 core_type,
> + const char *pmu_name, const char *cap)
> +{
> + struct env_pmu_caps *env_pmu_caps = env->env_pmu_caps;
> + char *cap_eq;
> + int cap_size;
> + char **ptr;
> + int i, j;
> +
> + if (!pmu_name || !cap)
> + return NULL;
> +
> + cap_size = strlen(cap);
> + cap_eq = zalloc(cap_size + 2);
> + if (!cap_eq)
> + return NULL;
> +
> + memcpy(cap_eq, cap, cap_size);
> + cap_eq[cap_size] = '=';
> +
> + for (i = 0; i < env->nr_pmus_with_caps; i++) {
> + if (env_pmu_caps[i].core_type != core_type ||
> + strcmp(env_pmu_caps[i].pmu_name, pmu_name))
> + continue;
> +
> + ptr = env_pmu_caps[i].pmu_caps;
> +
> + for (j = 0; j < env_pmu_caps[i].nr_caps; j++) {
> + if (!strncmp(ptr[j], cap_eq, cap_size + 1)) {
> + free(cap_eq);
> + return &ptr[j][cap_size + 1];
> + }
> + }
> + }
> + free(cap_eq);
> + return NULL;
> +}
> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index a3541f98e1fc..2b767f4ae6e0 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -50,6 +50,13 @@ struct hybrid_cpc_node {
> char *pmu_name;
> };
>
> +struct env_pmu_caps {
> + u8 core_type;
> + char *pmu_name;
> + u16 nr_caps;
> + char **pmu_caps;
> +};
> +
> struct perf_env {
> char *hostname;
> char *os_release;
> @@ -75,6 +82,7 @@ struct perf_env {
> int nr_cpu_pmu_caps;
> int nr_hybrid_nodes;
> int nr_hybrid_cpc_nodes;
> + int nr_pmus_with_caps;
> char *cmdline;
> const char **cmdline_argv;
> char *sibling_cores;
> @@ -95,6 +103,7 @@ struct perf_env {
> unsigned long long memory_bsize;
> struct hybrid_node *hybrid_nodes;
> struct hybrid_cpc_node *hybrid_cpc_nodes;
> + struct env_pmu_caps *env_pmu_caps;
> #ifdef HAVE_LIBBPF_SUPPORT
> /*
> * bpf_info_lock protects bpf rbtrees. This is needed because the
> @@ -172,4 +181,6 @@ bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);
> struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id);
>
> int perf_env__numa_node(struct perf_env *env, struct perf_cpu cpu);
> +char *perf_env__find_pmu_cap(struct perf_env *env, u8 core_type,
> + const char *pmu_name, const char *cap);
> #endif /* __PERF_ENV_H */
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index a27132e5a5ef..23d89dbfcd96 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -217,6 +217,19 @@ static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)
> return __do_read_buf(ff, addr, size);
> }
>
> +static int do_read_u16(struct feat_fd *ff, u16 *addr)
> +{
> + int ret;
> +
> + ret = __do_read(ff, addr, sizeof(*addr));
> + if (ret)
> + return ret;
> +
> + if (ff->ph->needs_swap)
> + *addr = bswap_16(*addr);
> + return 0;
> +}
> +

You will not need the do_read_u16, use do_read_u32.

Then change the other parts to the u32 type.

- Arnaldo

> static int do_read_u32(struct feat_fd *ff, u32 *addr)
> {
> int ret;
> @@ -1580,6 +1593,77 @@ static int write_hybrid_cpu_pmu_caps(struct feat_fd *ff,
> return 0;
> }
>
> +/*
> + * File format:
> + *
> + * struct {
> + * u32 nr_pmus;
> + * struct {
> + * u8 core_type;
> + * char pmu_name[];
> + * u16 nr_caps;

Update here.

> + * struct {
> + * char name[];
> + * char value[];
> + * } [nr_caps];
> + * } [nr_pmus];
> + * };
> + */
> +static int write_pmu_caps(struct feat_fd *ff, struct evlist *evlist __maybe_unused)
> +{
> + struct perf_pmu_caps *caps = NULL;
> + struct perf_pmu *pmu = NULL;
> + u8 core_type = 0;
> + u32 nr_pmus = 0;
> + int ret;
> +
> + while ((pmu = perf_pmu__scan(pmu))) {
> + if (!pmu->name || !strncmp(pmu->name, "cpu", 3) ||
> + perf_pmu__caps_parse(pmu) <= 0)
> + continue;
> + nr_pmus++;
> + }
> +
> + ret = do_write(ff, &nr_pmus, sizeof(nr_pmus));
> + if (ret < 0)
> + return ret;
> +
> + if (!nr_pmus)
> + return 0;
> +
> + while ((pmu = perf_pmu__scan(pmu))) {
> + if (!pmu->name || !strncmp(pmu->name, "cpu", 3) || !pmu->nr_caps)
> + continue;
> +
> + /*
> + * Currently core_type is always set to 0. But it can be
> + * used in future for hybrid topology pmus.
> + */
> + ret = do_write(ff, &core_type, sizeof(core_type));
> + if (ret < 0)
> + return ret;
> +
> + ret = do_write_string(ff, pmu->name);
> + if (ret < 0)
> + return ret;
> +
> + ret = do_write(ff, &pmu->nr_caps, sizeof(pmu->nr_caps));
> + if (ret < 0)
> + return ret;
> +
> + list_for_each_entry(caps, &pmu->caps, list) {
> + 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 0;
> +}
> +
> static void print_hostname(struct feat_fd *ff, FILE *fp)
> {
> fprintf(fp, "# hostname : %s\n", ff->ph->env.hostname);
> @@ -2209,6 +2293,31 @@ static void print_mem_topology(struct feat_fd *ff, FILE *fp)
> }
> }
>
> +static void print_pmu_caps(struct feat_fd *ff, FILE *fp)
> +{
> + struct env_pmu_caps *env_pmu_caps = ff->ph->env.env_pmu_caps;
> + int nr_pmus_with_caps = ff->ph->env.nr_pmus_with_caps;
> + const char *delimiter = "";
> + char **ptr;
> + int i, j;
> +
> + if (!nr_pmus_with_caps)
> + return;
> +
> + for (i = 0; i < nr_pmus_with_caps; i++) {
> + fprintf(fp, "# %s pmu capabilities: ", env_pmu_caps[i].pmu_name);
> +
> + ptr = env_pmu_caps[i].pmu_caps;
> +
> + delimiter = "";
> + for (j = 0; j < env_pmu_caps[i].nr_caps; j++) {
> + fprintf(fp, "%s%s", delimiter, ptr[j]);
> + delimiter = ", ";
> + }
> + fprintf(fp, "\n");
> + }
> +}
> +
> static int __event_process_build_id(struct perf_record_header_build_id *bev,
> char *filename,
> struct perf_session *session)
> @@ -3319,6 +3428,107 @@ static int process_hybrid_cpu_pmu_caps(struct feat_fd *ff,
> return ret;
> }
>
> +static int __process_pmu_caps(struct feat_fd *ff, struct env_pmu_caps *env_pmu_caps)
> +{
> + u16 nr_caps = env_pmu_caps->nr_caps;
> + int name_size, value_size;
> + char *name, *value, *ptr;
> + u16 i;
> +
> + env_pmu_caps->pmu_caps = zalloc(sizeof(char *) * nr_caps);
> + if (!env_pmu_caps->pmu_caps)
> + return -1;
> +
> + for (i = 0; i < nr_caps; i++) {
> + name = do_read_string(ff);
> + if (!name)
> + goto error;
> +
> + value = do_read_string(ff);
> + if (!value)
> + goto free_name;
> +
> + name_size = strlen(name);
> + value_size = strlen(value);
> + ptr = zalloc(sizeof(char) * (name_size + value_size + 2));
> + if (!ptr)
> + goto free_value;
> +
> + memcpy(ptr, name, name_size);
> + ptr[name_size] = '=';
> + memcpy(ptr + name_size + 1, value, value_size);
> + env_pmu_caps->pmu_caps[i] = ptr;
> +
> + free(value);
> + free(name);
> + }
> + return 0;
> +
> +free_value:
> + free(value);
> +free_name:
> + free(name);
> +error:
> + for (; i > 0; i--)
> + free(env_pmu_caps->pmu_caps[i - 1]);
> + free(env_pmu_caps->pmu_caps);
> + return -1;
> +}
> +
> +static int process_pmu_caps(struct feat_fd *ff, void *data __maybe_unused)
> +{
> + struct env_pmu_caps *env_pmu_caps;
> + u32 nr_pmus;
> + u32 i;
> + u16 j;
> +
> + ff->ph->env.nr_pmus_with_caps = 0;
> + ff->ph->env.env_pmu_caps = NULL;
> +
> + if (do_read_u32(ff, &nr_pmus))
> + return -1;
> +
> + if (!nr_pmus)
> + return 0;
> +
> + env_pmu_caps = zalloc(sizeof(struct env_pmu_caps) * nr_pmus);
> + if (!env_pmu_caps)
> + return -ENOMEM;
> +
> + for (i = 0; i < nr_pmus; i++) {
> + if (__do_read(ff, &env_pmu_caps[i].core_type, sizeof(env_pmu_caps[i].core_type)))
> + goto error;
> +
> + env_pmu_caps[i].pmu_name = do_read_string(ff);
> + if (!env_pmu_caps[i].pmu_name)
> + goto error;
> +
> + if (do_read_u16(ff, &env_pmu_caps[i].nr_caps))
> + goto free_pmu_name;
> +
> + if (!__process_pmu_caps(ff, &env_pmu_caps[i]))
> + continue;
> +
> +free_pmu_name:
> + free(env_pmu_caps[i].pmu_name);
> + goto error;
> + }
> +
> + ff->ph->env.nr_pmus_with_caps = nr_pmus;
> + ff->ph->env.env_pmu_caps = env_pmu_caps;
> + return 0;
> +
> +error:
> + for (; i > 0; i--) {
> + free(env_pmu_caps[i - 1].pmu_name);
> + for (j = 0; j < env_pmu_caps[i - 1].nr_caps; j++)
> + free(env_pmu_caps[i - 1].pmu_caps[j]);
> + free(env_pmu_caps[i - 1].pmu_caps);
> + }
> + free(env_pmu_caps);
> + return -1;
> +}
> +
> #define FEAT_OPR(n, func, __full_only) \
> [HEADER_##n] = { \
> .name = __stringify(n), \
> @@ -3382,6 +3592,7 @@ const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE] = {
> FEAT_OPR(CLOCK_DATA, clock_data, false),
> FEAT_OPN(HYBRID_TOPOLOGY, hybrid_topology, true),
> FEAT_OPR(HYBRID_CPU_PMU_CAPS, hybrid_cpu_pmu_caps, false),
> + FEAT_OPR(PMU_CAPS, pmu_caps, false),
> };
>
> struct header_print_data {
> diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
> index 0eb4bc29a5a4..e9a067bb8b9e 100644
> --- a/tools/perf/util/header.h
> +++ b/tools/perf/util/header.h
> @@ -47,6 +47,7 @@ enum {
> HEADER_CLOCK_DATA,
> HEADER_HYBRID_TOPOLOGY,
> HEADER_HYBRID_CPU_PMU_CAPS,
> + HEADER_PMU_CAPS,
> HEADER_LAST_FEATURE,
> HEADER_FEAT_BITS = 256,
> };
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 9a1c7e63e663..8d599acb7569 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -1890,16 +1890,22 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
> const char *sysfs = sysfs__mountpoint();
> DIR *caps_dir;
> struct dirent *evt_ent;
> - int nr_caps = 0;
> +
> + if (pmu->caps_initialized)
> + return pmu->nr_caps;
>
> if (!sysfs)
> return -1;
>
> + pmu->nr_caps = 0;
> +
> snprintf(caps_path, PATH_MAX,
> "%s" EVENT_SOURCE_DEVICE_PATH "%s/caps", sysfs, pmu->name);
>
> - if (stat(caps_path, &st) < 0)
> + if (stat(caps_path, &st) < 0) {
> + pmu->caps_initialized = true;
> return 0; /* no error if caps does not exist */
> + }
>
> caps_dir = opendir(caps_path);
> if (!caps_dir)
> @@ -1926,13 +1932,14 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
> continue;
> }
>
> - nr_caps++;
> + pmu->nr_caps++;
> fclose(file);
> }
>
> closedir(caps_dir);
>
> - return nr_caps;
> + pmu->caps_initialized = true;
> + return pmu->nr_caps;
> }
>
> void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 541889fa9f9c..593005e68bea 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -46,6 +46,8 @@ struct perf_pmu {
> struct perf_cpu_map *cpus;
> struct list_head format; /* HEAD struct perf_pmu_format -> list */
> struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */
> + bool caps_initialized;
> + u16 nr_caps;
> struct list_head caps; /* HEAD struct perf_pmu_caps -> list */
> struct list_head list; /* ELEM */
> struct list_head hybrid_list;
> --
> 2.27.0

--

- Arnaldo