[PATCH 33/49] perf header: Support hybrid CPU_PMU_CAPS

[kan . liang]

From: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>

On hybrid platform, it may have several cpu pmus, such as,
"cpu_core" and "cpu_atom". The CPU_PMU_CAPS feature in perf
header needs to be improved to support multiple cpu pmus.

The new layout in header is:

<nr_caps>
<caps string>
<caps string>
<pmu name>
<nr of rest pmus>

It's also considered to be compatible with old perf.data.

With this patch,

On hybrid platform with new perf.data

  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

On hybrid platform with old perf.data

  root@otcpl-adl-s-2:~# ./perf report --header-only -I
  ...
  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid

On non-hybrid platform with old perf.data

  root@kbl-ppc:~# ./perf report --header-only -I
  ...
  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake

On non-hybrid platform with new perf.data

  root@kbl-ppc:~# ./perf report --header-only -I
  ...
  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake

It's also tested for old perf with new per.data.

  root@kbl-ppc:~# perf report --header-only -I
  ...
  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/util/env.c    |   6 ++
 tools/perf/util/env.h    |  11 ++-
 tools/perf/util/header.c | 175 +++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 168 insertions(+), 24 deletions(-)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 9e05eca..8ef24aa 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].pmu_name);
 	}
 	zfree(&env->hybrid_nodes);
+
+	for (i = 0; i < env->nr_cpu_pmu_caps_nodes; i++) {
+		zfree(&env->cpu_pmu_caps_nodes[i].cpu_pmu_caps);
+		zfree(&env->cpu_pmu_caps_nodes[i].pmu_name);
+	}
+	zfree(&env->cpu_pmu_caps_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 9ca7633..5552c98 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -42,6 +42,13 @@ struct hybrid_node {
 	struct perf_cpu_map	*map;
 };
 
+struct cpu_pmu_caps_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;
@@ -63,15 +70,14 @@ struct perf_env {
 	int			nr_memory_nodes;
 	int			nr_pmu_mappings;
 	int			nr_groups;
-	int			nr_cpu_pmu_caps;
 	int			nr_hybrid_nodes;
+	int			nr_cpu_pmu_caps_nodes;
 	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;
@@ -84,6 +90,7 @@ struct perf_env {
 	struct memory_node	*memory_nodes;
 	unsigned long long	 memory_bsize;
 	struct hybrid_node	*hybrid_nodes;
+	struct cpu_pmu_caps_node	*cpu_pmu_caps_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 6bcd959..b161ce3 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1459,18 +1459,22 @@ 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,
+				  int nr)
 {
-	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);
+	/*
+	 * The layout is:
+	 * <nr_caps>
+	 * <caps string>
+	 * <caps string>
+	 * <pmu name>
+	 * <nr of rest pmus>
+	 */
+	nr_caps = perf_pmu__caps_parse(pmu);
 	if (nr_caps < 0)
 		return nr_caps;
 
@@ -1478,7 +1482,7 @@ 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 +1492,50 @@ static int write_cpu_pmu_caps(struct feat_fd *ff,
 			return ret;
 	}
 
+	ret = do_write_string(ff, pmu->name);
+	if (ret < 0)
+		return ret;
+
+	ret = do_write(ff, &nr, sizeof(nr));
+	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 *pmu = perf_pmu__find("cpu");
+	u32 nr = 0;
+	int ret;
+
+	if (pmu)
+		nr = 1;
+	else {
+		perf_pmu__for_each_hybrid_pmus(pmu)
+			nr++;
+		pmu = NULL;
+	}
+
+	if (nr == 0)
+		return -1;
+
+	if (pmu) {
+		ret = write_per_cpu_pmu_caps(ff, pmu, 0);
+		if (ret < 0)
+			return ret;
+	} else {
+		perf_pmu__for_each_hybrid_pmus(pmu) {
+			ret = write_per_cpu_pmu_caps(ff, pmu, --nr);
+			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);
@@ -1963,18 +2008,28 @@ 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, struct cpu_pmu_caps_node *n)
 {
-	const char *delimiter = "# cpu pmu capabilities: ";
-	u32 nr_caps = ff->ph->env.nr_cpu_pmu_caps;
-	char *str;
+	const char *delimiter;
+	u32 nr_caps = n->nr_cpu_pmu_caps;
+	char *str, buf[128];
 
 	if (!nr_caps) {
-		fprintf(fp, "# cpu pmu capabilities: not available\n");
+		if (!n->pmu_name)
+			fprintf(fp, "# cpu pmu capabilities: not available\n");
+		else
+			fprintf(fp, "# %s pmu capabilities: not available\n", n->pmu_name);
 		return;
 	}
 
-	str = ff->ph->env.cpu_pmu_caps;
+	if (!n->pmu_name)
+		scnprintf(buf, sizeof(buf), "# cpu pmu capabilities: ");
+	else
+		scnprintf(buf, sizeof(buf), "# %s pmu capabilities: ", n->pmu_name);
+
+	delimiter = buf;
+
+	str = n->cpu_pmu_caps;
 	while (nr_caps--) {
 		fprintf(fp, "%s%s", delimiter, str);
 		delimiter = ", ";
@@ -1984,6 +2039,17 @@ 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)
+{
+	struct cpu_pmu_caps_node *n;
+	int i;
+
+	for (i = 0; i < ff->ph->env.nr_cpu_pmu_caps_nodes; i++) {
+		n = &ff->ph->env.cpu_pmu_caps_nodes[i];
+		print_per_cpu_pmu_caps(fp, n);
+	}
+}
+
 static void print_pmu_mappings(struct feat_fd *ff, FILE *fp)
 {
 	const char *delimiter = "# pmu mappings: ";
@@ -3093,13 +3159,14 @@ 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_cpu_pmu_caps_node(struct feat_fd *ff,
+				     struct cpu_pmu_caps_node *n, bool *end)
 {
-	char *name, *value;
+	char *name, *value, *pmu_name;
 	struct strbuf sb;
-	u32 nr_caps;
+	u32 nr_caps, nr;
 
+	*end = false;
 	if (do_read_u32(ff, &nr_caps))
 		return -1;
 
@@ -3108,7 +3175,7 @@ static int process_cpu_pmu_caps(struct feat_fd *ff,
 		return 0;
 	}
 
-	ff->ph->env.nr_cpu_pmu_caps = nr_caps;
+	n->nr_cpu_pmu_caps = nr_caps;
 
 	if (strbuf_init(&sb, 128) < 0)
 		return -1;
@@ -3129,13 +3196,33 @@ static int process_cpu_pmu_caps(struct feat_fd *ff,
 		if (strbuf_add(&sb, "", 1) < 0)
 			goto free_value;
 
-		if (!strcmp(name, "branches"))
-			ff->ph->env.max_branches = atoi(value);
+		if (!strcmp(name, "branches")) {
+			n->max_branches = atoi(value);
+			if (n->max_branches > ff->ph->env.max_branches)
+				ff->ph->env.max_branches = n->max_branches;
+		}
 
 		free(value);
 		free(name);
 	}
-	ff->ph->env.cpu_pmu_caps = strbuf_detach(&sb, NULL);
+
+	/*
+	 * Old perf.data may not have pmu_name,
+	 */
+	pmu_name = do_read_string(ff);
+	if (!pmu_name || strncmp(pmu_name, "cpu_", 4)) {
+		*end = true;
+		goto out;
+	}
+
+	if (do_read_u32(ff, &nr))
+		return -1;
+
+	if (nr == 0)
+		*end = true;
+out:
+	n->cpu_pmu_caps = strbuf_detach(&sb, NULL);
+	n->pmu_name = pmu_name;
 	return 0;
 
 free_value:
@@ -3147,6 +3234,50 @@ 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)
+{
+	struct cpu_pmu_caps_node *nodes = NULL, *tmp;
+	int ret, i, nr_alloc = 1, nr_used = 0;
+	bool end;
+
+	while (1) {
+		if (nr_used == nr_alloc || !nodes) {
+			nr_alloc *= 2;
+			tmp = realloc(nodes, sizeof(*nodes) * nr_alloc);
+			if (!tmp)
+				return -ENOMEM;
+			memset(tmp + nr_used, 0,
+			       sizeof(*nodes) * (nr_alloc - nr_used));
+			nodes = tmp;
+		}
+
+		ret = process_cpu_pmu_caps_node(ff, &nodes[nr_used], &end);
+		if (ret) {
+			if (nr_used)
+				break;
+			goto err;
+		}
+
+		nr_used++;
+		if (end)
+			break;
+	}
+
+	ff->ph->env.nr_cpu_pmu_caps_nodes = (u32)nr_used;
+	ff->ph->env.cpu_pmu_caps_nodes = nodes;
+	return 0;
+
+err:
+	for (i = 0; i < nr_used; 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),			\
-- 
2.7.4