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

Ravi Bangoria
2022-05-09T04:55:55Z

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 */
+ char pmu_name[];
+ u16 nr_caps;
+ 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;
+}
+
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;
+ * 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