[PATCH v3 2/2] perf header: Support HYBRID_CPU_PMU_CAPS feature

Jin Yao
2021-05-11T05:31:24Z

Perf has supported CPU_PMU_CAPS feature to display a list
of cpu PMU capabilities. But on hybrid platform, it may have
several cpu pmus (such as, "cpu_core" and "cpu_atom"). The
CPU_PMU_CAPS feature is hard to extend to support multiple
cpu pmus well if it needs to be compatible for the case that
is old perf data file + new perf tool.

So for better compatibility we now create a new feature
HYBRID_CPU_PMU_CAPS in header.

For the perf.data generated on hybrid platform,

root@otcpl-adl-s-2:~# perf report --header-only -I

# cpu_core pmu capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid
# cpu_atom pmu capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid
# missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CPU_PMU_CAPS CLOCK_DATA

For the perf.data generated on non-hybrid platform

root@kbl-ppc:~# perf report --header-only -I

# cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
# missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT COMPRESSED CLOCK_DATA HYBRID_TOPOLOGY HYBRID_CPU_PMU_CAPS

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
.../Documentation/perf.data-file-format.txt | 16 ++
tools/perf/util/env.c | 6 +
tools/perf/util/env.h | 9 +
tools/perf/util/header.c | 163 ++++++++++++++++--
tools/perf/util/header.h | 1 +
5 files changed, 176 insertions(+), 19 deletions(-)

diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
index fbee9e580ee4..e6ff8c898ada 100644
--- a/tools/perf/Documentation/perf.data-file-format.txt
+++ b/tools/perf/Documentation/perf.data-file-format.txt
@@ -419,6 +419,22 @@ Example:
cpu_core cpu list : 0-15
cpu_atom cpu list : 16-23

+ HEADER_HYBRID_CPU_PMU_CAPS = 31,
+
+ A list of hybrid CPU PMU capabilities.
+
+struct {
+ u32 nr_pmu;
+ struct {
+ u32 nr_cpu_pmu_caps;
+ {
+ char name[];
+ char value[];
+ } [nr_cpu_pmu_caps];
+ char pmu_name[];
+ } [nr_pmu];
+};
+
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 744ae87b5bfa..1bea5b29b12d 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -208,6 +208,12 @@ void perf_env__exit(struct perf_env *env)
zfree(&env->hybrid_nodes[i].cpus);
}
zfree(&env->hybrid_nodes);
+
+ for (i = 0; i < env->nr_hybrid_cpc_nodes; i++) {
+ zfree(&env->hybrid_cpc_nodes[i].cpu_pmu_caps);
+ zfree(&env->hybrid_cpc_nodes[i].pmu_name);
+ }
+ zfree(&env->hybrid_cpc_nodes);
}

void perf_env__init(struct perf_env *env __maybe_unused)
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index e5e5deebe68d..6824a7423a2d 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -42,6 +42,13 @@ struct hybrid_node {
char *cpus;
};

+struct hybrid_cpc_node {
+ int nr_cpu_pmu_caps;
+ unsigned int max_branches;
+ char *cpu_pmu_caps;
+ char *pmu_name;
+};
+
struct perf_env {
char *hostname;
char *os_release;
@@ -65,6 +72,7 @@ struct perf_env {
int nr_groups;
int nr_cpu_pmu_caps;
int nr_hybrid_nodes;
+ int nr_hybrid_cpc_nodes;
char *cmdline;
const char **cmdline_argv;
char *sibling_cores;
@@ -84,6 +92,7 @@ struct perf_env {
struct memory_node *memory_nodes;
unsigned long long memory_bsize;
struct hybrid_node *hybrid_nodes;
+ struct hybrid_cpc_node *hybrid_cpc_nodes;
#ifdef HAVE_LIBBPF_SUPPORT
/*
* bpf_info_lock protects bpf rbtrees. This is needed because the
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index ebf4203b36b8..f7f2f026bb00 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -49,6 +49,7 @@
#include "cputopo.h"
#include "bpf-event.h"
#include "clockid.h"
+#include "pmu-hybrid.h"

#include <linux/ctype.h>
#include <internal/lib.h>
@@ -1459,18 +1460,14 @@ 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)
+static int write_per_cpu_pmu_caps(struct feat_fd *ff, struct perf_pmu *pmu,
+ bool write_pmu)
{
- struct perf_pmu *cpu_pmu = perf_pmu__find("cpu");
struct perf_pmu_caps *caps = NULL;
int nr_caps;
int ret;

- if (!cpu_pmu)
- return -ENOENT;
-
- nr_caps = perf_pmu__caps_parse(cpu_pmu);
+ nr_caps = perf_pmu__caps_parse(pmu);
if (nr_caps < 0)
return nr_caps;

@@ -1478,7 +1475,7 @@ static int write_cpu_pmu_caps(struct feat_fd *ff,
if (ret < 0)
return ret;

- list_for_each_entry(caps, &cpu_pmu->caps, list) {
+ list_for_each_entry(caps, &pmu->caps, list) {
ret = do_write_string(ff, caps->name);
if (ret < 0)
return ret;
@@ -1488,9 +1485,49 @@ static int write_cpu_pmu_caps(struct feat_fd *ff,
return ret;
}

+ if (write_pmu) {
+ ret = do_write_string(ff, pmu->name);
+ if (ret < 0)
+ return ret;
+ }
+
return ret;
}

+static int write_cpu_pmu_caps(struct feat_fd *ff,
+ struct evlist *evlist __maybe_unused)
+{
+ struct perf_pmu *cpu_pmu = perf_pmu__find("cpu");
+
+ if (!cpu_pmu)
+ return -ENOENT;
+
+ return write_per_cpu_pmu_caps(ff, cpu_pmu, false);
+}
+
+static int write_hybrid_cpu_pmu_caps(struct feat_fd *ff,
+ struct evlist *evlist __maybe_unused)
+{
+ struct perf_pmu *pmu;
+ u32 nr_pmu = perf_pmu__hybrid_pmu_num();
+ int ret;
+
+ if (nr_pmu == 0)
+ return -ENOENT;
+
+ ret = do_write(ff, &nr_pmu, sizeof(nr_pmu));
+ if (ret < 0)
+ return ret;
+
+ perf_pmu__for_each_hybrid_pmu(pmu) {
+ ret = write_per_cpu_pmu_caps(ff, pmu, true);
+ 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);
@@ -1962,18 +1999,28 @@ 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)
+static void print_per_cpu_pmu_caps(FILE *fp, int nr_caps, char *cpu_pmu_caps,
+ char *pmu_name)
{
- const char *delimiter = "# cpu pmu capabilities: ";
- u32 nr_caps = ff->ph->env.nr_cpu_pmu_caps;
- char *str;
+ const char *delimiter;
+ char *str, buf[128];

if (!nr_caps) {
- fprintf(fp, "# cpu pmu capabilities: not available\n");
+ if (!pmu_name)
+ fprintf(fp, "# cpu pmu capabilities: not available\n");
+ else
+ fprintf(fp, "# %s pmu capabilities: not available\n", pmu_name);
return;
}

- str = ff->ph->env.cpu_pmu_caps;
+ if (!pmu_name)
+ scnprintf(buf, sizeof(buf), "# cpu pmu capabilities: ");
+ else
+ scnprintf(buf, sizeof(buf), "# %s pmu capabilities: ", pmu_name);
+
+ delimiter = buf;
+
+ str = cpu_pmu_caps;
while (nr_caps--) {
fprintf(fp, "%s%s", delimiter, str);
delimiter = ", ";
@@ -1983,6 +2030,24 @@ static void print_cpu_pmu_caps(struct feat_fd *ff, FILE *fp)
fprintf(fp, "\n");
}

+static void print_cpu_pmu_caps(struct feat_fd *ff, FILE *fp)
+{
+ print_per_cpu_pmu_caps(fp, ff->ph->env.nr_cpu_pmu_caps,
+ ff->ph->env.cpu_pmu_caps, NULL);
+}
+
+static void print_hybrid_cpu_pmu_caps(struct feat_fd *ff, FILE *fp)
+{
+ struct hybrid_cpc_node *n;
+
+ for (int i = 0; i < ff->ph->env.nr_hybrid_cpc_nodes; i++) {
+ n = &ff->ph->env.hybrid_cpc_nodes[i];
+ print_per_cpu_pmu_caps(fp, n->nr_cpu_pmu_caps,
+ n->cpu_pmu_caps,
+ n->pmu_name);
+ }
+}
+
static void print_pmu_mappings(struct feat_fd *ff, FILE *fp)
{
const char *delimiter = "# pmu mappings: ";
@@ -3088,8 +3153,9 @@ static int process_compressed(struct feat_fd *ff,
return 0;
}

-static int process_cpu_pmu_caps(struct feat_fd *ff,
- void *data __maybe_unused)
+static int process_per_cpu_pmu_caps(struct feat_fd *ff, int *nr_cpu_pmu_caps,
+ char **cpu_pmu_caps,
+ unsigned int *max_branches)
{
char *name, *value;
struct strbuf sb;
@@ -3103,7 +3169,7 @@ static int process_cpu_pmu_caps(struct feat_fd *ff,
return 0;
}

- ff->ph->env.nr_cpu_pmu_caps = nr_caps;
+ *nr_cpu_pmu_caps = nr_caps;

if (strbuf_init(&sb, 128) < 0)
return -1;
@@ -3125,12 +3191,12 @@ static int process_cpu_pmu_caps(struct feat_fd *ff,
goto free_value;

if (!strcmp(name, "branches"))
- ff->ph->env.max_branches = atoi(value);
+ *max_branches = atoi(value);

free(value);
free(name);
}
- ff->ph->env.cpu_pmu_caps = strbuf_detach(&sb, NULL);
+ *cpu_pmu_caps = strbuf_detach(&sb, NULL);
return 0;

free_value:
@@ -3142,6 +3208,64 @@ static int process_cpu_pmu_caps(struct feat_fd *ff,
return -1;
}

+static int process_cpu_pmu_caps(struct feat_fd *ff,
+ void *data __maybe_unused)
+{
+ int ret;
+
+ ret = process_per_cpu_pmu_caps(ff, &ff->ph->env.nr_cpu_pmu_caps,
+ &ff->ph->env.cpu_pmu_caps,
+ &ff->ph->env.max_branches);
+ return ret;
+}
+
+static int process_hybrid_cpu_pmu_caps(struct feat_fd *ff,
+ void *data __maybe_unused)
+{
+ struct hybrid_cpc_node *nodes;
+ u32 nr_pmu, i;
+ int ret;
+
+ if (do_read_u32(ff, &nr_pmu))
+ return -1;
+
+ if (!nr_pmu) {
+ pr_debug("hybrid cpu pmu capabilities not available\n");
+ return 0;
+ }
+
+ nodes = zalloc(sizeof(*nodes) * nr_pmu);
+ if (!nodes)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_pmu; i++) {
+ struct hybrid_cpc_node *n = &nodes[i];
+
+ ret = process_per_cpu_pmu_caps(ff, &n->nr_cpu_pmu_caps,
+ &n->cpu_pmu_caps,
+ &n->max_branches);
+ if (ret)
+ goto err;
+
+ n->pmu_name = do_read_string(ff);
+ if (!n->pmu_name)
+ goto err;
+ }
+
+ ff->ph->env.nr_hybrid_cpc_nodes = nr_pmu;
+ ff->ph->env.hybrid_cpc_nodes = nodes;
+ return 0;
+
+err:
+ for (i = 0; i < nr_pmu; i++) {
+ free(nodes[i].cpu_pmu_caps);
+ free(nodes[i].pmu_name);
+ }
+
+ free(nodes);
+ return ret;
+}
+
#define FEAT_OPR(n, func, __full_only) \
[HEADER_##n] = { \
.name = __stringify(n), \
@@ -3204,6 +3328,7 @@ const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE] = {
FEAT_OPR(CPU_PMU_CAPS, cpu_pmu_caps, false),
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),
};

struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 3f12ec0eb84e..ae6b1cf19a7d 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -46,6 +46,7 @@ enum {
HEADER_CPU_PMU_CAPS,
HEADER_CLOCK_DATA,
HEADER_HYBRID_TOPOLOGY,
+ HEADER_HYBRID_CPU_PMU_CAPS,
HEADER_LAST_FEATURE,
HEADER_FEAT_BITS = 256,
};
--
2.17.1